Southern California Recreational and Commercial Marine Fisheries

Home , Pacific Bonito, Seriola dorsalis

MFR PAPER 1173 tions regarding the course of future exploitation of southern California fish resources except for the determination of approximate limits of sustainable yields and lower limits on age at first capture (Table 1). However, where resources are or appear to be exploited beyond Southern California Recreational maximum sustainable yield, reduction of catch and/or effort is strongly rec- and Commercial Marine Fisheries ommended. The two California pelagic wetfish stocks showing very large standing biomasses, northern anchovy and jack ALEC D. MacCALL. GARY D. STAUFFER, and JEAN-PAUL TROADEC mackerel, presently appear to be lightly exploited. Maximum sustainable yields of anchovy appear to be 10-20 times the present annual catch level of 130,000 OVERVIEW market boats which use such gear as tons, and jack mackerel should be able longlines and gill nets and supply the to sustain catches 4-8 times larger than Southern California marine recre- fresh and frozen fish market. Included the recent annual catch level of 55,000 ational and commercial fisheries exploit in this report are discussions on the tons. The “older” wetfish stocks- a large number of coastal fish species. flexibility and trends in target species of Pacific sardine and Pacific mackerel An initial analysis of the current status of the partyboat and purse seine fisheries, -are extremely depleted and show the more important stocks was under- and analyses of anchovy fishery inter- little likelihood of recovering to pre- taken in 1974. The results for northern actions and trophic relationships. vious levels of abundance in the near anchovy, Engraulis mordax, California The tone of this investigation has future, even under the present fishing barracuda, Sphyraena argentea, been that of expedient fishery analysis, moratoria. Mexico is making large Pacific bonito, Sarda chiliensis, jack in which detail is sacrificed for speed, catches of these species: however, it is mackerel, Trachurus symmetricus, difficult to determine the proportion of white seabass, Cynoscion nobilis, and achieving maximum cost-effectiveness, and identifying areas where further in- catches coming from northern stocks rel- yellowtail, Seriola dorsalis, are docu- ative to those coming from the southern mented in this report. Brief status re- vestigation is needed and is likely to be fruitful. Originally this work was rec- stocks, or the Gulf of California. ports for Pacific mackerel, Scomber ommended at the State-Federal Ma- The larger sport fish stocks are in var- japonicus, and Pacific sardine, ious states of exploitation. The Sardinops caeruleus , are included. rine Fisheries Research Program Plan- ning Workshop held 12-15 March 1973 yellowtail resource appears to be lightly These stocks are shared by various exploited, and has shown an apparent fleets fishing along the coast of southern in San Clemente, Calif. (proceedings compiled by Squire, 1973). increase in availability to sport California and the Pacific coast of fishermen since the cessation of large- Baja California. The U.S. partyboat This work should provide significant information for the formulation of posi- scale commercial fishing in 1954. The fishery, in which fishermen rent space increase in availability may be due, in aboard a boat for a day or half day, has tions and plans for regulatory agencies managing these resources. We have at- part, to more favorable ocean tempera- been popular in southern California tures. Maximum sustainable yield since the 1920’s (Young, 1969). In the tempted to avoid making recommenda- (MSY) appears to be 3-6 thousand tons last decade this fishery has caught about annually, with recent sport catches 4 million fish annually there. Fishing ranging from 0.5 to 2.0 thousand tons. from private boats, shorelines, piers, Alec D. MacCall is a member of the As the sport catch appears to take a staff of the California Department and jetties is also very popular but large fraction of the northward summer statistics have not been routinely col- of Fish and Game; Gary D. Stauf- fer, Southwest Fisheries Center, migration, it is unlikely that catches lected (Pinkas, Thomas, and Hanson, National Marine Fisheries Service, from California waters can be 1967 and Pinkas, Oliphant, and NOAA, La Jolla, CA 92038; Jean- significantly increased. Haugen, I%@. A small round haul fleet Paul Troadec, United Nations White appear to be somewhat Food and Agriculture Organiza- seabass supplies bait dealers with live anchovies depleted. Data from the commercial for fishermen on partyboats and private tion. This study was conducted in cooperation between the Califor- fleet operating in both Californian and boats to use as bait and chum. nia Department of Fish and Game Mexican waters indicate the species The U.S. commercial fishery has two and the U. S. Department of Com- may be harvested at near maximum merce, National Oceanic and At- major components: a small purse seine substainable levels. Catch per unit ef- fleet, which was once active in the sar- mospheric Administration, Na- tional Marine Fisheries Service, fort of white seabass from partyboats dine fishery and now harvests an- under contract 034-208-160. The has declined over the last 2 decades, chovies, jack mackerel, bonito, and authorship is arranged alphabeti- creating some uncertainty as to the true tuna (Penin and Noetzel, 1970) and cally. status of the stock. The white seabass

I Est,mated mean annual Catch Present malor fishery segments 1W Short tons 1% 1970172 total catch) POtentlal yoeld Geogmphical 1940- 1950- 1960- 1970- US-based US Mexican 103 state Of Stock ranw 1949 1959 1969 1973 sport Comm SportlComm Shorttons exploitation Remarks

Northern Southern Call- 3 18 30 129 5 55 40 1 500-2,OW Very lightly Allocat,on requirements anchovy tornla, northem (bat) BXplolled may reduce rates of Bale California BXplDlIaflOn Pacihc California. N. 428 91 to 3 some large '300-5W Depleted Rehabilitation unlikely sardine Bala Calllornls (bait) In near f"t"re PaCihC Central Call- 30 M 16 1 33 34 330-50 Depleted RehabMlat4On unlikely mackerel forma to centra1 I" near tuture Bals Callfornla Jack west coast Of 34 38 39 24 01 11 210-450 Probably Size of local stock IS mackerel North America lightly indeterminate but large exploited Calltornla Southern Cali- 21 19 12 05 48 48 41-2 Depleted Rehabilitation po5SibIe barracuda fornla to centra1 I" near future BBja Cailfomia Ysllowtall Southern Cali- 31 32 12 15 67 M 456 Lightly Migration into Calif fornia and Bale exploited 8s heavily exploited CalifOmla Paclflc California and 27 14 76 118 11 87 2 10-m Probably mod- BlOmaSS and pDlenlla! bonito maCallfornla erately to highly fluctuating With highly ex- recruitment California PlOlIed residency may be a temporary event California and 05 10 06 05 8 76 17 08 Moderstelyi Indices of BBla Callfornla highly ex- abundance conllict ploited

'At the 1970-1973 population level 'If rehabilitated IOthe pre-1944 pcppulation level $11 rehabilitated IOthe pr-1950 pop~lationlevel The California yield IS influenced by ocean temperature population may be overestimated by fishing has increased to unprecedented for stock assessment. If a series of an- commercial fishery data and under- levels in the past few years. Sport avail- nual squid abundance estimates be- estimated by partyboat data-a ability is an indicator of recruitment and comes available (such as by aerial sur- phenomenon that currently is being ex- is highly correlated with abundance of vey), assessment by methods similar to amined. We have investigated some of commercially exploitable fish 3 years those used for bonito should be possi- the potential results of various future hence. A crude production model indi- ble. developments in the sport and commer- cates that bonito are presently being Studies of interactions were brief. cial fisheries which may be of use in harvested at or above MSY (although due to the extreme complexity of the management decision-making. the assessment is confounded by the subject. The northern anchovy fishery The status of the California harra- possibility of a density-independent de- has a large number of interacting ele- cuda stock is difficult to assess with re- cline in recruitment). The 1973 catch ments, and regulation is poorly coordi- spect to a definite level of MSY, but appears to be considerably in excess of nated. The southern California live bait appears to be at a low level. Length equilibrium yield. However, since fishery is a very important user of an- frequency indicates a preponderance of Pacific bonito fishing success is chovies, and has occasionally reported very young fish in recent partyboat influenced by ocean temperatures, con- poor bait availability, allegedly due to catches and it is possible that the previ- clusions drawn from the crude produc- commercial fishing. Our results indicate ous allowance of fish shorter than 28 tion model must be accepted with cau- that the availability of anchovies to the inches in bag limits has contributed to tion. live bait fleet has increased considera- depleted spawning stock and conse- While it would be desirable to assess bly over the long term, and that while quently reduced recruitment. Mainte- the stocks of other species, such as there may be a slight reduction in rela- nance of the present strict observance Pacific hake. saury, squid, and the tive availability in the winter reduction of 28-inch minimum length is a rational rockfish group, the limited amount of season, the difference is very small and course of action. There appears to be data available for the southern Califor- even of questionable existence. The sufficient stock remaining to engender nia Bight prevents such undertakings. Santa Barbara bait fleet appears to be optimism regarding rehabilitation of the Rocldish appear to be abundant in anomalous in many respects, and may resource in the next decade, given southern California waters and are be- be in real difficulty, although it is favorable environmental conditions. coming progressively more important difficult to attribute its problems to the Abundance of barracuda off California as a sport fishing resource. Separation anchovy reduction fishery. is strongly influenced by ocean temper- of rockfish partyboat effort should lead Multiple species aspects of fisheries atures. to feasibility of southern California received brief attention. Quality of Pacific bonito appears to be a relative stock assessment for that species com- sport fishing seems to have been very newcomer to the sport catch, having plex. Squid is receiving increased atten- good during the late 1950's and most of been absent for a number of years prior tion from commercial fishermen and the 1960's. Sport fish now appear to be to 1956, and large-scale commercial marketers and is an important candidate returning to levels typical of the early

