The Detroit River, Michigan: An Ecological Profile - USGS National ...

COVERTop le.f't: Aerial photo of the Detroit River (July 19, 1984) , including LakeSt. Clair at the north, to take Erie at the south.Top right:%yfly nyn~ph and white bass,Lower: The Plesabi Fliner, a large self-unloading carrier of iron ore, limestone,or grain, passes the City of Detroit on the Detroit River.

Biological Report 85(7.17)April 1988THE DETROIT RIVER, MICHIGAN:AN ECOLOGIICAL PRQFllLEaBruce A. Manny and Thomas A. EdsallU.S. Fish and Wildlife ServiceNational Fisheries ResearchCenter-Great LakesAnn Arbor, MI 48105andEugene JaworskiEastern Michigan UniversityYpsilanti, MI 48197Project OfficerEdward C. PendletonNational Wetlands Research Center1010 Gause BoulevardSlidell, LA 70458Performed forNational Wetlands Research CenterResearch and Devel opmentFish and Wildlife ServiceU.S. Department of InteriorWashington, DC 20240a Contribution No. 683 of the National Fisheries Research Center-Great Lakes,U.S. Fish and Wild1 ife Service, 1451 Green Road, Ann Arbor, Michigan 48105.

DISCLAIMERThe findings of this report are not to be construed as an official U.S. Fishand Wildlife Service position unless so designated by other authorizeddocuments. Statements of conclusions, and suggested courses of study oraction, are exclusively those of the authors.Library of Congress Cataloging-inPublication DataManny, Bruce A.The Detroit River, Michigan.(Biological report ; 85(7.17) (Apr. 1988))Supt. of Docs, no. : I 49.89/2:85(7.17)"Performed for National Wetlands Research Center,Research and Development, Fish and Wi ldl ife Service,U. S. Department of Interior. I'Bibliography: p.I.. Stream ecology--Detroi t River (Mich. and Ont. )I. Edsall, Thomas A. 11. Jaworski, Eugene.111. National Wetlands Research Center (U.S.)IV. Title. V. Series: Biological report (Washincton,0. C. ) ; 85-7.17.QH105.M5M36 1988 574.5'26323'0974433 88-600043This report may be cited as follows:lulanny, B.A., T.A. Edsall, and E. ~aworski. 1988. The Detroit River,Michigan: an ecological profile. U. S. Fish Wildl. Serv. Biol. Rep.85(7.17). 86 PP-

PREFACEThis monograph is part of a series of publications about current issuesfacing the Nation's coastal environments. It synthesizes existing informationdescribing the ecological structure and function of the Detroit River, whichflows between Lakes Huron and Erie and forms the border between the UnitedStates (Michigan) and Canada (Ontario). Other reports in this series presentinformation about two similar rivers between these countries, the St. MarysRiver (Duffy et al. 1987), and the St. Clair River and Lake St. Clair (Edsallet al. 1987).In gathering the available information on the Detroit River, especiallythat pertinent to managing its biological resources, we found gaps in theinformation needed to protect and enhance these resources; they are identifiedin the report. Wherever possible, the river is treated as a distinct butintegrated unit of the Great Lakes ecosystem.In recent years, the Detroit River has received considerable attentionbecause its fishery resources move freely across the boundary between twonations and represent millions of dollars in revenue each year to each nation.Use of these same waters for navigation as well as for disposal of municipaland industrial wastes, coupled with rapid industrial and residentialdevelopment of the shoreline, has focused concern on preparation of an actionplan to control pollution by toxic substances, identify study needs, anddevelop management strategies. This report encompasses these needs and shouldbe useful in these important efforts.Any questions or comments about, and requests for, this publicationshould be directed to:Information Transfer SpecialistNational Wetlands Research CenterU.S. Fish and Wildlife ServiceNASA-S1 i dell Computer Complex1010 Gause BoulevardSl idel 1 , Louisiana 70458

CODUVERSlQN TABLEMetric to U.S.CustomaryMu1 tiplymillimeters (mm)centimeters (cm)meters (m)meters (m)ki 1 ometers ( km)kilometers (km)5 To Obtain0.03937 in~hes0.3927 inches3.281 feet0.5468 fathoms0.6214 statute miles0.5396 nautical mi lessquare meters (m2) 10.76 square feetsquare kilometers (km2) 0.3861 square mileshectares (ha) 2.471 acresliters (1)cubic meters (m3)cubic meters (m3)milligrams (mg)grams (g)ki lograms (kg)metric tons (t)metric tons (t)kilocalories (kcal)Celsius degrees (OC)0.2642 gal lons35.31 cubic feet0.0008110 acre-feet0.00003527 ounces0.03527 ounces2.205 pounds2205.0 pounds1.102 short tons3.968 British thermal units1.8(OC) + 32 Fahrenheit degreesU.S.Customary to Metricinches 25.40 millimeter;inches 2.54 centimeter;feet (ft) 0.3048 metersfathoms 1.829 metersstatute miles (mi) 1.609 kilometersnautical miles (nmi) 1.852 ki 1 oif,eterssquare feet (ft2)square miles (mi2)acresgallons (gal)cubic feet (ft3)acre-feet,ounces (02)ounces (oz)pounds (Ib)pounds (lb)short tons (ton)0.0929 square meters2.590 square kilometers0.4047 hectares3.785 1 i ters0.02831 cubic meters1233.0 cubic meters28350.0 mi 11 igrams28.35 grams0.4536 ki 1 ograms0.00045 metric tons0.9072 metric tonsBritish thermal units (Btu) 0.2520 ki 1 ocaloriesFahrenheit degrees (OF) 0.5556 (OF - 32) Celsius degrees

CONTENTSPagePREFACE ..............................................................CONVERSION TABLE ..................................................... i vFIGURES .............................................................. vijTABLES ............................................................... i xACKNOWLEDGMENTS .................................................... xiiCHAPTER 1 . INTRODUCTION . THE SETTING ............................... 11.1 The Detroit River as an Ecosystem ........................ 11.2 Glacial Origin ........................................... 11.3 Land Use History ......................................... 11.4 Development of the Navigation System ..................... 41.5 Biological Zones and Subsystems .......................... 71.6 Environmental Impacts and Use Conflicts .................. 9CHAPTER 2 . DESCRIPTION OF THE ENVIRONMENT ........................... 132.1 Climatic Influences ...................................... 132.2 Hydrology of the Detroit River ........................... 142.3 River Channel and Shore1 ine Characteristics .............. 172.4 Flow Model ............................................... 172.5 Geology of the Lake Plain ................................ 182.6 Wetlands and Submersed Macrophyte Beds ................... 192.7 Water and Sediment Quality ............................... 22CHAPTER 3 . BIOLOGICAL CHARACTERISTICS ............................... 273.1 Primary and Secondary Producers .......................... 273.2 Native and Exotic Fishes ................................. 343.3 Waterfowl ................................................ 41CHAPTER 4 . ECOLOGICAL RELATIONSHIPS ................................. 444.1 Primary and Secondary Production ......................... 444.2 Detri tal Flow ............................................ 464.3 Trophic Relations ........................................ 47CHAPTER 5 . COMMERCIAL AND RECREATIONAL ACTIVITIES ................... 495.1 Industrial Significance of the Waterway .................. 495.2 Commercial Fisheries ..............................*....... 505.3 Recreational Fisheries .................................... 515.4 Waterfowl Hunting ................................ . ..... 525.5 Recreational Uses ........................................ 56i i i

CHAPTER 6 . MANAGEMENT ISSUES AND RECDMMEMDATIONS ....................Combined Sewer Overflows ................................Dredging .................................................Water Levels ..........................................*..Waste Discharges and Spills of Hazardous Substances ......Fish Losses at Water intakes .............................Habitat for Canvasback Ducks .............................Protection of Remaining Wetland and Island Wabi tat .......Management Framework .....................................Recommendations ..........................................REFERENCES ...........................................................Page58

Number202 1PageNitellopsis (Nitellopsis obtusa) .............................. 33Several fishes that support major fisheries in the DetroitRiver (walleye. carp. white bass) ........................... 36Fish spawning areas in the Detroit River ...................... 37Canvasback ducks are protected from hunting on the DetroitRiver ....................................................... 42Lesser scaup are harvested frequently by Detroit Riverhunters ..................................................... 43Major recreational fishing areas in the Detroit River ......... 53Waterfowl hunter in a layout boat hunting diving ducks ........ 53Closeup of layout boat used to hunt waterfowl on the DetroitRiver ....................................................... 54Major migration corridors of the eastern population of thecanvasback duck ............................................. 66Wild celery (Val 1 i sneria americana) tubers. a preferred foodof canvasback ducks in the Detroit River .................... 67Herring gulls. a shorebird that nests in colonies on FightingIsland in the Detroit River ................................. 69viii

NumberTABLESPage1 Waterways, harbors and other areas of pub1 i c dredging in theDetroit River ............................................... 62 Mean monthly water temperatures (OC) in the Detroit River atBelle Isle, 1973-84 ........................................ 143 Flow distribution among various channels in the lower DetroitRiver ....................................................... 154 Areas of wetland and large submersed macrophyte beds in theDetroit River on July 25, 1982 .............................. 205 Area of wetlands in Michigan waters of the Detroit River in1978 ....................................................... 216 Average economic values of Michigan's coastal wetlands, 1980 . . 237 Concentrations of nutrients and major ions (mg/L) in waters ofthe upper and lower Detroit River ........................... 238 Water quality measurements at the mouth of the Detroit River,1969-81 ................................................... 239 Loadings of solids and dissolved ions and flow to Lake Eriefrom the Detroit River, 1969-81 ............................. 2410 Water quality parameters monitored monthly at the head andmouth of the Detroit River .................................. 2511 Contaminant levels in Detroit River sediments and the Ontariopollution guideline for each ................................ 2512 Distribution and relative abundance of submersed macrophytesin the Detroit River in 1978 ................................ 2813 Percent frequency of occurrence and biomass of emergentmacrophytes at Stony Island in the Detroit River, 1983-84 ... 2914 Fishes commonly found in the Detroit River . ...... ............. 3515 Fishes that spawn in the Detroit River ........................ 3616 Average density of fish larvae in the Detroit River, 1983-84 . . 3817 Fishes that use the Detroit River as a nursery area ...,....... 38

Number18 Average density and relative abundance of fish larvae in theDetroit River, 1977-78 ...................................... 39Fishes caught by electrofi shi ng among submersed aquaticvegetation in Gibraltar Bay, October 15, 1986 . . . . . . . . . . . . . . . 40Waterfowl that frequent Michigan's coastal wetlands ........... 41Annual mean standing crop,and net production of primary andsecondary producers and terrestrial inputs in the DetroitRiver ................ .. .... . ............ ................. . 44Underwater plants that provide cover and food for fish andwaterfowl in connecting channels of the Great Lakes ......... 45Annual net production by primary producers in the St. Clair-Detroit River system ........................................ 47Resource use of the Detroit River ............................. 49Average annual commercial fish production by decade inMichigan waters of the St. Clair-Detroit River system,1870-1969 ................................................ 512 6 Creel census estimates of average annual effort and catchfor the recreational fishery in Michigan waters of theSt. Clair-Detroit River system, 1942-77 ..................... 5127 Average annual recreational fishing effort and catch inMichigan waters of the St. Clair-Detroit River system,1983-85 .................................................... 5228 Major fish species composing the recreational catch in theSt. Clair-Detroi t River system, 1983-85 . . . . . . . . . . . . . . . . . . . . . 522 9 Annual average harvest of ducks in Michigan, 1961-70 . . . . . . . . . . 5430 Annual waterfowl hunting effort and harvest in Michigan,1971-75 ........,....... .... . ................................ 553 1 Annual average duck harvest, Wayne County, Michigan, 1971-80 . . 5532 Average concentrations of various pollutants entering theDetroit and Rouge Rivers from combined sewer overflows . . .. . . 583 3 Dredging and spoil disposal in the Detroit River, 1970-86 . . . . . 6034 Effects of water level on uses of the Detroit River ........... 613 5 Activity- and use-effect matrix for the Detroit River: . . . . . . . . . 6336 Petroleum products and other hazardous substances transportedon the Detroit River in 1477 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6437 Number and volume of spills of petroleum products and otherhazardous substances into the Detroit River, 1973-79 . . . . . . . . 64

NumberPage3 8 Nurnber and volume of spills of petroleum products and otherhazardous substances into the Detroit River during the periodof ice cover, 1973-79 ....................................... 6539 Wintering canvasback duck populations by flyway, 1955-82 ...... 6740 Average number of wild celery tubers at five waterfowl feedingareas in the lower Detroit River in May 1950-51, and 1984-85. 6841 Characterization of major islands in the Detroit River . . . . . . . . 70

We thank Pat Hudson for the analysis of primary and secondary production,Donald Schloesser and S. Jerrine Nichols for unpublished data, JohnHartig of the International Joint Commission for information on combined seweroverflows, Jerry Martz, Tim Payne, and Frank Horvath of the MichiganDepartment of Natural Resources for waterfowl statistics and information aboutthe Great Lakes Information System, Bonnie Boynton for editing, Sue Lauritzenfor layout, and Marilyn Murphy for typing the manuscript.The cartographic laboratory of the Department of Geography and Geology atEastern Michigan University in Ypsilanti drafted several of the illustrations.Reviewers of the manuscript included Paul Bertram, Walter Duffy, JohnForwal ter, Richard Greenwood, Robert Haas, Peter Kauss, Marge Kolar, TimKubiak, Joseph Leach, Edward Pendleton, Keith Rodgers, and Larry Sisk.This report was funded cooperatively under Interagency Agreement No.DW14930945-01-0 between the Great Lakes National Program Off ice of theEnvironmental Protection Agency and the National Wetlands Research Center ofthe Fish and Wildlife Service. This report is also produced as a part of theUpper Great Lakes Connecting Channels Study conducted jointly by State,Provincial, and Federal agencies of the United States and Canada.xii

CHAPTER 1. INTRODUCTION-THE SETTING1.1 THE DETROIT RIVER AS AN ECOSYSTEMThe Detroit River includes the lower51 km of the strait or channel connectingLakes Huron and Erie (Figure 1). Aninternational boundary divides the DetroitRiver about equally into United States(Michigan) and Canadian (Ontario) watersalong the commercial navigation channel,which is part of the Great Lakes-St.Lawrence Seaway System. Because theDetroit River can be delimited bothecologically and hydrologically, it isconsidered herein as a distinct GreatLakes subsystem.Limnologically, the Detroit River isa moderately productive ecosystem withwater temperatures suitable for cold-waterfish from September to June (Muth et al.1986). Despite intensively developedshore1 ines and tributary drainage basins,the Detroit River provides importanthabitat for fish and migratory waterfowl.Moreover, the waterway contai ns i sl andnestingcolonial birds; rare and endangeredspecies, including mussels; and is usedextensively for recreational boating.Within the river system, many use conflictsand adverse environmental impactsoccur as shoreline and island development,industrial discharges, municipal effluents,and tributary loadings alter thephysical habitat, water qua1 ity, andsediments.1.2 GLACIAL ORIGINAtop the limestone bedrock in theDetroit River area is a mantle of glacialdrift 6 to 30 m thick (Mozola 1969). Muchof this drift was deposited during the endof the Late Wisconsin glacial period aboct14,000 years ago (Hough 1958). Based onthe topography and soils, these glacialdeposits can be separated into till plainsand lake plains (Figure 2). The lakeplain, a lowland consisting of lacustrineclays and beach sand deposits, extendsfrom the till plains to the Great Lakesshore1 ines and includes most of theDetroit River area. During the LateWisco~sin glacial period, the Grosse Ile,Detroit, and Mount Clemens moraines weredeposited in the waters of ancestral LakeErie.During much of its postglacial history,the Detroit River area lay beneaththe waters of ancestral Lake Erie (Dorrand Eschman 1970). The present riverchannel was first established about 13,000years ago when falling water levels permittederosion of the lake plain andmoraines. Water levels in the DetroitRiver 12,000-4,000 years ago were lowerthan the present level of Lake Erie (174 mabove sea level): Once during thisperiod, the Great Lakes drained northwardthrough Georgian Bay and the Detroit Riverwas dry. During the last 4,000 years, theaverage water level of the Detroit Riverand Lake Erie has changed little (Hough1958).1.3 LAND USE HISTORYNorth American Indians were the firstto use the natural resources of theDetroit River. An archeological surveyalong the river's west bank revealed 32sites, most of which were prehistoric (&a.400 A.D.) late Woodland and HistoricIndian habitations (Peeb7es and Black1976). Wild rice (Zizania aquatics) grewat the mouths of the Huron and RougeRivers (McDonald 1951) and provided asource of trade for the Huron-WyandotIndians, who had established a settlementnear the present city of Wyandotte in 1650(Santer 1977). Because fish and wildlifewere abundant along the river, native

StatuteMilesKilometerFigure 1. Geographical setting of the Detroit River ecosystem.Indian economies at the time of Europeancontact were based on fishing, hunting,and gathering (Li tting 1973; Raphael1987). Indians who survived Europeaninducedwai-fare and diseases refocusedtheir lives on the fur trade and onEuropean goods and settlements (Peeblesand Black 1976).French settlement near the riverprobably began in about 1686 (Farmer1890). In 1701, Fort Pontchartrain, thefirst French trading post along theDetrof t River, was erected near the mouthof the Rouge River. American settlementbegan in 1794 on the west bank shortlyafter the battle between British and

TillSedimentsLake Bed. ClayGround Moraine, Waterlaid ~oraine */ MoraineI I3 [*may be veneered by lacustrine deposits)miles0 5 100 5 10 15kilometersFigure 2. Glacial geology of the Detroit River area (Martin 1955).

American forces at Fallen Timbers, TheBritish settled in the town of Sandwich(now Windsor, Ontario) on the east bank ofthe river following the war of 1812between Britain and the United States.During European exploration and settlement,mature oak-hickory forests grew onthe lake plains and elm-ash woodlandscolonized the '"lack swam " soils alongthe river (Gordon 19697. Land wasobtained from the Indians by land salesfrom 1790 to 1830, and by treaties,particularly the Treaty of Detroit in 1807(Hiqgins and Kanouse 1969). The Frenchsettled along the Detroit River in alonglot pattern of log cabins and stonewindmif 1s (Sant~r 1977). Each longlotpermitted access to the river and uplandwoods. 80th the French and native Indianscaught large numbers of lake whitefish,take trout, and lake sturgeon in the river(Sdnter 1977).The Detroi t-Chicago Rai lrnad,ctrrt~pltlted in 1851, $purred dyricul turaldevelo~~rnent drld i ni tiated conlnlercialactivity. By 1810, both shorelines ofchp ilctroi t R.i ver were colonized byfartrrers and stnal l merchants. At first,the wetlands along the river were~srentidl for survival of the settlers andwere i~sc.cl in many ways (Raphap1 1987).Then, wrtlands were diked and clcdred forpaslurt. and cropland. Ldndc, 2 to 3 kmPrrtrrr the wd t Prway were not farmed, butleft d% "thick woods." By 1900 th~sewoc,dlrlntfs werc" ci~ared d~ aqricultural.;c~tl.lrri~rnt spread inland.During the 1870's, a depth survey oft h Dptroit ~ River by Major Cornstock of the1J.S. Arirly Corps of Engineers revealed aU-shaped river channel with a sand bottom(see Lamson 1873). . Along the river shorelines,a fringe of emergent vegetationgrew in waters 0.3 to 2.0 m deep. Landwardaf this emergent riverine vegetationwas a strip of coastal marsh that extendedaver 1 knl inland in pldces, especiallynear the mouths of tributaries, such asthe Rouge River, According to the Comstocksurveys, waters in the Rouge Riverwere 4 to 6 m deep and the bottom wassandy. Thus, we believe that jn prehistorictimes, the i3ett-oft River- and itstributaries were relatively free offine-grained sediments and supportedextensive wetlands,After 1810, population growth andland-use intensity in the Detroit Riverarea accelerated as industrial developmenttook place in Wayne County (Sinclair1970). Industrial development of heavysteel, chemical , and refining industriesin the towns of River Rouge, Ecorse,Trenton, and Wyandotte dominated themetropolitan area by 1930. Stimulated bythe automobile industry and later by WorldWar II, industrial growth spread into thedownriver area. With the construction ofthe Ford Freeway in 1943 and the interstatesystem during the 1950is, many newautornobi le plants were established inDetroit. In contrast, except for the Cityof Windsor, which was initially tied toindustrial growth in the City of Detroit,much of the adjacent lake plain in Ontarioremained agricultural , producing corn,tobacco, and tomatoes.1.4 DEVELOPMENT OF THE NAVIGATIONSYSTEMThe Detroit River is part of theGreat Lakes-St. Lawrence Seaway thatextends from Montreal, the present landward1 imi t of year-round navigation byocean-going vessels, to Duluth, Minnesota,on Lake Superior, a water route of 2,177kni (GLWNR 1976). Completed in 1969, theseaway is maintained to a depth of 8.23 m(27.0 ft). This depth provides a vesseldraft of 1.77 m. To maintain the Seaway,the U.S. Army Corps of Engineers, pursuantto the Rivers and Harbors Act of 1899, isauthorized to dredge to a depth of 8.23 i0.6 m below low water datum. Navigationrelateddredging and gravel mining at thehead of the St. Clair River lowered thelevels of Lakes Michigan and Huron 0.27 mand decreased the storage volume of thetwo lakes by 32 km3 (Derecki 1985).In the Detroit River, the commercialnavigation system consists of the main,auxiliary, and side channels, commercialharbors and turning basins, and waterleveland cross-channel current-controlstructures (Figure 3). Those waterways,harbors, and berthing areas, all dredgedby the U.S. Army Corps of Engineers, arelisted in Table 1. In Ontario, the Cityof Windsor maintains a pubf~c harbor at adepth of 8.69 m. Canada allows the U.S.Army Corps of Engineers to maintain thenavigation channels in the Detroit River.

