Ichthyoplankton and Fish Recruitment Studies in Large Marine Ecosystems
KENNETH SHERMAN, REUBEN LASKER, WILLIAM RICHARDS, and ARTHUR W. KENDALL, Jr.
Introduction tablished by Congress in 1976 (Fig. I). In this paper we provide an over This law extended U. S. jurisdiction view of the research strategies and new Resource assessment studies of the to a 322 kIn (200-mile) wide strip of studies implemented by NMFS to over National Marine Fisheries Service ocean off all the U. S. coasts (over 3.5 come resource assessment problems 2 (NMFS) were expanded significantly million km ). posed by the large-scale temporal and during the middle 1970's to support the spatial biological and environmental conservation and management of ma changes influencing the abundance rine fishery resources within the U.S. K. Sherman is with the Narragansett Laboratory, levels of U.S. fishery resources within Fishery Management Zone (FMZ) es- Northeast Fisheries Center, National Marine the FMZ. The new studies are part of Fisheries Service, NOAA, Narragansett, Rl 02882; R. Lasker is with the La Jolla Laboratory, an NMFS-NOAA initiative known as Southwest Fisheries Center, NMFS, NOAA, La the Marine Resources Monitoring As Jolla, CA 92038; W. Richards is with the Miami Laboratory, Southeast Fisheries Center, NMFS, sessment and Prediction (MARMAP) ABSTRACT- Within the Fishery Man NOAA, Miami, FL 33149; A. Kendall is with program. agement Zone of the United States, seven the Seattle Laboratory, Northwest and Alaska The MARMAP program was built Large Marine Ecosystems (LME's)-ln Fisheries Center, NMFS, NOAA, Seattle, WA 98112. This paper is MARMAP Contribution around a matrix of existing NMFS sular Pacific, Eastern Bering Sea, Gulf MED/NEFC 83-24. fishery resource assessment activities of Alaska, California Current, Gulf of Mexico, Southeast Atlantic Shelf, and Northeast Atlantic Shelf-support multi billion-dollar fisheries, operating at differ ent trophic levels. The LME's are charac terized by unique bathymetry, hydrography, productivity, and population structure. To improve abundance forecasts of recruit ment success ofincoming year classes, two assessment strategies are used by NMFS in the LME's: I) Fisheries independent sur veys offish eggs and larvae on mesoscale grids of20-100 km at frequencies of two to twelve times a year to obtain estimates of the size of the spawning adult stocks, and 2) other studies within the mesoscale survey matrix aimed at discovering the processes controlling the annual recruitment success ofnew year classes. Processes under inves tigation include growth and mortality of eggs and larvae under variable density dependent predator-prey interactions and density-independent influences of changes in circulation, water-column structure, biological production, and pollution. The sampling designs of the multispecies ich thyoplankton surveys in the LME's provide measures-of spatial and temporal variabil ity within acceptable confidence limits for estimating changes in abundance levels of spawning stock sizes offthe northeast coast and in the California Current areas. Figure 1. - The 3.5 million km 2 area of the U. S. Fishery Management Zone.
Oct.-Nov.-Dec. 1983,45(10-11-12) Gloucester, Ma'isachUM'It<;
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Portland,O...,gon ------_.L Columhla Rl\'(,,1 ~ I~"('n('" '; Woods Hole. Mauachusetts f)evclOpl1H'II1 "lllgr,IOJ (, Northea<:'l h ... ht:flt:'l Center (r\W Rq,{1011l NORTHWEST REGION I ~t~~~\If)l(' l...lhoTato!"\, (:'\jEFe) Tiburon. California ---...... lihllWIl l..,nor..Hon (SWF<:) Narragansett. Rhode Island Narrttgan"ell Llbor;tlon jNEFC) Mont~rey. CaJifornia ---...... AtI"tnltl En\ ITO!llll(,IlI,11 (;roup PaniK EIl\lnllllllt'nl ~:I~~:1~lf~71~~t~~I::~I~('~~t'~olumbia Sen-ice Headqu;lrtt'ro; National SV<;ICllldlics Ltborarnry (NEFC) HAWAII ISW REGION) Beaufort., North Carolina Beaufort Laboratory (SEFe) Bay St. Louis. Mississippi :"l,IIHlflttl 1'I.-.heTI('<, CharleSlon, South Carolina l-llgll1('t'"flllg 1.,tlllJl,tIOI"V CharieslOn Laboratory (SEFe) ,Sf f(.) Pribilof hlands. Alaska Honolulu. Hawaii Miami. Florid. Prih.lo' IlllalHl ... HOllollllu LlhoTal(IT\ Snutheast Fi"hencs Center PI"O~ram (NW R('~lllll) (SWfC) Pascagoula, Mississippi (f1dqs.) i.~I~af;H'la 1. Figure 2. - The four fisheries centers and associated laboratories of the National Marine Fisheries Service, and the five regional headquarters and related offices. including studies dealing with the anal Fisheries Center, Seattle, Wash., is tlVlty within each of these regions yses of catch statistics, the results of responsible for studying resources in comprise coherent ecological systems fishery surveys (pelagic, demersal, the Gulf of Alaska, eastern Bering encompassing broad geographic areas ichthyoplankton), fisheries oceanog Sea, and off the coasts of Washington designated as Large Marine Ecosys raphy, and fisheries engineering. A and Oregon. The Southwest Fisheries tems (LME's). description of the early development Center, La Jolla, Calif., has responsi The fishery resources within the of MARMAP program elements is bility for the studies of the living re LME's are subject to management by given in a series of planning docu sources of the California Current, Regional Fishery Management Coun ments prepared by NMFS with the Hawaii, and the Pacific Trust Territo cils, and management plans must en assistance of the Ocean Systems Divi ries. The Southeast Fisheries Center, sure optimal sustained yields based on sion of TRW Company! (TRW Sys Miami, Fla., assesses the resources ecological, economic, and social con tems Group, 1973a,b, 1974.) from North Carolina to the Florida siderations. The ecological decisions The coordination and integration Keys, and in the Gulf of Mexico and are based on the best scientific infor of investigational components of Caribbean. The Northeast Fisheries mation available. Each fisheries center MARMAP are major research activi Center, Woods Hole, Mass., studies conducts ichthyoplankton studies as ties of the four NMFS fisheries centers the resources on the continental shelf an important part of the overall (Fig. 2). The Northwest and Alaska from the Gulf of Maine to Cape Hat MARMAP assessment to support the teras. The energetically related bio councils in developing management I Mention of trade names or commercial firms does not imply endorsement by the National logical communities, bathymetry, and conservation plans for regional Marine Fisheries Service, NOAA. hydrography, circulation, and produc- fishery resources. 2 Marine Fisheries Review ALL SPECIES Fisheries Studies in 1973; Parrish, 1975; Andersen and 10 Large Marine Ecosystems Ursin, 1977; Sheldon et aI., 1977; * 810MASS Beddington et aI., 1979; Grosslein et **** *** ****** 8 ** From the turn of the century through aI., 1980; Laevastu and Favorite, 1981; **** * Laevastu and Larkins, 1981; Mann, the middle 1970's, fisheries studies 6 were mainly focused on the yields of 1982; Sissenwine et aI., In press; 2 3 single species. This was not due to any Jones ; Laevastu and Favorite ; Sher 4 4 YIELD man et aI. ). lack of awareness of the interaction ~... and interdependence of species, but These models deal with multispecies ~ .. rather to budget constraints on fisher fishery interactions at different trophic ies research institutions. However, levels. They are important approxima (J) from a fisheries management point of tions of the consequences of predator C 0 .....L.,--,--.--,----r---r--,-,--,--.---, E 1960 1970 1980 view, the best and most sought data prey dynamics, based on fishery C imposed selective mortality, and hold .9 6 follow an accurate prediction of future ** *** HERRING stock sizes and of the effect of different promise for providing a basis for the ** .. MACKEREL levels of fishing or environmental per management of marine ecosystems. 4 * turbation on the continued production For example, possible species replace * *** BiOMASS of economically viable resource popu ments of heavily fished mackerel and *** ****** lations. herring stocks with smaller, fast-grow ~Y'ELD At present, NMFS under MARMAP ing, economically less desirable spe o .....L.,--,...---.---r.....,...---r--,-,---r-=.-T.~.!..., has a more holistic approach to fishery cies have been reported for the North '960 1970 1980 Sea based on a multispecies predator assessment studies, with a focus on 4 SPRAT BIOMASS *** whole ecosystems and the multispecies prey model simulation supported by .. SANOEELS ** *** interactions at different trophic levels yield data (Andersen and Ursin, 1978) • NORWAY * * POUT ** ** that influence the annual production of (Fig. 3). A review of the fish-stock ••• • Y'ELD fish populations. There are no shortcuts replacement concept can be found in ******* to obtain the comprehensive popula Daan (1980). However, if ecosystem 1960 1970 '980 tion and environmental information models are to assume an appropriate required to improve forecasts of fish role in the management of fishery re abundance within the FMZ. A bal sources, it will be necessary to over Figure 3. - Estimated changes in come present deficiencies in: the biomass of fishes in the North anced approach is being implemented Sea, 1960-76, with simulated yield by NMFS that allows for: and biomass projections to 1980. I) A time-series of measurements I) Identifying the linkages be The 1.0 million metric ton decline in in the form of standardized multi tween primary, secondary, and fish mackerel and herring stocks from species resource assessment and hy 1968-76 from excessive fishing production; mortality is thought to be compen drographic surveys, 2) quantifying predator-prey dy sated for in the North Sea Ecosystem 2) a systematic collection of fish namics; and by replacement with small, fast catch data, and 3) understanding the relationship growing, opportunistic species (i.e., 3) process-oriented studies deal ing between stock size and recruitment. sprat, sand lance, Norway pout). with biological and environmental Source: Andersen and Ursin (1977). linkages among key ecosystem com Ichthyoplankton Studies ponents important to fish production in inLME's the sea. Studies of single species alone do The role played by ichthyoplankton not provide sufficient data for effective in the transfer of energy in the food the density-independent (environmen management of multispecies fisheries web is critical to an understanding of tal) and density-dependent (competitor, operating at different trophic levels. predator) controls over the recruitment While it is important for management 2 Jones, R. 1976. An energy budget for North of new year classes in LME's. The six purposes to continue these studies, Sea fish species and its application for fish man LME's for which significant NMFS they are now being pursued by NMFS agement. ICES C.M.1976/F:36. resources have been dedicated to ich "Laevastu, T., and F. Favorite. 