L 1950's with respect to abundance of tion of statistical procedures and tests of ceeded. a reduction in fishingeffort is to large and medium sport fish. although validity in favor of approximate solu- be strongly recommended. species composition is now different. tions. Whereas in the more detailed Data This seems to be associated with the investigations. considerable work is de- The most important information to warm water period beginning in late voted to attempts at eliminating or jus- fisheries assessment and management is 1956 and continuing into 1960. The tifying assumptions. "quick and dirty" total catch. The first step (besides commercial wetfish Heet appears to be methods rely on assumptions as a familiarization with the species and flexible in its choice of target species modus operandi. Within the constraints fisheries) in these investigations was to and has gained independence of the of generating a useful and meaningful compile a complete table of catches availability of sardines. report and of conforming to knowledge since about 1950. This required colla- An analysis of trophic interaction in- and information regarding the subject. tion of data furnished by many sources dicates that while both forage (an- all reasonable assumptions necessary to (Table 2). both published and other- chovies and sardines) and game fish pursuance of the investigation are wise. Where data were unavailable. es- (yellowtail, bonito. albacore. bana- justified. The extent to which funda- timates were based on available infor- cuda. and white seabass) increased in mental assumptions. which significantly mation. suspected trends. and educated abundance between the 1950's and influence conclusions. are not met in the opinions. In many cases. the time series 1960s. there seems to be little evidence real world. will affect the accuracy of of catches for a particular fishery seg- that either prey or predator biomass the conclusions. ment were estimated by the ratio of shows strong dependence on the abun- This investigation attempts to deter- catch available for years indicated in dance of the other. It appears more mine the status of fish stocks and their Table 2 to known catch of a similar likely that the abundance of both is de- level of exploitation. Status. however. fishery. termined largely by external conditions. is a vague term. and may have different In order to make all catches compa- If any interdependence is in effect. it criteria for different users. particularly rable, and for use in surplus production should have been much weaker in the in the case of sport fishermen and com- models, catches were converted to es- I%o's than in the late 1950's. mercial fishermen. We have used MSY timates of weight. This task presented as a standard criterion in these assess- no obstacle in the case of the commer- DATA AND METHODS ments for several reasons: MSY is a cial fisheries. where landings are al- The following report briefly docu- measurable quantity. and is the stan- ready recorded in weight. and in the bait ments the analytical methods and data dard parameter determined from appli- fishery, where the weight to volume used for the "quick" stock assessment cation of simple fisheries yield models: ratio is approximately constant (IS of some of the more important recre- moreover. MSY is a likely upper bound poundsiscoop). In the sport fisheries. ational and commercial fisheries of for optimum sustainable yield whether however, the problem is not as simple. southern California. The analyses ofthe the optimizing criterion be economic Average weights per fish were calcu- various stocks utilized similar methods value, stability of yield. or recreational lated from length frequencies via and types of data, making a general dis- value. Optimum sustainable yield weight-length formulae. For most sport cussion of procedures appropriate. criteria are the subject of further inves- species. length frequencies were available only for a few years in the 1950's Stock assessment methods tigation. Thus. we do not wish to imply. in assessingstatus relative to MSY. that from special studies of the California Stock assessment methods were ap- catches should necessarily be brought Department of Fish and Game plied in a manner to give the most rapid to such levels. However. if MSY is ex- (CDFG). Fortunately length-frequency assessment of fisheries stocks. Sophis- tication and accuracy are desirable. but suffer low prionty in the face of an urgent need for information on critical fishery problems. Often the quick solu- cnmmaroa,-. ..- tion will serve as a guide in long-term Cal,lorn,a investigation of problems, and can be ca1,1oro,a wmers COFG 1915preSwm Published (CDFG Fish Bullatmi) Weight Mexican waters CDFG t9t6prsssnt Publmhec (CDFG Fish Bullstmr) Waghl considered as a "first cut." Voluntary lCDFGI 195I-present VOlYme Stock assessment procedures have INP '962-prsle"t Publtshed (FA0 YearWOok Ot Wenghl FA0 1% t -present Fishev Weight three time-consuming operations: I) collection of data. 2) development spon Calilom!a and refinement of models. and 3) Local partyboat COFG 1936-40 Publish& (COFG Fidh Bull 86) Yumler 1947-orese"t PUDlllhed (Young 1969) Number justification and elimination of assump- ~ongrange partyboat CDFG 1960;rerent NumDer tions. Expedient methods minimize Barge COFG 1947-present Number Private boat, COFG 7 964 PW14shed (Pmkas el a1 1968) Number these steps. Only available data are Pier and pw' COFG 1963 PublilhBd (PrnkS St a1 1967) Number used: where data are missing. reason- Shareline COFG 196566 Published (Pink84 et a1 19681 Number MBIlCD Number able estimates are made in order to fill the PaRYDOat Voluntaw IESFAS 1961 (971 gaps. Methods tend to be restricted to application of very simple models. These are further cimplified by relaxa-

3 sampling of sport catches has been made from more recent data. Individual recently instituted by CDFG. The estimates and assumptions are gener- 1972 and 1973 length frequencies made ally noted in the sections in which they available by it were agreat benefit to the occur. but many escape discussion. stock assessments. Where length frequency was lacking, reasonable esti- Methods mates were again employed. Wherever possible. stock status was The second important parameter determined by a surplus production or necessary for stock assessment is an "Schaefer" model. which in practice index of stock abundance. Traditionally consists of plotting abundance as catch this is obtained by measuring effort per effort against a mean effort averaged and calculating catch-per-unit-effort over half the fishable lifetime of the fish (CPUE) *hich is presumably propor- (Gulland. 1970). Usually effort (fishing tional to stock abundance'. Effort was 'Anglewangler day. mortality) is assumed to be related to available for commercial white seabass 'Deplh 5 20 fathoms. the amount of fishing done by the ex- and for the southern California party- ploiting fleets. A total effort index may boat sport fisheryin general. wherein no tistical information on geographical be derived from catches and abundance distinction was made between species distribution of effort. arbitrary non- indices that are somewhat independent sought. overlapping areas were used. Effort ac- of the fishing fleets. such as the aerial Partvboat effort and CPUE were ad- cording to CDFG block origins was index. as was done for Pacific bonito. justed to account for the change in the sonsistent with effort reported from The presumably steady-state relation- unit of effort from "angler-days" to each landings region. The "CPUE ship between effort and abundance will "anglers" (angler-trips)and for regional index" was felt to be the best partyboat generally show as decreasing CPUE differences between sizes of fishing area CPUE-based index of abundance in with increased effort. A line describing (Table 3). Conversion ratios for adjust- most cases, but no other comparable this relationship is sketched in, or a ing effort for the period 1947 to I960 abundance indices were available to straight line (sometimes not best ap- were estimated from 1960 and 1961 data venfy this. proximation) can be statistically fitted in which both units were recorded. The Other abundance indices used in to the observations. An approximation variation of conversion ratios within these investigations included aerial. of an equilibrium yield curve can then regions was much smaller than between acoustic. and eggand-larva surveys. be calculated by multiplying together regions. The ratios were significantly which are best for pelagic schooling the coordinates of the equilibrium different between regions based on an fish. Squire's (1972)day and night aerial abundance line (catch per effort x g analysis of variance with years as repli- indices of abundance were recalculated effort = catch). and plotting against the cates tF = 56.7. d.f. = 5.6P (F>4.39) to include only the southern California same effort axis as in the previous plot. = 0.05). As a result effort was adjusted area (regions A and B were excluded). This will usually give a concave down- for each region separately. Acoustic surveyscarriedout by CDFG ward paraboloid curve (a true parabola Abundance indices were calculated were useful in measuring anchovy results from the straight-line fit men- from partyboat catch-effort data in abundance. but due to lack of sufficient tioned previously). and estimated MSY three ways. First. annual catch divided overlap with egg-and-larva abundance corresponds to the peak of the yield by annual effort for all areas combined surveys verification of acoustic esti- curve. Exrrapolation of the equilibrium was called CPUE. This was used when mates by correlation methods is unfea- yield curve beyond points of observa- comparisons with early years were de- sible. Egg-and-larva surveys were also tion (particularly toward greater effort) sired. as only total Californiacatch was useful for jack mackerel and sardines. should be interpreted with caution. as available for 193640. Second. annual Recent CDFG tagging of jack and MSY's and corresponding effort levels catch per annual effort for the San Pacific mackerel provided useful obtained in this manner are very impre- Diego region alone was used as a possi- biomass estimates for those species. cise. For most of the stocks investigated ble index of abundance. San Diego Separation of stocks was given little in this study, MSY fell within the ob being presumably closest to the popula- emphasis as such problems could not be served spread of values. tion centers of our migratory southem resolved with available data. Where This approach assumes that CPUE. species. Third. a "CPUE index" was geographical limits for stocks were lack- particularly sport CPUE. is propor- calculated as the weighted average of ing, all catches were assumed to have tional to stock biomass. Changes in gear annual CPUE's of the six regions. come from a single panmictic stock. efficiency (e.g.. introduction of monofila- Weights were determined by estimating Population parameters such as those ment line in the mid 1950's) may increase the area of water less than 20 fathoms for growth. length-weight. and mortal- catchability. and artificially increase deep in the geographical area in which ity were generally available from pub- CPUE. More important. CPUE is in- each region's effort was presumably ex- lished sources or were in prest. Where fluenced by the availability of fish. The erted (Table 3). In view of lack of sta- values were lacking, reasonable esti- northern migration of game fish such as mates wereused.or. inthecaseofwhite vellowtail and barracuda from their 'Recent \["dies ruggesi that CPUE may not be 3eabass natural mortality. a new esti- population centers off Baja California linearly propontonal to ppulation YILC. matetdezcribedin moredetail later) was into southern California waters is