Figure 3. Navigation channels and areas of polluted bottom sediments(U.S. Army Corps of Engineers, Detroit District, Current Files),

Table 1. Waterways, harbors, and other areas of public dredging in the Detroit River (U.S. ArmyCorps of Engineers, Detroit District, Current Files).- . --Area Length !m) Depth (m)Main channelsHead of Detroit River ChannelFighting Island ChannelBal lards Reef ChannelLivingstone Channel, Upper and lowerAmh~rsthurg Channel, Mackette Reach,Amherstburg Redch, and Lime Kiln ReachWest Outer ChannelEast Outer ChannelTrenton Channel, Turning Basin,Trenton Reach, and Wyandotte ReachSide channels and harborsChannel north of'"'lTe~~~1 eCity of DetroitRiver RougeEcorssWyandotteTrentonWSndsor, OntarioNodataavai 'lableThe Detroit River is the busiest portin the Groat Lakes. Much of the corrmlercia?navigation through the river consistsof intralake shipments of iron ore, coal,limestone and gypsum, wheat, and oil(Monson 1980; F:.igure 4). Cornrnercial navigationin the Seaway has slowed over thepast 15 yedrs, owing to declining demandfar suck canrmadities. Passenger trafficis minintdl trnd has decreased sharply since1966, In 1972, 18,268 vessel transits,accounting for about, 119 mill ion t off refgtrl. passed through the Detroit River(USACP 1973). In 1983, the number oftr-dnsits decre~sed to 9,334 and thetonnage to 60.8 million t of freight(USACE 1984). Appraxiinately two-thirds ofthis freight movement is through traffic3s opposed to traffic generated out ofUetroit River ports.Dcfore completion of the Seaway in19651, water depths in the Detroit Riveraveraged 6-0 to 7,6 me At present, nearlyall main comercia1 channels and certainpublic harbors with two or more users aremaintained by dredging at 8.2 m below lowwaterdatum. Before the enactment ofPublic Law (P.L,) 91-611, referred to asthe Rivers and Harbors Act of 1970 or theConfined Disposal Program, nearly a1 1dredged material from the river and itstributaries was disposed of at two sitesin open Lake Erie or used as constructionma teri a1 (Raphael and Jaworski 1976).Blasting and grab dredges are used toremove rocky material ; hopper dredges areused to remove soft, unconsolidated sedirrrentsfrom the waterways. Limestone anddolomitic rock are encountered in newdredging work and occasionally in maintenancedredging being performed south ofFighting Is 1 and. Hopper dredges hydraulical 1y remove fine-grai ned sediments by~uit..iitn atrd &re used for much of the maintenancedredging. These dredges areequipped with overflow weirs that allowexcess water and fine suspended material

Figure 4. Large self-unloading lake carriers. such as the Mesebi Miner shown here passing the City of Detroit,Michigan, carry bulk cargoes of iron ore, coal, limestone, and grain (Photo provided by Albert G. Ballertl.to return to the river until a predetermineddred~e load density is attained(USACE 1976a). Since 1985, much of theactual dredging has been performed byprivate contractors.From 1963 to 1969, nearly 2.98million n13 of sediment were dredged fromthe Detroit River and disposed of in openwater. In 1970, with the passage ofP.L. 91-611, open-lake dumping of polluteddredged materials was terminated and about30,100 m3 of polluted dredge spoil wasplaced on Grdssy Island in the DetroitRiver. From 1979 to 1984, 3.41 million m3of dredge spoil were removed from theDetroit River and deposited in the PointeMouillee confined disposal facility inwestern Lake Erie near the mouth of theHuron River (U.S. Army Corps of Engineers,Detroit District, Current Files). A totalof 814,000 in3 of polluted material werescheduled for removal and disposal atPointe Mouil lee confined disposal facil i-ties in 1985. Most confined disposalfacilities in the vicinity of the DetroitRiver are clay-1 ined or have limestonecore dikes and are equipped with overflowweirs for the discharge of excess water.Retention ponds remove most of thesuspended load from this excess water.The Rouge River sediments were recognizedas being grossly polluted many yearsbefore the enactment of P.L. 91-611.Material dredged from the Rouge Riverharbor in 1950-71, was disposed of in theGrassy Is1 and containment site (Raphaeland Jaworski 1976). Grassy Island wasclosed in 1981 and was used only intermittentlyfrom 1971 to 1981 to contain smallamounts of spoi l s from maintenance dredging(D. Bilmyer, U.S. Army Corps ofEngineers , Detroi t ; pers . comm. ) . Beforethe construction of the Pointe Moui 1 leeconfined disposal facilities, somepolluted spoils were put in confined sitesalong the lower Raisin River and on MudIsland, a small containment site nearGrassy Island. Fighting Island was usedby private interests for the disposal ofcaustic soda and other chemical wastesfrom Wyandotte Chemical Corporation.Point Hennepin, the northern tip of GrosseIle, was also a private disposal site forsolid wastes.1.5 BIOLOGICAL ZONES AND SUBSYSTEMSThe Detroit River ecosystem can bedivided into upper and lower subsystems,based on the health of the macrszoabenthiccommunities (Figure 5j.The macrozoobenthos are a biologicalgroup sensitive tu both water and sediment

I mmCaddisfly larval casesuI mmMayfly nymphFigure 6. Pollution-intolerant burrowing mayfly (Hexagenia) nymph and caddisfly (Trichopteran) larva.The Detroit River can be separated high concentrations of polychlorinatedinto three biological zones: deep biphenyls and heavy metals (Hamdy and Postchannel, shal low-water nearshore, and 1985). The Detroit River has been desigterrestrial.Deep-channel environments nated as a Class A area of concern by thegenerally have water depths exceeding 4 m, International Joint Commission (IJC)relatively high flow velocities, and because of impairment of beneficial usescoarse sediments. Macrophytes and associ - by organic and heavy metal pollutionated periphyton and invertebrates are most (GLWQB 1983). More than 50 large indusabundantin the shallow-water nearshore tries are located along the Michigan shorezone. No submersed macrophytes occur at of the Detroit River, whereas only 11 aredepths greater than 4 m and most are located on the Ontario shore (Figure 7);restricted to depths less than 3 m in more than 100 industries of various sizessediment depositional areas (Schloesser hold discharge permits. The principaland Manny 1982; Fallon and Horvath 1985). industrial discharge area lies on theThe terrestrial biological zone includes American side of the river and extendsundeveloped island habitat, areas of from Zug Island southeast to Gibraltar incoastal wetland, and riparian environments the Trenton Channel. Major industriesalong less developed tributaries, such as include steel mills, petroleum refineries,the Canard River. Stony, Celeron, Grassy, electrical power generating plants, andand Mud Islands provide habitat for manufacturers of chemicals, automotiveshorebirds such as gulls and terns (Scharf parts, rubber products, salt, and1978). plastics. Approximately 100,000 gallonsof river water are withdrawn to produceone automobile. Industrial wastes of1.6 ENVIRONMENTAL IMPACTS AND USE concern include organics, i .e., poly-CONFLICTSchlorinated biphenyl s , hexachl orobenzene,octachlorostyrene, and polycycl ic aromatichydrocarbons; cyanide; oil and grease;her connecting channels phenols; and heavy metals, i .e., mercury,in the Upper Great Lakes, sediments in the cadmium, lead, iron, zinc, chromium,Detroit River are heavily pol luted with copper, nickel, and cobalt (Limno-Techhazardous and toxic substances, including Inc. 1985).9

which serves not only the City of Detroit,but also large metropolitan suburban areasin Wayne, Oakland, and Macomb Counties ofsoutheastern Michigan, including wastesfrom some 150 industries and dischargesfrom a large combined sewer system.In July 1976, the Michigan Departmentof Natural Resources revoked the City ofDetroit's National Pollution DischargeElimination System permit to dischargesecondary municipal effluents because theDetroit Wastewater Treatment Pl ant hadbeen performing be1 ow design standards foryears in regard to primary effluent bio-1 ogi cal oxygen demand (BOD), suspendedsol ids, secondary effluent phenols, fecalcol iforms, and total phosphorus removal(USEPA 1978). A1 though the discharge permitwas reinstated in 1983, the plant continuesto have difficulty meetingdischarge and operational standards.Fecal col iforms were widely distri b-uted in the waters of the Detroit River in1969 (Figure 8). In 1985, the distributionof degraded mussel comuni ties in theriver correlated well with this coliformmap; mussels survived only in the upperriver and in the cleaner waters at midchannelin the lower Detroit River (TomFreitag U.S. Army Corps of Engineers,Detroit District, pers. corn.; Hudson etal. 1986; van der Schalie 1986). Heavymetals, particularly copper, a1 so seem tooriginate from the Detroit municipalsewage outfall and the Rouge River. In1980, concentrations of cadmium (11-14ppm), chromium (140-330 ppm), and copper(54-370 ppm) in sediment near the mouth ofthe Rouge River exceeded Ontario and U.S.Environmental Protection Agency guide1 inesfor open-water disposal of dredged spoils(IJC 1982; Thornley and Hamdy 1984).c 1 OM) per 1OOmlSewage Outfall@ Drinking Water IntakeFigure 8. Distribution of fecal coliform bacteria in theDetroit River in 1969 (USEPA 1978).Another major impact on water qualityin the Detroit River is urban runoff and overflows into the Detroit and Rougethe combined sewage overflows from various Rivers at 82 points (USEPA 1978). Becausestreams and public drains that discharge of urban development in the Detroit metrointothe Detroit River. I1 legal connec- pol itan area, combined sewage overflowstions can add large amounts of hazardous are much more important on the Michigansubstances to such drain systems (Schmidt side of the river than on the Ontarioand Spencer 1986) particularly older, side. Contaminants in urban areas quicklypoorly maintained drains like those reach water courses due to extensiveserving the Detroit area f Ecol osciences drainage networks and impervious surface1985). When the combined sewers are (Sonzogni et al. 1979). Of major concerunable to carry all the flow during is contamination from urban areas borderperiodsof storm runoff, excess water ing the Rouge and Ecorse Rivers.11

The Rouge River drains an area ofabout 121,000 ha and consists of threemain branches, the Lower, Middle, andUpper Rivers. The stream is very eventresponsive and frequent f 1 oodi ng occursalong the Middle Rouge. With a meanannual discharge of only 26 m3/s, over 75% of the drainage passes through urbanareas, collecting considerable stormwaterrunoff and overflow from combined sewersduring wet weather. Because the LowerRouge is lined with concrete to ensuresufficient flow capacity, runoff rapidlyreaches the Detroit River during storn~s.The Middl~ Rouge exhibits low levelsof dissolved oxygen and is mocleratelycontaminated by fecal col i forms, dissolvedsol ids, and toxic substances, includingheavy metals (MDNR 1973). In contrast,the Lower Rouge is one of the niost grosslypollut,ed streams in the Great Lakes reqion(USACE 1982). In the dredged area, whichextends from the Detroit River to theturning hasin, guidelines for pollutrdsediments set by the U.S. EnvironmentalProtection Agency wera exceeded by a1 1 10of the sediment contaminants measured(USACE 1969) including oil and grease,volatile sol ids, biological oxygen demand,phenols , total orthophosphate, ammonia,orqanic nitrogen, iron, lead, and zinc.Dredqcld sediments from the Rouge Riverharbor have bscn contained since 1950.$ti 11, bottom sediments downstream of th4mouth of the Rouge River near Mud Islandarc oily and grab sanlples reek of volatilesol lds.The Ecorse Rjver drains an area of11,556 ha, occupied by 12 communitieswhose population tnt.dled 198,000 in 1980.The Ecorsc River has two open-channeltrlbutar?es, the North Branch and theSouth Branch (or the Sexton-Ki 1 foi 1Orain), Thrse brdnchcs join approximatelyl krn upstrilan~ from the point where theEcorse River enters the Detroit River nearGrassy Island (USPCE 1982). Frequentflooding, high turbidity, Tow dissolvedoxygen and high dissolved solid loadscharacterize the upper and middle sectionsof the Ecarse River, but water and sedimentquality are most severely degraded inthe lower river syscem, In 19-69, near theconfluence of the North and SouthBranches, the streambed war mantled by ablack, oily layer of sludge which averaged1.2 rn thick (Rydquist and Wilson 1969).The sludge layer had a high biologicaloxygen demand that resulted in streambottomdissolved oxygen levels that weretoo low (0.0 - 0.4 mg/L) to support fish(USACE 1982). From 1969 to 1977, thelower Ecorse River was inhabited only bysludgeworms (Rydquist and Wilson 1969;Youngbl ood 1980).The Canard River is the only largeCanadian tributary to the Detroit River.It drains agricultural areas, is borderedby extensive natural wetlands, and contributeslittle pollution to the DetroitRiver. Agriculture is extensive south ofthe City of Windsor, in Essex County,Ontario. Although the streams and publicdrains in Ontario are small, some nutrientsand suspended sediments enter theDetroit River front the Canard River.Other hunian activities that affectthe environment adversely and give rise toland-use conflicts in the Detroit Riverinclude 45 marinas that serve the Michioanside of the river and Z additional marinasthat cater to boaters in Ontario (USEPA1985). Residential and commercial development,as well as recreational facilities,extend from Lake St. Clair down toGrosse Ile along both sides of the river.Drinking water intakes serving over 3.75million people are located at Belle Isle,W i ndsor, Amherstburg, and Wyandotte (USEPA1985).Navigation and shoreline modificationshave adversely impacted fish andwild1 ife uses of the river, especiallywetland environments. Commercial navigationresuspends polluted bottom sedimentsin the river by wash from props and bowthrusters. Except for 11.1 km of shoreline,the Michigan side is bulkheaded andbackfilled with slag and other materials(Muth et al. 1986). As a result, much ofthe remaining emergent parshes and submersedmacrophyte beds are confined to thelee of islands ar are distributed in lowwave-energy environments. As shown inSection 2.6, these wetlands are importanthabitat for fish and waterfowl, andseveral en joy 1 egal protection from developmentas "Environmental Areas" underMichigan Act 245 of 1970, as amended, TheShorelands Protection and Management Act.

CHAPTER 2.DESGWlBTDlON OF THE ENVIRONMENT2.1 CLIMATIC INFLUENCESThe Detroit River area experienceslong, cold winters and short, hot summers(Balwin 1973). Continental polar airmasses dominate in winter; tropical airmasses prevai 1 in summer. Cyclonicstorms, which move from west to east, arecommon in winter and bring frontal precipitationto the area. In summer, both coldfront and convective thunderstorms occur.Precipitation averages about 76 cm,including 40 cm of snow (Eichenlaub 1979).Prevailing winds are from the southwest,and average approximately 16 km/hour. Theaverage date of the first frost in fall isOctober 21, the last freezing temperatureis P.pril 23, and the annual growing seasonaverages 180 days.During early winter, water from LakeHuron cools rapidly when it flows throughLake St. Clair, and ice enters the DetroitRiver from Lake St. Clair before it beginsto form in the river (USACE 1970b).Before 1930, ice covered most of theDetroit River from mid-December to mid-March; however, since the 1950's the riverhas rarely, if ever, been completely icecovered, perhaps because of increasedvolumes of warm industrial effluents addedto the river, as postulated by Hunt(1957). During the 1700's and 1800ts,horse-drawn sleigh races were held on iceof the river from Grosse Pointe, Michigan,to Petite Cote and from Third Street(Detroit) to the Rouge River mouth (Burton1922 in Hunt 1957). During the late1920' sTautomobi les frequently crossed theriver on the ice at several points alongthe river (Gervais 1980).support even one person (R. Assel, GreatLakes Environmental Research Laboratory,Ann Arbor; pers. comrn.). The absence ofcomplete ice cover on the river may beexplained in part by a general warmingtrend in mean Great Lakes water temperaturesfrom 1925 to 1939 (Beeton 19611,generally higher water flows in the riversince lowest lake levels in 1926 (Edwardset al. 1987), a general warming trend inGreat Lakes air temperatures from 1918 to1958 (Assel 1980), and maintenance of openchannels a1 1 winter for river navigation.However, water and air temperatures havedeclined in the Great. Lakes since 1955 and1958, respectively (Beeton 1961, Assel1980) and 11 large power generating plantsand numerous industries that dischargeheated effluents have been built on theDetroit River since 1928 (MDNR 1976).Therefore, the thermal contribution madeby heated effluents to the Detroit Riversince the 1920's may have been significantand the subject deserves further investigation.Ice cover develops a1 ong shore1 inesin the lower river, especially in thebroad, shal low expanses adjacent to theislands (Quinn et al. 1978), but the mainnavigation channels remain i ce-free.Minor ice jams may occur in the river withthe breakup of ice in Lakes Huron and St.Clair from late March to early May.Easterly winds can also move Lake Erie iceinto the lower Detroit River, causing temporaryice jams (Derecki 1984). Occasionallythe river can fill with ice whenthere is heavy ice movement from Lake St.Clair and the river mouth is blocked withice from Lake Erie (Derecki 1984).For many years, cross-channel icing Highest water temperatures generallyhas been rare and brfef in the Detroit occur in August a ~ average d 22.4 OC (TableRiver (CIRES 1983). Most winters see the 2). In the shallow nearshore areas, esperiveroccupied by slush or drifting ice cially in the lower river, water temperathatrarely freezes solid enough to tures may rise to 25.5 "C. Lowest temper-

Table 2 Mssn monthly water temperatures (OCI in the Detroit River at Belle Isle, 7973-84 (Modifiedfrom Muth et ai 1986).ahires (0.5 "C) occur i r ~ Jntrtrdry-l+.brunry.Thcslr Tt*ptryeralnre d %it~, co~tlbir~~d with t h ~fact Phdt dlswlved oxygfw levcis in thefletroi t I\ivi~r usus% l ly avprncjcl ovtXr 6.0t11cjl1 {Cl WQR 111143), ind'icatc. that ~n ctrl i.1-w~tt't* fi~h cn~vn~ilf?i fy of. ldke trout andotller hic?lr~~~~nido cn\lld .;urvivcs in sc.lfv-r"eddrcns of l h ~ river for a1 1 but two or.I IITF+F" t~otlf h', E F ~ f he YC~~Y' E t h d ~ a l .19ni:) .2 2 HYDF30kBGY QE THE DETROIT RlVERAta~ut 44 'i c ~ f the tt~td't f !OW of thefli~traft Klvrir tvltcrq fro111 Lnkc Huron viathc \,t. Cla~r. Rivpt- dnd lake St. Clair(T9er,rc,k 7 IQt34). Ihr dt schdrcje of ther.rvc3r dvf~rt~qrf 1 , i rltld 15 veryI - t Pdnti 1 ttq .f ,-om 14 ,400 m3Js inwl!ihr;.v. to 5,100 n13/s in sunlilier. (Deretki4 . F^~c!~J 111 the fleZritl.1. Kiv~r ist-el r:tivi?f y r cinstrlrtt corrrpr>t-ed Po that r t?orher Idrqa-) rlver-s, which fluctuate wldply7t.oi;r thi. sprtfig flood to iJi~ sunmer lowf 1 owt>.In ttir u p r 3 ~ Detroit ~ River, exceotfar channel divislnn by Peach islar~d andReIle Isle near ~ t kea@, s the rivet- formsa single, wrhll-defined channel about 700to 1,000 rn wide (Derecki 1984). Flow inthe lower river follows several channels(scc Tdhle 3 and Figure 9).Very 1 ittle flow passes through therdnal across Grosse Ile or through canalsnear Elba, Russell, and Swan Islands, butconsiderdble flow passes beneath thebridge that connects lower Grosse Xle withHickory Island, This water providescirculation in Gibraltar Ray, which is aproductive wetland l acated between HickoryIsland and the southeast end af GrosseIle.Dependinq on discharge, flow velocitiesin the Detroit River range from 0.30to C.88 mls (fiqure 91, but can be nearlytwic~ that rate near the surface of themain ctlannel s (USACE: 1976a). Surfacecurrents in the upper river reach 1.2 m/snear the Arrlbassadar Bridge and haveexceeded 1.7 mls in the AmherstburgChannel (Derccki 1984).Kater levels of Lakes St. Clair andErie vary seasonally and annually, anddirectly aff~ct wster depths acd f?@4velocities in the Detroit River. Thetotal Fall of the river between Lake St.Clair and take Erie is 0.9 m (Derecki

Table 3. Flow distribution among various chanrlels it-1 the lower Detroit River IDerecki 1984).Location and channel.- % of total flowHead of Fighting IslandUpper Trenton Channel (west of Grassy Islard) 26Fighting Island Channel 5 1Channel east of Fighting Island 2 3Head of Grosse 1 1 ~Trenton ChannelFighting Island ChannelChannel East of Fighting IslandSouthern End of Grosse TleTrenton ChannelChannel west of Stony IsldndUpper Livinqston~ ChannelAmherstburg ChannelEouth of the D~troi t RiverWest of Celeron IslandEast of Celeran IslandWest of Sugar IslandEast of Sugar IslandLivingstone ChannelEast of Livi~gstone ChannelAmherstburs Channel (Hackett Rcach)19R.S). Recause the river slope is relativelyuniform, this drop in level occursacross the entire length of the river.The averagc travel time for water to passthrough the Detroit River is 20 hours(Derecki 1984).In rrsponse to regional precipi tation,the Great I-ak~s fluctuate in unisonover an 8- to 20-yedr hydro~eriod(Jaworski and Raphael 1981). When waterlevels in the Detroit River are above orbe1 ow normal , above- and be1 ow-averagedischarges of 6,400 m3/s and 4,200 nl3/s,respectively , are produced (Derecki 1984).Jcf? jams in Lake St. Clair and in tireDetroit River can ternporari 1 y retard flowand raise water levels as much as 1.5 m(Ouinn 1976; Derecki 1984).In the main cnanneis, fio~ f"d4;eidecrease near the bottom and along theshore1 ine. Sediments are transported inthe main channels, partrcul ar1.y durir~ghigh-flow conditions when the flow velocityexceeds 0.42 m/s. In the shorelineand shallow water areas, where flaw velocitiesmay drop to 0.25 m/s or less, sedimentdeposition occurs (Figure 10). Ingeneral, the channel sediments are siltyand sandy because of the relatively highflow velocities. However, sediments nearMud Island and in the Trenton Channel aresludge-1 ike. Fine-grained materials,particularly clays, are deposited inhallow nearshore environments. Many ofthese deposition areas support extensivesubmersed macrophytc comnruni ties. Likewise,the macrozoobenthos appear to bemore numerous in shallow than in deeperwaters (Hudson et al. 1986)-There is a relationship between heavymetal accumu1at.ion and grain size of thebsttoni s~dimects the Detroit River. Zinc,nickel , chromium, cobalt, copper, and leadaccumulated in the fine clay fraction (i13 I and in the large silt-size

Figure 9. Average flow velocities (mls and ftls) in the Detroit River channels at high, medium, andlow water discharge levels (Dereeki 1984).

