THE SARDINE FISHERY ALONG THE WESTERN COAST OF BAJA CALIFORNIA, TO 1994

Transcription

1 FELX-URAGA ET AL.: SARDNE FSHERY OFF WESTERN BAJA CALFORNA THE SARDNE FSHERY ALONG THE WESTERN COAST OF BAJA CALFORNA, TO 1994 ROBEKTO FELX-URAGA, KEYNA MA ALVARADO-CASTLLO, AND ROBEKTO CARMONA-PNA Cenro nerdisciplinano de Ciencias Mannas (CCMAR) Apar~do Posal 592 La 'az, B C' S Mexico C P ABSTRACT Cach daa (3,416 MT during 1984 and 56,350 MT during 1994) indicae ha abundance of Pacific sardine (Savdinops sagux) along he wes coas of Baja California has increased dramaically. ncreases were closely relaed o abundan year classes in 1984, 1989, and The abundan year classes in 1984 and 1993 followed El Niilo evens. Seasonal paerns in caches lead us o hypohesize ha sardine migrae seasonally beween Magdalena Bay and Ensenada, moving norhward during he summer and fall and souhward during winer and spring. The period of highes abundance afer 1989 was associaed wih a norhern shif in he disribuion of sardme and increased caches in Ensenada. Peak caches occurred in a bimodal paern a 17" and 20 C near Ensenada in he norh, a 17" and 21" near Cedros sland, and a 19" and 24" near Magdalena Bay in he souh. This paern suggess he possibiliy of hree socks along he wes coas of Baja California. NTRODUCTON n Mexican waers, Pacific sardine is harvesed commercially along he wesern coas of Baja California and in he Gulf of California. The firs recorded caches of Pacific sardine (Suvdinops SU~UX) along he wesern coas of Mexico were in Ensenada during As he sardine fishery collapsed in California, he Mexican fishery moved progressively souhward (figure l), arriving a Cedros sland in 1961 and Magdalena Bay in 1972 (Murphy 1966). n his paper we describe some aspecs of he Pacific sardine fishery along he wesern coas of Baja California, emphasizing he period from 1981 o 1994, and hree fishing zones: Ensenada in he norh, Cedros sland, and Magdalena Bay in he souh (figure 1). The principal species in he commercial fishery along Baja California is Pacific sardine, bu he flee also harvess hread herring (Opishonema spp.), chub mackerel (Scomber jupouicus), and, o a lesser exen, round herring (Evumeus eres), anchovea (Ceengruulis mysiceus), and jack mackerel (Zuchuvus symmefvicus) (Hernindez-Vizquez 1983; Fklix- Uraga 1986). A Magdalena Bay and Cedros sland, around 80% of he cach is used for fish meal, and approximaely 20% is canned for human consunipion. The number of canneries and size of he flee in Magdalena Bay have been relaively consan since There are wo canneries wih fish meal plans, one in Por San Carlos and he oher in Por Lopez Maeos (figure 1). The number of boas in he Magdalena Bay zone ranges beween 5 and 7 per year, wih capaciies beween 60 and 120 MT per boa. The flee operaes mosly wihin he bay and leaves only occasionally o fish ouside near he mouh of he bay. On Cedros sland here is only one cannery wih a fish meal plan and only one boa (150 MT capaciy) ha caches sardine. The boa operaes near he island. Deailed informaion abou canneries and flee size has no been compiled for Ensenada. DATA AND METHODS Daa abou cach and fishing effor for pors in Lopez Maeos, San Carlos, and on Cedros sland during were obained from canneries' business records by Cenro nerdisciplinario de Ciencias Marinas personnel (able 1). Cach daa for Ensenada (able 1) were ----Az2 PACFC OCEAN Figure 1. Baja California and is hree main fishing grounds for Pacific sardine. 188