1 greatly influenced by oceanographic conditions. The apparent abundance. measured by sport CPUE. depends in part on the extent of this northern migration. The large catches during the warm water years of the late 1950's are examples. For the purpose of this report. the data points for these years are treated as outliers in the surplus produc- 1940 2 359 1950 279 tion models. '551 690 637 294 For relatively unfished stocks, where 1952 656 797 410 1953 !I 4Ml 1335 a07 biomass is many times larger than 1554 1937 1816 655 catch. as in the case of jack mackerel 1955 1855 1676 1386 1956 1307 1491 919 and northern anchovy. the surplus pro- 1957 1669 1964 I576 1558 2 675 2771 1832 duction model cannot be applied. In this 1959 (2418) 2299 3 686 case. we have used Gulland's (1970) 1960 3079 19i8 1961 3189 1264 approximation of MSY based on 1962 6248 43662 157 0 M5 unfished biomass and natural mortality. 1 %3 6030 4861 2 24 0 50 1964 5121 3886 3 86 0 57 which is itself postulated on surplus I965 7771 6211 4 08 0 71 production concepts. 1966 5116 4 154 107 3 05 0 86 1967 174 5 14 2 02 4 784 The Gulland formula is Y,,, = XME, 1968 195 135 0 30 where Y,,, is potential yield. M is 1969 * 03 4 39 134 1970 56 Y7 46) '!8 65) instantaneous natural mortality rate. 1971 101 3 23 126 4 166 1912 194 141 1 33 3 577 and Bo is mean virgin biomass of fish 1973 275 above length at first capture. X is a '974 13621 coefficient which is determined by M. K (von Bertalanffy growth rate)'. and length at first capture relative to maximum length. Values forX tend to fall around 0.5. which is a reasonable value if other parameters are unknown. Yield values obtained by this method are rec- interactions between resource uses. live fleet. only the central stock is con- ognized as first approximations. to be bait. reduction, and sport fish forage are ridered here. revised by more precise methods as a not considered for best allocation of re- Estimates derived from egg-and-larva time series of catch and effort (or abun- source. These are briefly discussed surveys. which may be our most reliable dance) is acquired. elsewhere in this document. source, correspond only to the spawning In fisheries where spawner-recruit re- Biomass biomass while data from other sources lationships are obscure and surplus may include biomass of immature fish. production models give inconclusive Estimates or indices ofabundancefor Therefore. the estimates are not di- results. we have attempted to investi- the northern anchovy have been ob- rectly comparable. Insufficient infor- gate yieldperrecruit(Y/R)asa basisfor tained through various independent mation regarding age at first maturity evaluating minimum length restrictions. methods. i.e.. egg-and-larva. acoustic. does not permit precise assessment of We found the short-cut yield tables in and aerial surveys (Table 4). Separate the ratio of total biomass to spawning Beverton and Holt (1966) very useful data are available by geographical biomass. However. as the majority of for this purpose. Where multiple areas. months. or quarters. According fish appear to be mature at 1 year fisheries interaction raised a particular to estimates from eggs and larvae col- (Kndggs. CDFG:'). which also corres- problem. as in the white seabass. a lected during 16 years. the subpopula- ponds to approximate age of recruit- complex Y/R analysis (Lenarz. Fox. tion centered off southern California ment to the fishery. exploited biomass Sakagawa. and Rothschild. 1974) was and northern Baja California (the cen- should not be substantially higher than employed. tral stock) makes up 66 percent of the spawning biomass. .As a first approxi- NORTHERN ANCHOVY overall total spawning biomass (range of mation. rpawning biomass is used here This report of northern anchovy. annual values: 40-83 percent) but in as exploitable biomass. If it would be En,qrniilis mordux, is an overvtew of the years since 1963 the ratio has been possible to expand exploitation upon relationship between present harvest about 80 percent. Acouctic surveys juvenile stages. the exploitable biomass levels and potential yields of the stock. from 4 years confirm the above estimate would exceed spawning biomass. Further investigations of the complex (range 65-86 percent). Increase in the Various estimates and indices have central stock accounts for the increase been compared. Correlation coefficients 'The von Benalanffy growth curre IS I, =L, in total biomass of the northem anchovy 11--r where I, 15 length at lime 1. L, IS since 1950 (Fig. I). Because of this and asymptotic maximum length. 1 IS a growth rate 'E. Knaggr. CDFG. 350 Golden Shores. Long constant. and r,, II hypothetrcal age at zero length. its proximity to the California fishing Beach. CA 90x02 Perc commun.

5 between the independent methods 1970). or when expanded to volume and for years in which the surveys have assigned a packing density of SO fish/mJ coincided are given in Table 5. Corre- (Mais. pers. commun.). Considering lations are in general not high and general knowledge on reliability of positive only in the case between esti- egg-and-larva survey methodology, to- mates derived from egg-and-larva sur- gether with the extent of sampling done veys and night aerial surveys. The ap- both in time and space. it is assumed parent contradiction between acoustic that biomass estimates used here pro- rurveys and night aerial surveys may vide a picture of the stock sufficiently result from the fact that these two accurate for present assessment prob- methods do not actually sample the lems. same portion of the overall biomass. Indices derived from nighttime aerial .4coustic surveys may not suitab!y de- surveys were regressed on concurrent tect fish occurring close to the surface. estimates of the spawning biomass of while aerial surveys record only fish the central stock to estimate the concentrations visible in the upper layer biomassin 1%7. 1971.and 1972(column of the sea. An important source of error 7. Table 4) for which no egg-and-larva is the fact that sonar-based acoustic surveys are available. iurveys have been employed only 5ince 1968 15536 7177 15694 38409 Catches 1969. Data for 1%6 and 1%7 have been 1967 34605 5387 22115 62307 '966 31 140 6691 14567 52396 inferred from echo-sounding surveys. 1965 2861 6348 lot88 19103 Catch statistics for the 1960-73 period The biomass estimates from the egg- 1981 2ae 5191 5059 12758 are given in Table 6. These data refer to '963 2285 4442 1039 7766 and-larva surveys and indices from the 1962 1282 6167 736 6285 the central stock which is essentialiy the aerial surveys are in more agreement '981 3156 5913 15w) l10269i only one exploited. The mean lengths of 1960 2523 4653 imn I 76871 particularly when night sightings are the catches for successive years have considered. As observed by Squire decreased. The trend and year-to-year ( 1972). this may be due in part to higher fluctuations can be caused by changes in efficiency of aerial surveys conducted at recruitment and natural mortality rates, night as compared with daytime obser- exploitation. and/or size selection of the vations. A correlation coefficient can- fishery. (Average lengths of fish in not be calculated for egg-and-larva iur- catch': 123.0 mm in 1%5-66: 123.1 mm. vey estimates and acoustic data because 1966-67: 120.5 mm. 1968-69: 120.9 mm. the time series do not overlap enough. 1969-70: 127.5 mm. 1970-71: 116. I mm. On the other hand. acoustic estimates 1971-72: and 116.0 mm. 1972-73.) of biomass tend to agree with egg- 1968 2048 59 003 1969 2933 114 054 Maximum potential yield and-larva estimates when schools 1970 - 157 - are assigned an arbitrary-but likely- 1971 (4 166) 91 0 02 Fishing mortality (F)can be derived 1972 1~5m '35 004 average value of 17 tons (Smith. 1973 - 119 - from catch data and biomass estimates (Table 7). The F values confirm that the ,rr rate of exploitation has been very low. Considering that. as mentioned above. biomass estimates do not include :he juveniie stages. fishing mortality may be lower than the average value of 0.03 observed from 1968 to 1972. Total mortalitv has been calculated by hZacCalll1973)from catch curves for 5 different vears. The value ofZ = I. I thus obtained indicates that natural mortality M cannot be smaller than I .OO- I .05. Sprat1 11975) gives values of 0.3 and 165.5 mm (standard length) for yon Bertalanffy growth curve param- etery K and L,. respectively. The average size at first capture. I,. is not exactly known. since recruitment occurs dunng a rather long period (affect- ing individuals from about 85 mrn to 1 IS