--. . ..- . -IMICHIGANlT------,/ LAKEespecially on the American side and on theCanadian side north of Windsor (Figure11). Loss of the shallow wetland areas,which were important fish and wildlifehabitat, is the most significant ecologicalimpact resulting from channel modifi -cations. These losses of functional mainlandwetlands make the remaining islandwetlands in the river more essential forproduction of fish and wildlife resourcesin the Detroit River.The Ontario shorel ine, except for theCity of Windsor and berthing areas, lacksshoreline protection structures and ismore natural than the Michigan shorel ine.However, the Ontario shoreline north ofthe Canard River is marked with scatteredmarinas, canals, and private boat slips.In places, Canadian farmers haveencroached upon the wetland margins of theDetroit River and its tributaries. Thus,a green buffer zone exists only intermittentlybetween farm fields and the river.Access to the water, whether for commercialnavigation and business or forrn~leapleasure boating and hunting, is important0 2 4 6 locally on both sides of the river.kllornelers2.4 FLOW MODELUsing hydrographic data, the GreatLakes Envi ronmental Research Laboratory inAnn Arbor developed a one-dimensionalLAKE ERIE variable-flow model for the Detroit Rivernear Wyandotte (Limno-Tech Inc. 1985). Amodel for the entire river, assuming idealFigure 10. Sediment deposition zones in the Detroit channels, is also avai lable. In general,River (Fallon and Horvath 1985).these models predict flow variations anddetermine short-term and annual loadingsof pollutants such as chloride (Quinn1976). Roginski (1981) developed a two-fractions (48 to 63 (Mudroch 1985). dimensional fini te-el ement differenceThese heavy metals are loosely held to model to assess the impact of combinedsediments by adsorption or cation-exchange sewer overflows on pollutant concentraprocesses.tions in the river. Wright et al. (1984)generated a theoretical plume mode1 thatcan define mixing zones for discharges2.3 RIVER CHANNEL AND SHORELlNE under various flow conditions in theCHARACTERISTICSDetroit River.In 1873, the channel just above the Because of the relatively high flowmouth of the Rouge River was trough- velocity and channelized water movements,shaped, with wetland shoulders and a sand cross-channel mixing does not readilybottom (Lamson 1873). The modern channel occur in the river. Rather, contaminantsis more rounded at the margins, and is from point sources tend to slowly disperseextensively bul kheaded and backfi 1 led, downstream as a plume. For example, unti 115

WESTEAST0 3 o 5 s i o 9;5 12'19metersWESTEAST6 10 915 1219 1524metersHori~ontul Soale 1:10.000Figure 11. Channel cross-section of the Detroit River just above the mouth of the Rouge River in 1873end 1973 (Lamson 1873 and U.S. Lake Survey Chart No. 41).recently, a chlorine plume approximately400 m long and 25 to 50 m wide could beidentified downstream of the DetroitWastewater Treatment Plant outfall (MDNR1984). More studies of cross-channelpollutant mixing are needed.2.5 GEBLOGY OF THE LAKE PLAINThe Detroit River flows throughglacial drift of Pleistocene age, whichis underlain by Paleozoic sedimentaryrocks (Figure 12)- The sedimentaryf do1on:i te) rock strata beneath the DetroitRiver crops out intermittently in thenavigation channels east of Grosse Xle(Mozola 1969). Much of the land surfaceis a low plain that dips toward thepresent Detroit River and was deposited inlakes that preceeded the Great Lakes as weknow them today. This low lake plain(Section 1.2) consists largely of lacustrineclays and irregular beach ridgedeposits.The topography of the Detroit Riverarea is relatively flat, broken only bythe valleys of the Rouge River and a fewlesser tributaries. Low glacial morainsand beach ridges of ancestral Lake Erieprovide slight re1 ief (USACE 1976a). Landelevations above mean sea level range from214 m near the tributary sources toapproximately 174 rn along the DetroitRiver. Generally, the relative relief on

Vertical Exaggeration . iilxmilesL!~4+o kilometer 5Glacial LlrtftAntrim ShaleTraverse CroupDundee l irne:,tont:Detroit River ilolornite0 Sylvania SandstoneFigure 12. Geological cross-section of the Detroit River (Mozola 1969).the lake plain is 1-5 m/km and most slopesare less than 3% (SEMCOG 1976).Soils ot: the lake plain consist of1 eve1 , poorly drained loams that developedon former lake bottom or lacustrine claysediments (USDA 1975). Sandy ridges markthe position of former shore1 ines, and onthe Michigan side an isolated sand sheetmarks remnants of the glaciofluvial deltaof the Huron River (SEMCOG 1976). Whenproperly drained and tiled, the loamysoils of the lake plain are highly productiveagriculturally. However, because thepermeabi 1 i ty of many surface andsubsurface soils is low (0.25 and 1.27cm/hour; USDA 1975), surface runoffcoefficients are high and the localstreams are "event responsive" (Sull ivanet al. 1981).Soil type should affect water qualityin tributary streams; however, given thenumber of discharges in the drainage basinand the urban and agricultural runoff,water quality in the local streams andpublic drains entering the Detroit Riverreflect land uses, not parent soils.Moreover, natural loadings of availablephosphorus from the lake plain soils aresmall compared to those from sewagetreatment plants (Sullivan et al. 1981).Only about 12% of the phosphorus inagricultural land drainage can be tracedto fertilizer use (USEPA 1971).2.6 WETLANDS AND SUBMERSEDMACROPHYTE BEDSCoastal wet1 ands and 1 arge submersedmacrophyte beds along the Detroit Riverwere nearly continuous in colonial times,but now exist as 31 small, isolated remnantsthat cover a total of only 1,382 ha(Figure 13, Table 4). Most of the remainingvegetation along the river consists ofsubmersed macrophytes , because the landformerly occupied by the swamp-shrubmeadowcommunities along the terrestrialmargin of the river has largely been convertedto other uses or inundated by highwater levels.Fifty-four per cent (748 ha) of theselargely unnamed wetlands are in Ontario.The largest wetland in the Detroit Riveris immediately north of the mouth of theCanard River in Essex County, Ontario.However, because it is largely diked forwaterfowl hunting purposes, it isfunctional only along its outer undikedmargins. Wetlands 3, 13, 25, and 26 havebeen rendered largely unsuitable for use

\ / ST LLAIR/;; ii(sciNMICI~ICAN1Table 4. Areas of wetlands and large submersedmacrophyte beds in the Detroit River on July 25,1982(Planimetered from Figure 13 by E. Jaworski).\ ,/I gj/ Wetland Area,/ // %??,I< ,'.I

are present today on the Michigan side ofthe river. We included in our assessmentthose large beds of submersed macrophytesthat were visible on a 1:130,000-scale1984 Landsat image, but not the manysmaller beds of submersed macrophytes thatwere not detected at this scale. Accordingto the National Wetlands Inventory ofMichigan, there were about 500 ha of wetlandsand submersed macrophyte beds inMichigan waters of the river in November1978 (Table 5). Given the lower waterlevel in 1978 than in 1982 and the likelihoodthat some submersed macrophyte bedswere obscured by turbidity, this figureagrees reasonably we1 1 with our estimate(Table 4). If turbidity were lower, manymore such beds would be visible becausemuch of the Detroit River littoral zone iscolonized by submersed macrophytes.One of the largest and most functionalwetlands on the Nichigan side isthe Gibraltar Bay area, at the southernend of Grosse Ile (Jaworski and Raphael1984). Other functional wetl ands includeBelle Isle, Stony Island, the easternshore of Grosse Ile, and Celeron Island.In addition to the difficulties inherentin mapping submersed macrophytebeds, there are mapping problems stemmi ngfrom seasonal changes in the kinds andamounts of wetl and vegetation. Schloesseret al. (1986b) found that submersed macrophytesare most visible on small-scale(1:5,000) aerial photographs taken duringAugust and September. Much of theNational Wetlands Inventory aerial ph~tographyof the Detroit River would not havedetected submersed macrophyte beds becauseit was obtained at a scale of 1:80,000.In 1955, Hunt (1963) mapped thedistribution of wild celery (Val1 isneriaamericana) in the lower Detroit River,particularly near Celeron and SugarIslands. Compared to our map (Figure 13),there has been a loss of submersed macrophytesin the lower Trenton Channel andnear Celeron Island since then.Herdendorf et a1 . (1981) compiled existingdata on coastal wetlands on the Americanside of the Great Lakes from topographicand Lake Survey charts. They identifiedonly 7 wetland areas in Michigan waters ofthe river, compared to our 16 areas.Given the rapid (20 hr) flushing timeof the Detroit River (Derecki 1984), wet-Table 5. Area of wetlands in Michigan waters of the 1 ands and submersed macrophyte beds mayDetroit River in 1978 (U.S. Fish and Wildlife Servicecritical stable habitat for19781. biological production in the ecosystem.Although the importance of detritus in theDetroit River ecosys tern is not adequatelyWet1 and Area (ha) auantified. we be1 ieve that aquatic macroihyticvegktation exertscontrolover biological production in the DetroitRiver as it does in other large rivers(Cummins et al. 1984). Therefore, thefunction of the aquatic macrophytes andtheir associated periphyton in the wetlandsof the Detroit River can be regardedas essential to the fisheries and water-North end of Belle IsleDetroit shore? i neSouth end of Belle IsleSouth of Rouge RiverEcorse River ChannelGrassy IslandNorthern Grosse IleStony IslandCanal on Grosse IleEl izabeth ParkEastern shoreline of Grosse IleGibraltar Bay areaShore1 ine north of Gi bra1 tarCity of Gi bra1 tarCeleron IslandTotalfowl. More research is needed to definehow important such wetlands are in thebiological production of the river.Some Detroit River wetlands may havesurprisingly large economic values (seeJaworski and Raphael 1984; Seegert 1984).An example is the Gibraltar Bay wetland(Figure 14). Water from the main channelof the Detroit River flows throughGibraltar Bay and out between Russell and

Figure 14. The Gibraltar Bay wetland at the southern tip of Grosse Ile in the lower Detroit River (Photo providedby Southeast Michigan Council of Governments. Aerial photograph No. 80-230-24-42, taken June 11, 1980).Hickory Islands. High primary productivityin Gibraltar Bay in August is evidencedby the presence of dense beds of wildcelery, wdterweed, muskgrass, Eurasianwatermi Ifoil, water stargrass, and othersubmersed macrophytes. The invertebratepopulations include clams, snails, midges,antphipods, springtails, and worms(JaworskS and Paphael 1984). Juveni leyellow perch, adult northern pike, anddabbling ducks feed among the submersednacrophytes in the wetland. The area isalso heavily used for spawning by numerousspecies of fish (see section 3,Z). Themost significant current uses ana ftlnctionsof the Gfbraltar Bay wetland arefish production, sport fishivg, andwaterfowl feeding.The potential value of the GreatLakes coastal wetlands, as exemplified byGibraltar Bay, niay exceed $5,000 perhectare (Table 6). Although no two wetlandswill have precisely the same functionand value per unit area (Raphael andJaworski 1979), the data in Table 6 illustratethe value of such coastal wetlands.2.7 WATER AND SEDIMENT QUALITYPollution from waste discharges hasimpaired water qua1 i ty and confl icted withbiof ogical productivity in the PetroitRiver for over 20 years (USDHEW 1965).The chemical characteristics of water inthe upper and lower Detroit River are

Table 6. Average economic values of Michigan'scoastal wetlands, 1980 (From Jaworski and Raphael7 986).FunctionDo1 1 ar value/ha/y rTable 7. Concentrations of nutrients and major ions(rng/L) in waters of the upper and lower sections ofthe Detroit River (Vaughan and Harlow 1965, EnvironmentalControl Technology Corp. 1974, Leach 1980,and Kauss and Hamdy 1985).Run-off nutrient control 1,680Sport fishing 1,054Fish production 1,040Waterfowl breeding and feeding 720Nonconsurnpti ve recreationWaterfowl hunting366103Trapping of fur bearers 74Water supplyComniercial fishing1613Total $5,066Chloride 7-9Calciuni 26-28PhosphorusA~ilmo n i a0.05-0.060.01-0.06Suspended solids 7-10Phenol s 0.003-0.005A1 kal ini ty (as CaC03) 75-84Magnes i uniNitrate6-70.2-0.3substantially different. The concentrationof most nutrients and major ions islower in the upper than in the lowerriver, owing to additions by the PougeRiver and the Detroit Wastewater TreatmentPlant (Table 7). However, pollutionabatement has reduced concentrations ofphenol, iron, chloride, phosphorus, andammonia in river water since 1970 (Table8). Moreover, phosphorus and chlorideloadings by the river to Lake Erie havedecreased steadily since 1967 (Table 9;Figure 15). These changes in concentra-tion and loading were calculated by theMichigan Department of Natural Resourcesfrom data they gather monthly at onetransect each at the head and mouth ofthe Detroit River (22 stations total;Table 10). Persistent toxic organiccompounds are not measured regularly inDetroit River water by the MichiganDepartment of Natural Resources.Because of the relatively high flowvelocity and vertical mixing, dissolvedoxygen levels in the river have remainedTable 8. Water quality measurements at the mouth of the Detroit River, 1969-87 (GLWOB 1983).Phc~li~ i s ( :,?/! ) 1.7 6.1 1.7 1.8 1.5 2.0 2.1 2.7 7.9 1.7 1.2 0.7 0.8Tc!,1!ron(n!cj,'L.)Chloride (~r!g/L)0.561%0.52IR0.37160.60170.39160.35160.11150.55150.42150.39150.35130.30130.2711Soluble pt~osphnrcic(rg/l.)Iota! )~hosphorus( i. 1 0.14 0.14 0.C8 0.07 0.08 0.E 0.06 0.05 0.04 0.04 0.03 0.02 0.02Ariirno~ir:. r~itrogen0.07 0.08 0.04 0.03 0.02 0.07 0.03 0.02 0.01 0.02 0.00 0.01 0.00(mg/L ) 0.13 0.13 0.16 0.15 0.10 0.12 0.13 0.10 0.10 0.10 0.08 0.07 0.08"1 trate Ill troypnimc/Ll 0.17 0.27 0.28 0.32 0.77 0.27 0.35 0.30 0.25 0.28 0.31 0.32 0.30pH [ T O ~ P S ~ ard 7.3 7.3 7.5 7.0 7.0 I . 1.5 1.5 I . i . 7.4 7.6 7.;highestidlb~~j 8.7 8.2 8.3 8.3 8.3 8.1 P.3 8.2 8.6 0.6 8.5 P.6 8.2nissolved nxyqev(i.loiL 8.6 7.1 7.8 9.1 7.9 8.9 9.8 0.6 8.7 8.8 9.3 9.5 9.6

c,sw'nO N . . .w. A . L~ m w ~ ~ ~ ~ m ~ m ~ w a m m a o m c n ~ a ~ m ~ ~ aW-Wv~vCOv~vh-h-mumve-evm~3~-0Cztwul0 LC,.Pt(U V)- 1 3"CJUIL300-LConaV)(UtJ.-Lc,'Ccm37(1w 0c, aJrC) 8L .r+-'a.I-- I-'Z C0ra,u Drar 3 nW O E8 L 5aJX LnL1-W-----hh.-.--.h--OOOOCOOUOOOQC~OOOOOOOGOOOOOOOOUOOOOOOOOOQOOOOU 4 d N O N a N W ~ m d m d h d m d O d ~ d c n d2 Z a-mvm-m-m-a-h-h-rn-w-hvrC)w 3: b,"- LY-0 wv)+J LM w; 3.:> LCT- 0OY-t'v) .-LO s 0'- w LC mI-' .cwa:Y- La.-GI-'.r-nv) rns Cc,?0 r= .r'rWb)m-F+' m >mrO(L5L LE tJ n+J3'P" a, 0V)Z(LZ

Mean totol phosphorus ond reocttve orthophosphote lood~ngrates w~th ossoc~ated 90% conf~dence intervalsTable 10. Water quality parameters monitoredmonthly by the Michigan Department of NaturalResources at the head and mouth of the Detroit River(IJC 1984).V26768 69 70 71 72 73 74 75 76 77 78 79 80YearsMeonchlor~de load~ng rates associated with90% conftdence ~ntervalsTemperaturepHA1 kal i nityConductivityTurbiditySuspended solidsDissolved sol ids, totalResidue, totalNitrate + NitrateAmmon i aNitroaen, organicPhosphorus, ortho and totalChl orophyl 1 aChlorideSilicaPhenols , totalCyanideTotal organic carbonBi 01 ogi cal oxygen demand, 5-dayChemical oxygen demandSulfateMarganese67 68 69 70 71 72 73 74 75 76 77 78 79 80YearsFigure 15. Long-term water quality trends at theDetroit River mouth, water years 1967-80 (MichiganDepartment of Natural Resources, Open Files).high (7.7-9.8 mg/L) from 1969 to 1981(GLWQB 1983).Because of the tremendous dilutioncapacity and the very short residence timeof water in the Detroit River, water qualitymay be acceptable even though thesediments are degraded. Sediments in theriver are seriously polluted with a varietyof toxic organic substances and heavymetals (Table 11). For example, PCB's,which are only slightly soluble in water,are present in the Detroit River sedimentin concentrations between 0 and 3,800parts per bill ion (ppb), greatly in excessof the Canadian guideline (50 ppb) fordisposal of dredged spoils in open watersof the Great Lakes. The highest PCBconcentrations in sediments are foundTable 11. Contaminant levels (mglkg dry weight) inDetroit River sediments and Ontario pollutionguideline for each (Compiled from IJC 1982, Limno-Tech Inc. 1985, Lum and Gammon 1985, and Bertramet al. 1987).Contaminant Level (range) GuidelineVolatile solids 11,000 - 379,000 60,000Oil and grease 100 - 29,000 1,500Polychlorinatedbiphenyls 0.02 - 3.8 0.05Cyanide 0.5 - 0.8 0.1Mercury 0.04 - 55.8 0.3Lead 4.8 - 960. 50Zinc 21 - 5,300 100Iron 15,800 - 3,710,000 10,000Chromium 4 - 330 2 5Copper 0.5 - 380 2 5Cadmi urn 0.30 - 17.0 1Nicke7 5 - 243 25Hexachlorobenz~ne 0.0031 - 0.36 noneOctachlorostyrene 0.001 - 0.01 none

aloncj the Michigan shoreline near Peachisland, 7ug Island, the Rouge Piver, andin the Trenton Chann~l (Thornley and liamdy1984; Kauss and Hamdy 1985). Levels ofPCB's 10 times as high as those along theCanadian shore were prevalent on theU.S. side in 1980. The highcst levels oforgarochlorine pesticides and PCB's wereobserved on the lJ.5. side of the rivernear Fort Wayne, Zug Island, Rouge River,and the City of Trenton. Mercury levelsin sediment declined in the iletroit Riverhetween 1968 and 1980, but cadmium,chronrius, capper, lead, nickel and zincconcentrations increased significantlyduring the same time period, especiallyaround the mouth of the Rouqe River(Thornley and tfanrdy 1984).Pallutants in the sedinients areeither atisorbed onto the clay or orclanicfractions, or concentraio in the int~rstitidlwdters and nidy he releasrxd upondredqlnq (Munawnr PI dl. 1985). Dredginqi tsei f disturbs sediraent, but rricrre iniportdntis spoil disposal by open-wntrr durripinowhcrc the rtidteriirl dirr/rc~r~,cs overlarcjr dress. Evc*ri tli~' ~tiateri~il thclt wt-S1ci.i dt t h ~ tyjriral dlsposal qite dcpthswill be subject to agitation and transportby waves and currents over time. The dispersionproblem is magnified by the factthat most trace contawinants are associatedwith thc fine fraction of the sediment(e,g., clays), which is very light,takes a long time to settle, and is easilycarripd by wdter currents. Through openwater spoil disposal, contan~inants becowemore readily available to the aquatic foodchain, eventua 1 ly becoming concentrated infish and endangerinq hurnan health. Thus,sound er~vironrnental practice requires thstcontaminated dredqe spoi 1 s be confined tosafeguard against contamination of thefood chain.There is evidence that contaojinantsin the sediments are toxic to phytoplankton(Munawar et dl. 1985) and are cyclinginto the biota. Herrina qull eggs fromfiohtinq Island (Stvuger et al. 1985) andCdrcdSsPs of wintering ducks (Smith et. al,1985) from thp fl~troit River contain highPCR concentrations, suqq~sting transferinto the food chaiit, However, the ecosystemeffects of the polluted bottornc,etlinlerits it\ the Detroit Piver are poorlyundcrstc.rod at th~s time.

