CalCOFI Reports, Vol. 11, 1967 - California Cooperative Oceanic ...

More documents

Recommendations

Info

16CALIFORNIA COOPERATIVE OCEANIC FISHERIES INVESTIGATIONSfrom July 1963 through June 1966. Coverage was ona quarterly basis through 1965 and then on a monthlybasis in 1966.The research vessel, Black Douglas, which was usedalmost exclusively for CalCOFI surveys, was retiredafter the last cruise in 1965 and replaced by the newreseasch vessel, David Xtarr Jordan, which began itswork in January, 1966. Jordan was designed specificallyfor oceanographic and biological research. It isof steel construction, 171 feet long, with a cruisingspeed of 12 knots, fuel capacity for 40 days, and arange of 12,000 miles. Special features include a bowthruster, underwater observation ports, biological,chemical, and hydrographic laboratories, researchsonar, radar and navigational equipment.Certain changes were made in coverage and methodsof sampling during these years. In January and July1964, a special grid of SO+ stations was occupied offPt. Arguello to determine more fully the areal distributionand seasonal changes in abundance of fishlarvae in that area. In all of the 1965 cruises, two sampleswere taken at most stations, one with the standard1-m net and the other with a fine mesh (0.27 mm)1-m net hauled together with or consecutively afterthe standard net. This was done in order to obtaininformation regarding the kind and degree of undersamplingby the standard net of anchovy eggs and ofvery small fish larvae. In 1966 almost all collectionswith the standard net were made in assembly with anewly-designed 3-m “anchovy egg net” (0.33 mmmesh).In calendar 1966, monthly coverage, the first since1960, was re-instituted in order to obtain data for abase year for studies of the anchovy population, inkeeping with the opening of an experimental reductionfishery. Adequate coverage of the pattern fromSan Francisco to southern Ba ja California usuallyrequires at least two ships. Since it was not always possibleto have two for each month, surveys for one shipwere planned always to include the pattern off southernCalifornia from Point Conception to San Diegoand either to work north to San Francisco or southnear Magdalena Bay.The monthly surveys of 1966 will permit us toobtain current estimates of abundance of other importantfishery resources in the CalCOFI area inaddition to the northern anchov3.--particularly Pacifichake, jack mackerel, sardine, and rockfishes.Cooperative Hake Xurveys. During the period ofthis report, three cooperative hake cruises were made,usually employing the Black Douglas of this laboratoryand the John N. Cobb of the Exploratory Fishingand Gear Research Base, Seattle, Washington.The purpose of the cooperative cruise was to determinethe location and extent of spawning concentrations ofadult hake off California and Baja California and thequantities that could be captured per hour of trawling.All of the cruises were made in February-March,the months of peak spawning of hake.In order to locate concentrations of spawning hake,the Black Douglas scouted for high concentrations ofnewly-spawned hake eggs by means of a systematicprogram of plankton sampling and examination ofsamples immediately after collection. When high concentrationsof eggs were found, the information wasradioed to the Cobb, which moved to the area, locatedthe position of spawning adults with its echo-soundingequipment and then lowered its large pelagic trawlto appropriate depths. IJsing this method a directrelation was found between areas of high egg concentrationand the presence of spawning adults. Severalsuch areas of adult hake abundance were surveyedoff southern California and northern Baja California.One of the concentrations was estimated to extend over23 square miles. The largest catches were obtainedoffshore from San Diego (in the vicinity of CalCOFIstation 97.35). A catch of 20,000 pounds was obtainedin one of the 1-hour sets. The location of spawningconcentrations changed from year to year. Hake wereencountered at depths of SO to 225 fathoms with thefish occupying the shallower depths at night.Males predominated in most catches, often contributing90 to 95 percent of the fish caught. Males appearedto be more permanent residents of spawningschools than the females. The latter