'From \ler,errmlih i 19691. Cdlm 119711. Sprm i19?. 1973a. bl. md Sunada 1197?1

6 mm). In the following calculations. the a commercial fishery and the marnte- value of 105 mm has been used. nance of a stable but unacceptable sport Considering that the stock is very fishery in which only small fish are near to virgin state. Gulland's equation available Here we attempt to assess the Y,,, = XMB, can be used for asses- present rtatus of the stock. sing the maximum potential yield. With Data Catch records for barracuda are simi- 0.63. the coefficient X would be about lar to those of other recreational 0.6cGulland. 1970. p. 5). The maximum species. Long time series of catch rec- potential yield should therefore be ords in weight are available for U.S. about 60 percent of the fishable bio- commercial fisheries operating in mass. As the latter has shown con- California waters and off Mexico, and siderable fluctuations during the years records in number for California party- under observation. several values of boat catch and Mexican commercial potential harvest can be derived (Table catches are known since 1%6. Catches 8). for other fishery segments were esti- From the analysis of available data. it level of exploitation. it does not seem mated from data for specific years as can be concluded that the central stock reasonable from YIR to implement in footnoted in Table 9. Sport fish catches ofnorthernanchovy canproducea yield Californiaregulatory measures aimed at were converted to weights by using from IO to 20 times higher than present limiting the size at first capture or the available length frequency data and the catches. There is some information that allowed landing sizes. length-weight curve given by Walford Mexico is considering development of ( 1932). and from weight given by Baxter Conclusions its present production to about 500.000 and Young 11953). Length frequency tons, of which 200.000 tons would be At present the potential yield of data for the California partyboat fishery caught by vessels operating from En- northern anchovy can be estimated at are available for the years 1953. 1959. senada. If this occurs, such vessels will above 2 million tons. Remembering that 1960. and I%I(Pinkas. 1Y66) and 1972 most likely exploit the central stock. biomass estimates used in this appraisal and 1973 (D. L. Schultze. CDFG pers. This target catch represents about one- include only the spawning population. commun.). The 1972 and 1973 samples eighth of the potential of the central this resource may even be substantially are not representative of the landings 5tock as derived from biomass rsti- larger than in the figures given in Table because undersized fish that were re- mates for the period 1951-72 and about 8. Because of high natural mortality of leased after capture were included. A one-thirteenth of its potential when cal- anchovy, there is no need to limit the constant 4.9 pounds/fish was assumed culated for years following the collapse size at first capture in California at the for the 1936-51 period (Baxter and ofthe Pacific sardine stock. The USSR present level of harvest. In this context. Young. 1953). No weight samples are has also shown interest in offshore it should be stressed that the stock ap- available for the period from 1952 to trawling for anchovies. with possible parently shows very large year-to-year 1957. Mean weight values for the catch rates as high as 15.000 tons per fluctuations. Therefore. in the event sport-caught fish were not assumed for ship-year. Their ultimate catches are that substantially higher levels of ex- this period because the fishery declined likely to depend on success of the ven- ploitation are considered. careful during these years but immediately in- ture and the course of international law. monitoring of the stock abundance and creased with the start ofthe warm water years. SMean weights of4.16.3.87. 2.64. Size of first capture size composition would be essential in order to prevent overexploitation dur- and 2.59 poundsifish for 1958. 1959. On the basis ofavailable values ofM. ing periods of successive low recruit- [email protected] 1961 respectively were esti- K. I,. and L,. yield per recruit tables ment. mated from mean lengths given in Pin- indicate that a reduction of size at first kas (1966). An estimate of 2.6 capture would lead to considerable BARRACUDA poundsifish based on the 1961 samples gain. ifthe fishery wereunrestrictedand The California barracuda. Sphyaena was applied to all following years if juveniles were fully vulnerable to arg'mrra. fishery has undergone a long through 1970. Because the two under- fishing gear. For example. with the pres- decline. beginning in the 1930s and end- size fish (less than 28 inches) allowance ent rate of exploitation (E = 0.05). if ing with the present virtual extinction of in the bag limit was eliminated. a value the size at first capture were at YO mm instead of the present assumed value of 105 mm. both annual yield and catch rates would. in theory at least. double. Because of the high rate of natural mor- corresponamg 8lOrnaSI pOte"tlP1 tality of anchovy. even for high rates of Time perma ~opuiatton mean ana range ymias exploitation 1e.g.. FiZ-0.8) maximum (I@ tonq I1W IO"*) yields and catch rates would be 1951.69 Tofa1 3 2W (6407803) 1 903 14004 700) ~1.72mer sara1ne coiiap~ Central stock 2 6W (29062031 1 500 I2003 7001 achieved with sizes at first capture 1965-69 Total 4 600 (2 200-7 800) 2 800 1 I 3004 7W) below 80 mm. Therefore at the present 1965-72 Cenlral stock 4 OM) (2 050-6 2001 2 4W (1 200-3 700) 7 IO00 1928 4385 2 2067 2 1929 3925 9 13027 '930 3513 6 12502 841 5 421 7 169 8 381 6 6139 '3C 0 492 5 15001 24501 (54261 0 45 11394 598 5 .6WI 29401 $58781 0 50 12690 3142 .3Ml ,1568' IIW81 038 11228 663 5 16701 32831 ,73751 0 44 1151 9 704 5 i?>Ol 43479) 17: 76) 0 48 12306 ,4232) 1211 4 3455) 13925 13775, 13309 (36161 1945 1744 6 21107 38551 1946 I636 1 1470 4 131071 1941 16959 969 5 677 4 ,101 1697) 13415) ,60811 0 56 1948 1lWl 1025 7 384 1 li0l ,201 (4241 120781 ~42041 0 49 1949 903 6 1570 3 366 4 1301 ,301 (4261 12087) 14561) 0 48 1950 890 4 13680 101 256 4 133 n ti! 01 l?31 1) 1162241 13680 81 0 42 '951 670 0 1436 9 '01 269 5 135 41 51 21 1356 11 117449) ,3851 61 0 45 '952 747 7 13465 (io1 336 9 144 31 (74 1) (455 31 1136591 1953 565 9 872 9 I301 3 70 6 12241 137 51 ,230 51 ,691 51 1954 485 9 1076 8 '401 282 6 ,37 41 1-9 11 ,398 81 1119641 '955 322 8 818 I ,501 1550 120 41 448 01 ,223 41 (67021 1956 502 702 4 1601 81 6 11 51 129 61 112891 (38611 1957 387 1 295 5 '601 577 2 I75 9) 1213 6) ,866 71 (LWO11 1958 753 3 162 0 lM1l 782 8 110291 ,313 11 ,11988) ea7 01 15962 31 0 84 1959 11104 42 2 ,601 t(956 115721 (478 21 11831 01 1-086 01 162% 61 0 85 19M1 11478 81 8 ,601 755 4 199 31 302 21 1115691 ,3064 21 143% 81 0 75 961 478 4 231 0 I601 391 9 I51 51 1-1 4 (5548) 1144831 2215 7) 0 65 '962 521 8 224 7 79 5 335 5 144 11 ,13411 ,51431 1'33721 216321 0 62 '963 347 4 31 4 dl 4 483 7 163 61 119381 ,761 *I 1926 91 12347 1) 061 1964 251 0 83 1 998 303 7 I39 81 112261 ,16571 (121081 I'M471 0 75 1W5 273 0 69 1 503 443 3 I58 3) 117631 1679 91 I1767 7) 12,w 1, 081 1968 233 3 65 6 61 9 892 7 ,1'73) 1358 41 113684, ,3557 81 13938 81 090 1967 281 2 32 0 32 6 470 5 .61 81 ,722 71 1787901 I2225 01 a 84 '968 1145 260 '4 4 312 2 i48 91 .57' 51 \148551 (16408) 0 91 1969 7c 8 38 32 358 5 147 11 1554 91 ('442 7) 1526 51 0 95 '970 22 5 21 33 373 8 (577 1) ,15CC 51 ('5284) 0 98 1971 '7 3 00 66 a05 1251 81 163861 1662 5) 0 96 '972 139 CO 151 36 2 ,19121 1591 61 161051 0 97 '973 37 6 00 ,151 92 5 11221 1475 61 142661 ,1479 41 0 96

of 3.0 poundsifish was used for 1971. in the warm bater years of IY57-60 hampies from U S. commercial and 1972. and 1973. Length frequency data (Figure 2). The C.S. commercial from partyboat fisheries >uggests that are also available for the California fishery landed an annual average of the bilrracuda \lock presently lacka the commercial fishene, for the )ears 1928 3.800 ihort tons of barracuda during larger iize groups (Figs. 3. 4). The (Walford. 1932). 1958. 1959. 1960 (Pin- 1920-25. These decreased to 1.401) ton, length frequencies for the commercial kaa. 1966). and 1973 (D. L. Schultze. annually for the years 1932 through fisher? may differ somewhat due to CDFG. pers. commun.) 1938. and then increased to 1.W tcns changes in fishing gear. The method of California partyboat records on catch for 1939-45. After 1945 the commercial capture waa predominantly purse seines and angler effort provide the only index catches steadilv declined to the pre\ent in 1928. gill nets and .jigs from 1958 to of abundance. The aerial survey level of 5-20 tons. However. from the 1960. and gill nets in 1973. Since sam- ISquire. 1972) recorded too few sight- beginning of sport fishing record5 in plea for yrara 1952 to I957 do not exist. ings of barracuda to he useful. Egg-and- 1936. sportsmen consistently landed it is not known ifthe above trend started larva wrvey5 gather barracuda larvae approximately 1.200 tons annually prior in rhe earlv 1950's or early 1960's. The but the data as of vet habe not been to IYi?. Dunng the warm water years. \\arm water )ear.: are associated with procesred. It IS not known if the obser- when barracuda were considerably anexten\ive northward migration ofthe vations are sufficient tu provide an more available. annual sport catches barracuda population. Occurrence of indey of abundance. ranged from I .300 to 3.500 tons. Pnor to large fish in these wnples may be a 1951 the >port catch amounted to [result of this migration. The decline in Historical trends 46 percent of the total landings but 5ince frequenc! of largerfish may have paral- Total landings of barracuda have 1968 it has made up more than 90 per- leled the decline in catch rather rhan the generall? declined vnce the mid- iY?O'> cent of the total. abrupt change suggested by the length except for short term peaks in 1966 and E.;amination of the length frequency frequencies available. In any event. the 8 POy CALIFORNIA BARRACUDA pOr CALIFORNIA BARRACUDA ao- , ': ; 71 2 crn (28"rur ~imit) /I/I /I