CHAPTER 3.B!QkOG!GAL CHARACTERBSTlGS3.1 PRIMARY AND SECONDARY PRODUCERS wide), P. richardsonii, Elodea canadensis,MyriophyllumEighty-two species of phytoplankton Heterantheraare present in the river at low densities stands are typically composed of 2 or 3(about 500 cells/ml). The phytoplankton species, but up to 11 have been recordedassemblage is dominated most of the year in a single stand. Chara is the onlyby diatoms (Fra ilaria crotonensis and taxon that occurs in monotypic stands.Tabel 1 aria fen* which are common Additional research is needed to determinein LakeHiron-- (Mi 11 iams 1962; Wujek, why Heteranthera and Chara are found in1967). In July and August, the bluegreen the Detroit River in remvely higher andalga Oscjllatoria sp., common in Lake St, lower abundance, respectively, than in theClair at that time (Winner et al. 1970), St. Clair River and Lake St. Clair. Incontributes substantially to the Detroit the Detroit River, the lower depth 1 imitRiver phytoplankton. Relative to other for plant colonization has not been adewaters,the mean number of diatom species quately documented, but most beds occur inin the Detroit River (29.8) is third water less than 7 m deep (Schloesser andhighest in the Great Lakes, about equal to Manny 1982). The area of the riverbedthat in major tributaries of the Ohio between the shoreline and the 3.74 depthRiver Basin (range: 23.4-29.3), lower contour is about 99 kmz. About 72% ofthan that in major rivers of the Pacific this area is occupied by submersed plantsNorthwest (27.2-37.0), and higher than (Hudson et al. 1986). The total areathat in the Mississippi and Arkansas covered by emergent macrophytes in theRivers (13.4-19.0) (Williams 1972). Detroit River is estimated to be 860 ha.Over 95% of the emergent vegetation isNo studies of periphyton have been found in the lower section of the river.conducted in the Detroit River. However,a recent study by Manny et al. (1985) at a Schloesser et al. (1985) studiedwave-exposed breakwater area in western submersed aquatic macrophytes at threeLake Erie suggests that the diatoms stations in the Detroit River; Belle Isle,Gomphonema and Diatoma, green algae (pri- the west side of Grosse Ile, and north ofmarily ~lothrix), the blue-green Sugar Island. Growth of submersed macro-Oscillatoria, and the red alga Ban ia phytes in the river follows one of threemight be common+during winter in seasonal patterns (Figure 16): dominantDetroit River. Clado hora, a filamentous taxon may grow alone (Pattern A); codomigreenalga, cou d be expected to be nant taxa may grow sympatrically withoutdominant during the summer months. Of species succession (Pattern 5); and codomthesespecies, the diatoms would likely inant taxa grow sympatrically with speciesoccur on submersed aqua tic vegetation in succession (Pattern C) . Differences inthe Detroit River. growth and seasonal succession of sometaxa were likely caused by presence orAt 1 east 20 submersed macrophyte taxa absence of overwintering buds, competi -occur in the river (Schloesser and Manny tion, and life-cycle differences. Peak1982; Hudson et al. 1986). In decreasing biomass productivity was attained inorder of relative abundance, the more either July, August,, ar October, dependingcommon forms are Vallisneria americana, on the taxonomic composition of plants atChara spp., Potamogeton spp. narrow-leaf each sampl ing station. At Belle Isle,forms (those with leaves less than 3 rnm Vallisneria americana was the dominant27

Table 12. Distribution and relative abundance of submersed macrophytes by water body segment (expressedas the percentage frequency of occurrence) at 595 stations scattered through the St. Clair-Detroit River systemin 1978 (Schloesser and Manny 1982).DistributionTaxonLake St. ClairDetroit St. Clair Anchor LakeRiver River Ba!! ProperVal1 isneria americana M~chx. (Wild celery)Characea~ (MmgPotamo eton richardsoni i (Benn. ) Rydh. f Redhead grass)F%&Tf'GmTF~(Eurasian watermilfoil)- odea -- candensi s Michx. (Waterweed)tieteranthera dubia (Jacq.) Mac M. (Water starorass)Total number of ~r~acrophyte taxa 13 16 17 7- - -- --- Nitel&sis obtusa, Nitella balina, Potamoqeton cris~s, Potamoqeton zosteriformis, Ranunculus lon irostris,automur G6e6efl a ~ a ~ i t t a ~ T r . ? ~ b ~ ~ % found ~ d in ~ the r t Detroit ~ ~ ~ li sd o y - ~m s e r et al. (1986BTwdson et a1 . (1986).plant in September and October (14 g/rnq. River consisted of 11 taxa (Table 13).At Grosse Ile, Elodea canadensis wasaeTypha angusti fol ia, Sparganium eurycarpum,prevalent in August and September (280 Scir us fluviatilis, and S. americanusg/m'). At Sugar Island, Potanio eton pro uced the highest biomass. In Anchorcris US was dominant in June ;APfi Ilum s ,caturn in August (100$m+Metkradubia in October(80 g/rn2), Biomass values at all thesesites were within the ranae reported for 1986).aquatic macrophyte stands in rivers attemperate latitudes (Edwards and Owens Three exotic submersed macrophyte1960; West1 ake 1963). taxa have been found in the Detroit River:Potamo eton cris us L., NitellopsisNo detailed studies of emergent &and-iophil lum spicatummacrophyte species composition, distribu- (Schloesser 1986). Potamogeton crispustion, and relative abundance in the river (Figure 171, generally assumed to havehave been completed, a1 though wet I and com- been introduced from Europe, was firstmunities have been mapped using aerial recorded in the Great Lakes in 1946 (Vossphotographs and satellite images (Jaworski 1972), and was first recorded in theand Raphael 1976; iyon 1979; Herdendorf et Detroit River in 1951 (Hunt 1963).al. 1981; Raphael and Jaworski 1982; Because P. crispus grows in early spring,McCullough 1985). In 1983-84, the emer- it has not been extensively surveyed.gent plants at Stony Island in the Detroit Curly pondweed gets its name from the wavy28

margins on the sides of its leaves.Leaves are dark green with a reddish hueand have small teeth along the margins.Plants may grow up to 2 m long. Thispondweed is a European invader of waterbodies in North America that may spread byrerooting of small plant fragments. Inspring , curly pondweed provides she1 terFor small aquatic animals used as food bymigrating waterfowl, and spawning substratefor fish. It is one of the mostabundant submersed macrophytes from Apri 1to June.Figure 36. Three patterns of seasonal growth of submersedmacrophytes (g/m" in the Detroit River,April .November 1978 (Schloesser et al. 19851.spicatu? (Figure 18)etroit River in 1954(Hint 1957); the species was first foundin Lake St. Clair in 1974 (Dawson 1975).By 1978, it was the third mast commonsuhnersed macrophyte in the Detroit River(Figure 19; Schloesser and Vanny 1984).Eurasian watermi lfoil is brownish-green,usually with some red on the stems. Stemsmay be up to 3 111 long and have clusters of4 to 5 feather-like leaves that are moreabundant near stem tips than on lowerstems, Each leaf has 5 to 24 pairs ofsmall leaflets. Eurasian watermilfoil isa European invader of water bodies inNorth America; it may spread from lake tolake by small fragments transported byboats and trailers. This milfoil cancrowd out other underwater plants used byTable 13. Percent frequency af accurrencs and mean dry weight, above-ground biomass(g/m2) of emergent macrophytes at Stony Island in the Detroit River, 1983-84(Hudson et el. 1986).TaxonaEleocharis spp.Phalari s arundinaceaSagittaria latifoliaSagi ttaria rigidaScirpus acutusScirpus amerlcanusScir us fluviatilisval idusOccurrenceBiomass1983 19ma TWO closely related species. &. smaili i and - E. erythropoda.

Figure 17. Curly pondweed (P6tamog@ron crispus; Schloesser 1986).

MICHIGANThe most recently found exotic macrophytein the river system is a macroalga(Characeae) , Ni tel lo sis obtusa (~igure20), native to -77- urope a n m a . Thisplant was first discovered on this continentin the St. Lawrence River in 1978.A1 though not extremely abundant, thistaxon has been found at two widely separatedlocations in the Detroit River(Be1 le Isle and Point Hennepin; Schloesseret al. 1986a) and in the St. Clair River.Sample Lucat~ons The occurrence of N. obtusa in the United. ~ A ~ ~ J ~ ~ ~ Iprr~e.i~ States only in watlrsfrequented by merchantvessels suggests that it is distributedby this mechanism. N. obtusa haslong, uneven-length branch%s that lookangular at the joints and may have onecream-colored bulb at the base of eachcluster of branches. Like the Nitellas,- N. - obtusa is sometimes found in deep,slow-moving water where other plants arescarce.Zooplankton in the Detroit River havenot been studied, but because of the shortflushing time, their composition andabundance in the Detroit River shouldresemble that in Lake St. Clair. In LakeSt. Clair, 14 taxa of planktonic copepodsand 18 of cladocerans are reportedlypresent (Winner et al. 1970; Leach 1973;Bricker et al. 1976). C clo s vernalisand Diaptomus ashlandi q are ominant inLake St. Clair. Difflugia is the mostcommon protozoan, and Conochi 1 us,Keratell a, Pol arthra, anchaeta, andRrachionus are +i- t e most common rotifers.Zooplankton numbers should peak betweenFigure 19, Distribution of MyriophyNum spicarum in June and September. A study of foodsthe Detroit River in 1978(Schloesser and Manny 1984).eaten by 1 arval ye1 1 ow perch during passagethrough the Detroit River identifiedzooplankton , including copepod naupl i i ,01 der cyclopoi d and cal anoid copepods ,fish and waterfowl. However, Eurasian cladocera, and rotifers (Poe 1983).watermil foil provides habitat to many Hence, zooplankton 1 i kely are a criticalaquatic animals because it has many fine food resource to larval fish in theleaves and overwinters as a decaying mat Detrait River. Additional research isupon which they feed. In general, water- needed to determine the biologicalmSlfoi1s were little noticed in the UnitedStates until the late 1950ts, when theysignificance of zooplankton in the river.became a nuisance in large water bodies Macrozoobenthos has been we1 1 docusuchas the Potomac River, Currituck mented throughout the river (Hiltunen andSound, the Chesapeake Bay, and TVA reser- Manny 1982; Thornley and Hamdy 1984;voirs. In the Great Lakes, massive Thornley 1985; and Hudson et al. 1986) butgrowths of M, spicatunr have been reported, nifcro- and meiozoobenthos have not beenbut these rFpresent only mi nor impediments studied, The number of macrozoobenthicto human water uses such as recreation and species in the Detroit River systemnavigation (Schloesser and Manny 1984). exceeds 300. 01 igochaeta , Chi ronomi dae,32

Figure 20. Niteliopsis (NiteNopsis obtusa: Schloesser 1986).

Gastropoda, Ephemeroptera, Trichoptera,and Amphipoda are the most significanton a biomass basis. Hydra is quite abundantbut contributes little to biomass.Ol igochaetes are most common in the lowerDetroit River, where pol lution-toleranttubificid species dominate on pollutedsediments. Chi ronomids are abundantthroughout the system, with Cricotopus,Parachi ronomus, Parakiefferiella, Rheotansarsus,-- and S%ictochironomus the mostcommon taxa. -bFicola -- and Elimia arecommon snail taxa. Hexagenia is the mostcommon mayfly. However, owing to thewidespread contamination of sediments inthe Detroit River, the average density ofmayfly nymphs in the river (88/n12) islower than that in Lake St. Clair(271/m*), the St. Clair River (95/m2), orthe St. Marys River (199/m2) (Edwards eta1 . 1987). Hexa enid populations in theDetroit River 78- ave recovered since 1967 inresponse to pollution abatement and up to1,925 nymphs/nrz were found in 1980 inCanadian waters (Thornley 1985).Che~mat~opsyche, Hydropsyche, and 0ecetisare dominant trichoptKn tdxd, dndI-1 alella is the most cornmon amphipod.?- p e x diversity within these taxd isgreatest in the Chi rononiidae (127), Tri -choptera (38), and 01 igochaeta (25).Freshwater mussels and crayfish are taxorloir~icallydiverse and abundant but havenot been adequately documented in thcriver. In general, the diversity andabundance of most macro;i.oobenthic taxa arelower in deeper, fast-flowing areas of theriver dnd higher in shdllow sedimentdeposi ti on zones (Hi 1 tuner1 and Manny1982).3.2 NATIVE AND EXOTIC FISHESFish exhihi"rsevea1 basically differentlife-histmy strategies in theiruse of the Dptruit River habitats. Some32 species are permanent rrsidents;another 28 species are mi~rants that usethe river as a feeding, spawning, ornursery ground or as a migratory pathwaybetween Ldkes Erie and Huron. Recentstudies of the movements of marked fish(Hdas et al. 1985) have revealed diverse1 ife-history strategies among the differentstocks of sane species using theriver. The present-day fish populationsof the Detroit River are a mix of about 65native and introduced (exotic) species(Table 14). At least 40 more speciesinhabited the river historically ormigrated through it (Bai ley and Smith1981; Edsall et al. 1988).A coniprehensive description of thefish spawnina and nursery areas of the St.Clair-Detroi t River system was recentlycompleted by Goodyear et al. (1982). Thisstudy showed that the Detroit River andits tributaries are important spawning andnursery areas for many species thatsupport rriajor fisheries in the waterwayand in Lakes Huron and Erie (Figure 21).Of the species of fish that have beenrecorded as residents or migrants in theDetroit River, 39 spawn in the river(Table 15). Spawning areas of thesespecies, shown collectively in Figure 22,are concentrated near the mouth of theDetroit River where a variety of suitablelake and riverine habitats are found.At this time, the most important users ofthe river for spawning are smelt, yellowperch, gizzard shdd, and white bass (Muthet al. 1986).Historically, large spawning runs oflake herring, lake whitefish, and laketrout entered the Detroit River from LakeErie in the fall. A portion of the lakeherring and lake whitefish ran up theriver into Lake St. Clair. Lake herrinaand lake trout spakrning grounds were notrecorded but some whitefish spawned nearthe mouth and the head of the DetroitRiver. All of these runs ceased in thelate 1800's or early 1900's because rockoutcroppings used for spawning were destroyedby construction of the shippingchannel or rendered unsuitable for spawningby water pollution (Smith 1917).Limited spawning by whitefish niay betaking place in the Detroit River, becausea few whitefish larvae were caught therein 1977 and 1983 (Hatcher and Nester 1983;Muth et al. 1986).Thp D~troit River was also an importantspawning ground for lake sturgeonthat entered tne river in the spring fromLake Erie. The lower river was believedto be the major spawning area but spawninggrounds have also been identified nearFighting Island in the midreaches of theriver and near Belle Isle at the head ofthe river (Goodyear et al. 1982). Lake

Table 14. List of65 fishes comnlonfy found in the Detroit River (Lee et a!. 1980;Goodyear et a!. 1582; and Haas et a!. 19%).Cot~iinon nameSea ldnlprey1 a ke s turqeonSpotted yarLongnose oarBowfinAmerican eelMoonchyeAlewifeGizzard shadChinook sal~tonCoho sal~iionPink saintonRdinbow troutBrown troutLake troutLake whitefishRainbow smel tNorthern pi k~Muskel 1 ungeGoldfishCornlor1 carpSilver chubGolden shinerErnerald shinerPuqnose nii nnowBlacknose shinerSpottail shinerSand shinerMimic shinerQuill backiongnose suckerWhitp suckerNorthern hogsuckerRignrouth buffdl0Srnallnlouth buffaloSpatted suckerRedhorse, unidentifiedSi 1 ver redhorseGo1 den redhorseShorthead redhorseRiv~r r~dhorseEiack bv? 1 headYellow bullheadBrown bull headChannel catfishStnneca tTrout-perchSlit b0tBrook si lversides(Continued}Scientific narliePetronrvzon niarinus- E T j ~ s ~ ~ n---- Lepi sosteus -- oc7i'TZEL epi sosteus osseusA~nia calvaG i m o s.-AH- --- tra taHi ~don tergisusA7Ossr seudoharen usKorosan~a -- e_d_ece e+lanum-c*tschancoyncs 1 sutcn y us -haSa r110 gaG5erl%-Ti% triltta+SalGi3T

Table 14. (Concluded).Common nameWhite perchWhite bassRock bassGreen sunfishPumpkinseedBl uegi 11Smal lmouth bassLargemouth bassWhite crappieBlack crappieLogperchYellow perchSaugerWalleyeFreshwater drumFour horn sculpiScientific nameMorone ameri canaMorone chrvso~s-1 it& rbpestrisLepomi s cyanel 1 usCe~omis aibbosusiZi%ZZrusE%~Eb. ..- e. - r - - u . s - do1 omieuiMicro terus salmoidesh u l a r i s e.--+Pomoxis ni romacul atusPercina cepro esP~rra . -. -- fl avescens- . - - -m stedi on canadenseStizostedion T i treumAnlodinotus arunniensTable 15. Fishes that spawn in the Detroit River(Goodyear et al. 1982 and R. Hass, Mich. Dep. Nat.- --_Resour.; pers, comm.).WalleyeCommon nameLake sturgeonTrout-perchSpotted garBurbotLongnose garBrook silversideBowfinWhite bassAlewifeRock bassGizzard shadGreen sunfishLake herringPumpkinseedLake whitefish Bl uegi 11Lake troutSmal lmouth bassRainbow smel tLargemouth bassNorthern pikeBlack crappieMuskel lungeWhite crappieGoldfishJohnny darterCarpYellow perchEmerald shinerLogperchSpottail shinerSaugerWhite suckerWalleyeNorthern hoq sucker Freshwater drumFigure 21. Several fishes that suppan major fisheries Chan~ei catfish Fourhorn scul pinin the Detroit River tfllustralions by E. e3. S. Logier and StonecatC. M. Godkin).

ONTARIOSpawning AreasSPORT FISHCOMMERCIAL FISH@j FORAGE FISHOTHER FISHFigure 22. Fish spawning areas in the Detroit River (Goodyear et al. 1982).

sturgeon populations have been sharplyreduced from historical levels by overfishingand pollution, but spawning wasreported in the midreaches of the DetroitRiver in the 1950's and in the lower riveraround Stony and Sugar Islands in the1970's (Goodyear et al. 1982).Walleye, ye1 low perch, and white bassare important recreational species thatspawn in the Detroit River. The river ispart of a complex migration route thesespecies follow between Lake St. Clair andLake Erie. Large post-spawning runs ofwalleyes enter the river from Lake Erie.Reduction in historical spawning runs ofthese species was attributed to pollution.In the 1970ts, walleye spawning was againdocumented and wall eye 1 arvae were collectedat several locations in the lower16 km of the Trenton and Rain Channels.Historical records of ye1 low perch spawningin the Detroit River are lacking, butin the 1970's spawning occurred in themouth of the Detroit River (Goodyear etal. 1982).The river is also an importantnursery area for fish because thedensities of larvae of all fishes cornhinedin the Detroit River and its tributariesin 1983-84 were higher than at the outflowof Lake St. Clair, (Table 16). Tow-netcatches of fish larvae in the DetroitRiver in 1977-78 and 1983-84 (Matcher andNester 1983; Muth et a1 . 1986) showed thatthe river is a nursery ground for 25species of fish (Table 17). Most abundantamovg the larvae were three forage fish,alewives, rainbow smelt, and gizzard shadTable 16. Average density of fish larvae in the DetroitRiver, 1983-84 (Muth et al. 19861.Averaae number of1 arvae/1,000 n13of waterLoca t i on 1983 198rOutflow of Lake St. Clairinto Detroit River 9 1 223Detroit River proper 214 33 5Detroit River tributary 319 485Table 17. Fishes that use the Detroit River as a nurseryarea (Hatcher and Nester 1983; Muth et al. 1986).AlewifeGizzard shadEmerald shinerWhite perchRainbow smel tLogperchSpottai l shinerWhite bassYellow perchDeepwater scul pi nCommon carpBrook si lversideTrout-perchWall eyeBurbotLake herringLake whitefishJohnny darterWhite suckerSpotted suckerRiver carpsuckerSl imy scul pi nFreshwater drumLake whitefishWhite crappie(Table 18). Yel low perch, logperch,emerald shiner and unidentified minnowswere also relatively abundant. The otherspecies represented in the catch tended tobe much less abundant (less than one larvaper 1,000 m3 of water). Because samplingin these studies was restricted to deeperopen-water areas, the re1 ative importanceof submersed vegetation as nursery areaswas not assessed. In the St. Marys River,the abundance of fish larvae increasedwith distance away from the channel areasinto the submersed and emergent vegetation(Duffy et al. 1987). Further research isneeded to assess the role of 1 ittoralaquatic vegetation as nursery habitat forfish larvae in the Detroit River.Submersed vegetation, also providesnursery habitat for juvenile fish in theDetroit River (Hami 1 ton 1987). Electrofishingat 16 sites in the Detroit River,including Gibralter Bay, in October 1986in beds of submersed macrophytes producednumerous young-of-the-year of 16 fishspecies as well as a variety of older fish(Table 19). In general, the electrofishingsurvey showed that fish could toleratepoor water conditions and that thedistribution of fish in the Detroit Riverwas limited chiefly by the lack of heterogeneousphysical habitat, (i.e., concretehreakwalls and piers create a hostileenvironment for fish).R E C ~ ~ ~ S of the early fisheries showedruns of native cold-water species, includinglake trout, lake whitefish, and lake

Table 18. Average density (no. larvae per 7000 m3 of water) and relative abundance of fishlarvae in the Detroit River, 1977-78 (Hatcher and Nester 1983).Species 1977 1978Averaae Re1 ati ve Average Re1 a ti vedensi ty abundance density abundanc~Rai nbnw smel tGizzard shadYellow perchAlewifeUni dent i f i ed mi nnowsLogperchEmerald shinerWhite bassCommon carpUnidentified dartersUnidentified sunfishesJohnny darterTrout-perchWall eyeSpottail shinerRurbotDeepwater scul pi nWhite suckerFreshwater drumLake whitefishBrook s i 1 vers i deAverage total densityherring entered the Detroit River fromLak~ Erie in the fall to use the spawninghabitat in the system. However, there isno evidence to indicate these native coldwaterspecies were year-round residents.Indeed, the thermal regime of the riversuggests they probably were not. In mostyears, water temperatures in the rivermight permit year-round residence of coldwaterspecies. However, temperatures inJuly and September approach or exceed thelimits at which most indigenous cold-waterspecies can use food effectively forgrowth, and temperatures in Augustapproach the lethal range for lake trout.Nevertheless, by vi rture of their propensityfor short migrations, which allowedthem to use the Detroit River during thecooler months, cold-water fish specieswere apparently able to successfullyexploit critical spawning and nurseryhabitat in the river that would otherwisehave been unavai 1 able to them.Among the numerous exotic fish thathave been introduced into the Great Lakes(Emery 1985), the common carp is linkedhistorically to the Detroit River, havingbeep first introduced to the Great Lakesin 1883 near the mouth of the SanduskyRiver in western Lake Erie. From there itspread throuqh the Detroit River to theupper Great Lakes, destroying beds of wildcelery and wild rice preferred as food by~ative canvasback and redhead ducks as itspread (Cole 1905, McCrimmon 1968).Because of their large impact on nativevegetation and their ability to toleratehigher lcve?s of pollutioq and higherwater temperatures than native fishes,carp have displaced many native fishes inthe river and dre ecological1y one of the

