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

More documents

Recommendations

Info

18 CALIFORNIA COOPERATIVE OCEANIC FISHERIES INVESTIGATIOSSof northern anchovy, Pacific sardine, and Pacificmackerel. Many hundreds of individuals of thesemluable commercial species were reared from theireggs to the juvenile stage in the laboratory. At thesame time approximately 18 other species of marinefish were successfully carried from hatching throughmetaniorpliosis to the juvenile form.Success in rearing may have resulted from thecombination of a suitable environment and a goodfood supply. Observations on newly-hatched larvaeindicated tlie need for large volumes of sea waterbecause of its stability of temperature, salinity, andbiotic factors. Large aquaria provide room for swimmingwithout frequent contact of walls, one of themajor causes of mortality of laboratory-rrarrd fishes.,4t first feeding, sardine and anchovy larrae requirehigh densities of food in tllrir immediate environment.Live plankton has been provided, which lias beenobtained by filtering large volumes of sea water toobtain sufficient numbers of minute plankton organismsof sizes that can be ingested by newly-feedinglarrae (organisms no largcr than 0.08 mni in diameter).As the larvae grew, larger food organisms weresupplied in high densities.Sardine and anchovy larvae, at first feeding, ciinswim only limited distances. Their swimniing abilityrequires that the entire volume of a 500-gallonaquarium must contain uniform distribution of foodorganisms at a density not less than 4 per cubic centimeterof water, regardless of whether only one larvaeor a thousand are being cultured. This problem wassolred by restricting the space for the larrae withuse of thin-walled plastic bags floated in the aquarium.The thin plastic permitted gas exchange to take placebrtween the wxtrrs inside and outside of tlie bag, whilethe soft material offered very little resistance whenstruck by a swimming larva. When larvae becomeable to hunt food over greater distances, the bags weresilt open and the growing fish allowed the freedom ofthe larger container.Life History Studies of Rockfish. A major goal ofthe Life History and Taxonomy program is to preparecomplete descriptions of the life history stages of thefishes that contribute eggs and larvae to the planktonof the California Current region. A4 major study isbeing made of rockfishes (Xebastodes spp.).The large number of rockfish species (more than50) pose an immense problem in attempting to identifyrockfish larvae collected in plankton. The problemis simplified by the fact that rockfish are live bearersthat retain their young to the larval stage. Such earlylarvae of 17 species haw been obtained from identifiedfemales and have served as a means for identifyingthe later larval stages in our collections.The complete series of derrloprnrntal stages fromthe developing embryo to the adult, have been describedfor Xebastodes pnzrci.spiiai.s. It was found thatyoung of this rockfish species spend the first severalinoiiths of their life as epipelagic larvae and transforminto juveniles at 30 mni length. Juveniles arefound in shallow coastal waters over rocky bottom3in association with Agile (Macrocystis, Laminarin, andEgrcgia) or over sand bottom in association with eelgrass (Zostera). Juveniles remain in vaters shallowerthan 20 meters during their first year of life, thenmove into deeper water. Most of the adults collectedwere found in depths of 80 to 300 meters during theinvestigation.Plartkton Dynamics. Since the start of the work onquantitative sampling of fish eggs and larvae in 1939.the California Current Resources Laboratory has beeninvolved in problems of quality control of planktoncollection. In 1963 the diverse plankton-samplingstudies were united under one program. The work ofthe Plankton Uynaliiics program is divided into fourareas : plankton sampler design and operation, planktonbchavior, riiicrodistributioll, and measures ofamount of zooplankton (biomass).It was our judgment in starting the plankton programthat two major problems were inhibiting theimprovement of precision and accuracy in quantitativezooplankton sampling. One problem area was thatof plankton behavior, of the responses of organismsto sampling gear. The other was an inadequate understandingof the operation of plankton sampling gear.As anticipated, the description of the performance ofsampling gear has proceeded at a faster pace than thestudy of the biological problems.Comprehensive tests of hydrodynamics of planktonsampling devices were carried out at the David TaylorModel Basin near Washington, D.C. Eighteen personsparticipated in or were actively associated with thesetests, including personnel from five BCF laboratoriesand from several university and industry groups.The tests showed that in “clean” water at the modelbasin, the amount of effective straining area ratherthan the size of the mesh apertures was the predominantconsideration. As long as the ratio of mesh aperturearea to mouth area was it least 4 to 1, littlediff erence was observed in filtering efficiencies of fineor coarse-meshed Nites nets in “clean” water attowing speeds of 13 to 3 knots. All had filtering efficienciesof 90 percmt or more when new (less if thenet previously had been used at sea).The tests also showed that bridles and tow cablescause major accelerations and turbulence in the waterahead of ncts. Although thew disturbances have littleeRrct iipon the actual filtering efficiencies of largenets, they provide cues to which animals may respondto avoid capture.Following the studies of plankton net performanceunder controlled model basin conditions, the nets weretaken to sea, in order to study the effects of cloggingon plankton net performance. The telenietering flowmeasuring devices used for the model basin tests wereadapted for use at sea. Clogging was monitored insrreral phytoplankton rich areas, usually near shore.as well as in clear waters, 250 miles seaward of Pt.Conception. The rate of clogging wvas found to bemarkedly dependent upon tlie composition of theplankton community. When a series of nets meretested in plankton-rich waters at the same locality.the rate of clogging was found to be affected by meshaperture size, mesh aperture amount and net form