P i

C. 41 30- ,!

20- - TOTAL SPORT 0 COMMERCIAL CATCH c:- ,O- o--e u 5. COMMERCIAL CITCH

LO.%*. 10 %__( 1915 1920 1925 1930 '935935 1940 iW5 19% 1955 1960 1965 I970 1975

YEAR

'CALIFORNIA BARRACUDA fishery has harvested the younger age groups. particularly 2-. 3-. and kyear 71Zcm (z~",~ze~~lmitI old fish in recent years. The number of sport-caught under- a -789cm size barracuda permitted per bag has been altered a number of times. Be- tween 1933 and 1949 spon fishermen 2 were allowed not more than five fish O20 ' 40 60 " 80 (00 120 weighing less than 3 pounds each. Be- . -779 crn tween 1949 and 1957 the undersize al- LENGTH (cm) lowance WAS five fish less than 28 inches. These size limits were effectively identical since a 28-inch barracuda weighs approximately 3 pounds (age 5 j'k years). The allowance was reduced to two undersized fish per bag in 1957. In only(Fig. 6). Formany oftheyears. the March 197 I the possession of barracuda points lie well above the I: I line. which under 28 inches was prohibited al- means that the sport catch rate was high together. As it is illegal to possess un- in the San Diego region. yet relatively dersize barracuda. sport fishermen re- low overall. This suggests that the bar- lease a large number of undersize fish as racuda migrations in the early 1950's indicated in length frequency samples for 1972 and 1973 (Fig. 4). If the released fish have poor survival. the beneficial effect on the stock may be reduced and/or retarded. The CPUE ( x catch in weighu p anglers) forthe U.S. panyboats has two penods of extreme highs. the years prior to 1948 and the warm water years tFi_e. 5). If these extremes are eliminated. the two remaining sequences are somewhat level. On the otherhand each segment shows a decline in itself. The CPUE index in numbers of fish for all regions combined was compared to the CPUE for the San Diego region 9 trends in the catches. nor do they indicate the present status of the stock. In order to ascertain recent levels of exploitation with regard to catch and effort. Schaefer model analysis was at- - 1.4 p temoted. 0, Various indices of CPUE were ex- s 12- amined for application to the model. As G previously discussed. distribution pat- = 1.0- W terns have varied. with the migration not extending much north of San Diego 8 0.8- in some years. Thus we have calculated 0 CPUE as total annual partyboat catch g 0.6 - 060 of barracuda divided by total annual f partyboat effort for southern California, 0.4 - multiplied by estimating average weight per fish to get CPUE in weight. This procedure allowed inclusion of 1936-40 partyboat catch information. which. while of relatively poor quality. provides the only "fix" on earlier levels of CPUE INDEX (fish/anqlerl exploitation. Total effort is then estimated as total landings divided by and late I%O's mav not have extended g1 BARRACUDA CPUE. Using Gulland's approach. ef- fully into the southern California firh- 7 fort is averaged over half the fishable inp._ grounds. # lifespan. hence we used 3-year Since World War I1 the pnce of averages. barracuda per pound (adjusted by the As each minimum size (or charac- wholesale price index) paid to teristic length frequency) results in a dif- fishermen. has remained relatively con- < ferent equilibrium line in the Schaefer stant (Fig 7) The pnce did drop dunng r model. the observed data points are warm water vears when the supply was difficult to interpret (Fig. 8). The south- high In recent years of very low supplv ern California sport fishery exploits a the pnce has increased. As market pnce fringe of the stock. with oceanic tem- did not increase dunng the long-term r perature strongly influencing availability decrease in landings. there was little F (Radovich. 1962. 1975). Such changes economic incentive to maintain a in availability result in a variable rela- fishery dt the level of the early 1950's ": a,- tionship between nominal sport fishing effort and actual fishing mortality rate. Stock assessment a.2 45 y1 15 €0 6s 10 -5 Four groups are apparent. correspond- YEARS . ing to different. presumably homoge- Pinkas' (1966) study on the California figur. T.-C~mm.rdai .s-v.~.l prIc*s lor barmcuda mdlUs1.d 4 wholwde pr(s. index. barracuda utilized a Beverton and Holt l(Y1.71. dynamic pool model to investigate op- CALIFORNIA BARRACUOA timum minimum size in relation to yield Before the mid-1950s the undersize fish per recruit. Maximum yield per recruit allowance should have had relatively lit- was estimated to occur at an age at first tle effect on yield. since the sport fishery capture of 5 years, or approximately 28 accounted for only 30-40 percent of the inches minimum length. This length re- total catch and large fish were presum- striction also should have helped insure ably in abundance. By the late 196)'s the reproductive capacity of the stock however. the sport fishery accounted as the onset of sexual maturity occurs at for more than 90 percent ofthe landings, age 2 for most individuals (Walford. and fish larger than 28 inches had he- 1932). come relatively scarce. so that the bulk Commercial fishing has observed a of the landings was composed of fish .y1 .,, 28-inch minimum size since the 1930's. under 28 Inches in length. in March Sport fishing has also had a 28-inch size 1971 the undersized fish allowance was limit but with the provision that a cer- abolished. making the theoretically op- tain number of undersized fish could be timum size limit effective once again. kept (five under-sized fish from 1933 to Yield per recruit considerations. 1957. and two under-sized fish to 1970). however. do not explain the observed

10 neous. periods in thefishery. Datapoints for the late 1930's comprise a loose group included primarily for the pur- u.S commercial SpDn Told MOXICO' Panywaa Gther Maxican Comm. poses of establishing a basic relation- Cd~t MBXICO commelcial Calif. Calif Waled Told Total and span ship between catch and effort for the Year (I01 Ib) (101 Ib) (I01 Ib) (101 fish) :101 fish) (101 Lshl (101 fish) (101 Ib) (101 Ibl earlier years of the fishery. Tentative 1950 33 662 (01 24 (2.11 (0.1) (461 (141 17091 values for 1936 and 1937 are shown. 1951 54 723 IO1 145 (13.1) 10.61 I2841 1851 (862) 1952 6 2.135 (0) 7 6 (6 9) (0.5) (15 01 (45) 12.1881 Presumably an effective minimum 1953 19 3.084 (0) 6.3 (5n 1051 (7251 (38) 13.1411 1954 219 2 100 (0) 70.1 (6341 (6.1) (139.61 (419) (2.7381 length of 28 inches was in effect during 1955 40 100 101 224 (2031 1221 (449) I1351 1275) the late 1930's (mean annual catch = 1956 22 105 (01 61 4 (55 51 1601 (122.91 (3691 (4%) 1957 110 109 (25) 2506 (2337) 13031 15226) (15681 I18121 3.000 short tons). A second group. 1958 4.805 742 1%) 4226 (382.0) 14W) l8Y.01 (2562) 18.1591 comprised of years 1947 to 1951. is 1959 3,003 9 175) 776.4 (701.1) (90.81 (1.568.3) (4.705! (7.792) 1960 1220 31 (100) 1.1999 (1 0835) 1140.4) (2.423.01 17.2701 18.6211 characterized by declining catches 1961 8.439 74 11631 6494 (767.0) (119.7) I1 736.1) 15.2081 (13.8841 1962 2,072 63 67 790.7 (730 2) (94.31 I1 625.2) (4.870) 17.072) (mean annual catch = 2,300 tons) and 1963 4.014 9 1 118 7757 (682.4) (91.71 11.528.81 14.5891 19.730) probably a minimum effective size limit 1964 2.606 6 1.125 1.298.8 (1,172.8) 1152.7) (2.82431 (7.873) 111.6101 1965 5.633 6 735 8063 (728.1) (%.OlI1.630.4) (4,891) (112651 of about 28 inches. The third group is ISM 18308 640 2.044 644.4 1581.9) 176.2) 11.302.5) (3.om1 125.1~1 composed of observations from the I967 17842 3.378 1 W 3500 (316.01 (4231 (708.31 12.1251 l24.6881 1968 14903 19 779 1,1029 (99601 (13161(2.25051 (6692) (22393) 1960's. a fairly stable period in effort 1969 13.175 4.027 147 1130.2 (1.02061 (139.91 (2rJo.7) (6.872) (24.2211 and landings (mean annual catch = 1970 8,794 399 (163) 651.9 (588.7) (783) (1.318.9) (3.957) (13.313) 1971 10.476 9793 (325) 152.8 (137.8) (16.7) 1307.3) (9221 (21.5161 1.200 tons). however, with an effective 1972 15.800 6.712 I3251 4190 137781 (5361 lBW.4) l2.5511 (25,188) minimum length considerably shorter 1973 18.477 12,263 710 4725 (426.11 lW.51 (939.1) (2,877) (34327) than 28 inches. The higher CPUE for 'Sourc(1. FA0 Yearbook 01 Fqsherf SIat1611CI. and calch data furnished by InaItl1ut0 N.CmnaI de Pgca 2ES11msIed by Thayer (1973. table 3) IbM reported partyboat Catch 1960 may be the result of successful 'Sum Of Bslimaled Enrensda pamyboat CNCh (e-1. catch = 0 117 CallfOmiapMybOat CIIICII. based On mean 01 1961 local spawning in previous years as sug- and 1971 reported calchas,wim~m~ll~~nliOforsarl,ar~aan-Ihnearlydecreasglng from 1958 tO'liOlrallOln 1950)snd gested by the large numbers of small California long range patwboai Catch barracuda in the 1960 length frequency Although it IS possible to draw a nia waters in the latter halfof 1956. Both (Fig. 4). curve through the six points from year sport and commercial fisheries pres- Imposition of a strict 28-inch mini- groups one and two. such a line would ently exploit this resource virtually un- mum size limit in March 1971 resulted probablv not be a valid equilibrium checked. Knowledge of potential sus- in a sharp drop in reported partyboat curve because of the changjng nature of tainable yields and fisheries interactions catch. although the number of anglers thefishery. From theexaminationofthe is lacking, making an attempt at stock fishing was unchanged. To adjust time series of catches and length fre- assessment vital. CPUE to pre-1971 conditions. party- quencies. it appears that the barracuda resource was fully exploited in the late boat CPUE values were increased by Data the ratio of total fish caught to fish of 1930s and quite heavily overexploited legal size (Fig. 4). This ratio was esti- by the 1960's. The decline of the stock Long time series of catch statistics mated from length frequency sampling may have partly resulted from recruit- are available for the U.S. commerical done aboard partyboats. For purposes ment failures. The large catches during fleet (in weight) and for the U.S. party. of this analysis. the length restriction the warm water years, which were boats (in numbers of fish caught). Since resulted in decreased fishing mortality facilitated by an influx of fish into 1%1 Mexican commercial catches are of younger fish. which takes the form California waters. almost certainly ac- regularly reported in the FA0 of reduced "effort" in Figure 8, ac- celerated the decline in the 1960's. It Yearbook of Fisk? Statistics and cording to the formula:f = C / CPUE,,,. may take several years for the stock to catches for 1%2-69 and 1973 were fur- wheref is a derived measure of effort. regenerate its number from the in- nished by the Instituto Nacional de presumably proportional to fishing creased spawning potential afforded by Pesca (INP). For the other segments of mortality. C is total landings of all strict maintenance of a 28-inch the fishery, information is much more fisheries segments. and CPUE,,, is minimum length. The unrestricted Mex- scanty. However. total annual catches as described above. In this case. C ican fishery and lowered survival of re- (Table IO) were reconstructed for the is smaller than the catch used to cal- turned undersized fish must be expected period 1950-73 on the basis of specific culate CPUE. andf is smaller than to have dampening effects on rehabili- annual catches occasionally reported actual number of anglers fishing. In tation of the fishery, but the end result for some particular segments of the Figure 8. the years 1971. 1972. and should be an improved angler CPUE fishery, general knowledge on the rela- 1973 were thus moved to the left of and overall yield of combined fisheries tive importance of respective fishery the earlier group. With time. we expect over what would be expected without sections, and known or assumed trends to see the points progress toward the the size limit. in their historical development. In 1973 upper right. as fish landed show in- U.S. commercial and sport catches- with distinction made between catches creasing mean weight. This should in- PACIFIC BONITO crease CPUE. and simultaneously in- taken off California and off Baja crease the proportion of legal fish to fish After an absence of several years. the California-were regularly sampled caught. which will increase "effort" as Pacific bonito, Surdu chiliensis. re- for length frequency (Fig. 9). Length it has been defined here. turned in numbers in southern Califor- distributions for U.S. sport fishery and 11 available weighvlength relationships long-range partyboat catch. while tak- TheCPUE(in numbersoffishcaught (Campbell. in press) were used for ing considerably larger fish. accounts perang1er)dataarealsoavailableforthe converting catch in numbers to weight. for less than I percent of the total catch. partyboats. Source data were processed The conversion was done using an and does not need to be included in the as follows: average weight of 3 poundsifish 11973 calculation. Lack of length frequency 1) Annual (5)for all southern partyboat average weight was 1.87 information for earlier years necessi- California areas combined. pounds). which has been the usual con- tates the use of a constant mean weght 2) Weighted mean. (or CPUE index) version used by CDFG. Also. the estimate.