2 ~ ~ FELX-URAGA ET AL.: SARDNE FSHERY OFF WESTERN BAJA CALFORNA TABLE 1 Annual Landings (MT), Fishing Effor (Trips), and Average Sea-Surface Temperaures (SST) for Three Fishing Zones along he Wesern Coas of Baja California Cedros sland Magdalena Bay Ensenada Cach Cach Cach Cach Cach Pacific all Fishing Pacific all Fishing Pacific Year sardine species effor SST sardine species effor SST sardine SST '186 1' , , , , ,808 2, , , , , , , , J , , , , ,s ,081.o , , ' , , , , , , , , , ,893.5.i, , , , , , , , , , , , '1, , , , , ,034.') 6, , , , , TABLE 2 Cach-a-Age daa (lo6 Fish) for Pacific Sardine Caugh in Magdalena Bay, Age groups Year i n.ooo (1.(1011 O.OO( o.oon ' ( O.OO~! provided by Walerio Garcia (Cenro Regional de nvesigaciones Pesqueras, Ensenada, pers. comm.), bu effor daa were no available. Sea-surface emperaure (SST) daa for Magdalena Bay, Cedros sland, and Ensenada during were obained from COADS (Comprehensive Ocean Aniosphere Daa Se; Roy and Mendelssohn 1994; able 1). SST daa for were &om Anonymous The SST daa from COADS were average emperaures in 2" laiude x 2" longiude squares. Squares along he coas a 24"-26" N., 28"-30" N., and 30"-32" N. La. were used for Magdalena Bay, Cedros sland, and Ensenada. Daa froin ATTC (ner-american Tropical Tuna Commission) repors were he emperaure a he isohermal neares each fishing zone. Average annual emperaures were calculaed for each region. Cach-a-age daa (number of fish in each age group caugh during each year) during were available for Magdalena Bay, bu no for Cedros sland and Ensenada. Cach-a-age daa for Magdalena Bay in Fklix- Uraga 1992 were updaed (wih he mehods of Holden and Rai 1975) o 1994 (able 2). A recruimen index for sardine in he Magdalena Bay fishery was esimaed from cach-a-age daa by summing he cach a each age for each year class. For 1991 o 1994, we esimaed a seasonal index of relaive cach for each fishing zone (cach increased considerably in Ensenada during his period). The seasonal cach was he cach during a season divided by he cach for he enire year. Seasons were winer (January-March), spring (April-June), summer Uuly-Sepember), and fall (Ocober-December). To deermine emperaure preferences for sardine, we summed monhly caches by 1 "C inervals and ploed he resuls. 189

3 FELX-URAGA ET AL.: SARDNE FSHERY OFF WESTERN BAJA CALFORNA RESULTS Cach and Effor The oal cach of sardine along he wesern coas of Baja California increased from abou 12,000 MT in 1981 o abou 56,000 MT in 1994 (able 1, figure 2). From 1985 o 1989, oal landings averaged 16,000 MT annually, and cach in Magdalena Bay was greaer han a Cedros sland or Ensenada. Afer 1989, he average cach was more han 40,000 MT annually, and caches were greaes in Ensenada, excep for 1994, when he cach was higher (34,000 MT) in Magdalena Bay. Thus he period of highes abundance afer 1989 seems associaed wih a norhern shif in he disribuion of sardine. The sardine cach a Cedros sland has averaged 1,600 MT annually and has been relaively consan since n mos years, he Cedros sland fishery was he leas inporan in erms of oal landings. Toal fishing effor (number of fishing rips) and cach by he sardine flee a Magdalena Bay and Cedros sland is relaed o he availabiliy of sardine and oher species (able 1). When fish are available, fishing rips and caches increase. The correlaion (1') beween fishing effor and oal landings (all species) a Magdalena Bay and Cedros sland during was ' = 0.88 (P < 0.00) and ' = 0.94 (P < 0.00). The correlaion beween fishing effor and Pacific sardine landings was Y = 0.66 (P = 0.001) for Magdalena Bay and ' = 0.64 (P = 0.01) for Cedros sland. Year-Class Abundance ndex The year-class index (figure 3) indicaes ha sardine recruimen increased coninuously afer 1981, wih paricularly srong recruimens during 1984, 1989, and The 1994 year class appears weak, bu his is probably due o limied daa for he mos recen recruimen. V Figure 2 California ENSENADA CEDROS SLAND / YEAR Pacific sardine landings (MT) along he wes coas of Baja LL z P i loo 50 01,,,,,,,,,,,,,, YEAR CL&SS Figure 3. Recruimen index (sum of cach a age for each year class) for Pacific sardine in he Magdalena Bay fishery. ""..... ENSENADA - CEDROS SLAND - MAGDALENA BAY WSpSmF WSpSmF WSpSmF WSpSmF SEASON OF YEAR ( ) Figure 4. Relaive Pacific sardine cach by year, season, and fishing zone, W = winer; Sp = spring; Sm = Summer: and F =fall. Seasonal Cach Seasonal cach during 1991 o 1994 (figure 4) shows ha he fishery in Magdalena Bay occurred mainly during spring and summer. n mos years, he fishery a Cedros sland also occurred during he spring and sunimer. During 1991, however, here were peaks during boh he suinnier and winer. n he Ensenada fishery, excep for 1993, only one peak occurred in each year, mainly in he fall. Cach and Temperaure Relaionship Annual average SST along he wesern coas of Baja California was relaively warm in 1983 and 1992 and relaively cool during (figure 5). Trends in emperaure a differen zones were similar, bu Magdalena 190