Table 19 Fishes caught in 19 rnrnutsrj of ~tectrof~shlng among smbntersed aquatic vegetatton in Gtl>raltar Bay, October 15, 19% (Ham~lton 19873" - - -- - - - " " - . -- -_--- ----Lencith rdnqcSp~r 7 ta5 Aqr class Total no. {cm)-_ *__ _^I_1I_ -____-__---I ----I_Yellow pcrrh '3 4 1 5 - 10Mraok srlversid~ ft 10 5Alclwifc? 0 7 5 - 7Pugnoccx ~ $ nnow 10 7 2 - 7Tunut perch C7 5 7 - 10lpottai 1 sh~nor O 5 2 - 7Gi;rzdrc% rhnd 0 4 5 - 15Rlack crnppice 0 3 2 - 7White p~rch 0 3 7Pumpkin?c*~d surifistr l; 2 2Ijnidenttiied ryprin~ds (i 2 5 - 10Pl tlntnnse minnow ir 7 10Stnal larauth bass 0 1 15Pluecjill 0 1 7Rd i nbaw rmrl t Ci 1 5Mht te, sucker (3 1 15Yet 1 nw parchWd 1 1 ayc.Rockbdsr;FJunrpklnst*~d \tittt lshYellow perchCanmnri r c% rCpGo1 dt4r1 st11 rlcbr.Mnc;kh,~dtlbid 1 leyr.Mt rrcrr' ~drl)Norther n pi kt.Rttreqillniort ~t~tpc~vt~rnt i~xrll 2~ f l:*h that i>cac.r~i rit t'oduc rd ifltc, thr r I vfq*. I ~ r r w pt;p14 litiirsnz;of roisrrilon r3r.p rl(3w :t?hdblt the+nc*?t'"c~ i t Wive!* dftd $d,jdr'~flt k4rltt'l. 1'1~>d'lt~5 ,whtlre they rclcctr? ly rmdo up r!ralc.!r of t h ~tornrrtt7r-cit3l f1561 Latch (~,c~"sE'cZ~(?~I 5.2).Otl-tgr ~xctPic f i shec, that ~r-~quetit theltetrnit KIVP~ ii)~ltiCi(4tlic~ pdr'd~litr "f2rfIdt~!prey, which spread thu>otrtah the O~ir'ojttJjk:py t~ th4 gpper* KriraF B tqLo* III the194Cts, bringing d~sir-dbl~ fl~hrs theidke trout to thc brink ut extinctsorduring the. 1950's nr?d 60's (ldwrli3 tQ?(?;Ctsristsc 1974). T ~ P sea Iarrrprey bas dlorirj, cnapl~t nted lrtrl cyr IP, tncludiny aCt-yedr ; a I c .rirvenr If} pprlnd inS ~ ~ ~ ~ tr~hlitari~sI C I Y 'ttldt rrtakes i t vulnerdbltl to cherilicdl fontruf and lrlteqratedi.rc>rt trrat,ailen*enf techn~q~i~s (Srriith 1971).Co~lrnl of the sea 1 arnprey continuesprewntly dnd wft? he requirrd in thetuttlrr : trrouqhout thp Great I rfki>s.Rn~nhah qrli~1Z dnfi ill~wife, which weredccldrntly ~ntvodareed Into the lower 1 akesIn 1Y3?, also spread through the Detroitfizlvrr to the uppi"r lakes, and now rrldke upthe bclik of the farai]~ fish base in all

the Great Lakes (Emery 1976; Goodyear etal. 1982).The latest exotic fish to spread fromthe lower Great Lakes to the upper GreatLakes through the Detroit River is thewhite perch. This species was firstintroduced into Lake Erie in 1953 and nowis abundant in western Lake Erie and LakeSt. Clair, where it has begun to hybridizewith native white bass (Todd 1986). Theinvasion of the Detroit River and adjacentwaters by white perch poses a dilemma. Insmall cold-water lakes in Maine, whiteperch are a serious competitor with andusually dominate ye1 low perch, trout, andsalmon, because they 1 ive much longer(12-13 years commonly) and reach good size(15-30 cm and 1-2 kg). Though they may bedisplacing native fishes, they are consideredmore palatable than other fishes bymany anglers ( AuCl ai r 1P60). Therefore,public attitudes towards the white perchare ambivalent. The proportion of exoticspecies in the Detroit River may increaseas the Michigan Department of NaturalResources seeks to upgrade cold-waterfisheries by stocking Pacific salmon alongthe urban waterfront (Fogel 1978, 1984).3.3 WATERFOWLImportant wat.erfow1 in Michiganinclude ducks, geese, swans, and coots(Table 20). At least 3 million waterfowlmigrate annually through the Great Lakesregion, which is situated at the intersectionof the Atlantic and MississippiFlyways (Be1 lrose 1968; Herdendorf et a1 .1986). An estimated 700,000 diving ducks,500,000 dabbling ducks, and 250,000 Canadageese migrate across Michigan each fa1 1.Detailed documentation of migratorywaterfowl use of the Detroit River isgenerally lacking and portions of thefollowing discussion (derived fromJaworski and Raphael 1978) includes waterfowluse of the western shore of LakeErie, the lower Detroit River, PointMoui 1 lee, and Lake Erie marshes, wetlandareas which collectively total 38,225 ha.Accurate counts of sumwer-residentducks are lacking, but at least sixspecies, including mallards, blue-wingedteal, wood ducks, black ducks, pintails,Table 20. Waterfowl that frequent Michigan's coastalwetlands (Johnsgaard 1975).Scientific naveDucks and rzergansersAix snonsaGeese and brantAnser caerulescensBranta bernicla%%i%i Fa-isSwans --Cygnus columbianusCygnus cygnusCygnus olor- CootsFulica americanaCommon nameWood duckPintailNorthern shovelerGreen-winged tealBlue-winged tealAmerican widgeon (Baldpate)Common mallardBlack duckGadwa 1 lLesser scaupRedheadRing-necked duckGreater scaupCanvasbackBuffleheadComon (American) goldeneyeOldsquaw Hooded merganserRed-breasted merganserRuddy duckSnow gooseBrant gooseCanada gooseWhistling swanTrumpeter swanMute swanAmerican cootand redheads, nested in wetlands along thelower river area in 1957-68 (Jaworski andRaphael 1978). Duck nesting densities inthe Pointe Mouil lee wetland area near thelower Detroit River averaged 145 nestingpairs/km2 of wetland during that period.A small (123 ha) federal refuge, theWyandotte National Wildlife Refuge, wasestablished in 1961 off the northern endof Grosse Ile in the Detroit River as abreeding ground for migratory waterfowl ;it is an important nesting and stagingarea (Jaworski and Raphael 1978). InSeptember, 1 ocaT nesting waterfowl gather

in this area and are soon joined by otherwaterfowl from more northerly breedinggrounds. In October, they begin migratingsouthward.Beginning in the 1930ts, warm industrialeffluents from the Detroit metropolitanarea prevented ice from forming alongthe entire river south to Gibraltar (Hunt1957). Attracted by the open water,thousands of ducks wintered along thelower Detroit River and foraged on thebottom in littoral areas (Hunt 1957).Canvasback (Figure 23), redhead, ma1 lard,scaup (Figure 24), and Canada geeseaccount for a majority of the waterfowlwintering on the Detroit River in recentyears. Canvasback, redhead and greaterscaup tend to eat plants, whereas lesserscaup, common goldeneye, bufflehead, andruddy duck rely principally on animalfoods (Bell rose 1976). In 1980 and 1981,about 11,700 and 4,500 ducks, respectively,wintered on the Detroit River (Jones1982). Peak abundance of ducks using theopen waters of the lower Detroit River inwinter months has exceeded 26,000 (Jones1982).The spring migration of waterfowlbegins in March following ice breakup onwater bodies used for resting. Springflights through the Michigan area may lastonly about 45 days, but can be impressive.For example, on March 27, 1941, anestimated 400,000 canvasback, scaup,redhead, buff1 ehead, go1 deneye, and otherducks congregated on the east side ofGrosse Ile in the Detroit River (Miller1943).Figure 23. Canvasback ducks are protected from hunting on the Detroit River (Printed with the permissionof David Maass, the artist; 1982-83 Federal Duck Stamp).

Figure 24. Lesser scaup are harvested frequently by Detroit River hunters (Photo provided by E. R. Quortrupl.In the past, 24 species of ducks regularlyfed in the Detroit River (Hunt1957). Major concentrations of feedingducks are usually observed in littoralwaters around Belle Isle and Mud,Fighting, Sugar, and Celeron Islands, andGrosse ile (Jones 1982). Mergansers feedprimarily on fish, whereas American go1 d-eneye prefer crayfish, clams, and otherinvertebrates. Many diving ducks, such ascanvasbacks, redheads, and scauy, feed onsubmersed aquatic plants, includingVal 1 isneria americana, Potamogeton spp.,and Elodea canadensis. In general, submersemantsand their associated invertebrateanimal cornmunlties provide most ofthe foods reauired by waterfowl(Schl oesser 1986).

CHAPTER 4.ECOLOGlCAL WELATlONSHlPS4.1 PRIMARY AND SECONDARY PRODUCTIONAs noted earlier (Section 3.1), thephytoplankton and periphyton in theDetroit River are not well studied. Fortunately,production by plants avd animalsin connecting channels of the Great Lakeswas recently reviewed (Edwards et al.1987). This review concluded that sub-mersed aquatic macrophytes are the padorprimary producers of organic matter in theDetroit River (Table 21). Production ofemergent macrophytes in Table 21 representabove ground biomass only. The amount ofallochthonous input of organic matter(leaves and insects) into the DetroitRiver is unknown so estimates in Table 21were based on data in the scientificTable 21. Annual mean standing crop, and net production of primary and secondaryproducers, and terrestrial inputs in the Detroit River (Edwards et al. 1987).Producers Standing croo Net production Total(g AFDW/~~)~ ( t AFDWIyr) Production(%IPrimary producersPhytoplanktonPeri phytonSubmersed macrophytesEmergent rnacrophytesTotalSecondary producersZooplanktonMacrozoobenthosTotalTertiary producersFishTerrestrial inputsLeaves and insects 260Sewage 25,665a Ash-*ree dry weight.44

literature (VPI 1985; Gasith and Hasler1976). Direct sewage inputs to theDetroit River in Table 21 were estimatedby Edwards et al. (1987) from STORETretrieval of 1984 water year data. Theestimate of fish production in Table 21 isextremely tenuous because it was derivedfrom estimated primary production usingthe 10% trophic transfer rule of Lindemann(1942). A more adequate estimate wouldinclude production by resident and mi gratoryfish stocks, neither of which hasbeen measured yet. More research isneeded to determine fish production in theDetroit River.The next most important primary produceris the phytoplankton. Sewageeffluects now add about as much organicmatter to the river as all natural primaryproduction combined. Presumably, theproduction of fishery resources in theDetroit River is more dependent on naturallyproduced organic matter than onorganic matter in sewage. Fish and waterfowl,for example, feed directly onmacrophytes and the invertebrate animalsthat colonize macrophytes (Table 22).However, fi 1 ter feeding benthic animals,such as caddisflies and small clams, wouldremove particulate organic matter from thewater indiscriminantly before they wereconsumed by fish. Additional research isneeded to determine how much organicmatter in sewage effluents forms the basisfor the food web in the river.Production data (Table 21) are animportant first step in understanding foodchain dynamics of the Detroit River, butone must know how each level is used ortransferred to subsequent trophic levels.This understanding would integrate thesimultane~us effects of all componentsaccording to their interrelationships inthe ecosystem. The Detroit River producesnet biomass and does nct. simply transportphytoplankton and zooplankton from LakeTable 22. Underwater plants that provide cover and food for fish and waterfowl in connecting channels ofthe Great Lakes (Schloesser 1986Ia.Clasping NarrowEurasian leaf leafwater- Water h'ater- Wild prrd- pond-Muskprass Coontail niil foi 1 Nziad stargrass weed cel~r;! weed weed- FishAlewifeBlack crdppieBlueoil1R1tin;riose minnowRrown bull headLarclevouth bassPuskellungeNorthern pikeRockhassvfjl low verchb aterfowlAmerican coot x x x x xBlack duckRufflrl-padCawasbackCommon scooterGo1 deneyfbrez ter scavpLessel SCaUpRall?rdRedheadRirignecka Fish feed primarily upon the invertebrates that colonize the plants; waterfowl feed on both the plants and theinvertebrates.

Huron to lake Erie. tiowever, availableinformation is inadequate to determine bowmuch of the phytoplankton, macrophytes,and zooplankton produced in the river isused by river biota. If only a smallamount of phytoplankton and zooplanktonbiomass passing through the Detroit Riveris retained, then the littoral plant complexof emergent and submersed macrophytesand the associated periphyton are the dominantprimary producers and macrozoobenthosare the main secondary producers inthe river.Not included in Table 21 are pools ofdissolved organic matter (DOM) and particulateorganic matter (POM), which oftenexceed by many times the amount of organiccarbon of the 1 iving plankton, macrophytes,and fauna produced in streams(Wetzel 1975). The only DOM measuren~entsavailable are from Lake Huron and average2.7 g/m3 (Robertson and Powers 1967). Theamount of POM corning into the St. Clair-Detroit River system from Lake Huron maybe about 0.7 g/m3(Robertson and Powers1967); an average of 1.4 g/rn"as measureddt the mouth of the St. Clair River, andup to 2.0 g/m3 in Lake St. Clair (Leach1972). A single POM sample from the mouthof the Detroit River measured 3.8 g/mJ(Robertson and Powers 1967), but bedloadnioven~ents of POM hsve not been studied sothis value of 3.8 g/m3 may underestimatePOM in the Petroit River. In 1982, stlspendedsol ids increased niore than two-fol dfrom an average of 8.8 g/v3 in headwatersto 19.6 g/tnht the nlouth of the DetroitRiver (Kauss and Mamdy 1985). Estimatedloadings of suspended sol ids by i.he rivert.o Lake Erie are very ldrge (4,600 t/day;Table 9). Therefore, much POM is eitherproduced in or added to the Detroit Rivercontinuously. Additional research isneeded to d~termine the loadings of crganicmatter in all fornis by the DetroitRiver to take Erie.For at least 30 years, the largestcontributors of organic nratter to theDetroit River have been sewage treatmentplants (see Sections 1.6 and 6.4). Macrophytesproduce large quantities of organicmatter and alsn provide much of the physicalstructure available in the river.Large plant debrFs (trees) that serve ascenters of fish production in other rivers(Karr and Schloesser 1'378; Renke et al.1985) are removed during periodic channeldredging of the Detroit River.The amount of organic matter producedin littoral waters, its storage, and itstransport deserve more attention. Withoutthis information, a full understanding offish and other secondary production in theDetroit River will not be possible.4.2 DETRITAL FLOWO f the nearly 210,000 t. of plantbiomass produced in the St. Clai r-Detroi tRiver System each year, only 13% originatesin the Detroit River (Table 23). Incontrast to the dominance of emergentaquatic macrophytes in the St. Clair Riverand Lake St. Clair, most primary production(441) in the Detroit River was producedby submersed macrophytes. Some ofthis plant biomass is consumed directly bywaterfowl (Dawson 1975; Jones 1982) but weassume most of this plant biomass becomesdetritus each year. We do not know howmuch of it is used for animal productionin the river or in Lake Erie.Owing to the short flushing time ofthe connecting channel, almost all thephytoplankton biomass (71,490 t), representinq34% the total plant biomass producedin the connecting channel system,likely passes through to and is used inLake Erie. The fate of the remainingplant biomass is incompletely known. In1985-86, aquatic macrophytes drifting downthe Detroit River were studied by the U.S.Fish acd Wildlife Service (NationalFisheries Research Center-Great Lakes,unpubl .). Preliminary analysis of thesedrift data suggest that most plant biomassis produced from June to September in theDetroit River and drifts down to Lake Eriefrom July to September. 1-arqe movenlentsof dead a ~ d decaying plant matter werealso observed rear the bottom in the St.Clair River in spring (Edsall et al.1988). Apparently, much of the peri phytonavd submersed macrophytic biomass producedin the Detroit River dies back in fall,remains on the bottom during winter, andmoves downstream to Lake Erie in spring.If true, this analysis partly explains theh?gk productivity of benthic rnacroinvertebratesin the westerr hasin of Lake Erie.For at least half tbe year, the production

Table 23. Annual net productian by primary producers in the St. Clair-Detroit River System (Edwards et al. 1987).-- ----- -----4nnual netgroductior (t ash-free d;ik;t/yr)-- -ktroi t St. T7Z-r Total % of TotalProducers River River St. ClairPrimary producersPhytoplankton 7,430 3,400 60,160 71,490 3 4Periphyton 4,370 1,160 l6,7?1) 22,250 11Subnlersedrciacrophytes 12,380 2,290 13,780 ?a ,450 14Fniergen tnidcrophyter: 4,030 22, b20 613,990 87,640 4 7Total 28,210 79,970 151,6511 209,830;,: of total 13 14 72of niacrozoobcltithos probably benefi ts fromt..n abundd~lt food supply, owing to thelarge accumulation of decaying niacrophytesfrom the Detroit River.The rate with which detritus isproduced, processed, and moved downstream,in largc measure deterniines the productivityof and energy flow through bioticcommunities in rivers !Curnrnins et al.1984; Minshall et a1 . 1985). 1n fact, themost inclusive theory available (Cunini'inset a1 . 1984) suggests that riverside vegetationexerts primary control over bioticassociations in the river by providingorganic rnattcir that can be utilizeddirectly by a~imals. The orqanic matteradded to the Detroit River by sewagetreatment pi ants may be too contaniinatedwith toxic substances to directly supporthiqher fornis of anirrral 1 i fe. Therefore,bion~ass produced b.v emergent and subnlersedaquatic rnacrophytes is probably the basisfor most animal production in the riverand some animal production in western LakeErie. Any human activity that reduces theproduction of aquatic rnacrophytes in theriver may also reduce the production offish and wildlife resources in both theDetroit River and western Lake Erie.The trophic structure of the DetroitRiver has not been adequately described.A number of biological surveys have documentedbiotic communities in the river,particularly diatoms, emergent wetlands,rnacrozoobenthos and fish (Wujek 1967;daworski and Raphael 2978; Thornley 1985;ttaas et a1 . 1985). These studies indicatethat the river is becoming more biologi -cally productive in response to controlsivplernented to reduce pollution andimprove water quality. However, we do notunderstand in detai 1 how the varioustroyhic levels in the river relate to oneanother. From calculations of detri talbiomass (Section 4.2) and studies of fishlarvae (Section 3.2) it is apparent thatthe Detroit River is a large source ofdetrital organic matter and larval fishthat support productivity in western LakeErie. The river does not simply transportorganic matter from Lake St. Clair to LakeErie, but rather is a net producer oforganic matter. No information exists onhow much pollutant loading, past orpresent, depressed biological productionin the river. Research on this topicwould be useful in restoring beneficialuses of the river, in conformance with the1978 Water Qua1 i ty Agreement betweenCanada and the United States.If only a small amount of driftingorqanic matter (primarily p?ankton andpart iriilate detritus) entering the DetroitRiver from Lakes Huron and St. Clair isdeposited or utilized in the river, thenthe 1 i ttoral emergent and submersed

macrophyte beds in the river are the secondary production in the Detroit Riverdominant primary producers. Conversely, is based mainly on drifting phytoplanktonif large amounts of the drifting organic and detritus. Measurements to resolvematter from upstream waterbodies are this trophic question are needed anddeposited and used as an energy source by should include organic matter added bythe resident biota of the river, then municipal sewers and urban runoff.

CHAPTER 5.COMMERCIAL AND RECREATIONAL ACTIVITIES5.1 INDUSTRIAL SIGNIFICANCE OF THEWATERWAYThe Detroit River is the most heavilyindustrialized connecting channel in theGreat Lakes (USACE 1976b). Like theIndiana Harbor-Calumet Waterway of southernLake Michigan and the Toronto-HamiltonHarbor area of Lake Ontario, the principalindustries include steel mills, electricalpower generating plants, and automobi lemanufacturing faci 1 i ties. Such primaryindustries develop on the shore1 ine, relyon Great Lakes shipping, stockpile rawmaterials, and use relatively large quantitiesof freshwater for cooling or industrialprocesses (Table 24). These industries,though vital to the Great Lakeseconomy, have intensively developed theshoreline and reduced the amount anddiversity of habitats available to Fishand wildlife.Industrial use of the waterwayderives, in large part, from the GreatLakes-St. Lawrence Seaway and the Detroitand Windsor harbors, as well as the portsof Rouge River, Ecorse, Wyandotte,Riverview, Trenton, and the City ofDetroit (USACE 1979). As discussed inSection 1.4, navigation on the DetroitRiver consists largely of intralakeshipments of bulk commodities such ascoal, limestone, iron ore, grain, andliquid fuels. Since the early 19701s, thetraffic volume and number of vesseltransits has declined by half because ofan overall decline in Great Lakescommercial shipping.The most significant adverse environmentalimpacts of commercial navigationare associated with dredging, disposal ofdredged materials, and the operation oflarge or deep-draft vessels (USDI 1985).Dredging of the Detroit River navigationalchannels resuspends and disperses contaminatedsediments. The plumes of turbidityfrom dredging upriver tend to remain closeto the shore, but diffuse across theTable 24. Resource use of the Detroit River (USEPA 1985Ia.Use categoryExtent of useCommercial shippingThrough trafficFreight handled at portsDrinking water supplyMajor population centerPoint source dischargerRecreational fishingShore1 ine land useApprox. 75 million t (1981)33.4 mill ion at 16 ports (1981)19 water intakes, serving 3.95 million peoplePopulation over 5.0 million in 5 major cities28 municipal facilities, 111 industrialApproximately 1.5 mj 11 ion angler dayslyearIndustrial, commercial, and residentialdevelopments occupy about 78% of theMichigan shore1 inea Michigan waters only.49

entire river below Fighting Island (USDI1985). Vessel -i nduced currents resuspendcontaminated sediments and also fragmentor uproot submersed vegetation in thelittoral areas. Strong currents areproduced by vessel passage and the actionof the bow thrusters of lake carriersthat occupy over 50% of the crosssectionalarea of the ship channel in thenarrow parts of the river. Ship channelsare largely devoid of submersed vegetationand lined with coarse sediments.Deepening of the Great Lakes-St.Lawrence Seaway does not appear to beeconomical 1y feasible at this time;however, there has been much researchregarding the potential environmentalimpacts of winter navigation (USACE 1976b,Niimi 1982). The potential impact ofwinter navigation on fish spawning isuncertain, but ice scour could disruptspawning substrate. An ice jam in the St.Clair River in 1984 reduced watertemperatures and delayed fish spawningactivity for about 2 months (Muth et a1 .1986). Winter navigation apparently doesnot affect fpeding by wintering waterfowlbecause they tend to cluster in shallow,ice-free areas adjacent to islands or themainland, few of which are near +he shipchannels (Davis and Erwin 1982, Jones1982). However, ice scour and ice jamsassociated with winter navigation reducedthe taxonomic diversity of benthos (from24 to 25 abundant species) in littoralareas of the Detroit River for one year(Hudson et al. 1986). In the St. MarysRiver, winter navigation resuspendeddetritus and accelerated the downstreamlosses of organic matter (Poe and Edsall1982). Such impacts of winter navigationhave not yet been documented in theOetrni t River.The industrial use of the DetroitRiver is not expected to change much inthe near future. However, there will bemore attention to discharges of industrialand niunicipal wastes into the river,Recause the Detroit River was designated aClass A Area of Concern by the InternationalJoint Commission. There are 42such areas in the Great Lakes, In theDetroit River, criteria were exceeded foracceptable concentrations of fecal col i-form bacteria in water, PCB's in fish andwaterfowl, mercury it7 sediments and fordamage to benthic invertebrate communities.These criteria were defined inthe 1978 Water Quality Agreement betweenCanada and the United States or jurisdictionalstandards to protect beneficialuses of the river. In 1986, the InternationalJoint Commission recognized thatremedial actions were needed to restoremunicipal and industrial water supplies,recreation, and healthy aquatic life. Aremedial action plan for the Detroit Riveris being developed in 1987 by Michigan andOntario.Because of inadequate moni toring andsurveillance data, there is no agreementthat water qua1 ity in the Detroit River isgood or that it has been improving since1970 (MDNR 1984). Reductions in pointsourceloading, coupled with the rapidflushing rate of the river, tend toimprove water quality, but high levels ofheavy metals and chlorinated organic compoundsin river sediments, especially onthe Michiqan side south of the Rouge Rivermouth, continue to exceed safe guide1 ines( Limno-Tech 1985). These pol luted sedi -ments, plus combined sewer overflows anddischarges from the Detroit WastewaterTreatment Plant (Section 6.1) are the mainreasons for the area-of-concern designationand fish-consumption advisories.5.2 COMMERCIAL FISHERIESThere is presently no commercialfishery in the Detroit River. A commercialfishery primarily for lake whitefish,lake herring, walleye and ye1 low perchfirst developed in the river in the early1800's (Haas and Bryant 1978). By the18701s, catches of 10 major native speciesin the St. Clair-Detroit River system wererecorded aonually and in 1900 catches ofcarp, a nonnative species introduced intothe Great Lakes in the 18801s, were addedto the record (Table 25). These recordsshow that the catches of lake sturgeon,lake herring, lake whitefish, smallmouthbass, yellow perch, and walleye werehighest in the late 1800's and thereafterdecreased substantially. Smal lmouth bass,lake herring, and lake whitefish disappearedfrom the catch by 1910, 1930, and1950 respectively, while lake sturgeon,.vellow perch, and walleye continued tocontribute significantly to the fishery