1978. Numerical within a broader matrix that measures evaluation of marine ecosystems. Part I. Deter thyoplankton investigations include interactions leading to changing abun ministic bulk biomass model (BBM). NMFS the Eastern Bering Sea, Gulf of Alaska, Northwest and Alaska Fisheries Center, Seattle, dance levels among the key species in Wash. Processed Rep., 22 p. Washington-Oregon Coast, California the ecosystem. Single-species yield 'Sherman, K., E. Cohen, M. Sissenwine, M. Current, Gulf of Mexico, and the models have been augmented with Grosslein, R. Langton, and 1. Green. 1978. Northeast Continental Shelf (Fig. 4). Food requirements of fish stocks of the Gulf of multispecies models that are ecologi Maine, Georges Bank, and adjacent waters. Each is characterized by unique ba cally sensitive (Regier and Henderson, ICES C.M.1978/Gen8 (Symp.). thymetry, hydrography, productivity, OCT.-Nov.-Dec. /983, 45(1O-1l-/2) 3 designed to encompass the temporal and spatial extent of spawning using a systematic grid of stations. A detailed description of the methods used by NMFS for multispecies ichthyoplank ton sampling is given in Smith and Richardson (1977). Within the mesoscale (20-100 km) WASHINGTON _ OREGON multispecies ichthyoplankton time series surveys (bimonthly to semi CALIFORNIA CURRENT ...... annual), studies of the recruitment process are nested for target species on a finer horizontal and vertical scale 6 (Lasker, 1981a; Lough and Laurence ) aimed at discovering the processes controlli ng annual recruitment suc cess of new year classes. Processes Figure 4. - The six Large Marine Ecosystems where NMFS ichthyoplankton assessment studies are underway. under investigation include growth and mortality of eggs and larvae under vari able density-dependent predator-prey interactions and density-independent influences of changes in circulation, and population structure. Collectively, Oregon coast by NMFS. Assessments water-column structure, biological they yield approximately 5 percent of of spawning biomass are an integral production, and pollution. Among the the global fish catch, and support a part of fish stock assessments in the target species of recruitment studies multibillion-dollar annual fish catch California Current region and off the are walleye pollock,Theragra chalco ing, processing, and marketing in northeast coast. gramma; Pacific king crab, Paralitho dustry. The eggs and larvae of nearly all des spp.; Pacific sardine, Sardinops In the LME's, two assessment strat marine species in an LME can be quan sagax; Pacific anchovy, Engraulis egies - ichthyoplankton surveys and titatively sampled with a single device mordax; Atlantic mackerel, Scomber trawl surveys - are used by NMFS to - the plankton net. The early develop scombrus; Pacific salmon, Oncorhyn improve abundance forecasts of recruit mental stages are all vulnerable to chus spp.; striped bass, Morone saxa ment success of incoming year classes. the paired 60 cm bongo nets used on titis; Pacific hake, Merluccius produc Fisheries-independent surveys of fish NMFS surveys (Posgay and Marak, tus; silver hake, Merluccius bilinearis; eggs and larvae are conducted on meso 1981). Trawl surveys employing net Atlantic menhaden, Brevoortia tyran scale grids of 20-100 km at frequencies systems, and in some areas acoustic nus; Gulf shrimp, Penaeus spp.; blue of two to twelve times a year to esti signals and net systems, (e.g., for juve fin tuna, Thunnus thynnus; spot, Lei mate the size of the spawning adult niles and adults of demersal and pelagic ostomus xanthurus; Atlantic croaker, stocks. Ichthyoplankton surveys rep species) are more selective samplers. Micropogonias undulatus; Atlantic resent the most effective sampling The sampling designs of the multispe cod, Gadus morhua; and haddock, strategy available for measuring abun cies ichthyoplankton surveys within Melanogrammus aeglefinus. dance levels of all fish species inhabit the LME's provide measures of spatial ing the LME's. The CalCOFI (Califor and temporal variability that are within Southeast Fisheries Center nia Cooperative Oceanic Fisheries acceptable confidence limits for esti Initiation of Gulf of Investigations) studies pioneered by mating changes in abundance levels of Mexico Ichthyoplankton Surveys Ahlstrom (1954) attest to the tractability parental spawning biomass in the Cali of measuring population-level changes fornia Current and off the northeast The ichthyoplankton programs of in the ichthyoplankton of the Califor coast (Stauffer and Charter, 1982; Pen the Southeast Fisheries Center, under nia Current system. The CalCOFI nington and Berrien5 ). To obtain sam the direction of William Richards, prototype ichthyoplankton survey ples of ichthyoplankton used in spawn have included pioneering surveys of was used as the standard approach in ing biomass estimates, the sampling is the ichthyoplankton populations of the MARMAP and adapted for use in the LME's under investigation by NMFS. 5 Penni ngton, M., and P. Berrien. 1982. Measur Ichthyoplankton surveys have only re ing the effect of the variability of egg densities "Lough, R. G., and G. C. Laurence. 1982. Lar cently been implemented in the Gulf over space and li me on egg abundance esti mates. val haddock and cod survival studies on Georges In Report of the Working Group on Larval Fish Bank. In Report of the Working Group on of Mexico, eastern Bering Sea, Gulf Ecology, Lowestofl, England 3-6 July 1981, p. Larval Fish Ecology, Lowestoft, England 3-6 of Alaska, and off the Washington- 127-141. ICES C.M.1982/L:3 July 1981, p. 103-119. ICES C.M.1982/L:3. 4 Marine Fisheries Review 95· go. 85· Gulf of Mexico. From 1977 through 1982, the first comprehensive surveys were conducted over the entire region, including a total of 500 stations and 1,500 MARMAP-type bongo and neuston samples. Station locations are shown in Figure 5. Preliminary results are given in a report by Richards et al. 7 In addition to ichthyoplankton tows, the 1978-81 time-series included water-column measurements of tem perature, salinity, nutrients, chloro phyll, and light penetration. Preliminary analysis of species abundance relationships demonstrated significant differences in rank order of abundance of the 20 most numerous families among the northeast, south east, northwest, and southwest quad rants of the Gulf of Mexico (Table 1). A total of 137 genera and species in 91 Figure 5. - Station pattern of the Gulfof Mexico ichthyoplankton surveys, 1982. families were identified from the sam ples. Mesopelagic families including the Myctophidae and Gonostomatidae were the predominate ichthyoplankton groups in the collections followed by the third- and fourth-ranking Bregma Table 1.- Rank order 01 the 21 most abundantlamllies, Oregon /I Cruise 87, 1978 overall and by quadrant in the Gull 01 Mexico. cerotidae, and the Scombridae (Pott Rank by quadrant hoff et ai., 1981). These analyses were Overall rank Northeast Southeast Northwest Southwest performed on the 1978 time-series. 1 Myctophidae Myctophidae Myctophidae Myctophidae Myctophidae Other samples are presently being 2 Gonostomatidae Gonostomatidae Gonostomatidae Gonostomatidae Gonostomatidae sorted and the larvae identified to the 3. Bregmacerotidae Scombridae Bregmacerotidae Bregmacerotidae Apogonidae 4. Scombridae Bregmacerotidae Scaridae Gobiidae Bothidae family level by the Plankton Sorting 5. Paralepididae Stromateidae Bothidae Clupeidae Bregmacerotidae and Identification Center in Szczecin, 6 Stromateidae Paralepididae Scrombridae Stromateidae Stromateidae Poland (Sherman and Ejsymont, 1976). 7. Gobiidae Carangidae Labridae Paralepididae Paralepididae 8. Bothidae Bothidae Gobiidae Serranidae Scombridae 9. Serranidae Synodontidae Tetraodontidae Synodontidae Gobiidae lchthyopIankton 10. Synodontidae Scaridae Gempylidae Scombridae Serranidae Identification Studies 11 Scaridae Serranidae Carangidae Bothidae Gempylidae The waters studied by the SEFC 12. Clupeidae Gempylidae Ophidiidae Engraulidae Engraulidae 13. Apogonidae Apogonidae SCorpaenidae Carangidae Anguilliformes contain a basically tropical fauna, char 14. Carangidae Labridae Synodontidae Anguilliformes Carangidae acterized by a large number of species 15. Labridae Gobiidae Serranidae Gempylidae Labridae (estimated at 1,500). Ichthyoplankton 16. Engraulidae Anguilliformes Stromateidae Apogonidae Scaridae 17. Gempylidae Engraulidae Apogonidae Labridae Scorpaenidae samples from tropical waters are gener 18. Tetraodontidae Scorpaenidae Paralepididae Scaridae Synodontidae ally characterized by few specimens 19. Anguilliformes Tetraodontidae Anguilliformes Ophidiidae Tetraodonlidae 20. Ophidiidae Ophidiidae Engraulidae Tetraodontidae Ophidiidae but a great many species in each sam 21 Scorpaenidae Clupeidae Clupeidae Scorpaenidae Clupeidae ple. Consequently, a large amount of effort has gone into studies to develop methods of identification of larval fish and eggs. In the late 1960's and early 1970's, over 60 species were reared in the laboratory from which identifica studies on tuna (Potthoff and Richards, tion series were developed. Interest 1970; Richards and Dove, 1971; Pott 7Richards, W. J., M. F. McGowan, and J. A. ingly, the first laboratory rearing of Ortner. 1982. Summary of Gulf of Mexico hoff, 1974, 1975; Richards and Pott ichthyoplankton research 1977-1982 with bluefin tuna was accomplished by Edward hoff, 1974a,b; and Potthoff et aI., tuna population estimates and preliminary anal Houde and William Richards (Houde 1980), on billfish (Richards, 1974; yses of larval bluefin distribution and ichthyo plankton assemblages. NMFS Southeast Fisher and Richards, 1969). Identification of Potthoff and Kelley, 1982), on clupe ies Center, Miami Laboratory, Ref. Doc. larval series of tropical fish includes oids (Houde et aI., 1974; Richards et Oct.-Nov.-Dec. /983, 45(/0-11-/2) 5 aI., 1974), and on reef fishes (Saksena Bluefin Tuna Assessments Table 2. - Estimates of bluefin tuna larvae and spawn ing stock with 95 percent confidence limits from Gull of and Richards, 1975; Richards and Sak Mexico ichthyoplankton surveys. sena, 1980; Houde and Potthoff, 1976). One of the priority species targeted Item 1977 1978 1981 In addition to these publications, taxo for fisheries-independent estimates of Total larvae nomic studies are continuing on reef parent stock biomass is the bluefin times 1010 256± 826 594± 461 338±635 Spawning fish and oceanic pelagic larvae. tuna, Thunnus thynnus. Estimates stock 302,206 699,951 398,892 ± 1,007,555 ±622,959 ± 791 ,402 Stations 48 135 76 Stations with bluefin larvae 15 49 13 Actual catch of bluefin larvae 34 292 51 ~, Maximum catch ." .'.' : " .'. ,;.1, :,i per tow 33 19 ... , ) c' l~ , Stations with T; I"J > 10 larvae 0 j~ ';... •. ~. ~'. ", of spawning stock sizes were derived from larval abundances in 1977, 1978, and 1981 (Table 2). These estimates were of the same order of magnitude as fishery-dependent estimates derived from virtual population analyses. Dis tributions of bluefin tuna larvae in the Gulf of Mexico are shown in Figure 6. • :i,',; Correlations between bluefin tuna lar \ .\ ' 0-0 • _1-5 " d" val abundance and surface temperature, '. ; \~ :; l' • _6-10 . ,. latitude, and zooplankton displacement .' .". ._11-20 '" A ._21-50 volumes provide evidence of nonran dom distribution of bluefin tuna larvae 85' in the Gulf of Mexico. Further analyses of the relationship between bluefin tuna larvae and environmental param .' / I,' '\ ",. '\ ~ " : eters will provide additional informa 30' ! .', ~. . '. ;.