PACIFIC BONITO z[l7- (5). .,,- ] with weighting factor 1973 - z a, MEXICO CALIFORNIAN. 1,102 proportional to the area (0-20 fathoms). illustrated in Figure 10. until about 1957-58. catches as a whole were at a -US. PARTYBOATS -1973 rather low level-although showing marked oscillations. They subsequently I" LOCAL LONG RANGE OFF MEXICO (-' /'I N=I,PSS \ N.116 increased in two steps. The first. from 1 " \ T-2.671bs. I\ late 1950's to mid-1960'5. corresponded I '\ to the development. both in Mexico and I California. of sport catches. The sec- I I \ S- I '\ ond. beginning in the mid-1960's. cor- I responded to an expansion of US. I I .-. commercial landings (Table IO). <' From length frequency distributions of U.S. catches sampled in 1973 (Fig. 9). it is clear that the various fishery sections exploit dityerent parts of the population. Such segregation in sizes caught reflects an uneven geographical distribution of vanous age groups. PACIFIC BONITO Roughly. older fish are more available COMMERCIAL CALIFORNIA WATERS offshore and in iMexico. although large fish are taken in the Santa Barbara area A COMMERCIAL CALIFORNIA and MEXICAN WATERS 30 in the fall. The local U.S. sport fishery ALL including SPORT essentially takes individuals less than60 cmlage I). Long-range U.S. partyboats harvest older fiFh. but make a small contribution to the sport catch. Commer- cial vessels tend to take larger fish: I year old and above off California. 3 years old and above off Mexico.

Sport fishery and recruitment to commercial fishery Indices of apparent abundance have been derived by Squire (1972) from tonnages of bonito estimated during aerial surveys (Table I I).Day and night indices have been calculated sepa- ratelv. Since the 1963 bource data cov- 1924 30 ered the last penod of the year only. indices for that year were discarded in the following analy\es. The aerial survey indices have been recalculated to exclude the area north of Pt. Concep- tion in order to correspond with other biomass estimates. particularly southern California partyboat CPUE for 1965 bonito. 1964 1965 A number of correlations between 1966 aerial survey indices and partyboat 1967 1968 CPUE-with various yearly lag times 1969 and combination-were calculated 1970 '971 (Table I I). Highest values ofthe corre- $912 111 020 059 023 074 146 128 026 024 011 lation coefficient (r)were found with in- I day - 058 OM 039 060 069 026 056 OM 071 dices derived from daytime observa- I night 05a - OM 015 044 066 007 030 040 046 tions. Squire (1972) felt that daytime aerial observations were more efficient than night observations for estimating bonito abundance. The highest correlation was observed hetween partyboat CPUE and daytime aerial index 3 years later (Fig. I I).Taking into account age composition of catches made by sport and commercial fisheries respectively ''r (Fig. 9) and the fact that airplanes are .I3 mainly assisting the commercial fishery I and therefore likely concentrate their surveys over commercial fishing 4 grounds. it is reasonable to assume that , .9m ,' '"I ,, aerial surveys mainly reflect changes '$72 occurringin that part ofthe bonitostock exploited by commercial vessels. while partyboat CPUE provides an index of prerecruit abundance before they ctart to he exploited by the commercial fleet. However. there is not an exact 3-year lag in age composition of partyboat and 25 D/c commercial catches. Moreover. while partyboats may essentially exploit a >ingle age group. commercial vessels ^10 32 exploit several age groups. In order to 3'3s ERIC WWEI DAY !NOEX >L L-.-.-- AERIAL WWEY 'Jay lNDEX account for mortality. plus selectivity by commercial fishing. various reason- Figure 1l.dylnuion 01 a.d.1 survey day figuto iz.--l.gr.rion m ..d.i su~yday Index ag.im1 p.nvoo.1 CPUE ln6.r 3 ye.m Index ap.ln.1 CPUE .QusIM mr mahilly and able combinations of partyboat CPUE .. rll.. . r.cIUllm."l. (in numbers) over years were tentatively correlated with daytime aerial survey ples from the partyboat catch are domi- Annual catches of I.000-4.000 tons of indices. The highest correlation (r = nated by a cingle age group. this may not bonito were taken commercially from have been the case in earlier years. California waters between and 0.71) was found for the combination: 1926 Consequently. partyboat CPUE may 1941. hut information on the effort re- Day At,=% CPUE,-,e-'+ reflect the spectrum of age groups avail- quired to make those catches is lacking.

L/~cPuE,.,~-?+,=I~CPUE,-,K' able to the commercial fishery (or more Between 1942 and 1927 annual catches (Fig. 12). precisely. the aerial index) 3 years later were very low. never exceeding 500 IA value of I .O was arbitrarily used for rather than reflect the recruitment tons and often below 50 tons. Partyboat Z.) This formula attempts to relate 3trength of a single year class as sug- CPUE of bonito was low before 1926. abundance as measured bv the daytime gested by the 1973 frequencies. Ineither Reporting of bonito-like apecies by aerial index (day AI) to the history of case. partyboat CPUE appears to he a partyboats was fairly good (Pacific recruitment as measured by partyboat valid indicator of recruitment to the mackerel. 90 percent: "other species." CPUE index values. The CPUE's were commercially exploitable phase for re- 68 percent) in the period 1947-51 (Bax- multiplied by coefficients to account for cent years. The historyofCPUE values terand Young. 1953). During the 1920's mortality and recruitment (22 percent (Fig. 13) indicates recruitment. from and 1930'7. bonito were commonly and 50 percent were used for the presumably local spawning. was very caught from fishing piers along the coast younger age group\). low before 19.57. after which it sharply and from fishing barges anchored Although 1973 length frequency sam- increased. offshore tJ. Radovich. pers. commun.). 13 ?ACiFIC BONITO creasing effort In a nearly linear fashion. The relationship does su-pgest a concave A LClLf =Or upward curve. but this has little effect on conclusions. The sudden increase in commercial catch in 1% apparently was greater than equilibrium level as . Mould be expected from large-scale 2 i fishing of a previously unexploited - block. However. for the level of re- w cruitment since 1960. the stockappears 1.0 - / \ Pli 4 i \! i to be intensively exploited. In fact. the 1973 catch of 34 million pounds appar- I 'i \h ently is aubsrantially above the MSY \i' auggested by the analysis. Given that recent partyboat CPUE values do not indicate any strong year classes in the present population. this high catch may prove to be disastrous to the bonito stock. Determination of equilibrium abundance and yields are confounded by a possibly density-independent decrease in recruitment. highly variable availability due to behavioral changes tCollins. CDFG'I and generally low precision and coverage of available data. Nonetheless it appears likely that tisheries take an appreciable share uf each year class. Inthe absence of information on mortality rates (oreven comparative mortality rates for similar species) yield per recruit analysis was not attempted. Moreover. lack of mortality rate esti- matzs preclude analysis of the interaction between sport catch and commercial yield or rates of euploitation. Companson of numbers of fish caught by rport and commercial vessels re- K). The units of measurement for this Stock assessment rpectively (Table 131. and observations ratio orf'are abatract. The mean index made above wggest that the sport rate The present state of the bonito re- for biomass tBl and total catch were of exploitation is relatively low. How- source has been assessed using total plotted against the effort index (Fig. 14). ever. expansion ofthe sport fishery will catch and a combination of partyboat In order to take into consideration the directly affect the recruitment to the CPUE and aerial survey data index for average duration of the exploited phase phase exploited by commercial vessels the years 1963 through 1972. Previous (slightly above 4 years). the effort index and conoequently affect their catches. discussions suggested that aenal survey was averaged for 2 successive years. Expansion of commercial activities data index has some validity as a mea- The biomass index decreases with in- will not directly affect the sport fishery. which evploits younger fish. However. decrease in sport CPUE could result from a reduction of parental stock to a point where recruitment is significantly reduced. tip to now this has most likely not occurred: however. the 1973 fishing 1963 171 5 141 ' 53 4589 ' J3 9VO 6782 - wason appears to have been consider- 19M 180 3737 241 7873 193 '1613 5031 6406 1965 1 48 6374 153 4691 133 1265 6496 72M ably in excess of equilibrium yield and 1966 -49 21192 096 3908 126 25100 19860 $4178 1967 103 22563 050 2 125 089 24688 27843 23852 may have aeverely affected the re- 1968 0 54 5701 128 6692 367 22393 33424 30634 \ource. .4lthough such events cannot be 1969 028 '7349 146 6872 354 24221 45152 39288 '970 001 9356 074 3957 - 13313 - - neglected. their occurrence IS very '971 S 56 20594 023 982 1149 21 5-6 43900 - 1972 111 22637 0 59 2551 3 95 25 188 264W 35'82 'R Coilin*. CDFG 150 Goiden Shore,. Long Beach. CA WXO? Perc. sammun difficultto determine for a stock subject to large natural fluctuations in recruitment. as is the Pacific bonito. JACK MACKEREL The jack mackerel. Trachurus sym-