IiEPOHTS TOLUME XI, 1 JULY 1963 TO 30 JUXE 19GG 19(whether cylindrical, conical, or cylindrical-conical) -listed in order of importance.Mesh aperture sizes markedly affected the rate ofclogging. The smaller mesh sizes clogged at a ratewhich was related to the area of the individual meshaperture. We concluded that the finest mesh practicalfor the usual survey tows should be 0.3 mm meshaperture width but that even in such a net the combinedareas of the apertures would have to be atleast 8 times the mouth area to get sustained filtrationfor 15 minutes at 2 knots.It was found that mesh aperture amount alsoaffected clogging strongly. For instance, in a givenbody of water a 20 percent increase in reserve filteringarea would allow a net to filter twice the amountof water before filtration efficiency was adversely affected.Our studies of the effect of net form on cloggingrate showed that cylindercone nets clog moreslowly than conical nets.An important finding of thr research on planktongear is that the basic filtration characteristics of atowed plankton net in the field may be effectirclypredicted by establishing the proportions of meshaperture area necessary for each size of planktonmesh. We hare applied these data to the design ofa small inesli net to retain the eggs of the iiorthernanchovy. Since January, 1966, this net has performedwith the predicted efficiency in more than 1.000 towsin all areas of the survey region of the Californiacoast.Expc~inientrrl Tagging of dnchc,c*ies. Before thebeginning of the anchovy fishery, it was understoodthat a. tagging program would be needed to aid intlie studies of tlie population structure, movements.and abundance of these fish, as well as to measuretlie eft'ects of fishing pressures. Anchories are extremelydelicate and susceptible to injury whenhandled, therefore experiments were made to dcteriniiiewhetlzer tagging was feasible and practical.Since tags were to be recovered froin magnets infish canneries, steel internal tags mere chosen formarking the fish. It was found that the same type ofinternal tag (13 x 3 x $ mni), used successfully onthe Pacific sardine, herring, mackerel, and anchoveta,could also be used on the anchovy. Mortality was decreasedby coating the tags with 3 percent tetracyclinepaste aiid inserting them posteriorly through an incisioncut just dorsal to the tip of the pectoral fin.Coiitrary to expectations, greater mortality was foundto owur among fish that had been anesthetized beforetagging than among those tagged withotlt anesthetic.Better survir-a1 occurred in freshly-caught anchoviestlian in fish that had been held in live bait t;inks forseveral days.The California Department of Fish and Game hassuccessfully used these methods to tag iiiany thousandsof anchovies off the coasts of California andBaja California duriilg 1966.Since the metal internal tag is not visible and eventhe incision scar is completely indiscernible after 2or 3 weeks, we have been unable to get tag returnsfrom the bait fishery. Several methods of externallymarking the tagged fish have been tested. The mostpromising mark is created by injecting a red fluorescentpigment just under tlie skin of the operele.This mark is readily visible in live or dead fish, isnot injurious to the fish, and, when properly injected,does not fade.Genetic Studies. Serology, which was successfullyemployed in distinguishing tlie three subpopulationsof sardines, is also being applied in the search fornorthern anchovy subpopulations. In order to fiiidblood groups that may be usrd in charactcq-iziiiganchovy subpopulations, it was necessary to producenew blood-typing reagents. We have developed sonlenew techniques that have enabled us to collrct relwtivelylarge volumes of high titer reagents froin inimunizedfish. These reagents produced in fish show iigreater degree of specificity t hati reagents that wereformchrly produced in warm-blooded animalsElectrophoresis of tissue proteins from anchorit>\has also been tried. The electrophoretic patterns producedin polyacrylamide gel from the soluble proteinsof the eyt' lenscs showed iio dift'ereiicrs in anchoviessampled from southern Raja California. to Sal1Francisco. The most promising proteins iiow ;ippear tobe the transferrins, a specific group of iron-carryingproteins found in the blood sera. Transferrins labeledwith radioactive iron and electropliorrsed on rtarcligel show polymorphism, which appe,rrs to be controlledby a 3-allcle genetic system. The frequencyof o(wmmice of these genes in anchovies taken fromvarious areas can be used in looking for subpopulations.Behavior Xtiidics on Anchot%es. One of the inajorendeavors of the Behavior Program during the pastseveral years has been to develop a quantitative descriptionof anchovy feeding : to discover what its foodprrferences are, how it captures different kinds oforganisms. and how the rate at which it removes foodfrom the water depends on the amount present, thcsize of the fish and its state of hunger.Expclriments have shown that predation is by filteringon orgaiiisnis less thaii I inn1 in length ;~ntl byparticulate biting on organisms a few mni or morein length. It has been shown tils0 that thr largerorganisms are preferred, but that the filtering attarkdirected at tlie smaller orgmisnis is riot abandoiiedin favor of biting unless the 1;wger organisms areabundant mougli to providc a grcater rate of caaloricintake .Other experiments have shown that the rate of iiitakeoil both sizcs of food orgaiiisius, when they arepresent in surplus qnantity, increases with growth ofthe fish up to a weight of about 4.0 grams, beyondwhich it taper., off steadily toward itii asymptoticle\ el. Though this relation between size and feedingrate has the same pattern for the two sizcs of food organisms.the rates are higher for tlie larger items, indieatingthat xn anchovy at any size is able to consumemore in veight and lieiice in calories of tlie large orgitiiisnisthan of the small organisms. Another \et ofrxpcrimeiits has shown that for an nncliory of any
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 and 18: REPORTS vor,uiwIi; SI, 1 JULY 1063
Page 19: REPORTS TOT2T71\IF: SI, 1 JUJIT 196
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 ...

Create successful ePaper yourself

Delete template?

Save as template?