~ ~.I 0 ;", ( .:. tion on the species' life history. The spatial and temporal distributions will 0 .0• be used as a basis for stratification of • o .: •• the ichthyoplankton sampling design 0 • 0 0 000 0 0 ~*: 0 000 to reduce the variance of the popula • 0 •• •0 fo tion size estimates. 0 o • ;0 0 00. 0 0 • •• • 0 0 25 • 0 0 0 0 0 0 0 .00 0 • SEAMAP 0 0 00 000. 0 The MARMAP studies of ichthyo 000000 plankton in the Gulf of Mexico have O. 0 -0 0 • -1'5 been designated as the SEAMAP -0'10 • 00 (Southeast Area Monitoring Assess • -11'20 00 _21'50 0 ment and Prediction) program which is • a joint Federal-State program coordi • _51'100 2 nated through the Southeast Fisheries .\ .-101'150 Center. During 1982, the first year of B SEAMAP operations, ichthyoplank ton sampling was expanded in the Gulf 9s" 90' 85' of Mexico in cooperation with scien tists and ships from Mexico, Texas, Figure 6. - Distribution of bluefin tuna larvae (estimated number under 10 m2 of sea surface) from bongo net tows conducted in the Gulf of Mexico Florida, Louisiana, and Mississippi. A during (A) Oregon /I 7705, 1977; (B) Oregon /I 7803, 1978. listing of survey dates and sampling 6 Marine Fisheries Review Table 3. - Summary of ichthyoplankton cruises and types of samples collected in the Gulf of Mexico 1977-82. Environmental parameters No. of completed Surlace Chiaro· Secchi Irra- Nutri· 14C Gelb· Year Cruise Dale stations Bongo Neuston XBT temp. phyll Salinity disk diance ents uplake stoff 1977 Oregon //·77 29 Apr· 24 May 48 XX X 1978 Oregon //-87 2 May-30 May 134 XXXXX 1980 Oregon //·105 25 Feb. - 27 Mar. 80 X XXXX X XXX 1981 Oregon //·117 1 May-26 May 102 XXX X Oregon //-120 15 Aug. - 28 Aug. 45 X XXX 1982 Oregon //·126 15 Apr-23 May 120 XXX XXXX SEAMAP June - July 491 XXXX XX operations is given in Table 3. The closing net system (MOCNESS). Lar in the California Current ecosystem is Instituto Nacional de Pesca of Mexico vae are examined to determine age shown in Figure 7. The ichthyoplankton employed three Mexican vessels to composition and prey composition and abundance information obtained by provide complete coverage of Mexican preference. Analyses of stable carbon Ahlstrom was instructive in document waters. Ichthyoplankton stations in the ratios are conducted on components of ing the failure of sardine recruitment in Gulf of Mexico were occupied by six the planktonic food web in the northern the California Current ecosystem and research vessels. All the cruises were Gulf in conjunction with larval fish the increase in anchovy biomass, par conducted in May, June, and July, the feeding studies to evaluate the impor ticularly in the absence of commercial peak spawning time for many Gulf tance of terrestrial organic matter as a fishery and associated catch statistics species. The ichthyoplankton samples source of carbon in their prey. In the for the anchovy stocks during the from the surveys will be processed by transfer of carbon up the food chain, 1950's and 1960's (Ahlstrom, 1966; the Polish Sorting Center. In 1983, the dinoflagellates and tintinnids have been Kramer and Smith, 1971) (Fig. 8). H. cooperative SEAMAP survey for ich established as the principal food source Geoffrey Moser continues ichthyo thyoplankton has been repeated. In for first-feeding Gulf menhaden, Bre plankton work at the SWFC today and addition, a survey was conducted in voortia patronus, larvae, whereas zoo emphasizes the ecological interrela the fall to obtain data on fall-spawning plankton is utilized as food by larval tionships of all species of larval fish species. croaker and spot. Shipboard feeding ex with their surrounding biota (Ahlstrom The continued SEAMAP coopera periments, using laboratory-reared lar and Moser, 1981; Stephens and Moser, tion will allow for fisheries-indepen val menhaden and spot, are conducted to 1982; Butler et aI., 1982). dent estimates of stock size for all Gulf evaluate the effects ofnet collection pro Considerable effort has been ex of Mexico species with pelagic eggs cedures on the fate of soft-bodied prey, pended over the past two years in orga and larvae. The information will pro including tintinnids. In addition, labora nizing a symposium to honor Ahlstrom. vide needed data on fishery resources, tory studies are conducted on spot and The symposium, held 15-18 August the nature of the early life history of Gulf menhaden to describe morphologi 1983, was an attempt to summarize these resources, and the mechanisms cal indicators of starvation at different what is known of the systematics of which affect growth and survival of temperatures and growth rates. early life histories of fishes and pro early life history stages. Among the duce a compendium of egg and larval multispecies target resources to be stages on a global scale. The published investigated are tunas, mackerels, clu Southwest Fisheries Center proceedings will extend the utility of peoids, and reef fishes. Pioneering Studies ichthyoplankton studies in fishery as sessments by providing a ready source Ichthyoplankton and The NMFS Southwest Fisheries for the identification of egg and larval Pollution Stress Center (SWFC) has an extensive larval stages for stock assessment purposes. Under the direction of Ford Cross, fish program in its Coastal Fisheries the SEFC Beaufort Laboratory is con Resources Division, led by Reuben Physiological Ecology Studies ducting studies of the impact of pollu Lasker. Studies on larval fish at the Physiological studies on larvae in the tants in the Mississippi River plume on SWFC were begun by the late Elbert laboratory began with Reuben Lasker's larval menhaden, croaker, and spot. H. Ahlstrom who is acknowledged as a work in the late 1950's. These investi Ichthyoplankton sampling is conducted pioneer in larval fish identification and gations have now shifted to the field from Cape San Bias, Fla., to Galves as the originator of egg and larvae sur where laboratory data on larval fish are ton, Tex., with a principal transect off veys to determine the distribution and applied to ecological situations. This the Mississippi River Delta. Collec number of fish in the sea (Ahlstrom, work attempts to provide insights into tions are made with the standard bongo 1954, 1959, 1965). The areal extent of the relationship between the size of a sampler and the multiple opening- the CalCOFI ichthyoplankton studies fish stock and recruitment. Laboratory Oer.-Nov.-Dee. 1983, 45(lO-lJ-12) 7 CALCOFI 40· 40· BASIC STATION PLAN SINCE 1950 POINT CONCEPTION ,.P 35· • 35· ,'f> ,of>. • 30· 30' 25' 25· 20' 20' Figure 7. - CalCOFI area and ichthyopiankton station pattern since 1950. 8 Marine Fisheries Review C) ~ ~ ;: 12 C:J '"<"'l ...... SARDINE LARVAE SARDINE LARVAE ANCHOVY LARVAE B ANCHOVY LARVAE .~ A 1962 1954 1954 1962 ~ ! I ~ I ...... I / I !:...... N ~ CUMULATIVE TOTALS CuMULATIV[ TOTALS llIlill 1~IO IIIIlll 1-10 0 II-lOa I 0 II-lOa 101-1,000 .0' 'Ot-I,OOO '.001-10,000 • 1.001-10,000 •a OVER 10,000 •a 0\1[" 10,000 STATIONS OCCuPIEO STATIONS OCCuPIEO Figure 8. - Changes in the abundance of sardines and anchovies have been documented through the CalCOFI ichthyoplankton survey method. A = Relative abundance of sardine and anchovy larvae in 1954. B = The decline in sardines and population increase in anchovy based on CalCOFI surveys in 1962 (Ahlstrom, 1966). '0 Figure 9. - Spatial and temporal SALINITY (%.) distribution of first feeding an o LINE 90 chovy larvae (A), associated salinity (B), temperature (C), and chlorophyll fields (0) in the southern California Bight 1974-75 (Lasker, 1978). CHLOROPHYll Q PROFILES SO. CALIFORNIA BIGHT TEMPERATURE (OC) LINE 93 o c 10 Marine Fisheries Review anchovy, Engraulis mordax, in the sea on egg and larval survival (Hunter, 2.0 at 13°-14°C, showed that they needed 1972, 1981; Hunter and Kimbrell, o ." I ~; 3040-50,um (diameter) particles ml- 1980a,b; Hunter and Coyne, 1982) . . to stimulate feeding and gut filling. In Hunter's Physiological Ecology " This result was verified with labora group, Gail Theilacker and Charles o Southern ~ 10 California tory experiments. Hunter (1977) has O'Connell have established criteria for BIght shown that the anchovy larvae need as determining whether larvae in the sea I ! many as 230 40 ,urn particles d- . are starving (Theilacker, 1978; O'Con Chlorophyll layers were discovered nell, 1980). Angeles Alvarino pro 197.4 " not far off the southern Cal ifornia vides information on the distribution coast which contained enough parti and abundance of invertebrate preda cles of Gymnodinium splendens to tors of larval fish (Alvarino, 1980, Figure 10. - Cumulative carbon support the anchovy larvae (34-300 1981). Robert Owen studies small production of the southern California Bight, 1974 through 1978 (Lasker, ml-l, 40-50,um in diameter). One such scale distribution of larvae and their 1981). layer formed a patch about 100 km in food (Owen, 1980, 1981); and Richard length (Lasker, 1975). Methot and Roger Hewitt have been Lasker (198Ia) ranked anchovy year making a careful analysis of the mor classes between 1962 and 1977. The tality of northern anchovy eggs and 1975 year class was the lowest in rank larvae in relation to the environment and field data have been documented in a calm year with high productivity, (Hewitt, 1981; Methot, 1981; Hewitt which support the hypothesis that sta but Gonyaulax polyedra predominated. and Methot, 1982). bility of the ocean is an important factor Scura and Jerde (1977) had shown that Paul E. Smith is responsible for in survival of anchovy year classes. G. polyedra is not very nutritious and studies of biomass estimation using The holistic ecosystem approach for that anchovy larvae do not eat diatoms. egg and larval abundance as indicators investigating the oceanographic factors The 1976 year class was the highest in of adult fish abundance (Smith, 1972). controlling year-class recruitment in rank in a calm year with low productiv He provides the SWFC Coastal Divi relation to the growth and survival of ity, but Gymnodinium splendens pre sion with the development and evalua anchovy larvae in the sea has been most dominated. From these studies it was tion of survey systems, particularly the productive. The CalCOFI sampling concluded that larval anchovies prob design and testing of new plankton area encompasses the temporal and ably use particles the size of G. splen nets, and is responsible for designing spatial extent of spawning, thereby dens in the chlorophyll layers. Year the surveys themselves. allowing for a series of successful large class strength of anchovies may depend CalCOFI Population Assessments scale, at-sea experiments within the upon the presence of G. splendens (as CalCOFI sampling grid on predator opposed to Gonyaulax polyedra) and The Coastal Division also has respon prey relationships between anchovies upon the maintenance of the layers. sibilities to the Pacific Fishery Manage and their prey field. Temperature, sa Poor year classes may be the result of ment Council for biomass estimation