appeared to enterthe spawning schools for a brief period, spawn theireggs, and then leave.Anchovies were taken in more than half the trawlhauls made by the Cobb during the cooperative cruiseof 1964. The most interesting phenomenon relatingto these fish was their consistent occurrence duringthe day at depths of about 12.3 fathoms, and on oneoccasion at a depth of 185 fathoms. At dusk theechograms showed the schools rising to the surface.Distribution of Schooling Fish as Determined bySonar. With the commissioning of the David XtarrJordan in January 1966, the Behavior programstarted a field study of the distribution, movementsand abundance of schools of anchovies and other pelagicspecies. The Simrad sonar installation will bethe primary tool in this project. To date four surveyshave been carried out in conjunction with monthlyegg and larva cruises. Analysis of the sonar recordshas revealed that a few large aggregations of fishschools occurred on each cruise. In half a dozen casesthe peak counts were higher than 100 schools per 10miles and in one case as high as 200. These aggregations,furthermore, were extended over distances of20 to 40 miles, some along the coast and some onstation lines extending offshore, and a number of themwere identified as anchovies by underwater observation.Targets of a biological nature also occur frequentlyin the outer portions of the survey patternbut so far these have been scattered and usually weakin signal strength. Trawling gear, which will be usedto obtain samples for identification and life historyinformation, has been tested but not yet usedroutinely.The potential of sonar for ecological surveys andresource evaluation is evident not only in the highrate of target registration, but also in the way thelimited sonar data already taken relates to other kindsof information collected. A major shift in distributionof anchovy concentrations within a period of 4
REPORTS TOT2T71\IF: SI, 1 JUJIT 1963 TO 30 JUSE 1966 17weeks, for instance, appeared to be associated witha marked shift in surface temperature distribution.Also, simultaneous depth sounder records indicatethat some of the variation in distances at which schoolgroups are detected from the vessel is probably relatedto the depth of the groups. On one occasion schoolswere observed to move vertically in close coordinationwith the deep scattering layer. The accumulation ofsuch information, along with studies based on trackingschools, an operation already attempted with moderatesuccess, should provide rillu>lble field information forunderstanding the beharior of these fishes in relationto features of their environment, and perhaps alsofor estimating their seasonal and regional abundance,at least in a relative spnse.Rc~o wcc If ~'CI of ion. Per II aps th e prim. ii c (~111-plishment of the California Current Resources Liiboratoryhas been the denionstration that systematicsurreys of fish eggs and larvile constitute one of thebest means available for evaluating fish resources.These surreys have shown that there are a number ofimportant fish resources in the California Currentregion that are underutilized or not fished at all. Themost iihiindant of thew is the anchovy, which hasshown a 10-fold increase during the 16 years of Cal-COFI surreys. Second only in abundance to anchoryInrvae are those of the Pacific hake. Jack mackerellarvae are less abundant in the area surveyed butinore widely distributed. This species spawns throughoutthe CalCOFI area, but eggs and larvae are moreCommon in the outer half of the CalCOFI pattern;the offshore extent of spawning of jack mackerelseldom is cwrnpletely delimited by CalCOFI surveys.Of more importance is the documentation of the interactionbetween the sardine and anchovy populations.The anchovy population increased in abundanceits the sardinc. decreased. Competition, coupled with aselective fishery for the sardine, gradually allowed theanchovy to become predominant in its trophic level.We are vitally interested in whether the action isreversible. Can the abundance of the sardine populationgradually be increased by applying differentialfishing pressure to the anchovy resource 2Kcaring Pelagic Marine Pishcs. The program forrearing pelagic marine fish larvae has the basic objectiveof developing techniques mid equipment by whichmarine fishes