metricus (Ayres). fishery has been one 1950 133.255.6 04 'WOO1 06 (2 41 1140.2591 of the mainstays of the southern 1951 69.838.1 0 0 l4.wOl 02 IO 81 (93,039) 1952 146.521 7 33.1 13.WOI 44 111.6) (149 572) I California wetfish fleet since the decline 1953 55.7509 14 l3.0Wl 196.3 1588 91 1785 2) 159.538) of the Pacific sardine. On rare occasions 1954 17.333.6 04 440 19.4 158 2) in 61 (17.852) 1955 35.7547 00 13.300 39 5 (110 5) 115601 (49.213) large sport catches are made but jack 1966 75,762.1 0 0 14.200 23.5 (70 51 194.0) I90.056l mackerel remains primarily of commer- 1957 62.011 6 0.0 '(6.0001 69 I20 7) (27 61 (90.0391 , 1958 22.065.0 6.2 12.004 27 9 183 7l I111 6) (24 184) cial interest. 1959 37.5072 40.0 Ism) 11.8 i35 4) 147 2) (36.0941 1960 74945.5 40 cs.omi 6.5 I25 5) 134 01 179.9041 Catches I961 97606.3 00 3.934 289 iffi.7) (1 15.6) (101.656) 1962 89.978.9 00 6.970 9.0 I27 01 I36 01 196.993) 1963 95.4423 150 30.153 93 I27 9) 137.21 1125.640l Long time series of landings in weight 1904 69.692.9 0.0 8.671 6.6 (19.01 Iz8.41 l96.59Ol are available for the main segments of 1965 66686 4 0.0 8.420 25.6 (76.0) 1102.4) (75.109) 1966 40.8624 250 12.919 19.0 (57.0) 176 0) 153.082) the fishery: California cannery land- 1967 38.160.5 0.0 4205 16 2 (48.6) 184 0) (42.530) ings. Mexican cannery landings. and 1oBB 55,6677 1580 3.549 13.6 140.81 11441 (59.4291 1969 51.921 2 103.0 3.336 11 3 145.2) 155.4051 California live bait landings (Table 14). 1970 47746 5 0.0 v.rnoi 15.7 1626) 1528091 A similar time series in numbers of fish 1971 59003.0 9.0 15.0031 10 6 11241 (64.9341 1972 51.1176 5.0 15.wOl 5.9 156.146) landed is available for the California 1973 20.615.8 438 156 I47 41 121,117l partyboat fishery. and landings for other sport fisheries were estimated by means of a simple ratio to partyboat landings (3.0 fishipartyboat fish). Sport-caught fish were arbitrarily assigneda weight of I pound apiece in the calculation of total landings. In the year of largest sport landings, 1953, sport-caught fish com- prisedonly I .3 percent oftotal landings, and the percentage for most years falls far below this value. Commercial landings have been PKIFIC BONITO strongly influenced by the availability of more lucrative species. Landings during 'T /I/ the 1950's tend to be inversely related to sardine availability. The slight decline

1950 5 66 0 91 5 1951 6 94 0 102 26 1952 1 277 0 270 15 1953 3 401 0 404 13 1954 34 273 0 307 140 1955 6 13 0 19 45 1956 3 14 0 17 123 1957 17 14 3 34 523 1958 745 96 6 647 854 1969 466 1 10 477 1568 19M) 169 4 13 206 2.423 1961 1300 10 1 1319 1.736 1962 321 8 9 338 1.623 1963 622 1 90 713 1530 1964 404 1 146 551 2.624 1965 873 1 95 969 1630 1966 2030 109 z86 3213 1303 1967 2766 439 174 3379 708 1966 2.3;; 2 101 2.414 2.231 1969 2.043 523 10 2.584 2.291 1970 1363 52 21 1438 1.319 1971 1.624 1.272 42 2938 307 1972 2.419 872 42 3.333 650 1973 2.665 1.593 92 4370 959 The preaent level of fishing is very low. with an F of 0.0?-0.04 (Table 16). indicating that the yield could be increased manyfold. Application of 1950 6646 1951 4233 Culland', quick calculation of potential 3971 1952~ ... yield IY,,, = 0.5 r M x givea 1953 1484 5,)) 1954 2413 llO.UO0 td 450.~Q0 tons. assuming i955 2635 = 1956 7 372 .W 0.6 and using the 1972 ebtimates 1957 2876 of biomass. B,,. Yield values will vary 1956 030 '959 545 according to the biomass. and would 19M) 655 he proportionately larger if the stock 1961 981 '962 2516 were at the 1964-66level ofabundance. 1963 3122 298 341 There are indications that estimation 1964 3045 218 162 1965 2661 1 36 0 71 } 1 4-2 2 1Soawrwng b!Omass CalCOFl area based of MSY may not he so simple. Knaggs 19% 6288 194 328 on eggs ana iarvaei md Barnett 11975) have noted a de- '967 141 020 1968 225 030 crease in average age of the catch. 1969 065 011 1970 058 016 w hich suggest%the possibility of a much 1971 092 004 higher total mortality rate or smaller '972 0 74 0 13 0 7.1 5 (Exploited biomass DBSBO on tapqng.) stock size than generally believed. Uncorrected tor temperature 1957.59 are probably unaerestlmatea Fishermen are of the opinion that jack 'MacGregor l19MI 'AnlsIrom 11968) mackerel abundance has decreased 'Knaggs 119731 considerably (E. Knaggs, pers. commun.). Comparative biology and ex- in landings hce 1965 has been primar- and-larva surveys \how the stock to be ploitation of similar Trdirrrirs species ily due to expansion of fisheries on the extremely widespread. Ahlstrorn ( 1968) and detailed analysis of aged landing Pacific bonito and on the northern an- estimated the spawning biomass in the data may resolve this dilemma of re- chovy. CalCOFl region to have been between >pomeof the California stock to appar- Status of the stock I.JandZ.4 x IO6tons. basedoneggand ently very low fishing mortality. and its exploitation larval occurrences in 1%-66. Knaggs Aged landings ofjack mackerel were ( 1973) estimated from tag returna that PACIFIC MACKEREL not completed in time to be included in between 0.7 and 1.5 x 10' tons were this report: however. they are now available to the fishery in 1972. These Inception of Pacific mackerel. available (Knaggs. 1974and Knaggs and estimates are in agreement with trends S~oniherjirponi~i~s.canning in the late Barnett. 1975). This information will af- in theaerial aurvey indextsquire. 1972). 1920's caused a sudden nse in landings. ford an opportunity for detailedanalysib This wggests that jack mackerel are which. augmented by what was the of the fishery by use of cohort analysis nou about halfasabundant as they were strongest year class (IY32) in the docu- (Murphy method); the present discus- in the mid-1960'5. However. egg-and- mented history of the fishery. peaked at iion I\ reatncted to very 5imple and larva e>timates of spawning biomasa do a record 146 million pounds in the general terms. not nece5sarily correrpond to exploit- 1935-36 aeason. Subsequently. the Vanou\ indices of abundance (Table able biomass. h~venilesare exploited. cstchea went through d long. fluctuating IS) rhow that the resource tends to be while old fish emigrate from the fishing decline. ending witb a severely depleted highly variable in magnitude and egg- grounds. 5tock in 1933 (Fig. 15). However the 1953 apawning was highly successful. PKIFK MACKEREL leading to a resurgence of the stock and I -ita, B ornos, the fiahery. which remained healthy CIM? am".,. *.os, throughout the decade. Beginning in . :atcn 1963. a sequence of six exceptionally severe recruitment failures resulted in extinction of the commercial fishery. The Pacific mackerel remainsarather popular and sufficiently abundant target ofaport fishermen. although lacking the esteem _riven to the larger game fish. Exploitation and dynamics The Paciiic mackerel has been subject to severe and rather unpredictable fluctuations in recruitment. although a &year cyclic pattern has been de- mibed. Parrish i 1971) showed that the fishery has depended largely upon occa- thresholds. the adopted regulation en- PACIFIC SARDINE sures that the maximum amount of The purpose of this report on Pacific fishing is controlled and that it will sardine, Sardinops caerirleiis, is not to gradually increase. tending towards an discuss the population dynamics of the asymptote of F = 0.3 as the stock gains stock but only to document the total in size. biomass time series. The southern Direct limitation of effort would California spawning biomass of Pacific achieve the same effect of limiting F. sardine may presently be less than 5.000 sional strong year classes and has without the difficulties and costs inher- tons (P. Smith. National Marine tended to overexploit successive weak ent in forecasting recruitment and sub- Fisheries Service. tNMFS). pers. year classes. As the spawning biomass sequent fishable biomass. This aspect is was reduced. variance in spawning suc- commun.). and a moratorium on fishing particularly relevant to the Pacific is in effect. Accordingly. no further at- cess increased, augmenting the depen- mackerel stock. which has shown tempt is made to determine the status of dency on strong year classes. while re- fluctuations large amplitude. How- of the stock. ducing the mean age and number of age ever the practical difficulties involved in classes in the population to a point We are interested though in the sar- implementing management based on ef- dine stocks because. along with an- where the stock could not withstand an fort limitation may well counterbalance chovies, they make up a major portion extended period of recruitment failure. its previously mentionedadvantages. In of the forage for many of the southern However. intensive fishing is probably that respect it should also be noted that California sport fishes. .41so. the pres- not the only cause responsible for such while quota limitation alone is collapse. ent wetfish fleet is the remnant of the insufficient to prevent economic sardine purseseine fleet. Duringthe col- As for most stocks where similar overfishing, enforcement of quotas ad- lapse of the sardine fishery the events were experienced. the respec- justed on early estimates of the recruits tive roles of natural causes and of those fishermen began redirecting their effort should dampen year-to-year oscilla- towards otherpelagic species, including due to fishing have not been satisfactor- tions in the fishable biomass and thus ily explained. Long-term fluctuations in Pacific mackerel. jack mackerel. and provide the fishery with greater stability later. anchovy and bonito. The re- the environment and the species com- than was had previously. position of the southern Califomia sponse of the sardine resource to fishing pelagic community have been observed Present state of pressure is now mainly of academic interest and is discussed by Clark and since the late 1950's and early 1960s. exploitation c.g.,waters generally wanner than dur- and perspectives Marr (1955) and Murphy (1966). ing the previous decade. progressive Various indices of biomass reflect the As a result of the above restrictions tremendous decline in the stock from predominance of anchovy over the sar- on commercial fishing. sport fishing is dine. and reestablishment of a local 1.3 million tons in 1940 to the presently the largest user of Pacific 1.000-5.000 tons at present (Table 18. population of Pacific bonito. a likely mackerel in California (Table 17). Fish- competitor with the Pacific mackerel. Fig. 16). Sardine biomass combined ing mortality is at present low (P = with anchovy biomass estimates show 0.06). indicating that it is not necessary an interesting cycle with the lowest Management to implement further restrictions on the amount at I million tons in 1950 increas- In response to the collapse of the sport fishery. ing to over 6 million tons by 1961 (Fig. stock a moratorium on commercial Recovery of the stock to commercial 16). Combined forage fish biomass has fishing was adopted in 1970. Later. a viability is now largely a matter of for- increased 6-7 fold since its low in 1950. more comprehensive management bill tune. as the spawning biomass is so Such cycles in biomass are appar- was passed by the California legislature small that local environmental ently common events in history as dem- which provides for the rehabilitation fluctuations may have a large influence onstrated by occurrence of fish scales and subsequent regulation of a sus- on spawning success. Moreover. poten- in ocean bottom sediments examined by tained and controlled commercial tial response of the stock in the present Soutar and Isaacs (1974). Their work fishery should the stock recover and in- environmental regime is unknown. suggests that for the Santa Barbara crease over a minimum biomass. In es- Based on knowledge of present biomass Basin the level of anchovy stock over sence, the law provides for a harvest and recent recruitment. it is unlikely the past 150 years has been relatively equivalent to 20 percent ofthe spawning that a fishery will develop in the next 5 constant. The level since about 1920. biomass in excess of 10,OOO tons and to years. though. appears to be below average 30 percent of the spawning biomass above 2O.ooO tons. The closure of the commercial fishery for spawning biomass below 1O.ooO tons-the present wuation-aims at ensuring that a 1972 1O.WO 15.772 4951 4159 1080 14W) 924 006 006 minimum parental stock is maintained 1973 ll.OD3 15224 3765 4254 56.7 438 920 and a minimum sport fishing stock is provided. Above the 10.000-ton and 10,0@3-tOII (Fig. IT). During the same period the sediments reveal cyclic occumences of sardines. Sardines probably peaked during 1854 to 1864. 1889 to 1899. and 1914 to 1924 (Fig. 17). Just prior to the decade of 1870. sardines apparently de- 1340 2.359 2359 12% 1296 3655 clined to a very low level but the stock 1941 2.871 2871 2001 2.W1 4872 19.42 ' 933 1913 had rebounded by 1890. During the last 1943 1647 1647 150 years sardine scale deposits only 1944 "42 1142 1945 691 69 1 exceeded those of the anchovies in four 1948 a12 41 2 5-year periods. Sca!e deposition rate for 1947 307 387 1948 524 524 anchovies. however. seems to be higher 1949 682 682 per unit of biomass than for sardines. 19% 279 2'9 716 116 995 1951 690 637 664 570 5% 562 1226 Despite this. it seems that. on the 1952 856 707 827 554 542 546 1375 1953 11 4Ml 1335 1370 709 450 11s 2.529 average. the anchovy biomass has ex- 1954 1937 1816 1877 668 658 1326 3.203 ceeded that of the sardine. Therefore. 1955 1855 1676 1766 425 404 829 2,595 1956 1 307 1491 1399 293 351 322 1721 since anchovies may usually be the dom- 1957 1869 1.w 1917 21 2 231 223 2.140 inant species. if the sardine stock does 1958 2 875 2.771 2 823 281 299 290 3 113 1959 1.7 124181 2.299 2 359 1W ,.I 1.54 2.513 rebuild. it should not be expected to 1960 3 079 3 079 201 201 3.280 overweigh. on the average. that of the 1961 3 189 3 189 132 132 3.321 1962 6 248 6 248 151 151 6.399 anchovy. 1963 6.030 6 030 78 78 6 108 19M i 121 5 121 1c4 104 5.225 WHITE SEABASS 1965 7 771 7771 226 226 7 997 1966 5.116 5.116 5 267 1967 - - - The white seabass. Cynoscion 1968 12.167) 12.16~1 - nobilis. is one of the most highly es- 1969 (3.378) 13.3781 3 405 1970 teemed game fishes found in southern 1971 California waters. both in the catching and in the eating. Accordingly. it com- mands a high market price. Recent conflicting trends in indices of apparent abundance or availability have given rise to concern over the status of the Ftock. This study attempts. with the limited information available. to assess the present condition of the stock. interactions between the fisheries seg-