of linity, and chlorophyll profiles are used layer breakdown due to wind mixing the northern anchovy and for monitor to identify oceanographic features that or to the presence of G. polyedra. ing the populations of a variety of other concentrate phytoplankton cells of the Working closely with the Coastal commercially valuable pelagic fish in appropriate size and food quality for Division, Richard Parrish, Andrew the California Current ecosystem. anchovy (Fig. 9). It is interesting to Bakun, Craig Nelson, and David Husby Using the extensive background infor note that during the 5 years from 1974 have applied newly devised oceano mation on anchovy larvae and adults through 1978, the greatest abundance graphic indexes to the study of this obtained over more than 20 years, a of phytoplankton measured as the aver hypothesis and the concomitant larval new "egg production method" for 2 age production of mg C/m d-I was drift theory of larval mortality (Bakun, biomass estimation was devised by a highest in 1975, the year of the poorest 1973; Parrish, 1976; Bakun and Nelson, Coastal Division team (Parker, 1980). anchovy recruitment during the 5-year 1977; Parrish and MacCall, 1978; The egg production method produced time-series of observation (Fig. 10). Bakun and Parrish, 1980, 1982; Parrish by the SWFC for estimating the biomass Recruitment studies on the anchovy et aI., 1981; Husby and Nelson, 1982; of anchovy is used by the Pacific Fish conducted by Lasker and his group Brewer and Smith, 1982). ery Management Council to manage have demonstrated the importance of John R. Hunter began his larval fish the anchovy fishery. Besides its use off moderate levels of stability in the Cali studies by describing the behavior of California, the method is being tried off fornia Current upwelling system to anchovy larvae. While this work has Peru and South Africa. A number of support the growth of the appropriate continued on a number of species, he other important techniques have been dinoflagellate prey, Gymnodinium has in recent years shifted his emphasis developed at the SWFC, e.g., spawning splendens. Lasker (1975), with labora to a study of the effect of alterations in and rearing of many species of fishes tory-spawned larvae of the northern the reproductive physiology of fishes with pelagic eggs and larvae (Lasker et Oct.-Nov.-Dec. 1983, 45(10-11-12) 11 aI., 1970), precise ageing of larvae by 1400 W 120' W counting daily increments on larval otoliths (Brothers et aI., 1976; Methot, 198]; Methot and Kramer, 1979), the resonance frequency acoustic technique for counting larvae and juveniles in the 60' N sea (Smith, ]972, 1978), histological and morphological measurements of larvae to indicate starvation (O'Connell, 1976, ]980, ]98]), the use of ovarian GULF OF ALASKA follicle histology to determine fre 50' N quency of spawning (Hunter and Mace wicz, 1980), and others. In the study of fish recruitment, the SWFC Coastal Division maintains over 25 years of egg, larva, and oceano 40' N graphic data collected by CaICOFI. Many of the results appear in an annual peer-reviewed journal, the CalCOFI Reports. Processed data for the large area ofthe California Current ecosystem are published in the occasional publica tion, the CalCOFI Atlas, now in its thirtieth volume (Lynn et aI., 1982). A Figure II. - Extent of ichthyoplankton studies of the Northwest and Alaska short review and bibliography of the Fisheries Center in three LME's - Eastern Bering Sea, Gulf of Alaska, and off division's recent work are available in the Washington-Oregon Coast. a book entitled "Marine Fish Larvae" and edited by R. Lasker (l98Ib). Ichthyoplankton and 8 Monthly Repor( ). derstanding causes of variation in year Pollution Stress Studies are underway at the Honolulu class strength of fishes, tractable prob Studies of the impacts of pollution on Laboratory of SWFC to develop meth lems are being resolved by building on the early life stages of marine fish are ods for breeding and rearing tuna in a growing information base that is de 9 conducted at the SWFC Tiburon Labo captivity for eventual assessment of veloping step-by-step (Kendall et aI. ). ratory under the direction of Janet environmental impacts on larvae and Identification Guide Whipple. The target species in the juveniles. study is the striped bass, Morone saxa Early life history studies are focused tilis. The abundance of striped bass in Northwest and Alaska on providing sufficient taxonomic ex the San Francisco Bay and Delta region Fisheries Center pertise to identify the eggs and larvae has decreased in recent years. Con of the most important species. Descrip Areas of Interest cerned with the future of this popular tions have been prepared of the diag sport fish, a joint study team of scien The Northwest and Alaska Fisheries nostic characteristics used for identifi tists from the Center's Tiburon Labora Center is responsible for recruitment cation of Pacific tomcod, Microgadus tory, the University of California at processes studies for fishery resources proximus; walleye pollock, Theragra Davis and Santa Cruz, and the Califor in three LME's: Eastern Bering Sea, chalcogramma; and Pacific cod, Gadus nia Department of Fish and Game have Gulf of Alaska, and off the Washington macrocephalus (Fig. 12). At present been studying likely causes of the de Oregon Coast (Fig. II). Studies are only about half the larvae collected can cline. Preliminary results of the team's carried out under the direction of Arthur be identified to species. A major effort effort indicate that chronic toxic chem Kendall. In each of these areas the level now underway is the preparation of a ical exposures affect every stage of the of background information on the fish laboratory guide for identification of striped bass life cycle, including sig stocks varies, as do the fisheries-related nificant depression in viable egg pro problems. Within the framework of un- 9Kendall, A. w., Jr., 1. R. Dunn, and A. C. duction and concentration of petrogenic Matarese. 1980. Early life history of fishes hydrocarbons at levels sufficient to studied to help explain variations in abundance. "SWFC Monthly Report. 1982. Tiburon Labora Resource Ecology and Fisheries Management cause mortalities of larvae and juve tory. NMFS Southwest Fisheries Center, La Division of Northwest and Alaska Fisheries niles (Whipple et aI., 1981; SWFC Jolla, Calif., August 1982:22. Center, Seattle, Wash. Monthly Rep. July 1980. 12 Marine Fisheries Review early Iife history stages of northeast Pacific fishes. Along with this effort is the initiation of a cooperative program on the identification of rockfish, Sebas ~~::.~ tes spp., larvae. Larvae of this commer cially important genus are among the most abundant in the surveys in spring " .< ... '. ---_.---=------and summer, but cannot be identified to 5.7 mm species. It will be necessary to conduct rearing experiments from identified ------:;;:,;---- \ adults to resolve the Sebastes taxo .. . - ...~, \ nomic problem. ·~:V Eastern Bering Sea Ecosystem 8.4 mm In recent years ichthyoplankton stud Pacific tomcod ies in the Eastern Bering Sea ecosystem have been targeted on the eggs and larvae of walleye pollock. From these studies, information has been obtained on spawning times and places, vertical distribution, and growth patterns (Fig. 13). The National Science Foundation sponsored Processes and Resources of the Bering Sea (PROBES) shelf program 6.2mm has augmented our knowledge of the ecology of developing walleye pollock eggs and larvae with results from plank ton and physical oceanographic studies aimed at describing the processes in volved in the initiation and maintenance of the spring phytoplankton-zooplank ton bloom which provides the food base Walleye pollock for larval and juvenile pollock. Future studies in the Eastern Bering Sea eco system will focus on two problems: I) Acquiring sufficient information on the spatial and temporal distributions of newly-spawned pollock eggs and larvae ~ ,~ and 2) the need to measure interannual ... variabil ity of the key ecosystem compo nents (e.g., light, advection, prey field, • 5Bmm predation field) that influence the growth and survival of pollock. Initial estimates of the size of the spawning biomass ofpollock were made in spring 1977. These surveys, and others conducted by scientists of Japan and the U.S.S.R., indicated that wall eye pollock spawning begins as early as mid-February and continues through Pacific cod June, and that their planktonic eggs in the eastern Bering Sea are found pri marily south and east of the Pribilof Islands and north of Unimak Pass. Figure 12. - Larval stages of three species of northeast Pacific gadids from a Estimates of the total number of eggs in new taxonomic key in preparation by the staff of the NWAFC. the water column were made for five Oct.-Nov.-Dec. /983, 45(/0-11-12) /3 500 c N=I,027 o' 400 " ,": :: :: . ... ':;i:: E 300 :l -:= . :'. 55 N 01 ; I·.·· C .. ~ t.: . -:= 0 200 <5 50' N 160 E 165" E. 170~ E 175" E 170" W 165' W 60 N '1~;- :l'i~~' 100 B I t bJ «. Jf -. -, ,~+ 'A - IT1ttl":~~ i- : 60' N °0~----'1'::-0----:2'::-0----:3'::-0---4":-0----:5:'::0---.J60 ~ r y- fl - .!'1 ''T''-r .1- ."'j-~I-+" .i~:rl.I1 f ~~ II,::: Increments ,,- ~ "t-T211:--1 -~ '1-'---. " 'i32 • 1 ,-- - Figure 13. - Areas where walleye pollock eggs and larvae . -,------' . 6 1 312131 ' ' - I. I; .. I . '1 33' 21 - .- have been caught in plankton tows in the eastern Bering Sea. 1 l' - j 121 .541 'f-!~ i . _. .. 2rfJ3 663.1 ~ Shaded area of A is where pollock eggs have been caught; =}- 55' N -'--~t- ,"1'~ ~ ~~ ~:.- superimposed numbers are areas of maximum abundance in j, 1-'-~4 - .:- five different years. B shows numbers of stations in each i .L I Ir; ~ +::~.;..:;= ~ j~LJ/'! area at which larvae have been caught in spring, and C is r i'" -1!