may be cultured under laboratory conditionsfrom the egg stage through the larval and metainorphicstages to the juvenile and eventually adultstage. Many scientists have attempted to rear pelagicmarine fishes during the past century because of thewide scientific and commercial applications inherentin this accomplishment. Rearing pelagic fish larvaeunder laboratory conditions opens ninny avenues ofscientific inquiry and provides new areas of specificstudies on larval fish survival, taxonomy, embryology,physiology, and behavior.Progress during the past 3 years of experimentsjn rearing pelagic fish larvae at this laboratory hasculminated in outstanding success in multiple rearingsFIGURE 4.School of Pacific mackerel, reared from eggs by Dr. George Schumann.-photo by Gearge Mattson.
Page 1 and 2: STATE OF CALIFORNIAMARINE RESEARCH
Page 3 and 4: STATE OF CALIFORNIADEPARTMENT OF FI
Page 5 and 6: RONALD REAGAXGovcriwr of the Slate
Page 7 and 8: PART 1REVIEW OF ACTIVITIESJuly 1,19
Page 9 and 10: REPORTS YOLUAIE SI, 1 JULY 1963 TO
Page 11 and 12: REPORTS VOLUNE XI, 1 JULY 1963 TO 3
Page 13 and 14: REPORTS YOLUME SI, 1 JULY 1963 TO 3
Page 15 and 16: REPORTS VOLUME XI, 1 JULY 1963 TO 3
Page 17: REPORTS vor,uiwIi; SI, 1 JULY 1063
Page 21 and 22: IiEPOHTS TOLUME XI, 1 JULY 1963 TO
Page 23 and 24: REVIEW OF THE PELAGIC WET FISHERIES
Page 25 and 26: KEI'OiiTH TOLUJIE SI, 1 JULY 1963 T
Page 29 and 30: PART IISYMPOSIUM ON ANCHOVIES, GENU
Page 31 and 32: OCEANIC ENVIRONMENTS OF THE GENUS E
Page 33 and 34: KEI'OKTS VOLIXI.: SI, 1 JULY 1963 T
Page 41 and 42: ~~~REPORTS VOLUME XI, 1 JULY 1963 T
Page 45 and 46: REPORTS VOLUME SI, 1 JULY 1963 TO 3
Page 47 and 48: 130'E 132' 134' 136' 138' 140' 142-
Page 49 and 50: REPORTS VOLUSIE SI, 1 JULY 1963 TO
Page 57 and 58: KI3I’ORTH VOLUJIE XI, 1 JULY 1963
Page 61 and 62: REPORTS VOLUME SI, 1 JULY 1963 TO 3
Page 65 and 66: REPORTS VOLUIIE SI. 1 JULY 1963 TO
Page 67 and 68: REPORTS T’OLUME XI, 1 JULY 1963 T
Page 69 and 70:
INFLUENCE OF SOME ENVIRONMENTAL FAC
Page 71 and 72:
REPORTS Y‘OLUJIE XI, 1 JULY 1963
Page 73 and 74:
REPORTS VOLUME XI, 1 JULY 1963 TO 3
Page 75 and 76:
~table shows the values calculated
Page 77 and 78:
ateREPORTS T-OLTJIT", SI, 1 JULl 19
Page 79 and 80:
REPORTS POLGNE SI, 1 JU LY 1963 TO
Page 81 and 82:
REPORTS VOLUXE XI, 1 JULY 1963 TO 3
Page 83 and 84:
Page 85 and 86:
_________--_____REPORTS VOLUJIE SI,
Page 87 and 88:
REPORTS TOLTIJIE SI, 1 JULY 1963 TO
Page 89 and 90:
-20/5-0 10-f 5-w 25-0 20-= 15-: 10-
Page 91 and 92:
REPORTS VOLUNE SI. 1 JULY 19G3 TO 3
Page 93 and 94:
Page 95 and 96:
Page 97 and 98:
REPORTS VOLURlE SI, 1 JULY 1963 TO
Page 99 and 100:
Page 101 and 102:
Page 103 and 104:
Page 105 and 106:
Page 107 and 108:
THE PREDATION OF GUANO BIRDS ON THE
Page 109 and 110:
iod and after 8 AM during the rest
Page 111 and 112:
Page 113 and 114:
Page 115 and 116:
FISH E RYThe California anchovy fis
Page 117 and 118:
~~ ::REPORTS VOLUME XI, 1 JULY 1963
Page 119:
CO-OCCURRENCES OF SARDINE AND ANCHO
Page 122 and 123:
120 CALIFORNIA COOPERATIVE OCEANIC
Page 124 and 125:
CALIFORNIA COOPERATIVE OCEANlC FISH
Page 126 and 127:
Page 128 and 129:
126CALIFORNIB COOPERATIVE OCEANIC F
Page 130 and 131:
Page 132 and 133:
~~ ~130 CALIFORNIA COOPERATIVE OCEA
Page 134 and 135:
132 CALIF0RhTTIA COOPERATIVE OCEANI
Page 136 and 137:
Page 138 and 139:
THE ACCUMULATION OF FISH DEBRIS IN
Page 140 and 141:
Page 143 and 144:
PART IllSCIENTIFIC CONTRIBUTIONS
Page 145 and 146:
Page 147 and 148:
REPORTS VOLUME SI, 1 JULY 1963 TO 3
Page 149 and 150:
Page 151 and 152:
REPORTS VOLU&IE XI, 1 JULY 1963 TO
Page 153 and 154:
Page 155 and 156:
Page 157 and 158:
SUMMARY OF THERMAL CONDITIONS AND P
Page 159 and 160:
SEASONAL VARIATION OF TEMPERATURE A
Page 161 and 162:
Page 163 and 164:
including the semiannual harmonic?
Page 165 and 166:
Page 167 and 168:
REPORTS VOiLUME XI, 1 JULY 1983 TO
Page 169:
Page 172 and 173:
170 CALIFORNIA COOPERATIVE OCWIC FI
Page 174 and 175:
172 CALIFORNIA COOPERATIVE OCBANIC
Page 176 and 177:
Page 178 and 179:
Page 180 and 181:
Page 182 and 183:
Page 184 and 185:
Page 186 and 187:
184CALIFORNIA COOPERATIVE OCEANIC F
Page 188 and 189:
Page 190:
CONTENTSI. Review of Activities Pag
show all

CalCOFI Reports, Vol. 11, 1967 - California Cooperative Oceanic ...

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?