4 FELX-URAGA ET AL.: SARDNE FSHERY OFF WESTERN BAJA CALFORNA w - $ A... -.,,...,,"!._ EN SE NADA 1611 ' YEAR Figure 5. Annual average sea-surface emperaures near Ensenada, Cedros sland, and Magdalena Bay. ""... ENSENADA CEDROS SLAND MAGDALENA BAY " 1'4 1'5 1'6 1'7 18 1' TEMPERATURE "C Figure 6. Pacific sardine cach by emperaure a Ensenada, Cedros sland, and Magdalena Bay, Bay was consisenly warmes (average 21.7"C compared o 18.5" a Cedros sland and 17.6" a Ensenada). The difference in average emperaure during beween Ensenada and Cedros sland was only abou l", whereas he difference beween Cedros sland and Magdalena Bay was abou 3". Peak caches in he hree fishing regions occurred a differen emperaures, and here were wo peaks a each locaion (figure 6). A Ensenada, he firs peak in sardine cach was a 17", he second a 20". The firs peak a Cedros sland was also a 17", bu he second was a 21". For Magdalena Bay, he firs peak was a 19"; he second was beween 24" and 25". DSCUSSON ncreases in oal cach (a crude index of abundance for sardine; e.g., Lluch-Belda e al. 1989) during 1985, 1990, and 1994 (figure 2) were associaed wih srong year classes during 1984, 1989, and 1993 (figure 3). The srong year classes in 1984 and 1993 niay be due o El Niiio evens during 1983 and 1992 (Murphy 1960; Huao-Soberanis and Lluch-Belda 1987; Fklix-Uraga 3 992). ncreased caches a Ensenada during 1992 coincided wih decreased caches a Magdalena Bay in he saine year (figures 2 and 5). This could be due o he 1992 El Niiio even, which caused norhward nioveniens of sardine from Magdalena Bay. The paern of highes relaive cach by season (spring-summer in he souh, and fall in he norh) during (figure 4) indicaes seasonal migraions of sardine beween Ensenada, Cedros sland, and Magdalena Bay. Seasonal migraions may amplify or conribue o increases in abundance of sardine in norhern areas when he populaion is growing (Lluch-Belda e al. 1989, 1991). Pacific sardine are caugh over a wide range of emperaures along he wesern coas of Baja California (figure 6). Peak caches occurred a hree differen eniperaures: 17", 20"-21", and 24"-25". This paern suggess he possibiliy of hree differen socks along he coas of Baja California. ACKNOWLEDGMENTS We hank John Huner (Souhwes Fisheries Science Cener, La Jolla, Calif.) for he opporuniy o paricipae in he 1995 CalCOF Conference. We hank Larry Jacobson (Souhwes Fisheries Science Cener, La Jolla) and wo aiionyiiious reviewer7 for suggesions and coniniens ha improved he manuscrip. Principal suppor for his work was provided by Direccibn de Esudios de Posgrado e nvesigacibn del nsiuo Poliecnico Nacional. LTERATURE CTED Anonymous <egi\ro\ mensudes dr emper~urd cuperficial proniedio. Coiiiisihn nei-aiiierican,i del Aiin Trop~cal, CAT. FPlix-Umga, K Edad, creciniieno >J esrucui-a pobl.1cion.d de Smdiriop5 rqos munilen rn Uahi~ Magdalena, chi-ane 1'18 1 J Tryis de iiiac Crnro iirrdisciplinari(i de (:iencids Marinas..P.N., La 'az, 13. M.xico, 102 pp Coniporicihn por ed'ider de la s'irdinx monerrey Snrdirrops i-ncrrlirrz cqurada rii 3ahia Magdalem, U.C:.S., MCxico, de 1081 a nver. Mar. CCMAR 7(1).c1-13. Hcriiindez-Vazquez, S. 1'983. Aidisn y noriiializacihn del rsfuerzo pwluero de la flora sardinerci de Bahici Magddena, B.C.S. MGxico ( ). Tesis de marsria. <:enre iicrdisciplinario de (:iencia\ Marinds,.P.N., La Paz, U.C.S., Mxico, 112 pp. Holden, M. J., and 11. F. S. 1Lii Miodos pard inveslgar lo7 recursos y sii aplicacihn. Manual de Ciencia 'e\qnerd. Pare 2, FAO, 123 Hudo-Soberam, L., and D. Ll~ich-Uelda Mc\osc& cycles in h ria of en\~rroriiiienal indices relaed o he ydrdiiie fshr~y in he Gulf of Califorma. Calif. Coop. Oceanic Fish. nves. Rep. 28:

5 ~. FELX-URAGA ET AL.: SARDNE FSHERY OFF WESTERN BAJA CALFORNA Ll~ici-Uelda, )., K. J. M. Crawford, T. Kawasaki, A. D. MacCa11, R. H. l xrish, <. A. Schwarzlose, and 1. E. Smih. lu89. Worldwide flucuaiwx of sardiiic and anchovy crock\: he regime prohleni. S. Air. J. Mar. Sci. 8: Lluch-Uelda, )., S. Hernanciez-Vazquez, and K. A. Schwarzlose A hypoheical model for he flucuaion of he California sardine populaion (Snrdiriiips sqns ncrrkn). ri Long-erm variabiliy of peldgic fi\h populaion\ and heir enviroinien, T. Kawasaky e al., eds. rrgamon Press, pp Murphy, C; Oceanography md variaions in he Pacific sardine populaion. Calif. Coop. Ocednic. Fish. nves. Rep. X:i l opulaioii hiology of he Pacific sardine (Snrdi)mp i n ~ ~ l ~ n ). roc. Calif. Acad. Sci. 34(l):l-X7. Roy, C., and <. Mendelssohn COAS on CDOM volume 5: Eafem P~ific Ocean. OKSTOM and NOM. Climae and Easern Ocean Syems (CEOS) Program. 192

6 BENTLEY ET A.: PACFC SARDNE EGG PRODUCTON OFF OREGON, 1994 EGG PRODUCTON OF PACFC SARDNE (SARDNOPS SAGAX) OFF OREGON N 1994 PAUL J. UENTLEY, <OUERT L. EMMETT Norhwes Fishene\ Sciriice Cener Nmoiial Manle Fishener Sewice, NOAA Monlake Boulevard Ed\ Seale, Wnshln~on NANCY C. H. LO, H. C;EOFF<EY MOSER Souhwes Fisheries Science Cener N.iiona1 Marine Fishme\ Srlvice, NOAA 1'.0. 3ow 271 La Jolla, C~,ilifornia ABSTRACT Since he lae 1970s, he Pacific sardine (Sardinops sapx) populaion off he wes coas of he Unied Saes has been increasing. n 1994, an ichhyoplankon survey o assess anchovy biomass was conduced off he Oregon coas fiom he Columbia River o he Coquille River (jus norh of Cape Blanco) and ou o 190 kin offshore. Saniples colleced during he survey conained numerous Pacific sardine eggs and larvae, which were used o esimae daily egg producion (0.42 eggs/o.05 m'/day) and egg moraliy (0.13/day). The spawning biomass of Pacific sardine was calculaed o be abou 50,000 MT. There appears o be an associaion beween geographic disribuion of sardine eggs and he 14 C isoherin derived from he 1-rn o 10-n deph zone. We hypohesize ha he isoherm of 14 C fornis a disinc boundary for spawning sardine off Oregon and may prove useful for deermining boundaries for fuure spawning surveys. NTRODUCTON The Pacific sardine (Sardirzups sapx) fishery, which ranged from Baja California, Mexico, o as far norh as Briish Columbia, Canada, was he larges coiiiniercial fishery in he Wesern Hemisphere in he early 1900s (Wolf 1992). During ha period, sardine evidenly spawned hroughou nios of heir range. Spawning occurred during he summer in Oregon and Briish Colunibia waers (Walford and Mosher 1941; Ahlsrom 1948). Since he decline of he sardine populaion in he 1940s, no landings have been documened in waers off Oregon and Washingon (Kadovich 1982; Wolf 1992), and o our knowledge no spawning has been documened in waers norh of California. n 1994, he Naional Marine Fisheries Service (NMFS) conduced an ichhyoplankon survey off he Oregon coas o esimae norhern anchovy (Engradis nzo~dax) biomass. During his survey norhern anchovy eggs were rarely colleced, bu Pacific sardine eggs were abundan hroughou he sudy area. Pacific sardine eggs were found as far norh as Tillamook Head, Oregon, indicaing ha he Pacific sardine may again be using norhern porions of is hisorical spawning range. This apparen expansion of spawning range o Oregon waers is consisen wih he raes of increase in bioniass and spawning area ha have been observed off California since he mid-1980s (Deriso e al. 1996). n his paper, we describe he geographic disribuion of Pacific sdrdine eggs and larvae and esimae egg producion and moraliy in our sudy area off Oregon in July We also provide a crude esimae of Pacific sardine spawning biomass. MATERALS AND METHODS Survey Descripion The ichhyoplankon survey used he egg producion mehods of Lasker (1985) and was conduced aboard he 17.4-in research vessel Sea Offer during 5-26 July Sampling was conduced over a grid of 234 saions along 12 eas-wes ransecs, which encompassed an area of 69,308 kin' (figure 1). Transecs exended 47N 46N 45N 44N 43N " 1 ' ' ' ' Tillamok Tillamook 1... knewpor 1... A - S W 1 Coquille River OREGON 1 1 L - - O h 5okm lookm 15okm 42N ' " ' " ' ' " '\ 126W 125W 1214WCAuFoRNA Figure 1, A grid of 234 sampling saions occupied during he ichhyoplankon survey, 5-26 July