~':-= otolith length in micrometers plotted against the number of i-'- t I ~~ .. r1 1 - ~ i :-,-- daily growth increments observed. Each point represents . t-t : - 50" N one larva. time-periods from 16 April to 10 May Comparisons of estimates of abun have not been analyzed, the earlier sur 1977; the maximum estimate was 7.8 x dance of walleye pollock eggs and lar veys confirmed the presence of walleye 10 12 eggs in the period 19-27 April. vae during similar time-periods in 1976 pollock eggs as early as mid-February In 1977 walleye pollock larvae ap and 1977 indicated that eggs were more and as late as mid-June. Future research peared to be distributed to the west of abundant in 1976 than in 1977, but more plans, directed toward early life history the area where peak spawning occurred. larvae were present in 1977 - possibly of the walleye pollock, include addi This observed distribution, however, indicating a change in spawning time. tional work to determine the time and cannot be explained by circulation of Comparisons of the spatial distribution area of spawning and the annual varia water masses as presently understood. of eggs and larvae in 1976 and 1977 tion of larval abundance in the eastern It may be caused by different survival suggested that the centers of abundance Bering Sea. rates in different areas. Modal lengths were also different in both years. King crab, Paralithodes spp., popu of walleye pollock larvae increased To investigate further these apparent lations have varied in the eastern Bering from 5.5 mm in mid-April to 8.3 mm in temporal and spatial shifts in the distri Sea from about 5 million exploitable mid-May. Estimates were also made of bution of walleye pollock eggs, addi males in 1971 and 1981-82 to about 50 abundance of larvae by time periods. tional sampling was conducted in the million in 1978-79 (and, perhaps, in The maximum estimated numbers of eastern Bering Sea in February and 1964-65). While fishing may well have 12 larvae (7.5 x 10 ) occurred during the March 1978; June and July 1979; and affected these fl uctuations, independent same time-period as the highest egg mid-January to mid-February 1980. estimates of portions of the stock not abundance. Although samples from the latter cruise affected by fishing (females and juve- 14 Marine Fisheries Review niles not harvested) have shown similar Gulf of Alaska Ecosystem tively confined oceanographic setting, fluctuations. Also, other crabs and lends itself ideally to tractable recruit shrimps with similar life histories have In the Gulf of Alaska, the importance ment experiments, with a high like shown major variations in abundance of ShelikofStrait is being evaluated as a Iihood for prediction of year-class independent of fishing. After hatching, principal spawning ground for walleye strength and understanding causes of its larval crabs remain in the water column pollock stocks. Through time-series variability. To gain insight into mech for about 6 weeks where they feed and surveys of pollock eggs and larvae, anisms causing variation in recruitment molt into successive forms that even estimates of pollock spawning biomass and year-class strength, studies will be tually settle to the substrate to begin have been made. Their populations conducted on linkages among circula benthic life. During this period, they have shown fluctuations of within-year tion, spawning, egg and larval growth, are subject to variations in transport, class strength of from two to five times survival, and advection in the Gulf of turbulence, temperature, food, preda the mean number. Research to date indi Alaska ecosystem. tion, etc. As benthic animals, the juve cates that the spawning and subsequent Samples from surveys conducted nile crabs occupy nearshore shallow egg and larval drift follows a remark before 1981 have been used to describe habitats and concentrate in large shoals ably consistent pattern from year to the ichthyoplankton community in the or "pods" that may, at times, be vulner year. For example, a single spawning vicinity of Kodiak Island (Kendall and able to mass mortality caused by preda concentration in Shelikof Strait near Dunn, In prep.). These and later collec tion, or by small-scale spatial-temporal Kodiak Island contained 2.5 to 2.7 mil tions will also be used to map the dis anomalies in environmental conditions. lion metric tons of pollock in March tribution and abundance of walleye pol At about 3-4 years of age, the crabs re 1983. The spawning is restricted in time lock in the Shelikof Strait region (Fig. cruit to the offshore populations where (late March-early April) and localized 14). Surveys in this region have been they become closely associated with geographically (in lower Shelikof Strait conducted jointly with scientists and the adult life history categories. in an area 20x70 km). The eggs, and vessels of the Soviet Union and South Our approach to recruitment studies later the larvae, form a large patch that Korea. Future studies will include: of king crab will be to build on the his drifts with the prevailing current to the I) Investigation of the factors influenc toric data base, and especially the southwest along the Alaska Peninsula, ing survival of planktonic early life results of the large recent efforts by mainly at depths between 20 and 50 m. history stages of fish in relation to re OCSEAP (Outer Continental Shelf En Development time for the eggs is about cruitment of incoming year classes, and vironmental Assessment Program, 2 weeks; the larva start to feed in the 2) evaluation of the use of early life BLM and NOAA) and by PROBES. first week after hatching and remain stages for measuring sizes of parental The program will incorporate the talents planktonic for about 6-8 weeks. The spawning biomass. of the NMFS, National Ocean Survey, dominant transport feature of Shelikof Species of primary interest include: Pacific Marine Environmental Labora Strait is the Kenai Current, which flows Walleye pollock, rockfishes, flatfishes, tory of NOAA, and Northwest and westward along the Alaskan coast from Pleuronectidae; greenlings, Hexagram Alaska Sea Grant institutions, and will the vicinity of the Copper River to midae; and sculpins, Cottidae. The include review of existing data sets, Unimak Pass. The two dominant mech areas of primary interest include Sheli identification of critical factors, design anisms of current variability are fresh kof Strait and the continental shelf off of experiments in the laboratory and water runoff and wind stress. There are Kodiak Island. Specific projects on field, and development of analytic and strong annual and interannual signals in Gulf of Alaska early life history stages prediction models. Recruitment studies the freshwater discharge, and these are will include studies on: I) Distribution will include surveys to establish an correlated with fluctuations in transport. and abundance of eggs and larvae of interannual time-series to follow sur Hydrographic data and satellite in walleye pollock, 2) description of the vival of the successive life stages of frared (IR) observations show warm ichthyoplankton community of the Ko individual year classes. These hypoth waters entering Shelikof Strait during diak area, 3) identification of species of eses will be tested: That larval survival March. The juxtaposition of these warm Sebastes larvae, 4) annual changes in is associated with the biological bloom waters with cold, less saline water from relative abundance of various species in that follows retreat of the ice front and/ Cook Inlet that flows over a rough relation to environment, and 5) labora or that larval survival depends upon the topography and is influenced by strong tory guide for identification of eggs and thickness and stability of the mixed local winds, can lead to intense mixing larvae of fishes of the northeast Pacific layer depth in April in the mid-shelf and upwelling. These intense mixings Ocean. region. An experiment will be con can be sustained by storms, and ad Washington-Oregon ducted in 1986 to follow the ice melt vected by the currents on time scales of Coastal Ecosystem back of the eastern Bering Sea. The weeks. These transport variations affect experiment will examine the role of the the distribution of the pollock eggs and In 1980, a cooperative program was ice and its meltwater in establishing a larvae and probably alter their survival initiated with scientists from the TlNRO "nursery layer" and its impact on crab rates. The intense, localized nature of Laboratory in the U. S.S.R. to determine survival. this early life-history pattern, in a rela- the annual cycle of ichthyoplankton Oct.-Nov.-Dec. /983.45(10-11-/2) /5 occurrence off the Washington-Oregon veys will be the first large-scale ichthy Table 4. - The percent by weight and region of food types in the diet of Pacific hake determined by Polish coast (Fig. 15). Two surveys per year oplankton surveys of the area to sample scientists' in summer 1979. are conducted on Soviet vessels, sam in all seasons. Following completion of Percent by region pling about 125 stations per survey. the definition of peak spawning periods Food type Eureka Columbia vancouver The surveys are conducted at different for the dominant species and/or spe Euphausiids 94.2 94.0 85.6 times of the year, so that after several cies groups, specific unresolved prob Juvenile rockfish 1.0 1.6 Pacific herring years the complete cycle of fish egg and lems concerning recruitment can be Adult 5.9 Juvenile 6.6 larval occurrence can be documented. addressed. Species targeted for recruit Osmerids 04 Standard MARMAP bongo samplers ment studies are: Sablefish, Anoplo Pacific hake 0.5 Sablefish 2.0 0.1 are deployed on each survey. These sur- poma fimbria; rockfish, Sebastes spp.; Flatfish 04 Squid 1.6 Shrimp 1.6 Other fish 3.2 1.7 Other in- vertebrates 04 0.1 'Jackowski, E. 1980. Biological characteristics of Pacific Whiting from Polish surveys of the west coast of the U.S.A. and Canada in 1979. Unpubl. manuscr. presented at the U.S.- Poland bilateral meetings, 1980. and flatfishes (Limanda sp., Platichthys sp., Eopsetta sp.). Results from these surveys will be compared with those of CalCOFI to the south, thereby linking the ichthyoplankton data base from off Baja California to Cape Flattery. A description of survey operations and preliminary results from the first two surveys are given by Kendall and Clarklo, II. Using the CalCOFI data base, it has EGGS Fall, Sp""g been possible to relate the seasonal pat I terns of distribution of larvae, juveniles, lS3°W lSZ>W 150" W and adults of the Pacific hake, Mer luccius productus, to spawning, feed ing, and schooling areas in the Califor nia Current and Washington-Oregon coastal ecosystems (Bailey et aI., 1982) (Fig. 16). In cooperation with Polish scientists, preliminary information has been obtained on Pacific hake predator prey relationships (Table 4). Pacific Salmon The Pacific salmon group is usually second only to shrimp in ex-vessel value to U. S. fishermen ($438 million in 1981). This species group provided ]OKendall, A. w., Jr., and 1. Clark. 1982. Ichthyoplankton off Washington, Oregon, and Northern California, April-May 1980. NMFS Northwest and Alaska Fisheries Center, Seattle, Wash. Proc. Rep. 82-11, 44 p. lS3°W 152"W lS00W 14g- W II Kendall, A. w., Jr., and 1. Clark. 1982. Ichthyoplankton off Washington, Oregon, and Figure 14. - Areas where walleye pollock eggs and larvae were caught in Northern California, August 1980. NMFS North neuston and plankton tows off Kodiak Island, 1977-78. Eggs were caught in west and Alaska Fisheries Center, Seattle, Wash. fall and spring; larvae were caught in spring and summer. Proc. Rep. 82-12,43 p. 16 Marine Fisheries Review 43 percent of U.S. exports of edible fishery products ($462 million in 1981). Salmon are anadromous and return to 5 4 3 2 coastal rivers and streams to spawn, but 48°N are subject to interceptions by foreign 6 nations during their far-ranging migra tions in the ocean. Recruitment research will focus on chinook, Oncorhynchus tshawytscha, and coho, O. kisutch, salmon in the 24...'-__,+=-3__-2+2------>,. 21 Columbia River estuary, in ocean plume and coastal waters off Washington and Oregon, and during their ocean migra 33 32 31 tion offsoutheastern Alaska. These spe 46°N cies and stocks were selected for study because they contain large proportions of tagged fish. A recruitment problem 44•.f- 4+"3__-4:.