Table 25. Commercial fish production in Michigan and Ontario waters of the St. Clair-Detroit River system,1870-3969 (Baldwin et al. 1979Ia.catfishTotalLake I nke i.di(? Nnrtlit%r,ri

interpreted with caution because theearlier records did not include the winterfishery, fishing activity on the St. Clairand Detroit rivers, or both. In 1983-85,an extensive survey of the recreationalfishery in Michigan waters of the St.Clair system (the St. Clair River, andLake St. Clair), and the Detroit River(Haas et al. 1985) revealed an averageannual fishing effort of 4,172,000 anglerhoursand an averaqe combined catch of2,813,000 fish by boat, shore, and iceanglers. The average annual fishingeffort in 1983-85 was higher in the St.Clair system, but the catch was higher inthe Detroit Piver (Table 27). Boatanglers expended about 66% of the effort,followed by shore (?2%), and ice (16%)anglers and the total catch by thesegroups was roughly proportional to effort;. boat anglers caught 64% of the totalcatch, shore anglers 19%, and ice anglers16%. Yellow perch and walleyes contributedan average of about 70 % of the totalnumber of fish caught by anglers in 1966-77 in the St. Clair-Detroit River system.In 1983-85, white bass was the single mostabundant species caught in the DetroitRiver, followed by walleye and yellowperch (Table 28).Records show the recreational fisheryin Ontario waters of the Detroit River(Sztramko 1980) to be substantiallysmaller than that in U.S. waters (Haas etal. 1985). Each year from 1976 to 1979,in Ontario waters of the Detroit River,anglers expended an average of 149,787hours of fishing effort and caught anaverage sf 142,363 walleyes, wki te bass,freshwater drum, ye1 1 ow perch, smal lmouthfable 27. Average annual recreational fishing effortand catch in Michigan waters of the St. Clair-DetroitRiver system, 1983-85 (Haas et al. 1985).Catch ofall speciesSection Angl er hours conlbi nedTable 28. Major fish species composing the recreationalcatch in the St. Clair-Detroit River system,1983-85 (Haas et a!. 1985Ia.DetroitSt. ClairSpecies River sys temWall eye 12 48Drum 7 8Ye1 1 ow perch 10 3 5White bass 6 3 0a Percentage of total catch by species.bass, and rock bass. In 1983, in Michiganwaters of the Detroit River, anglersexpended 1,523,485 hours of fishing effortand caught 1,782,802 white bass, walleyes,:{el low perch, rock bass, and drum.The value of the recreational fisheryin just Michigan waters of the St. Clair-Detroit River system in 1975-77 was inexcess of $10 mill ion annually (Haas andBryant 1978).Major recreational fishing areas, asidentified by charter boat operators, areillustrated in Figure 25. Study of thesefishing areas reveal s a positive correl a-tion with nearshore environments, wetlands,and relatively higher waterquality. In the upper Detroit River,walleye fishing takes place in nearshoreand island environments. In the lowerDetroit River, fishing tends to focus onwhite bass, northern pike, and otherspecies, in the main chanoels near Stonyand Bois Blanc Islands. Large catches ofwhite bass are taken east of Grosse Ile,west of Stony Island, and adjacent toSugar Island. The major fishing area in .the southern part of the Trenton Channelis not of high environmental quality, butis an area where walleyes are caught asthey migrate upstream in late spri~g andearly summer.Detroit River 1,409,000 1,421,000St. Clair systeni 2,763,000 1 ,392,000Total 4,172,000 2,813,0005.4 WATERFOWL HUMTlNGMichigan has long enjoyed a traditionof quality duck hunting, as evidenced bythe popularity of duck shooting clubs that

Grosse Ile to the Detroit River LightPoint, which is located at the southernend of Livingstone Channel (Hunt 1963;USDI 1967).During the 1941 waterfowl huntingseason, an estimated 4,800 hunters harvesteda total of 44,500 ducks in thelower Detroit River and adjacent Lake Erie(Miller 1943). A daily kill of severalcanvasbacks, redheads, or both was commonat that time. Because most of theshooting was done in open water, huntersused floating blinds, drift boats, andlayout boats to distribute their decoys,and pick up the kill (Figures 26 and 27).A high proportion of the waterfowltaken annually in Michigan comes from theSt. Clair-Detroit River system becausewaterfowl congregate there. In 1961-70,St. Clair County, which borders the St.Clair River and Lake St. Clair, and WayneCounty, which borders the Detroit River,col 1 ecti vely contributed an average of 11%Yt\ I LAKE FHIEFigure 25. Major recreational fishing areas in theDetroit River (Lake St. Clair Advisory Committee 1975).trace back to the mid-1800's. Dawson(1975) and Jaworski and Raphael (1978)provide useful descriptions of thisactivity, upon which we have drawn freelyin the following discussion.The lower Detroit River from thenorthern end of Grosse Ile to open watersof Lake Erie serves as an importantresting and feeding ground for migrantdivinq ducks (Miller 1943). Before 1960,great- rafts of canvasback, redhead, scaup(locally called bluebills) , and otherdivers fed intensively on wild celery andother aquatic resources in a zone stretchingfrom Gibraltar and the southern tip ofFigure 26. Waterfowl hunter in a layout boat huntingdiving ducks, circa 19QO (Miller 1943).

During 1971-75, 116,744 waterfowl huntersexpended 1,232,526 "recreation" days ofhunting effort and bagged about 685,000ducks, geese, and coots annually inMichigan (Table 30).At present, waterfowl hunting in theDetroit River is characterized by fewerhunters and a declining duck harvest.Using Wayne County data as the best availablemeasure of waterfowl hunting in theDetroit River (Table 31), it is evidentthat diving ducks dominated the annualkill, from 1971 to 1980, and that lesserand greater scaup composed 56% of theducks taken. According to Martz and Ostyn(1977), over half of the scaup arrive insoutheastern Michigan, including theDetroit River, in November, which is nearthe end of the 55-day waterfowl season.Whereas diving duck; are taken withFigure 27. Closeup of layout boat used to hunt water- f 1 oati ng bl i rids, sneak (or drift) boats,fowl on the Detroit River, circa 1- (Miller 1943). Note and the few rema i ni ng 1 ayout boats (cf .the canvas coaming that may be raised to keep Outthe waves that often roil over the decking.Figures 26 and 27), the ma1 1 ard and otherdabblers are hunted from the shore or fromblinds.Michigan's waterfowl hunting regulaofthe total duck harvest in Michigan's 83 tions provide for a daily limit of birdscounties and about one-third of the total worth a total of 100 points, based on theduck harvest in the 41 coastal counties of Mississippi Flyway Point System. Accordthestate (Table 29). During this time, ing to that system a female mallard or athe average duck harvest in St. Clair black duck is 100 points; a redhead is 70County was the highest in the State points; a drake mallard, bufflehead,(16,426) and Wayne County was sixth common goldeneye, or ruddy duck is worth(10,080) (Carney et a1 . 1975). 35 points, and a scaup is 20 points.According to the Michigan Department ofHunting of waterfowl (primarily scaup Natural Resources Small Game Fi 1e computerand mallard ducks) in Michigan during the print-out for Wayne County, in 1985 aOctober-November hunting season continuesta be an important recreation81 activity.total of 589 waterfowl hunters expended3,259 recreational days and bagged a totalTable 29. Annual average harvest of ducks in Michigan, 1961-70 (Carney et al. 1975).County Dabblers Divers Total %St. Clair 8,475 7,951 16,426 7WayneA17 41 other coastal2,210 7,870 10,080 4counties 40,050 27,632 67,582 28All 40 inland counties 102,581 44,196 146,777 61Total 153,316 87,649 240,96554

Table 30. Annual waterfowi hunting effort and harvest in Michigan, 1971-75 (Michigan Departmentof Natural Resources, Biennial Reports).Year Effort Harvest - Number gf Number ofhunters recreation days Ducks Geese CootsAverage 116,744 1,232,526 597,966 35,536 51,460a Includes waterfowl hunters under the age of 16 not requiring a Federal DuckStamp.Table 31. Annual average duck harvest, WayneCounty, Michigan, 1971-80 (Carney et al. 1983).Divinp ducksDabbling ducks! esser scaup 4,77? Ma1 lard 1,643Greater scaup 1,480 Black duck 292Ruddy duck 858 American wigeon 163Common qoldeneye 443 All others 385Rufflehead 375ell others 838Total 8,767 2,483of 3,176 ducks, 468 geese, and a fewcoots. These figures compare mostunfavorably to the number of hunters andthe duck harvest cited above for the 1941.hunting season. The population in theDetroit area has increased markedly since1941, yet the number of waterfowlersdropped by approximately 32%, and the duckkill declined 93%.Examination of the current waterfowlcensus data reveals a long-term populationdecline of many waterfowl species, especiallyof canvasback and redhead (J.Martz , Michigan Department of NaturalResources ; pers. comm. ) . However, thedecline in the annual harvest of waterfowlin the Detroit River may reflect not onlypopulation declines and changing huntingreaulations, but a1 so the qua1 i ty andquantity of feeding and resting habitat inthe lower Detroit River (cf. Section 6.6).Since 1979, the season on canvasbackhas been closed in fvIichigan but Ontariohunters are still allowed to shootcanvasback ducks. Today most hunterswould be pleased indeed to bag onerelatively large duck, such as acanvasback or mallard, per daily outing.A1 though Michigan 1 icensed approximately116,750 waterfowl hunters annual 1yin the 1970's (Table 30), there are manypotential hunters who do not participatebecause of a lack of accessible qualityhunting. Today the prospective hunter,particularly from metropolitan southeasternMichigan, usually applies for areservation at a publ ic game area, becausepermission from private shooting clubs orowners of the few remaining wetlands isdifficult to obtain. An estimate of theunsatisfied waterfowl hunting demand maybe obtained by comparing the number ofapplicants for reservations at the publ icgame area to the number of availableblinds or hunting areas. In 1976, atthree public game areas located withincoastal wetlands, there were 10,700 appl i-cants, but only 3,460 possible reservations(Michigan Department of NaturalResources, Permanent Files). Hence, only32 % of the applicants could be served,

and ttiere is a large unsatisfied demandfor quality waterfowl hunting.A study by the Great Lakes BasinCommission (1975b) showed a projectedincrease in hunters throughout Michigan,but a projected decrease in acres ofwildlife habitat and a decrease in potentiallyhuntable land. Another study ofMonroe County, just south of the DetroitRiver mouth, revealed that wildlife inNorth Maumee Bay was suffering from adegraded and decreasing habitat base andthat future waterfowl hunting opportuni -ties in the North Maumee Bay area werelimited due to restricted access, poorwater quality, lack of supportive facilities,and vandal ism (Jaworski and Raphael1978). A recent study of wild celerytubers available as food for ducks in thelower Detroit River showed a net decreaseof 73% in the densities of tubers intraditional feeding areas (see Section6.6).Waterfowl hunting does contribute tothe economy of Michigan. The 1980National Survey of Hunting and Fishingindicates that each American waterfowlhunter spent an average of $120 on equipment,1 icenses, transportation, and miscellaneous related i ten~s. A1 though mostwaterfowl hunters are residents of ruralareas and hunt in nearby counties, huntersfrom Detroit, Lansing, Grand Rapids, andFl int often travel considerable distancesto hunt waterfowl and probably spend muchmore than $5, the transportation componentof the estimated annual waterfowlhunter expenditure. Therefore, an econamicevaluation based on estimated annualexpenditures may underestimate realexpenses,Using the 1977 estimated averagewaterfowl-hunter expenditure of $130.25,Michigan's waterfowl hunters contributedover $15 million dollars to the stateeconcmy, and in terms of harvest, waterfowlhunting is worth $37.79 per bird. Ifdata on number of hunters and distancetraveled were available for each coastalwetland, the economic importance of waterfowlhunting and protection of wetlandscould be determined. Further, if expendituresby potential hunters were included,the value of waterfowl hunting in Wichigancould exceed $30 mill ion.Other econcmic techniques, forexample, aethods based on opportunitycosts or on the willingness of participantsto pay, may yield values higher thanthe above analysis. Other values, incl udingthe harvest of Michigan-reared birdsin other states, in addition to thoseestimated above, may also increase thevalue of waterfowl hunting.Lastly, the meat from harvestedwaterfowl is important because manyfamilies, particularly in rural areas,supplement their diet with wild game.5.5 RECREATIONAL USESRecreational boating in the DetroitRiver is well established due to relativelygood water qual ity and marinas andpublic boat launch areas. In the DetroitRiver area, nearly 60% of the boatingactivity was related to fishing (Stynesand Safronoff 1982). May, June, and Julyare the most important months for recreationalfishing in the Detroit River (Haaset al. 1985). Boating activity duringwaterfowl hunting season in October andNovember has not been adequately quantified.In general, there is a relativelylarge unfulfi 1 led demand for recreationalopportunities and facilities in the Cityof Detroit and the Wayne County area. In1976, an interagency task force found thatdevelopment of marinas and other recreationalfacilities in the Detroit Riverwas hampered by lack of aid to developproperty, inaccessibility of availableland on the riverfront, and incompati bilityof other existing land variances(WCPC 1976). Local recreational planshave not been prepared, due to inadequatefunding, lack of land for public acquisition,incompatibility with industrial use,and localized areas of degraded waterqual i ty (WCPC 1977).Much of the available land for recreationaldeveloprent lies in the townshipof gross^ fle. Although most of theisland and wetlands along the shores ofGrosse Ile are currently zoned as "naturalareas" with on1 y approved researcha1 1 owed, the township's development plan

is under revision. From a legal stand- marina facilities nearly resulted in thepoint, the shoreline of Grosse Ile is a loss of Gibraltar Ray on southern Grosseresource of State and National importance Ile to commercial development (Seegert(Dean 1986). Pressure for additional 1984).

CHAPTER 8. MANAGEMENT ISSUES AND RECOMMENDATIONS6.1 COMBINED SEWER OVERFLOWSUntil recently, water from stormdrains was combined with that in sanitarysewers and allowed to overflow into surfacechannels at designated points whenvolume exceeded capacity. Numerous combinedsewer overflows (CSO's) enter theDetroit River, including 64 on the Michiganshoreline, 24 on the Ontario shoreline,and 165 on the Rouge River, whichempties into the Detroit River. Theextensive system of rural, suburban, andurban storm drains are a direct man-madeextension of the river system. Inaddition to providing efficient drainageof precipitation runoff and high groundwater,the stormwater drainage system alsotransports to the river pollutantsgenerated by modern society, includingeffluents from landfills containing sanitaryand hazardous wastes. This immensesewer system, into which millions ofgal lons of domestic and industrial wastesare discharged daily is, in effect, aparallel river system designed to carrywast.ewater used by society. As with theriver, this wastewater flows downstream ininterceptors that parallel the river. AtDeti-oi t 's Waste Water Treatment Plant theyare treated and returned to the naturalenvironment as discharge to the DetroitRiver. Combined sewer interceptors thatserve the Rouge River Basin, including allthe separate sanitary sewer systems,represent an interconnection between thesewer systenl and the Detroit and RougeRivers, This interconnection provides theavenue for wastewater pollutants to enterthe Rouge River through combined seweroverflows during virtually a1 1 periods ofwet weather.Combined sewer overflows are not onlya source of raw sewage during wet weather,but also a source of toxic substances(Table 32). Concentrations of many ofthese pollutants in CSO's exceed safelevels. During an average year, the totalCSO volume from sewers to the Rouge Riverand from the City of Detroit to theDetroit River is very large (22.7 and 47.1mill ion m3, respectively, GiffelsIBlackand Veatch 1981; Ecolsciences 1985).Sediments in many of the sewer pipesprobably contain very high concentrationsTable 32. Average concentrations of variouspollutants (mg/L) and fecal bacteria (no. oforganisms1100 ml) entering the Detroit and RougeRivers from combined sewer overflows (GiffelsIBlackand Veatch 1W1).Rouge DetroitPol 1 utant River RiverBiological Oxygen Demand 73Total Suspended Solids 149Total Dissolved Solids 357Total Volatile Solids 210Total Phosphorus 6Inorganic Phosphorus 1Fecal Col iform 5,170Feca 1 Streptococci 505Arsenic 9 1Cadmi um 28Chromi urn 79Copper 129I ron 2,550Lead 166Mercury 34Nickel 455Si 1 ver 33Zinc 222Chlorides 74Oil and grease 154Pcfychf orinated hipheny?~ 17Phenol s 14Total Kjeldahl Nitrogen 6

of persistent toxic substances originatingfrom past spills, landfills, and illegaldischarges. For example, recent studiesshowed that sediments in sewer pipesentering the Detroit River possessed veryhigh PCB concentrations (up to 4,900 mg/kgdry weight; Kenaga 1986) and that suchsewer pipes are active sources of PCBcontamination in sediments of the DetroitRiver (Kenaga and Crum 1987). These findingsindicate that not only the overflowsfrom such pipes, but also the sedimentsthey carry, should be careful ly moni toredto identify sources of contaminants.Clearly, CSO's are a major active sourceof toxic substances to the Detroit Riverand a more vigorous enforcement ofpretreatment programs is needed to controlthese substances at the source.A recent study of improper waste dischargesto a stormwater system in AnnArbor, Michigan, concluded that urbannon-point pollution is not limited to roadrunoff, but also contains wastes frompermitted and illegal discharges, manythat were previously unsuspected (Schmi dtand Spencer 1986). The Ann Arbor studyevaluated the magnitude of the problem,isolated individual pol 1 utant dichargers,and demonstrated that control of illegaldischarges rapidly reduced pollutantconcentrations in the stormwater drains.Of the 160 businesses investigated, 50%had at least one storm drain connectionthat discharged potentially hazardoussubstances. Improvements in water qual i tywere noted as these discharges wereeliminated. It is recommended that asimilar approach (e., control at thesource) is warranted to eliminate illegaldischarges to stormwater systems thatenter the Rouge and Detroit Rivers.Operation of the sewer interceptorsystems and planning for pollution controlhave not been coordinated in a basinwideeffort to control the discharge of pollutants.In disregard for the manner inwhich hydrologic systems function, interact,and transport pollutants, sewer planningin the Rouge and Detroit River Basinshas been estab? ished along pol i ticalboundaries rather than along subdrainagebasin boundaries. Until recently, planswere formulated by local politicalentities to secure mu1 timill ion dollarFederal construction grants and enhancesewage transport facilities within theirown jurisdictions, with little regard forthe benefits or impacts such measuresmight have on river water quality inadjacent jurisdictions.In 1985, it was recognized that waterquality in the Rouge and Detroit Riverscould be greatly improved by creating abasinwide authority that would formulateand implement a coherent plan fcr reducingcontaminant inputs by CSO's (Ecol sciences1985). Moreover, monitoring and survei 1 -lance to estimate pollution entering therivers from CSO1s was recognized asnecessary but almost nonexistent.In 1986, the Rouge River BasinCommittee was organized with support fromthe State of Michigan and the SoutheastCouncil of Governments to address theseissues. The Committee includes draincommissioners and wastewater engineersfrom each jurisdiction, political leaders,and representatives from citizens actiongroups. Through cooperation and mutualrespect, with support at State and Federallevels, this Committee will strive toreduce pollutant loadings by CSO1s to theDetroit and Rouge Rivers. They recognizethat everyone benefits from improved waterqual ity.The Michigan Department of NaturalResources has monitored ambient waterquality in the Detroit River for the last20 years (MWRC 1967). The sampling methodwas designed to document water-qua1 i tytrends and calculate annual pol 1 utantloads to Lake Erie, particularlyphosphorus. These measurements showedthat water quality has steadily improvedin the Detroit River over the past 20years (see Table 8 and 9 in Section 2.7).In 1985, this sampling design was reviewedfor relevance of the data to modern waterqual i ty concerns. Recent methods forcalculating pollutant loads have shownthat monthly surface grab samples on theDetroit River may neither be adequate forload determinations, nor of sufficientaccuracy for modern resource managementneeds. While a new sampling design isbeing developed, the existing moni toring

program, with some modification, will be activities are regulated by the Corps andcontinued so that there is no break in the by the Eichigan Department of Naturalrecord. Resources (Raphael et al. 1974).6.2 DREDGINGEnormous quanti tics of sediment havebeen dredged from the Detroit River andits tributaries (Table 73). Dredging wi 11continue to be authorized to maintain theseaway navigation channels, approach channels,and berthing areas in the Detroit,Piver (Section 1.4). However, due torecent high water levels and a decline invessel traffic on the Great Lakes, thereis little current economic justificationfor other than maintenance dredging. Inboth Michigan and Ontario, much of theactual dredging work is contracted out toprivate industry. In Ontario, the OntarioMinistry of the Environment and Departmentof Public Works regulate dredging of thepublic harbors near Windsor and privatesites along the east bank. In Michigan,the U.S. Army Corps of Engineers reqrrlatesall public dredging activities in theriver, including the isstlance of Section10 permits authorized under the Rivers andHarbors Act of 1899. Private dredgingSedinient contaminant regulations willcontinue to require the confinement ofpol 1 uted dredged materi a1 s removed fromthe Detroit River. In Ontario, pursuantto the Environmental Protection Act of1971 and the Ontario Water Resources Actof 1972, the discharge of any polluteddredgi ngs above levels prescribed by theseregulations is prohibited. Similar regulationsare in effect in the United Statesas a result of Public Law 91-611, Amendmentto the Rivers and Harbors Act of1970, and Public Law 92-500, Clean WaterAct of 1972, as amended (Paphael et al.1974). Chemical testing of bottom sedimentsto be dredged is performed by theOntario Ministry of the Environment forOntario waters, and by the Corps for Michiganwaters. The most direct andinformative approach to estimating thebiological effect of in-place pollutants,for the purpose of deciding where thedredge spoils should be disposed of, ismeasurement of contaminant uptake byaquatic organisms exposed to the sedimentsTable 33. Dredging and spoil disposal in the Detroit River, 1970-86 (U.S. Army Corps of Engineers,Detroit District. Open Files).Dredging Project Year Volume (in3) Disposal siteDetroit River 19701971197519761980198119821983198419851986Rouge River19761985~onf i nedaOpen lake (Erie)Open lake (Erie)Open laks (Erie)Conf i nedaConf i nedConfined (Pt. Mauillee)Coofined (Pt. Mouillee)Confined (Pt. Fouillee)Confined (Pt. Mouillee)Confined (Pt. Mouillee)Confi nedaConfined (Pt. Mouillee)Total 5,830,545a Principally on Grassy and Rud Islands in the Detroit River.