+=-----4-<1~ exists in that increased releases of coho salmon from hatcheries since the mid 1970's have accompanied declining returns. 54 53 52 51 Recruitment studies are aimed at reducing uncertainty in predictions of salmon returns through better under 61 64 63 6 standing of the factors that affect early 44°N ocean survival of salmon. This will be OR acquired experimentally through: 74 I) Studies on salmon physiology and 7 71 ecology during the period of transition from fresh to salt water; 2) studies on environmental conditions limiting early ocean survival - particularly food 84 availability and predation; 3) modelling studies to optimize the regimen for re 93 42°N lease of salmon from hatcheries; and 4) development of predictive models to forecast year-class strength. The envi ronmental factors to be examined in 103 clude conditions abetting food produc tion, such as upwell ing (caused by 114 113 meteorological events and southward flowing currents) or the formation of CA temperature fronts (caused by eddy dynamics or current shears). 400 N 125 124 123 Ichthyoplankton and Pollution Stress Under the direction of George Sny der, studies are being conducted at the NWAFC Auke Bay Laboratory on the effects of petrogenic hydrocarbons on 130 0 W 128°W 126°W 124°W the viability of early life stages of coho Figure 15. - Station locations and cruise track for the ichthyoplankton surveys salmon. Short-term exposures of coho within the coastal Washington-Oregon LME - April-May 1980. salmon eggs, alevins, and fry to aro matic hydrocarbons common to crude oils demonstrated that sensitivity to the aromatics increased from egg to fry, Oct.-Nov.-Dec. /983, 45(/0-11-12) /7 with the greatest impact between egg PACIFIC WHITING and the early alevin stage (Korn and MIGRATION BEHAVIOR Sl'30'N CANADA Rice, 1981). ( Northeast Fisheries Center Stressed Northeast Shelf Ecosystem By July/August WASHINGTON moving to outer 47"30'N The continental shelf ecosystem off continental shelf the U. S, northeast coast supports a fisheries industry that contributes $1 billion annually to the economies of the Heceta Bank coastal states from Maine to North Car OREGON olina, However, the fish stocks of the 43'30'N region have been heavily exploited. A From 1968 through 1975 the total catch able finfish biomass declined by approx imately 50 percent (Fig. 17). This de cline was correlated with high fishing 39'30'N mortality (Clark and Brown, 1977). Since 1975, a small recovery trend has CALIFORNIA WINTER been observed among the demersal spe Migrating offshore over slope in California current (south) cies (i.e., Atlantic cod, Gadus morhua; pollock, Pollachius virens; flounders, 3S'30'N Paralichthys sp., Hippoglossoides sp., Los Angeles " Limanda sp., and Pseudopleuronectes Larvae up to .=::8 ·o'='" • Los Angeles Bight sp.). Atlantic herring, Clupea haren 300mlieS~ ." ___ of~h~,=--- ~-_._'-----'t:..:...... -c.="-,-,---I gus; and Atlantic mackerel, Scomber ~ scombrus, stocks remain depressed. 3"30'N The dramatic decline raised several important questions. Would the reduc Spawning ~ tion of predation pressure by the loss of Feeding pelagic zooplanktivorous fish result in Main Schooling Area 27'30'N elevated levels of zooplankton? Would ~ small, fast-growing, opportunistic zoo .' planktivorous species replace the her 138'W '28'W ring and mackerel populations? Would the depressed stock return to former Figure 16, - A = Migratory patterns of Pacific hake. B = seasonal patterns of distribu 160 tion of larvae, juveniles, and '"c 0 adults of the Pacific hake .~ with relation to spawning, t! "D feeding, and schooling areas (J) '" '6. 7 in the California Current and :::> 9 u .~ 75% decrease in Washington-Oregon Coast u 6 0 B a; biomass 1968-75 ecosystems. Adapted from dJ E S c Bailey et al. (1982). '"2: .Q 4 .!!! '0 '§'3 (ij ~ .0 E '"E :::> o 1 c in (J) 01 1968 '69 '70 '71 '72 '73 '74 '75 ~ (J) Year .£t Figure 17, - Decline in the fishable DEC JAN fEB MARCH APRIL MY biomass of Georges Bank, Gulf of Month Maine, and southern New England \968-75. Adapted from Clark and Brown (1977). 18 Marine Fisheries Review abundance levels with the control of fishing mortality imposed by the estab 20 20 lishment of the FMZ and the significant '"~ reduction of large-scale factory-trawler -... '"VI operations? In an effort to address Z 16 16 0 SAND lANCE these questions, ichthyoplankton sam I- V pling was expanded in 1977 to cover the ~ I- 12 12 northeast shelf ecosystem and provide UJ ATLANTIC " fisheries-independent information on ~ HERRING the total ichthyoplankton community of I 8 the system. I UJ ,- , V , , , Sampling Strategy z , , ~ 4 /\ , , Following the CalCOFI model, a sys 0 ,: Z ATlANTIC :- .... ::::J , tematic network of sampling for ichthy co MACKEREL ~ oplankton was established on a grid net 0 0 work with stations spaced 25-30 km 1968 '70 '72 '74 '76 '78 YEAR apart over the entire 260,000 km2 of the northeast shelf (Fig. 18). At each sta tion, collections were made with paired Figure 19. - Decline of Atlantic bongo nets fitted with 0.333 mm and herring and mackerel and apparent 0.505 mm mesh nets. From two to replacement by the small, fast twelve surveys were made each year growing sand lance in the northeast from 1974 through 1981. All ichthyo continental shelf ecosystem. plankton and zooplankton collections were sent to the Polish Sorting Center in Szczecin, Poland, for processing. In addition, from 1977 through 1982, water column sampling was conducted for subareas - Gulf of Maine, Georges temperature, salinity, nutrients, oxy Bank, Southern New England, and the gen, chlorophyll, and primary produc Figure 18. - Station locations for Mid-Atlantic Bight (Sherman et aI., tion (l4C) (Evans and O'Reilly, In sampling ichthyoplankton on the In press). press; O'Reilly and Thomas, In press). northeast continental shelf eco Wallace Smith and his team at the system. Sandy Hook Laboratory have observed Sand Lance Explosion distribution patterns of larvae that are From our analyses of ichthyoplank related to circulation, bathymetry, and ton species composition and abundance plankton production. The "Shelf Gyre" data, we observed a population explo Atlantic herring and Atlantic mackerel species include redfish, Sebastes sp., sion of sand lance, Ammodytes spp., abundance. in the Gulf of Maine, and Atlantic cod from 1974 through 1981, coi ncident and haddock on Georges Bank. Further Ecosystem Linkages with a decline in Atlantic herring and south the "Shelf Plain" species include Atlantic mackerel (Fig. 19). A similar The 1977-81 MARMAP surveys pro bluefish, Pomatomus saltatrix, in the coincident shift in abundance occurred vided new information on the produc Mid-Atlantic Bight and Southern New in the North Sea where the declining tivity of the shelf ecosystem. With the England, and searobin, Prionotus spp., Atlantic herring and Atlantic mackerel exception of the shelf-slope front, the in the same regions. "Shelf Estuarine" stocks appeared to be replaced by in shelf ecosystem is highly productive. species include the northern anchovy, creases in the populations of small, fast Mean annual values of carbon produc Engraulidae; and croaker, Micropo growing sprat, Clupea sprattus; sand tion ranged from 260 g C/m2 in the mid gonias undulatus, in the Mid-Atlantic lance, and Norway pout, Trisopterus shelf off Cape Hatteras to 450 g C/m2 Bight area. Two "Shelf Migrants" esmarkii (Sherman et aI., 1981). NEFC on Georges Bank (O'Reilly and Busch, were identified: I) The Atlantic mack studies under the direction of Wallace In press) (Fig. 20). The shelf ecosystem erel migrates from the Mid-Atlantic Smith and his team at the Sandy Hook was divided into subareas based on Bight northward in spring in synchrony Laboratory focus on measuring the areal differences in bathymetry, hydrog with the northern spring increase in impact of the perturbation of sand raphy, circulation, and population struc zooplankton, and 2) the Atlantic men lance abundance on the production of ture. Recurrent annual cycles of zoo haden, Brevoortia tyrannus, an autumn other fish stocks on the shelf, particu plankton abundance were observed spawner, was observed to migrate larly with respect to any recovery in from 1977 through 1981 in each of four southward from Southern New England Oct.-Nov.-Dec. 1983. 45(10-Jl-12) 19 76 74 72 66 ,-yj'. .•:1', NOVA SCOTlA 44 ESTIMATES OF ANNUAL PHYTOPLANKTON PRIMARY PRODUCTION (Particulate + Dissolved ) organic carbon) ,- BY REGION 290 gC m-2 y-l NH - -y--:..--;" -'\9 ,~ MA~, 42· 38 ~ Data collected in these areas is not included in the Regional Estimates of Annua 1 production ---- 36 -- 100 ISO 200 0 so KILOMETERS 74 72 70 68· 66" 2 Figure 20. - Average annual primary production (g C/m ) per year based on the MARMAP HC method (O'Reilly and Busch, In press). to the Mid-Atlantic Bight in autumn season off Delaware and Chesapeake chuss); and sand lance, Ammodytes from an area of moderate zooplankton Bays. Silver hake, Merluccius bilin sp., are found in each of the four abundance to the highest concentrations earis; other hakes, Urophycis spp. subareas and are classified as "Ubiqui of zooplankton on the shelf in this (predominantly red hake, Urophycis tous Shelf" species. 20 Marine Fisheries Review M S 0 ND E MAM A 0 N,D ME MAM J ,A 0 0 0 GULF OF MAINE 9 MID -ATLANTIC BIGHT ::::: "- ~ 150 150 Ji '"0 0 u.J '" u.J 10,000 -;;- ~ SAND LANCE -10,000 X. ~ SEAROBINS 0 ::> 0 ::> \..... BLUEFISH 100 Z 100 , Z 0 '1,000 0 1,000 "' u.J > u.J > Z " ~ Z 100 ~ 100 0 a< 0 a< 50 >- 50 ~- >- M ME F ,M A M A,S 0 ND E M, A M, J AS 0 ND 0 0 Q GEORGES BANK Q MID -ATLANTIC BIGHT "- "- u ~150 ~ 150- '"S2 u.J / \ '"Q u.J \ X 10,000 x. ~ / 10,000 ~ ::> / \ 0 ::> 0 / \ 100 Z 100 ~ / 0 I \ -1,000 0 "' 1,000 - > COD I \ u.J > u.J \ Z • .1. •• , ~ Z ~ " I 100 100 a< 0 I , a< 0 50- >- SO- I Figure 21. - Synchrony of peak larval production plotted with median zooplankton abundance in four subareas of the northeast shelf ecosystem - Gulf of Maine, Georges Bank, Southern New England, and the Mid-Atlantic Bight. The single light line represents the 5-year (1977-81) mean values of zooplankton volumes (eel 100 m3 ) bounded by two standard errors (dashed lines). Mean ichthyopiankton species abundance (1977-80) (N x 109 ) is shown for: Gulf of Maine redfish (bold Iine); Georges Bank cod (dotted line), haddock (bold line); Mid-Atlantic Bight sand lance (dOlled line, upper right), bluefish (bold line), and searobi ns (double line); anchovies (bold line, lower right), and croaker (dotted line, lower right). Spawning strategies are adaptations temporal and spatial range within the sidered a temporary replacement for the of the spawning biomass to topographic shelf ecosystem, thereby enabling them overfished mackerel and herring popula and circulation features of the northeast to respond rapidly to favorable environ tions (Sherman et aI., 1981). shelfand the annual plankton production mental conditions (Sherman et aI. 12 ). cycle in each of the four subareas Studies off the northeast coast have Spawning Stock Estimates Gulf of Maine, Georges Bank, Southern demonstrated that sand lance is an Among the species for which spawn New England, and the Mid-Atlantic opportunistic species that can be con- ing biomass estimates were made from Bight. Under average conditions, the the MARMAP ichthyoplankton collec gyre, shelf-plain, and shelf-migratory tions are silver hake, mackerel, sand spawners reach peak abundance in syn 12Sherman, K., W. Smith, W. Morse, M. Ber lance, bluefish, and yellowtail flounder, chrony with the seasonal pulses in their man, 1. Green, and L. Ejsymont. 1983. Spawn Limanda ferruginea. Other species zooplankton prey (Fig. 21). The ubiqui ing strategies of fishes in relation to circulation targeted for biomass estimates are patterns, phytoplankton production, and pulses tous spawners appear to maintain rela in zooplankton abundance off the northeastern haddock, Atlantic cod, redfish, and tively high densities of eggs over a wide United States. ICES C.M.1983/L:28. searobin. OCI.-Nov.-Dec. /983, 45(/0-//-/2) 2/ Density-Dependent Recruitment Studies To improve forecasts of abundance it is necessary to obtain a better under standing of the relationship between the abundance of early developmental stages and new recruits to the fisheries. Within the sampling network of the MARMAP multispecies ichthyoplank ton surveys, studies are conducted of the factors controlling growth and sur vival of the target species Atlantic cod and haddock. Age and growth and pred ator-prey studies of larvae are directed by Gregory Lough and his team at the NEFC Woods Hole Laboratory. Under the direction of Geoffrey Laurence of the NEFC Narragansett Laboratory, studies are now underway to confirm laboratory determinations of optimal prey densities with at-sea experiments on Georges Bank on the availability A and abundance of suitable densities of zooplankton prey of cod and haddock (Fig. 22). Plans are also being prepared NO cc:>::::-,::;.~ , v} to conduct predation experiments on _--"-"'0'-_-';"0:.....'_---"oo"-'__'.:c-"'"_-----:;'?!l eggs and larvae in large enclosures. Figure 22. -A Schematic representation NO G.e.n:D U'l.?.c.~/·""...o ... J = ---~·o' Preliminary observations made by of the well-mixed and stratified waters on -----i'7r-'----.:;-7'-' Geoffrey Laurence and his team indi Georges Bank and mean circulation flow cate that larval growth and survival are (arrows) during spring and summer. B = very high in large, predator-free, ftow Vertical distribution of gadid (haddock and cod) larvae and dominant copepods (Co/ through net mesh enclosures placed in a anus jinmarchiclls, Pselldoca/anus sp.) highly productive estuarine environ in relation to thermocline on the south, ment (Laurence et aI., 1979). east part of Georges Bank before storm. (MOC ESS-I m, 0.333-mm mesh, 21 May 1981, 2303-2358 D.S.T., 400 55'N, Density-Independent 67°16'W. Bottom depth: 78-80 m.) Note Recruitment Studies different log-scales used for copepods and gadid larvae. Warm-core rings have been observed entraining large volumes of shelf water across the shelf slope front into a nutri ent-poor environment. It has been hy BC------'------" pothesized that eggs and larvae of shelf species advected off the highly produc tive shelf in an entrainment feature would not survive in the prey-poor environment. Collections made in an entrainment experiment conducted by Replicate experiments are planned to stock exposed to heavy metals and Geoffrey Laurence and his team on the confirm these preliminary results (Lau other toxins. Initial results indicate survival of ichthyoplankton in an en rence and Burns, 1982). significant impact of the exposure to trainment feature revealed that no shelf larvae hatched from the Hudson River Pollution Studies species were in the entrainment. The parent stock. only ichthyoplankton observed in the In cooperation with the U.S. Fish Other arragansett Laboratory pol collections were larvae of bathypelagic and WildUe Service, studies were made lution-related studies underway in shelf-slope species, suggesting that under the direction of Lawrence Buckley cooperation with the Environmental warm-core rings are not responsible for (Narragansett Laboratory) of the viabil Protection Agency are focused on the advective mortality of shelf larvae. ity of striped bass larvae from parent impacts of exposures of larvae to urban 22 Marine Fisheries Review sludge compounds identical to those The most recent example of the Literature Cited movement toward total ecosystem man now being disposed of on the continen Ahlstrom, E. H. 1954. Distribution and abun tal shelf by the State of New York. agement is found in the language of the dance of egg and larval populations of the One of the encouraging advances by Commission for the Conservation of Pacific sardine. Fish. Bull., U. S. 56:82-140. 1959. Vertical distribution of pe Lawrence Buckley and his group is the Antarctic Marine Living Resources. lagic fish eggs and larvae off Cal ifornia and application of an RNA/DNA analysis Article II of the Convention calls for Baja California. Fish. Bull., U.S. 60:107 for determining the growth potential of holistic management wherein: " ...The 146. 1965. Kinds and abundance of larvae collected routinely during the regime should provide for the effective fishes in the California Current region based MARMAP surveys. High ratios indicate conservation of the living marine re on egg and larval surveys. State of California a "healthy" physiological condition sources of the Antarctic ecosystem as a Marine Research Committee. Calif. Coop. Oceanic Fish. Invest. Rep. 10:31-52. for the larvae, whereas low values indi whole ...." Considerable progress has ____. 1966. Distribution and abundance cate that the growth potent ial of the been made by the international scientific of sardine and anchovy larvae in the Califor nia Current region off Cal ifornia and Baja larvae is impaired (Buckley, 1980, community in the coordination and inte California, 1951-65: A summary. U.S. Fish 1982). The RNA/DNA analysis will be gration of studies in the Antarctic lead Wildl. Servo Spec. Sci. Rep.-Fish. 534, 71 p. conducted on batch samples of larvae ing to population assessments of the ____, and H. G. Moser. 1981. System atics and development of early life history collected on MARMAP surveys in an principal ecosystem populations, in stages of marine fishes: Present status of the effort to classify, temporally and spa cluding krill, Euphausia spp., and its discipline and suggestions for the future. tially, larvae in "poor condition." predators and prey under the aegis of Rapp. P.-v. Reun., Cons. int. Explor. Mer 178:541-546. the Biological Investigations of Marine Management of Alvarino, A. 1980. The relation between the Antarctic Systems and Stocks (BIO distribution of zooplankton predators and an Large Marine Ecosystems chovy larvae. Calif. Coop. Oceanic Fish. In MASS) program (Beddington and May, vest. Rep. 21: 150-160. A growing awareness by marine 1982). The approach in dealing with ____. 1981. The relation between the dis resource managers of the interrelation the world's largest marine ecosystem tribution of zooplankton predators and an chovy larvae. Rapp. P.-v. Reun. Cons. int. ships among species and their environ has been a combination of international Explor. Mer 178: 197-199. ments has led to legislated mandates for krill biomass assessment surveys, an Andersen, K. P., and E. Ursin. 1977. A multi the conservation and management of analysis of catch data, and surveys species extension to the Beverton and Holt Theory of Fishing, with accounts of phos total ecosystems. This concern is ex of marine birds, mammals, and fish phorus circulation and primary production. pressed in the language used in the Mag (Laws, 1980; Everson, 1981; Pomme Medd. fra Dan. fisk. havunders. NS 7:319 435. nuson Fishery Conservation and Man ranz et aI., 1981; Hureau, 1982; BIO ____ , and . 1978. A multispe- agement Act of 1976 which requires MASS Working Party on Fish Biology, cies analysis of the effects of variations of that: 1982; BIOMASS Working Party on effort upon stock composition of eleven North Sea fish species. Rapp. P.-v. Reun. " ... Conservation and management Bird Ecology, 1982a,b,c). Initial results Cons. int. Explor. Mer 172:286-291. measures shall be based on the best sci of this effort have been most effective Bailey, K. M., R. C. Francis, and P. R. Stevens. entific advice available .... To the ex in refining estimates of krill biomass in 1982. The life history and fishery of Pacific whiting, Merluccius producluS. Calif. Coop. tent practicable, an individual stock of the region (BIOMASS Report Series, Oceanic Fish. Invest. Rep. 23:81-98. fish shall be managed as a unit through 1980, 1982). Bakun, A. 1973. Coastal upwelling indices, For effective management of any west coast of North America, 1946-1971. out its range, and interrelated stocks of U.S. Dep. Commer. , NOAA Tech. Rep. fish shall be managed as a unit or in LME, it is necessary to survey the pop NMFS SSRF 671, 103 p. close coordination." 13 ulations and their environments. Un ____, and C. Nelson. 1977. Climatology of upwelling related processes off Baja Cali A good deal of the precedent can be fortunately, surveys can become dull, fornia. Calif. Coop. Oceanic Fish. Invest. attributed to the two-tiered management routine affairs, but they are critical Rep. 19:107-127. practice enacted by the International components of a total ecosystem re ____, and R. H. Parrish. 1980. Environ mental inputs to fishery population models Commission for North Atlantic Fish sources assessment program. Techni for eastern boundary current regions. In G. eries (ICNAF). In 1972 ICNAF estab cal advances in hydroacoustics, satel D. Sharp (editor), Workshop on the effects of lite remote sensing of ocean features environmental variation on the survival of lished total biomass quotas of finfish larval pelagic fishes, p. 67-104. IOC Work for the northwest Atlantic and assigned (Lasker et aI., 1981; Pelaez and Guan, shop Rep. 28, UNESCO, Paris. total allowable catch levels to all target 1982), and electronic particle sampling ____, and . 1982. Turbulence, transport, and pelagic fish in the California species of the fisheries to be followed and data processing at sea (Lough and and Peru Current Systems. Calif. Coop. on an annual basis (ICNAF, 1973; Gross Potter, In press) and in the laboratory Oceanic Fish. Invest. Rep. 23:99-112. lein et aI., 1979). (Jeffries et aI., 1980), when applied Beddington, J. R., and R. M. May. 1982. The harvesting of interacting species in a natural to the MARMAP type multispecies ecosystem. Sci. Am. 247(5):62-69. ichthyoplankton time-series surveys ____ , , C. W. Clark, S. J. and target-species recruitment studies, Holt, and R. M. Laws. 1979. Management of multi species fisheries. Science 204 (4403): will contribute to increased sampling 267-277. efficiencies and reduced costs of the BIOMASS Report Series. 1980. Krill abun 13 Fishery Conservation and Management Act of dance estimation. Report of the Third Meet 1976, USA (FCMA). Public Law 94-265, 94th assessment surveys of large marine ing. Hamburg, Federal Republic ofGermany, Congress, H.R. 200, 13 April 1976. ecosystems. 30-31 May 1980. SCAR/SCOR/IABO/ Oct.-Nov.