of concern (Will ford et a1 . 1987).However, such bioassays are recommendedonly when chemical characterization ofbulk sediments does not exceed contaminantguidelines or it is suspected that aspecial contaminant problem may exist at aparticular site (IJC 1982). The containmentsite for most pol l u ted dredgedmaterial derived from the Detroit andRouge Rivers, including private dredgings,is located at Pointe Mouillee. The PointeMouillee confined disposal facility wasfirst utilized in 1983, and dredgedmaterial input has not yet exceeded itsdesigned capacity of 23 million m3 (USACE1974). Creation of islands and managementof them for waterfowl production, as isplanned for Pointe Mouillee, illustratesone way to mi tigate envi ronmental impactsof dredging and enhance waterfowl production,a long term goal of the U.S. Fishand Wildlife Service in the Nation's largerivers (Schnick et al. 1982). However,using contaminated materials for islandcreation may result in an attractivenuisance. Waterfowl may be attracted to asite which may ultimately provide undesirablenesting space. Contaminant studiesof waterbirds at Great Lakes confineddisposal facilities are ongoing.U.S. Army Corps of Engineers' civilworks projects are not regulated underindividual or general permits. However,an environmental impact statement onDetroit River maintenance dredging wasprepared in 1976. Supplements to thisstatement are issued when needed. Theadverse environmental effects of maintenancedredging, e.g. increased turbidity,removal of benthic macroinvertebrates, andincreased bioavai labil i ty of contaminants--particularlywith overf 1 owdredging--are usual ly regarded as shortterm. Moreover, removal of pol 1 utedbottom sediment may be characterized asremedial, if done properly without overflowdredging. A harmful environmentalcondition is el iminated and containedwithin confined disposal facilities. Insome cases, leaving contaminated sedimentsin place may be a better option. To date,the overall productivity of benthicanimals in the Detroit River has probablybeen reduced by dredging, but this lostproductivity has not been accuratelyestimated.6.3 WATER LEVELSVater levels in the Detroit Riverhave recently been at record high levels(Quinn 1981; Edsall et al. 1988). Erosionand flooding along the Detroit River arenot as severe as, for example, in Lake St.Clair, because 78% of the Michigan shorelineof the Detroit River is already bulkheaded(Muth et al. 1986). However, somelocalized erosion is occurring on thenorth end of Belle Isle and along the eastside of Grosse Ile. Both public agenciesand private landowners have instal ledadditional bul kheads and ri prap to combaterosion.Fluctuating water levels are vital tomaintaining wetlands in the Great Lakes(Jaworski and Raphael 1981; Keddy andReznicek 1986), but can produce both positiveand negative impacts on various wateruses (Table 34). In general, high waterlevels tend to favor fisheries, boating,and navigation. In contrast, low waterlevels tend to increase habitat for shorebirdsand reduce shore1 ine erosion. Inthe Detroit River, the positive effect ofhigh water levels on fish spawning andnursery areas results largely from inundationof islands. Because the banks of theTable 34. Effects of water level on uses of the DetroitRivera.UseFish spawningNursery of juvenile fishRecreational fishingFeeding of wading andshorebirdsNesting of colonial birdsFeeding of diving ducksRecreational boatingCommercial navigationa + = Favored0 = Not significant- = Negative effectWater levelLow ~igh-

iver are almost enti rely bul kheaded orcovered with riprap, remaining wetlandsand submersed vegetation cannot moveshoreward in response to high waterlevels, Negative effects of high waterlevels include inundation of nestingislands and beach habitat required bycolonial shore birds--one reason for therecent decf ine in common tern and pipingplover populations in the Great Lakes.Hunt (1963) showed more widespreaddistribution of the submersed macrophytesaround Grosse Ile, Sugar Island, andCeleron Island during a low-water periodthan was visible on aerial photos takenduring a high-water period in 1982.However, more field work is needed todetermine the effect of high water levelson submersed macrophyte beds in theDetroit River. Wild celery is still themost abundant submersed macrophyte aroundGrosse Ile (Schloesser et al. 1985), butpresent high water levels and other factorsmay further reduce the distributionand abundance of this plant and the migratorywaterfowl that depend on it for food(Section 6.6).The high water is causing retrogressionof what little emergent vegetationremains along the Detroit River. Forexample, the diked cattail marshes at themouth of the Canard River are dying back,as mvro open water and submersed macrophytesprevail. Also, in Gibraltar Ray atthe south end of Grosse Ile and along thewest shore of Stony Island, cattails haveclied back and much of the wetland is nowsubmersed macrophytes. Even the matureswarnp oak (Quercus bicolor) hardwoods onRussell Island just west of Gibraltar Bay,are threatened by high water (Jaworski andRaphael 1984). The long-term fluctuationof water levels in the Great Lakes is anatural phenomenon. It appears that currentwater levels are causing no significantproblems in the Detroit River, and nomanagement strategies are called for tomitigate erosion and floodin! along theriver.6.4 WASTE DISCHARGES AND SPILLS QFHAZARDOUS SUBSTANCESllse of the Detroit River for municipaland industrial waste discharges con-fl icts with most other uses of the river,Large quantities of sewage organic matterare added to the Detroit River from themunicipal sewage treatment plants ofDetroit, Wyandotte, Trenton, and GrosseIle, which serve over 3 million people,From data presented by Vaughan and Harlow(1965), we calculated that in 1965, thesesewage discharges added over 235,000 tof solids and biological oxygen demand tothe Detroit River. This amount is 8.3times more organic matter than thepresent-day total annual primary productionof all plants in the Detroit River(28,210 t; Table 21). Solids in theeffluent from the largest of these plantsserving the City of Detroit (226,665 t)were reduced in 1969, when the plant wasupgraded to i ncl ude secondary treatment.In 1984, additions of suspended solids bythe Detroit Wastewater Treatment Plant tothe river totaled only 25,665 t (U.S.Environmental Protection Agency STORETData Files for 1984). Although reduced,the loadings of organic matter from sewagetreatment plants sti 11 nearly equalprimary production of organic rnatter byaquatic plants in the Detroit River.A preliminary activi ty-effect matrixwe constructed following the procedures ofLeopold et al. (1971) indicates thatindustrial discharges, municipal sewageeffluent, urban runoff, and combinedsewer overflows are the primary causes ofadverse environmental impacts in theDetroit River (Table 35). These threeactivities are interrelated because theya1 1 influence water aual ity. Water andsediment quality is most degraded in nearshorehabitats along the City of Detroit'sshoreline and at the Rouge and EcorseRiver mouths. Water qual i ty concernscaused the City of Detroit to install asecond, supplemental water intake insouthern Lake Huron near Port Huron in1980. However, it costs less to pumpwater from the original intake at BelleIsle, so most of the supply has originatedfrom the river in recent years.Pol luted bottom sediments, particularlyin the Trenton Channel, and associatedwater qual i ty problems f Sections 1.6and 2.7) persist in the Detroit River(MDNR 1985a). Except for nitrates,pollutant levels in water have declsince 1967, but relatively clean water is

Table 35. Activity- and use-effect matrix for the Detroit River.Activity-. ~ffect~ -Nearshnrehahi tatfor IslandWater qua1 itybevthos habitat tfigratory-----7-Fish Human Sediment and for waterfowluse USP quality plants wildlife use TotalIndustrial discharg~s 2 2 2 2 0 1 9Funicipal sewage effluents 7 2 2 2 0 1 9Urban runoff and sewer overflows ? 2 1 2 0 1 8Recreational boating 0 1 0 2 2 2 7Agricultural devel opment 0 1 0 1 0 1 37Commercial navigation 1 2 (2 I 1 0 5Bul kheading and backfill i ng 0 0 0 2 1 2 5Total 7 10 5 l? 4 8 4 6a 2 = Major adverse impact.1 = Kinor adverse impact.0 = No adverse impact.found only in the upper river and themiddle channel area of the lower river.Polluted bottom sediments occur throughoutthe river, but sediments on the Michiganside below the mouth of the Rouge Riverand in the Trenton Channel are most heavilypolluted (Bertram et al. 1987).Because fish accumulate contaminates fromwater and sediment, consumption warningshave been issued by Michigan and Ontariofor fish caught in the river (MDNR 1985).The prcbabi 1 i ty of hazardous substancespills into the Detroit River ishigh (Schulze and Horne 1982). To evaluatethe potential hazard posed to fish andwildlife resources in the Detroit River byspills of oil and other hazardous substances,the records of hazardous substancesshipped through and spilled in theriver, and also contingency plans thathave been formulated to minimize theenvironmental impact of such spills wererecently reviewed by Manny and Inman(1986). The foll owing summarizes theirfindings.Spi 11s of hazardous substances, especiallyoil, pose a threat to fish andwildlife resources in the Great Lakes(Emery 1972; Kiellor 1980) and have causedlarge losses of waterfowl throughout theGreat Lakes in past years (Hunt 1965),particularly in the Detroit River (Hunt1961). Fuel oil is particularly dangerousbecause it floats on water and containstoxic water-sol uble compounds such asbenzene, toluene, and naphthalene, whicheven in low concentrations (about 1 mg/L)reduce growth, reproduction, and survivalof many aquatic plants and animals(Anderson 1977; Burk 1977).The number of shipments of petroleumproducts on the Great Lakes has reportedlydecreased during the past 15 years, butthe average size of oil tankers and thenuvber of tank barges in use on the GreatLakes has increased during the same period(Scher 1979). During recent years, petroleumshipments have also continuedthroughout the winter on the Great Lakesas part of the Navigation Season ExtensionProgram proposed by U.S. Army Corps ofEngineers. Most petroleum shipmentsthrough the Detroit River originate withinthe St. Clair River or Lake Erie. In1977, over 3 million short tons ofpetr.uieum products and 309,000 short tonsof other hazardous substances were shippedon vessels through the Detroit River(Table 36). Values given in Table 36

Table 36. Petroleum products and other hazardoussubstances transported on the Detroit River in 1977(USACE 1977; Statistics Canada 1977Ia.Products transportedPetroleumAmount(short tons)Crude petroleum 14,421Crude tar, oil and gas 268,138Gasol i ne 352,223Distillate fuel oil 507,233Residual fuel oil 2,003,064Lubricating oi 1s and greaseAsphalt, tar, pitch176,077280,984Other products 695Tota 1 3,602,835Detroit, Michigan (A.G. Ballert, GreatLakes Commission, Ann Arbor, Mich. ; pers.comm.).From 1973 to 1979, there were 581spills of petroleum products totaling over704,000 L and 45 spills of other hazardoussubstances totaling over 334,000 L intoMichigan waters of the Detroit River(Table 37), primarily from land-basedfacilities located along the upper riverreaches. Spills into Michigan waters ofthe Detroit River greatly exceed thoseinto Michigan waters of the St. ClairRiver (Edsall et al. 1988). A comparisonof spi 11 s into American and CanadianTable 37. Number and volume (L) of spills of petroleumproducts and other hazardous substances intothe Detroit River, 1973-79 (U.S. Coast Guard 1980).Other Hazardous SubstancesAnimal fats and oils 130,664Vegetable oi 1 s 14,690Sodium hydroxide 2,641Dyes, tanning materials 1,611Benzene, to1 uene 50,654Drugs 2,092Soaps and detergents 9,874Paints and varnishes 1,374Ferti 1 i zer 36,881Insecticides, disinfectants 4,179Copper, lead and 7inc 57,398Tota 1 312,058Spi 11Petroleum productWaste oilsLube oilsOther oilsFuel oilsBunker oilsGasol i neHydraulic oilAnimal oilVegetable oilGreaseNumber Volumea Includes through traffic and shipmentsinto, out of, and within the Ports ofDetroit and Windsor.differ from those in Table V-3 of Schulzeand Horne (1982) because we included notonly total upbound and downbound trafficon the Detroit River, but also shipmentsinto, out of and within the Ports ofDetroit and Windsor. In 1977, theselatter shipments composed the majority ofhazardous substances transported aboardvessels on the Detroit River, DuringJanuary and February 1979, when the riverwas ice-covered, up to 6,600 short tons offuel oil were shipped about every 2 dayson the St. Clair River from Sarnia,Ontario, to power-generating plants inTotal 581Other hazardous substancesAmmonia 4Ammonium compounds 2Sodium Oisul fite 1Sodi um hypochl ori te 1Copper and zinc compounds 3To1 uene 2Phenol 1Glycol 1Sulfuric Rchydrochloric acid 5Sodi um hydroxide 1Miscellaneous 24Total 45

waters of the Detroit River could not bemade because records of spills intoOntario waters were not available. Only asmall proporti on of the petroleum productspills (2% by volume), but a much largerproportion of s ills of the other hazardoussubstances ! 69% by volume) occurred inwinter (Table 38), when much of the riveris covered with ice. Winter spills are ofparticular concern because current technologyis largely inadequate to detect,contain, or recover spi 11s of hazardoussubstances under ice, particularly infast-fl owi ng waters l i ke the Detroit River(SLEOC 1979).Under criteria established by theU.S. Fish and Wildlife Service (Adams etal. 1984), there are extensive fishspawning grounds, productive wet1 ands , andother environmental ly sensitive areas inthe Detroit River (Sections 1.5, 2.6, and6.7) that would be ranked as high-priorityareas for protection from spills ofhazardous substances. Manny and Inman(1986) therefore concluded that spi 11 s ofpetroleum products and other hazardoussubstances represent a threat to biologi-Table 38. Number and volume (L) of spills of petroleumproducts and other hazardous substances intothe Detroit River during the period of ice cover,1973-79 (U.S. Coast Guard 1980).Petroleum productSpi 11 Number VolumeFuel oils 5 8,346Bunker oil 3 6,370Other oils 2 197Waste oil 2 79Tar or pitch 1 19lube oil 1 11Total 14 15,022Other hazardous substancescal resources in the Detroit River. Theyalso concluded that the huge volumes ofhazardous substances transported throughthe river on vessels (Table 36) representa potential threat to those same resourcesbecause even through vessel accidents havecaused no large spills of hazardoussubstances yet (Schulze and Horne 1982)just one serious vessel grounding orcollision, particularly in winter, couldproduce a catastrophic spill andlong-lasting reduction in the biologicalproductivity of the Detroit River.6.5 FISH LOSSES AT WATER INTAKESWater withdrawal from the DetroitRiver by industries and municipalitiesposes a threat to fishes using thesewaters. In 1982, more than 30 waterintakes were operational in the DetroitRiver (IJRT 1982). No complete assessmentof fish losses at these intakes has beenmade, but annual losses at nine Michiganthermal electric generating stations onthe Detroit River in the mid-1970's wereabout 1,176,000 juvenile and adult gizzardshad and other clupeid fishes and39,536,542 clupeid larvae (MDNR 1976). Amore extensive review estimated the annualfish losses at 17 thermal electricgenerating stations in the St.Clair-Detroit River system were about7,422,000 juveniles and adults, and94,159,000 larvae in the mid-1970's (Kelsoand Milburn 1979). The significance ofthe fish losses at water intakes in theDetroit River has not been established,but the water-use rate at electricgenerating stations provided by Kel so andMilburn (1979) was equivalent to about 8%of the total flow in the river per day. Ause rate much lower than that (Spigarell iet al. 1981) from Lake Michigan in 1980caused ecologically significant losses ofrecreational and forage fish (Manny 1984).The cumulative impacts of power-plantwater withdrawal on fish larvae and fishproduction in the Detroit River need to bemore adequately assessed.To1 uene 2 3,785Phenol 1Miscef 1 aneous 11 226,4756.6 HABITAT FOR CANVASBACK DUCKSTotal 14For mavy years, the Detroit River has232*152 been an important resting and feeding areafor the eastern (Atlantic) population of

canvasback ducks (Aythya vall isneria) Frsrn there about ha1 f of* the populationduring their fall migration (Figure 281. moved south to the lower Missl'ssippiHistorically, migrants first moved to Valley and the gulf coast, and half movedstaging areas in the upper Mississippi eastward to feeding and resting dreas inRivpr from breeding grounds in the the Great Lakes. A high of 64,000 canvasprairie-potholeand parkland country in backs wintered on the Detroit River inthe western llnited States and Canada. 1955 (Eulartz ef al. 19761, but generally,,. - - -^ ---" ". ._-. _ ^__- _glb Malor staging areasFigure 28. Major migration corridors of the eastern population of the canvasback duck (USDI 19839.

most birds historically proceeded to theAtlantic coast,Table 39. Wintering canvasback duck populations byflway, 19!55-82 (USDI 19833.Migration routes evolve in responseto available foods, as birds interrupttheir fl ight to repleni sh energy reserves(Be11 rose and Cron~pton 1970). Formerstaging areas in the midwest, includingthe DetraSt River, are not used now asmuch as they were before 1970. Instead,most canvasbacks wintering in the Atlanticnow stage on three pools of the upperMississippi River, then migrate to theDetroit River and western Lake Erie. Herethe birds feed and rest before continuingtheir migration eastward to the Atlanticcoast (Serie et a1 . 1983).YearNumber of ducks (thousands)by flyway in JanuaryCentral Mississippi Atlantic TotalThe enti re overwintering easternpopulation of canvasbacks, which wasestimated at more than 400,000 birds inthe early 1950is, decf ined to less than147,000 by 1960 and thereafter variedbetween 131,000 and 284,000 birds (Table39). Surveys conducted by the MichiganDepartment of Natural Resources from 1950to 1976 (Martz et al. 1976) yieldedresults that para1 leled the nationaltrends. Peak concentrations of canvasbacksduring 1954-58 along Lake St. Clair,the lower Detroit River, and adjacent LakeErie numbered 260,000. Numbers of canvasbackson the Detroit River were hi hest inNovember-December of 1951-55 ?61,500-104,600), and lowest in 1966-70 (1,075).By the mid-1970is, canvasback numbers onthe Detroit River rarely exceeded 50,000(Jaworski and Raphael 1978). Over thepast 12 years, the number of canvasbackswintering on the Detroit River has variedfrom a high of 31,500 in 1981 to none in1977 (Michigan Department of NaturalResources, Open Files).Causes for the nationwide decline incanvasback duck numbers are incompletelyknown, but migration routes by waterfowlare partly dependent on foods availablealon the flyways (Bellrose and Crompton19707. The canvasback has rigid habitatrequirements and behavioral traits thatlimit their adjustment to environmentalchange, includinq a stronq dependence onwild- celery (~al1 i sneria '. americana) asfood and an intolerance of disturbance bvboat traffic, A recent survey of th&tubers of Val 1 isneria americana (Figure29), a preferred food of many waterfowl inAverage 15bib! t *iJ'W iWrn'9rnPplnt- LF.F I~C,, --'- . . , . . . .. .1. . !.. . . - -.Figure 29. Wild celery (Vallisneria smericana) tubers,a preferred food of canvasback ducks in the DetroitRiver.