-Dec. 1983,45(10-11-12) 23 ACMRR Group Spec. South. Ocean Ecosys (editors), Environmental biomonitoring, as prep. tems Their Living Resour. BIOMASS Rep. sessment, prediction, and management Korn, S., and S. D. Rice. 1981. Accumulation Ser. II. certain case studies and related quantitative and depuration of aromatic petroleum com 1982. Meeting of the Group of issues, p. 289-357 Stat. Ecol Ser. I I. Int. ponents (toluene, naphthalene, and two Specialists on Southern Ocean Ecosystems Co-op. Publ. House, Fairland, Md. methylnaphthalene) by early life stages of and Their Living Resources. Report of the ___---:' R. W. Langton, and M. P. Sissen coho salmon (Oncorhynchus kisulch) and pink 1982 meeting of the Group of Specialists. wine. 1980. Recent fluctuations in pelagic salmon (Oncorhynchus gorbuscha). Rapp. Nikko, Japan, 3 I May-4 June 1982. SCARf fish stocks in the northwest Atlantic, Georges P.-v. Reun. Cons. int. Explor. Mer 178:87-92. SCOR/IABO/ACMRR Group Spec. South. Bank region, in relation to species interac Kramer, D., and P. E. Smith. 1971. Seasonal and Ocean Ecosystems Their Living Resour. tions. Rapp. P.-v. Reun. Cons. int. Explor. geographic characteristics of fishery re BIOMASS Rep. Ser. 24. Mer 177:374-404. sources: California Current Region - Y. BIOMASS Working Party on Bird Ecology. Hewitt, R. 1981. The value of pattern in the Northern anchovy. Commer. Fish. Rev. 1982a. Recording observations of birds at distribution of young fish. Rapp. P.- v. Reun. 33(3):33-38. sea. SCAR/SCOR/IABO/ACMRR Group Cons. int. Explor. Mer 178:229-236. Laevastu, T., and F. Favorite. 1981. Holistic Spec. Living Resour. South. Ocean. BIO Hewitt, R. P., and R. D. Methot, Jr. 1982. Dis simulation of marine ecosystem. In A. R. MASS Handb. 18. tribution and mortality of northern anchovy Longhurst (editor), Analysis of marine eco ____. 1982b. Monitoring studies of sea larvae in 1978 and 1979. Calif. Coop. systems, p. 702-727. Acad. Press, Inc., birds. SCAR/SCOR/IABO/ACMRR Group Oceanic Fish. Invest. Rep. 23:226-245. Lond. Spec. Living Resour. South. Ocean. BIO Houde, E. D., and T. Potthoff. 1976. Egg and ____, and H. A. Larkins. 1981. Marine MASS Handb. 19. larval development of the sea bream Archo fisheries ecosystem: Its quantitative evalua 1982c. Penguin census methods. sargus rhomboidalis (Linnaeus): Pisces, Spar tion and management. Fish. News Books SCAR/SCOR/IABO/ACMRR Group Spec. idae. Bull. Mar. Sci. 26(4):506-529. Ltd., Farnham, Surrey, EngI. Living Resour. South. Ocean. BIOMASS ____ , and W. J. Richards. 1969. Rearing Lasker, R. 1975. Field criteria for survival of Handb. 20. larval tunas in the laboratory. Commer. Fish. anchovy larvae: The relation between inshore BIOMASS Working Party of Fish Biology. Rev. 31(12):32-34. chlorophyll maximum layers and successful 1982. Recommended methods for standardi ____ , , and Y. P. Saksena. first feeding. Fish. Bull., U.S. 73:453-462. zation of measurements of fish. SCARf 1974. Description of eggs and larvae of the ____. 1978. The relation between ocean SCOR/IABO/ ACMRR Group Spec. Living scaled sardine, Harengula jaguana. Fish. ographic conditions and larval anchovy food Resour. South. Ocean. BIOMASS Handb. 13. Bull., U.S. 72:1106-1122. in the California Current: Identification of Brewer, G. D., and P E. Smith. 1982. Northern Hunter, J. R. 1972. Swimming and feeding be factors contributing to recruitment failure. anchovy and Pacific sardine spawning off havior of larval anchovy, Engraulis mordax. Rapp. P-v. Reun. Cons. int. Explor. Mer Southern California during 1978-1980: Pre Fish. Bull., U.S. 70:821-848. 173:212-230. liminary observations on the importance of 1977. Behavior and survival of ____. 1981a. Factors contributing to vari the nearshore coastal region. Calif. Coop. northern anchovy Engraulis lIIordax larvae. able recruitment of the northern anchovy Oceanic Fish. Invest. Rep. 23:160-171. Calif. Coop. Oceanic Fish. Invest. Rep. (Engraulis mordax) in the California Current: Brothers, E. B., C. P. Mathews, and R. Lasker. 19:138-146. Contrasting years, 1975 through 1978. Rapp. 1976. Daily growth increments in otoliths 1981. The feed ing ecology of ma P.-v. Reun. Cons. int. ExpIor. Mer 178:375 from larval and adult fishes. Fish. Bull., U.S. rine fish larvae. In 1. E. Bardach, J. 1. Mag 388. 74:1-8. nuson, R. C. May, and J. M. Reinhart ____ (editor). 1981b. Marine fish larvae Buckley, L. 1. 1980. Changes in ribonucleic (editors), Fish behavior and its use in the - morphology, ecology, and relation to fish acid, deoxyribonucleic acid and protein con capture and culture of fishes, p. 287-330. IC eries. Wash. Sea Grant Program, Univ. tent during ontogenesis in winter flounder, LARM Conf. Proc. 5, Int. Cent. Living Wash. Press, Seattle. Pseudopleuronecles americanus, and effect of Aquatic Resour. Manage., Manila. ____, H. M. Feder, G. H. Theilacker, starvation. Fish. Bull., U.S. 77:1703-1708. ____, and K. M. Coyne. 1982. The onset and R. C. May. 1970. Feeding growth and 1982. Effects of temperature on of schooling in northern anchovy larvae, En survival of Engraulis mordax larvae reared in growth and biochemical composition of lar graulis mordax. Calif. Coop. Oceanic Fi h. the laboratory. Mar. BioI. 5:345-353. val winter flounder Pseudopleuronecles Invest. Rep. 23:246-251. ____, J. Pelaez, and R. M. Laurs. 1981. americanus. Mar. Eco1. - Prog. Ser. 8:181 ____ , and C. A. Kimbrell. 1980a. Early The use of satellite infrared imagery for 186. life history of Pacific mackerel, Scomber describing ocean processes in relation to Butler, J. L., H. G. Moser, G. S. Hageman, and japonicus. Fish. Bull., U.S. 78:89-101. spawning of the northern anchovy (Engraulis L. E. Nordgren. 1982. Developmental stages ____, and . 1980b. Egg canni- mordax). Remote Sensing Environ. 11:439 of three California sea basses (Paralabrax, balism in the northern anchovy, Engraulis 453. Pisces, Serranidae). Calif. Coop. Oceanic mordax. Fish. Bull.. U.S. 78:811-816. Laurence, G. C., and B. R. Burns. 1982. Fish. Invest. Rep. 23:252-268. ____, and B. J. Macewicz. 1980. Sexual Ichthyoplankton in shelf water entrained by Clark, S. H., and B. E. Brown. 1977. Changes maturity, batch fecundity, spawning fre warm-core rings. Am. Geophys. Union/Am. of biomass of finfishes and squids from the quency, and temporal pattern of spawning for Soc. Limnol. Oceanogr. San Franc., Calif., Gulf of Maine to Cape Hatteras, 1963-74, as the northe~n anchovy. Engraulis lIIordax, dur 5-7 Dec., Abstr. determined from research vessel survey data. ing the 1979 spawning season. Calif. Coop. ____, T. Halavik, B. Burns, and A. Fish. Bull., U.S. 75:1-21. Oceanic Fish. Invest. Rep. 21:139-149. Smigielski. 1979. An environmental chamber Daan, N. 1980. A review of replacement of Hureau, J-c. 1982. Methods for studying early for monitoring "in situ" growth and survival depleted stocks by other species and the life history stages of Antarctic fishes SCARf of larval fishes. Trans. Am. Fish. Soc. mechanisms underlying such replacement. SCOR/IABO/ACMRR Group Spec. Living 108:197-203. Rapp. P.-v. Reun. Cons. int. Explor. Mer Resour. South. Ocean. BIOMASS Handb. 17. Laws, R. M. 1980. Estimation of population 177:405-421. Husby, D. M., and C. S. Nelson. 1982. Turbu sizes of seals. SCAR/SCOR/IABO/ACMRR Evans, C., and J. P. O'Reilly. In press. A man lence and vertical stability in the California Group Spec. Living Resour. South. Ocean. ual for the measurement of Chlorophyll a, net Current. Calif. Coop. Oceanic Fish. Invest. BIOMASS Handb. 2. phytoplankton and nannoplankton. SCARf Rep. 23:113-129. Lough, R. G., and D. C. Potter. In press. Rapid SCOR/IABO/ACMRR Group Spec. Living IC AF. 1973. Annual Proceedings. lnt. Comm. shipboard identification and enumeration of Resour. South. Ocean. BIOMASS Handb. 9. Northwest Atl. Fish.. Dartmouth, .S., Can. zooplankton samples. J. Plankton Res. 5(5). Everson, I. 1981. Antarctic fish age determina Jeffries, H. P., K. Sherman, R. Maurer, and C. Lynn, R. J., K. A. Bliss, and L. E. Eber. 1982. tion methods. SCAR/SCOR/IABO/ACMRR Katsinis. 1980. Computer-processing of zoo Vertical and horizontal distributions of sea Group Spec. Living Resour. South. Ocean. plankton samples. In Y. S. Kennedy (editor), sonal mean temperature, salinity, sigma-T, BIOMASS Handb. 8. Estuarine perspectives, p. 303-316. Acad. stabil ity, dynamic height, oxygen, and oxy Grosslein, M. D., B. E. Brown, and R. C. Press, Inc., NY gen saturation in the California Current, Hennemuth. 1979. Research, assessment, and Kendall, A. w., Jr., and J. R. Dunn. In prep. 1950-1978. In A. Fleminger (editor), Calif. management of a marine ecosystem in the Jchthyoplankton of the continental shelf near Coop. Oceanic Fish. Invest., Atlas 30, 513 p. northwest Atlantic - a case study. In J. Kodiak Island, Alaska. Northwest and Alaska Mar. Life Res. Program, Scripps Inst. Cairns, Jr., G. P Pati!, and W. E. Waters Fisheries Center, Seattle, Wash. Manuscr. in Oceanogr., La Jolla, Calif. 24 Marine Fisheries Review Mann, K. H. 1982. Ecology ofcoastal waters: A Spec. Living Resour. South. Ocean. B[O Mar. Sci. 25(4):523-536. systems approach. Stud. Eco!. 8,322 p. Univ. MASS Handb. 12. Scura, E. D., and C. W. Jerde. 1977. Various Cal if. Press, R,~rkeley. Posgay, 1. A., and R. R. Marak. 1981. The species of phytoplankton as food for larval Methot, R. D., Jr. 1981. Spatial covariation of MARMAP bongo zooplankton samplers. J. northern anchovy, EngraLilis mordax, and daily growth rates of larval northern anchovy, Northwest Atl. Fish. Sci. 1:91-99. relative nutritional value of the dinoflagel EngraLilis mordax, and northern lampfish, Potthoff, T 1974. Osteological development lates Gymnodinium splendens and Gonyau StenobranchiLis leLicopsarLis. Rapp. P. - v. and variation in young tunas, genus ThLlnnLls lax polyedra. Fish. Bull., U.S. 75:579-583. Reun. Cons. int. Explor. Mer 178:424-431. (Pisces, Scombridae), from the Atlantic Sheldon, R. w., W. H. Sutcliffe, Jr., and M. A. ____, and D. Kramer. 1979. Growth of Ocean. Fish. Bull., U. S. 72:563-588. Paranjape. 1977. Structure of pelagic food northern anchovy, EngraLilis mordax, larvae 1975. Development and structure chain and relationship between plankton and in the sea. Fish. Bull., U. S. 77:413-423. of the caudal complex, the vertebral column, fish production. J. Fish. Res. Board Can. O'Connell, C. P. 1976. Histological criteria for and the pterygiophores in the blackfi n tuna 34:2344-2353. diagnosing the starving condition in early (Thunnus atlanticLls), (Pisces, Scombridae). Sherman, K., and L. Ejsymont. 1976. The post yolk-sac larvae of the northern an Bull. Mar. Sci. 25(2):205-231. Pol ish Plankton Sorting and Identification chovy, EngraLilis mordax Girard. J. Exp. ____, and S. Kelley. 1982. Development Center to support fishery assessment investi Mar. BioI. Ecol. 24:285-312. of the vertebral column, fins and fin supports, gations. Int. Comm. Northwest Atl. Fish. ____. 1980. Percentage of starving north branchiostegal rays and squamation in the Ser. 3938 (D.c. I), Res. Doc. 76/V[/115. ern anchovy, Engraulis mordax, larvae in the swordfish, Xiphias gladius. Fish. 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