the sediments of the lower Detroit River,indicates that, over the past 35 years,the densities of tubers have decreasedsubstantially at three locations andincreased moderately at two 1 ocati onswhere ducks once fed, resulting in a netdecrease of 73% in tuber densities (Table40). The declines of such preferred foodsas wild celery, fennel -leaf pondweed, andfingernail clams have been cited as possiblecauses for the disappearance ofcanvasbacks from formerly used areas(Mills et a1 . 1966; Trauger and Serie1974). The loss of these important waterfowlfoods explains in part why fewerwaterfowl now use the Michigan migrationcorri dor .In Michigan, canvasback habitats alsohave been adversely affected by many formsof human activity. These include oil,chemical, and heavy metal contaminationfrom industry and municipalities; nutrientsand sediments from agriculture; sedimentresuspension, addi tion of greases andoils by commercial and recreational navigation;and finally, disturbances fromrecreational boating activities includingfishing, sailing, pleasure motoring, andhunting (Hunt 1957; Martz et al. 1976).These problems continue to affect canvasbackhabitat in the Detroit River,although oil pollution in the river hasbeen significantly reduced since the1950's (Hunt 1961, Schloesser and Man~y1986b).Federal and State plans have beenformulated for rehabilitating the easternpopcrlation of canvasback ducks and theirhabitat. The Federal plans identifypollution and limited food resources asprimary causes of dwindling migrationhabitat and reduced numbers of birds (USDI1983), particularly industrial pollutionand the loss of wild celery beds in theDetroit River (Oetting 1985). The Stateplan predicts slow improvement of canvasbackhabitat in the Detroit River, ifpol 1 ution controls are continued (Martz eta1 . 1976). The overall strategy of theseplans is to provide adequate migrationhabitat across the Great Lakes states,rather than crowding fa1 1 -migrating canvasbacksinto the two or three pools onthe upper Mississippi River where suitablehabitat is still available for them.6.7 PROTECTION OF REMAINING WETLANDAND ISLAND HABITATSpeci a1 protection of remaining wetlandsand islands in the Detroit River iswarranted because most of the naturallyproducedorganic matter for animals livingin the Detroit River probably derives fromthese environments . Second, prior 1 oss orpollution of the Michigan shore1 ineascribes greater biological function andvalue to the remaining wetland and islandhabitats. Finally, wetlands aroundTable 40. Average number of wild celery tubers at five waterfowl feeding areas in the lower Detroit Riverin May 1950-51 and 1384-85 (Schloesser and Manny 1986b).1950-51 1984-85 Net changeAreaLocati on ( km2) No. /m2 No. /area No. /m2 No. /area No. /m2 No. /area6 7Ballards Bar 1.717 19 3.3~10~ 5 8.6~10~ -14 -2.4~10~Sugar Island Bar 0.745 23 1. 7x105 5 3.7~10 -18 -1.3~10~Humbug Bar 0.228 2 4.6~10~ 0 0 -2 -4.6~10~North Bar 0.237 2 4. 7x105 4 9.5~10~ El +2 4 .8x105Swan Island Ear 0.234 2 4.7~10 5 1.2~10 -+ 3 7.3xiO7Total 3,161 5.2~10~ 1 .4x107 -3.6~10

islands provide protective habitat forplanktonic ljfe and higher life forms.1-be differences in land use betweenthe Flichigan and the Ontario shorelinesare striking. As discussed in sections1.3 and 1.6, the Michigan shoreline isheavily industrialized, especidlly betweenLug Island and Trenton. In contrast, theOntario side is largely agricultural southof Windsor, though the shore1 ine is dottedwith n~arinas, recreational facilities, andprivate boating dreas. Most of the nonindustrialland uses, such as nesting bycolonial birds (Figure 30), occur on theislands in the river. In terms of openspace, recreational land, dnd naturalareas, it is the islands and their associatedshoreline that offer the best fishand wild1 ife habitat available today.Several studies have demonstratedthat wave forces generated by commercialvessels moving up and down the DetroitRiver reduce the distributiori dnd abundanceof dquatic macrophytes and macrozoobenthosby uprooting or fragmenting plantsand resuspendi ng 1 i ttoral sediments(Schloesser and Manny 1986a), especiallyunder ice where the channel is constricted(Poe et al. 1980; Poe and Edsall 1982;I-iston et a?. 1986). Because of theirdetrimental impact on the biologicalproductivity of the Detroit River, vesselspeed limits should be reexamined todetermine if they could be reduced in theriver near remaining wetlands.Figure 30. Herring gulls. a shorebird that nests incolonies on Fighting lsland in the Detroit River (Photoprovided by Victor B. Scheffer). Michigan (P.B, 346).69The adverse impact of isolating andfragnlenting wetlands on the mainland andislands by means of roadbeds, canals,earthen dikes, and other developmentsappear5 not to be fully recognized.A1 though most people would not considerisolated or fragmented wetlands to beadversely impacted or lost, the importanceof maintaining hydrologic connectionsbet.ween wetlands on islands arid theDetroit River through underground waterflows, was recognized in recent planningcorisi dera tions recom~ended to the GrosseTle Planning Commissicv (Dean 1986).There were 1,382 ha of wetlands inthe Detroit River in 1982 (Table 4, section2.6). The wetlands are more widespreadin the southern section of theriver; their contribution, in an ecologicalsense, is also areater on the easternthan on the western side of the river(Figure 13).The existing wetlands on the Michiqanside of the river are protected largelyas a result of the permitting processoutlined in Federal Section 404 of theClean Water Act (P.L. 92-500) and Section10 of the Rivers and Harbors Act of 1899.The Regulatory Branch of the U.S. ArmyCorps of Engineers is empowered to protectGreat Lakes wetlands from destruction anddl teration. In Michigan, Section 404permits are issued by USACE for wetlandsin the Detroit River. The Land ResourcesDivision of Michigan Department of NaturalResources has assumed the Federal 404permit program for lands inland of theGreat Lakes and connectinq channels. TheState uses the ~oemaere-~nderson WetlandsProtection Act of 1979 (P.A. 203) toprotect isolated wetlands aver 1.5 ha indrea, in certain counties, and allwetlands contigicous to a river or lake,regardless of size. The State of Michigana1 so empl oys the Great l-dkes SubmergedLanes Act of 1955 (P.A. 247) and otherstatutes to lease bottom lands and protectGreat Lakes coastal environments. Someprotection of islands along the GreatLakes snoreline is afforcled by theYichiqan Shorelands Proiecr~on 6ct ofi57S. To deveiorj anv Michinan shore?ineof the Detroit Ri;/erYia permii is requiredunder the In1 and Lakes and Streams Act of

As review agencies, both the U.S.Fish and Wildlife Service and the U.S.Environmental Protection Agency carefullystudy proposed development projects toavoid or mitigate wetland losses. Ingeneral, permits from the State or Federalagencies are not issued to develop wetlandsunless the proposed project is waterdependent; high quality wetlands are notinvolved; and there is no feasible andprudent alternative on upland areas.There is greater need for wetlandsprotection at the local level than at theState or Federal level. The largest undevelopedwetland area under control oflocal government in the Detroit River isin the township of gross^ Ile. Throughits 1969 Master Plan and the ZoningDistrict Maps, some development has beenallowed in wetlands. A t present, the needfor additional private marinas and pressurefor coastal residential developmentis influencing the township board toreview the coastal lands zoned for recrea-tion (Seegert 1984). Currently the wetlandsin Gibraltar Bay and near Celeronand Sugar Islands cannot be developedunless the zoning is changed to activerecreation or some more intensive use.Proposals to rezone these wetlands formore intensive use (a marina) were submittedto the township in 1986, but no wetlanddevelopment has been authorized todate. To adequately protect remainingwetlands in the Detroit River, some fundsor incentives from local, State, orFederal governments may be needed (Dean1986). In particular, the islands in theDetroit River, should be the subject ofcomprehensive planning and protection fromdevelopment. As shown in Table 41, thereare 12 large islands, 7 in Michigan and 5in Ontario. Grosse Ile, by far thelargest island in t.he river, is privatelyowned and the shoreline is largely developed.Mud, Grassy, and Fighting Islands,along with Point Hennepin on the northerntip of Grosse Ile, are spoil islands.Vegetation on these islands appears to beTable 41. Characterization of major islands in the Detroit River.Shore1 i neName Area (ha)a length (km) Land use Ownership JurisdictionPeach Island b 37.2Relle Isle 385.8Mud Island 9.3Grassy I slandC 23.1Fighting Islbnd 492.2Grass Island 74.3Turkey Island 46.5Grosse Ile 13 2,348.9Stony I slandb 37.2Sugar Island 18.6Celeron Island 53.5Bois Blanc Island 90.8UndevelopedUrban parkSpoi 1 islandSpoil islandSpoil islandUndevelopedUndevelopedMi xedMostly undevelopedUndevelopedUndevelopedPartial 1 y developedPubl icPubl icPublicPubl icPrivatePublicPubl icMostly privatePrivatePubl icPubl icMostly privateOntarioMichiganMichiganMichiganOntarioOntarioOntarioMichiganMichiganMichiganMichiganOntarioTotal 3,617.4a Planimetered from U,S. Geological Survey Topographic quadrangle maps.Includes adjacent wetlands.This island is a National Wildlife Refuge administered by the U.S. Fish and WildlifeService.

succeeding to dense upland habitat, consis ti ng 1 argely of grasses, wi 11 ow trees,and cottonwood trees.Peach, Grassy, Turkey, Stony, BoisBlanc, Sugar, and Celeron Islands areundeveloped, pub1 icly owned, and have thegreatest management potential. As notedin Section 3.3, Grassy Island is part ofthe Wyandotte National Wildlife Refuge,managed by the U.S. Fish and WildlifeService. O f the others, only Sugar andCeleron Islands are located in Michiganwaters. Because wetlands occupy over halfof the land area on these islands, theyare especially important fish and wildlifehabitat that could be managed effectivelyto enhance fish and wildlife resourcesusing established procedures (Schnick etal. 1982). However, given the proximityto the cities of Detroit and Windsor,disturbance by boaters, picnickers, andsight-seers is a major problem. Gulls,wading birds, shore birds, and waterfowlnesting on these islands are especiallyvulnerable to human disturbance (Davis andErwin 1982).Any wetland protection pol icy for theDetroit River ecosystem should include themore extensive Ontario wetlands, particularlythose south of the Canard River. Ajoint U.S.-Canadian study to determine thevalue of the islands in the Detroit Riveras fish and wildlife habitat is clearly inorder. It is timely to perform such astudy, because dredged spoi 1 s are nolonger disposed of on Mud and GrassyIslands, and enhancement of fish and wildliferesources on the islands would greatlyincrease the recreational potential ofthe Detroit River urban riverfront.Because fish and wildlife produced inDetroit River wetlands freely cross theinternational border, management of thewetland habitat in the river should becoordinated by a joint internationalauthority, such as the Habitat AdvisoryBoard of the Great Lakes Fishery Commission.6.8 MANAGEMENT FRAMEWORKNumerous organizations, each of whichhas its own mission and expertise withregard to the management of the DetroitRiver ecosystem, have jurisdiction in theDetroit River (GLBC 1975~). Because ofthe international nature of the DetroitRiver waterway, programs of theInternational Joint Commission (IJC), andthe Great Lakes Fishery Commission (GLFC)are most relevant.The IJC was created in 1909 by theBoundary Waters Treaty between Canada andthe United States. The GLFC was createdin 1955 by the Convention on Great LakesFisheries between Canada and the UnitedStates. The principal advisor to the IJCon water qua1 ity issues is the Great LakesWater Quality Board, which is composed ofagency and scientific leaders. TheCanadian-U.S. Water Qua1 i ty Agreement of1978, administered by the IJC, containsboth ge~eral and specific objectivesdesigned to reduce pollution discharges tothe Great Lakes. As a result of the 1985Report of the Water Quality Board to theIJC documenting the loss of beneficialuses in the Detroit River, the Province ofOntario and the State of Michigan aredeveloping a remedial action plan torestore all beneficial uses of theresources in the Detroit River, includingmunicipal and industrial water suppl ies,recreation, and aquatic life.The GLFC is composed of four Canadianand four United States Commissioners, anda Secretariat to assist them. Its purposeis to coordinate efforts between the twocountries to maintain high, sustainedproductivity by Great Lakes fish stocks.The GLFC recognizes that authority formanagement and regulation of fish in theDetroit River is vested in the State ofMichigan and Province of Ontario andrelies on a number of people from thoseagencies to conduct its business. Theprincipal advisor to the GLFC on habitatissues is the Habitat Advisory Board,composed of agency and scientific leaders.New cooperative agreements betweeninstitutions in the United States andCanada are needed to address the followingdata gaps:(a) The trophic structure of the DetroitRiver ecosystem, including a mass balancefor organic detritus from coastal wetlandsand contaminants from Lake St. Clair, theDetroit Wastewater Treatment Plant, andall industrial waste discharges combined;

(b) Detailed mapping of remaining wetlandsand littoral island habitat in the DetroitRiver and research to define their functionand value in producing fish andwild1 ife; and(c) The effect of the polluted bottomsediments on the fish and wildliferesources of the river, particularly inthe areas around Fort Wayne, Zug Island,the Rouge River mouth, and in the TrentonChannel.In June 1977, the GLFC publ ished afeasibility study for rehabilitation ofaquatic ecosystems in the Great Lakes(Francis et al. 1979). The StrategicGreat Lakes Fisheries Management Plan,(GLFC 1980) concluded that comprehensiveplans to rehabilitate the Great Lakesecosystem can be developed. In 1986,through its Habitat Advisory Board andLake Commi ttee structure, the Great LakesFishery Commission developed guide1 i nesfor including fishery information, goals,and objectives in the remedial action planfor the Detroit River. If objectives areincorporated, the plan will ensure thatfish from the Detroit River are palatableand acceptable for human consumption; thatfish habitat is restored to full productivecapacity within a specified time byreducing pol lutant loadings and removingin-place pol luted sediments, if necessary;and that impacts of water quality affectingfish and wildlife habitat in the riverare mi tigated so self-sustaining populationsof edible fish are maintained andsocioeconomic benefits from the fisheryaccrue to society.As a common property resource andopen hydrologic system b~tween two countries,the Detroit River is used by manywho are not subject to comprehensive andaccountable management. Current insti tutionalprograms and authorities result ineither narrow, closely defined responsi -bi1it:ies or poorly defined multijurisdictionalarranqements. Arrangementsbetween Candda and the United States needto be strengthened to facilitate theexchange of moni torino data on water andsediment quaiity in the Detroit River; inparticuiar, ?ersistent water dnd sedimentqu2l ity problerr!~ in the pi tier Qeserveprompt remedial action by Ontario Ministryof the Environment and Michigan Departmentof Natural Resources. A1 so, greaterefforts must be made to provide results ofscientific research on fish, wildlife, andtheir habitat in the Detroit River toregional and local governments with zoningand planning authority. In the UnitedStates, the Southeast Michigan Counci 1 ofGovernments, via the (Michigan) Counci 1 onEnvironmental Strategies and the RougeRiver Basin Committee, could reducecombined sewer overflows to the Rouge andDetroit Rivers.Public Act 247 concerns leasing ofState-owned bottomlands in the Great Lakesand Lake St. Clair. It does not includethe Detroit River from the northern tip ofPeach Island to the southern tip ofCeleron Island. However, P.A. 346 andP.A. 203 require permits for constructionactivities on both publ ic and privatebottomlands and wetlands in Michiganwaters, including the Detroit River.In Ontario, diking of wetlands alterstheir tax status. The Provincial Ministryof Revenue considers marshland to berecreational land and taxes it at twicethe rate of farmland (McCul lough 1985).Therefore, the pressure to drain marshesand convert them to farmland is now greaterbecause generous tax subsidies forfarmland are available from the Provincialgovernment.The loss of wetland productivity dueto fragmentation, degradation, and conversionof marshes to competing land usesmust be addressed because they are essentialhabitat for production of fish andwildlife in the river. In Ontario, theproperty taxes on marshland need review,and in both countries the private sectorshould be educated regarding the value ofwetlands. Because many of the islands inthe river are in public ownership orundeveloped, a joint Michigan-Ontariomanagement policy would be timely.5.9 RECOMMENDATIONSUse of the Detroit River for thedilution and disaosal of liauid and solidwastes is h n'ear conflict with oasicbiologics? processes in the river, inc?udingthe production of valuable fish andwi ldl i fe resources. However, manyconfl icts between uses could be resol ved,

y irnpl ernenling the following spills into the river, especially duringrecanmendat ions. winter .I. Sewaqe treatnlent plants discharqinginto the river anti its tributar-irs couldhe upgraded to tertiary effluent level fororganic ntatter and heavy n~etals, dndoperated at desigr stdnaards.2, Metland habitat on islands in the rivercould bt? protected and ffianag~b for productionof fish and wildlife.3, Combined sewer overflows dnd industrialdischarges to the river and ~ t s tributariescould be reducer! r3~d thfrir toxicsubstances content more adrohatelymonitored,4. Contaminated sediments could he r~movedfrom catch basins dnd pfpes that dischargeinto the river and its tributaries and beproperly disposed of,5. Mew connections to sewers that haveinsufficient storm wdter capacity couid bedelayed unti 1 combined sewer overf1ows areef irninatcd.6. tieavily polluted bottom :ediments intahc river and its tributaries could bedredged (with no ovclrf 1 ow), decontami -nated, and disposed of in acceptablydesigned and monitored confined disposalsites, preferably on land.7. Confined disposal facilities could heprotected and rnanaqpcl for production offish and wildlife, if studies show suchsites are not toxic to plants and animals.8. Roating activity could be restricted tomain channels during spring and fall nearareds where large nui~ihers of nigratorywaterfowl feed and rest in the river.9. Protection of remaining wetlands couldbe encouraged by restricting shorcl .inedeveloprr\ent along and in the river.10. The development of new wetlands orrecreation of once-existent wet1 ands couldbe encouraged in and along the river.XI. Adequate containment safeguards aroundhazardous substance storage and handlingfacilities on shore could be installed andmaintained to prevent oil and containinant12. A joint Canadian-U.S. repository forrecords of hazardous substances spi 1 ledinto the river and stored in landfillsthat drain into the river could beestabl ished.13. A public edircation carlipaign could belaunched to promote the river. and itstributaries as vctluable natural resources,di scouraee pollution of them, and generatesupport for planned pollution controlefforts.Lastly, to better visualize andmanaqp competing uses of the river, ageographic i~formdtion system, similar tothat of the U.S. Army Corps of Engineersfor the Tennessee-Tombiqbee Waterwdy(IJSACF 1985), could be ~mployed. The database of such a system consists ofdiclitizcd maps, such as of water depthsand fish spdwninq areas, which areprojected in a corrnnon, sufficient scale.Software routines, such as suitability

Such information systems are capableof integrating chemical, physical, biological,and land-use information andcreating maps displaying this information.We recommend that a aeographic informationsystem be used to illustrate use conflictsin the Detroit River and formulate managementa1 ternatives for remedial actionsneeded to resolve the conflicts.It should be recognized that effective,balanced management of the DetroitRiver to minimize conf 1 icting uses necessitatesan ecosystem approach (Ryder andEdwards 1985). Briefly, an ecosystemapproach for the Detroit River wouldrequire (1) knowledge of how badly theriver is polluted, (2) selection of objectivesfor remedial actions, (3) selectionof plant and animal species that areexpected to respond to remedial action byincreasing in number and distribution, and(4) documentation of the critical habitatand niche requirements of those selectedspecies.An evaluation of the state-of-thehealthof the ecosystem could then be madein terms of the degree to which the criticalhabitat and niche requirements of theselected species are met or can be metunder extant environmental conditions orunder conditions which may prevail, ifcultural stresses were increased ordecreased. Such an ecosystem approach hasbeen developed for managing fish populationsin large rivers (Petts et al. Inpress), and it shows promise as a meansfor generating quantitative empiricalcriteria that could be used tc regulatethe impact of cultural stresses on naturalresources in the Detroit River.Because the Detroit River is connectedhydrologically with Lake St. Clair, theurban sewer systems in Michigan andOntario, and western Lake Erie, it will benecessary to include information aboutpollution loadings, land uses, and shippingactivities to minimize use conflictswithin the river itself. The dischargesfrom the Rouge and Ecorse Rivers, forexample, are relatively small, but theimpact of wastes discharged into thesetributary waters on the water quality andbottom sediments in the Detroit River issubstantial.In applying an ecosystem approach, itshould be understood that the DetroitRiver is common (pub1 ic) property, sharedby all, and, therefore, vulnerable to thetragedy of the commons (Hardin 1968).Briefly stated, each individual orindustry that empties wastes into theDetroit River gains by having cheaplydisposed of them, but all those downstreamare robbed of clean water for their use.This attitude is linked to long-standingtraditions in western society (White 1967)and will not change significantly untilall who use the River come to regard it asthey would their own private property. Insome areas around the Great Lakes, urbandwellers have developed new protectiveattitudes towards natural resources alongtheir waterfront (~etterolf 1984). Shouldeveryone come to regard the Detroit Riverin that manner, future generations willenjoy a quality of life from the River atleast equal to that their parents enjoyed.

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.50272 -101REPORT WChlMENTATlON 1 !?mWRT 2PAGE4. Tttie and Subtitleijio!ocjicdl QP[)LI~~liw Dtttroi t River., Michigan: 1-11) f.i.ulocji~~ i i't'ol i lc)?!I(! I j ) j3 RsirDbent 9 Acrar$,on NOI. Author(%?St-ijce A . i4ar!:?yi , 1 ihomas A. tilsci! l ' , ,l,ld kuq_jcnc , ~;iwc~r~~hi~'" . . ., . . ". ~9. Authorii ~i i I iat,ions:lNal.iur,iii i i st~r-ies ~rrlcj Kesedr-ct) -'ll:riy~Q~r,Ln~erit u t i;e:tyraphyCeiitr~--Gr.t.at i-akes ,tird i;eol oily.~." , .-".0. S. Depa\*t.mt.nt o t the Inttirior il. 5. L rlv i r~cri,i~~crlt;l l i!rot.cct. ionf is\, aritj Wi Id1 i ft. ScrvicrAgcr\cyNat i oila i Wet,IcltitJs l?c:,eat~ctl (;r,c;ll LLiktts Nat. i ilrtal f t'ucjrqi~?iCenterOi I iceWashi nytorl, OC 20240 Chi c~+go, il.. i;Ot2l!,. . __ . .. _ "Id. Ab~tract. ._. _^ . ._. ^ _....(Ltmlt. 200 words)l^II."p-.-----....-..-... " .-'.l^.-.l-l-.,.l.-.-. "-A part ot the cc~ririectirlg charirit!l sy:,tc!ni Lretwt:en i.izke Iiurori nritl lakc: Iric, thtxIktr-o it K ivc?r forms an ir~tegt*~r 1 I ink betweer1 thi! t.wo lakes tois bot 11 ~ILIIII~~I~NII~bi(Floqicn1 resources such ds ti st), ~i~itrient.s, avcl plant c!et,r5i t.tis. [hi:) p~~of i 1 ~ :summarire.; exist irig sc ierjti t. ic irbforntat io11 on the eco Iogi(.,%l ~,lr~ac2.iir3~ andfi~nct.iunir~g ot this ecnsy:,t,un~. Topics iitc lude t,lit: !jeologii:a l tli\t,o~'y of t.hcr.eqiori, c I imat ic irrf lucnces, river hytlr.0 logy, lower- troptt ic- Iovel biot.iccorrrpoilent.;, native dnd irltrodt~cti I1 supports diverse f ish, wal.t.t.f owl,ar~d bertth ic pupu lat ions. Nana