- - - ., . . 1950 t 123 408 '(741 54 7 47 (2.137) 1951 955 578 f741 444 52 12.0521 1952 692 455 174; 41 0 60 (1 6441 1953 57 1 402 1741 28 2 58 I1 2355) 1954 4% 772 I741 41 6 79 !1.7251 '955 545 370 174) 30 1 76 11 3301 1956 dld _. 667 (74) 198 71 (1 4011 1957 1.262 245 174) 190 75 I1 6241 1958 2.751 99 174) YO 10 2 13.3221 1959 3.386 30 1741 '0 6 67 13.659) 1960 1.087 149 174) 15 7 17 (1.525) 1%) 458 236 1741 14 1 75 1967) 1962 209 366 158 14 6 78 18561 1963 372 519 47 19 8 90 11 2Wl 1964 551 840 82 149 er 11 684) 1965 578 851 87 96 I, I1 6731 1966 875 €63 69 40 56 I1 5Ml 1967 5oB 715 36 34 55 11 3461 1968 210 652 16 41 57 (1861 (9751 1989 251 w 93 41 56 11891 I 1.1861 1970 426 675 &4 65 I1991 I1 2911 1971 552 272 53 65 120 8) (1 050! 1972 548 227 57 11861 (1 065) 1973 397, 581 228 70 !9 0) 123 11 --I1 0391 ments. and the possible effects of various management alternatives. Data available Catch and CPUE data available for the various fishery segments suffer from similar limitations as describedfor other sport species. Long time series of catch statistics are available for fleets respon- 1951 5.476 16.973 435 0.0486 123.2 sible for the bulk of total catches, i.e.. 1952 4.496 9.369 380 00585 179.6 19% b.456 6.417 501 00360 201.7 the U.S. and Mexican commercial 1954 6.W 16.243 751 0.0%3 106.6 fisheries (only since 1966 for the latter). 1955 4 597 6.081 484 0.0516 169.4 1956 7.500 15.689 772 00314 86.3 Annual numbers of fish caught by 1957 5.057 11.491 417 0.0243 162.1 1956 6.521 23.712 572 00547 141 7 partyboats have also been regularly re- 1959 13.916 29.918 552 00170 123.6 ported for the whole period under re- 1960 7 631 12.136 293 00340 128.9 1961 4 157 7.074 278 O.OzB4 142.2 view. For the other sectors, quantita- 1962 3.779 7.102 340 0.0388 125.7 tive information is only available for a 1963 6.232 11.033 317 0.0493 1147 1984 8.917 19.406 633 0.0340 88.4 few occasional years. On the basis of 1985 10.274 18.199 561 0.0196 93.4 such information and on known or as- I986 10.213 16.738 473 00089 92.6 1587 6.734 16.284 556 0.0066 61.0 sumed trends in the history of their re- 1588 6,113 14.6C6 570 Owgo 69 3

1 989 9.391 19.294 e4 0 Ma~~ ~. 69.9 spective developments, annual catches ism 6.408 17 839 794 Ow18 75.2 have been reconstructed for 1971 6,242 13.49 409 0.0109 80.1 1972 5,015 10.618 394 0.0085 1065 insufficiently documented fishery sec- 1973 - - - 0 OQ7 - tions. Assumptions made are given in footnotes on Table 19. Catches in numbers of fish have been converted to catches in weight using the following mean weights of fish caught by fishery sectors: 8.8 pounds when one or two undersized fish can be kept and 16.9 pounds when no fish under 28 inches can be kept. Since unreported catches represent only a small percentage of total catches in weight (e.&. 5.5.6. and 1 I percent in 1968.1969.1970. and 1971. respectively) estimated total catches should not depart significantly from actual figures. TheCPUEdataforwhiteseabassare available for the period considered for U.S. commercial fishery in units of: I) Pounds of fishiboat: 2) pounds of fishiboat landing more than i ton during the year: 3) pounds landedboat landing. The CPUE for the U.S. partyboat fishery is calculated in units of numbers of fish/angler weighted by the surface area of six geographical subareas, Le.. CPUE index. These data are summarized in Table 20 and in Figure 18. Historical trends in annual catches and CPUE Information presented in Figure 18 shows that total white seabass catches have decreased during the period under review. i.e.. from 1950 to 1972. If year- to-year fluctuations in fishing activity. recruitment. and availability (in particu- coefficient. q. is positively correlated on fishing power tR. Collins and C. lar the rudden increase observed in with population size. The positive trend Hooker. CDFG. pers. commun.). The 1958-59 and said to be associated with in U.S. commercial fishery CPUE. 1958 and I959 values have been deleted exceptionally warm waters) are ne- which bas seen an average increase of in the fitting because of abnormally high glected. total catches regularly de- 27 percent hetween 1951 and 1972, sug- catches. Subsequent CPUE observed creased by 42.3 percent from 1950 to gests 4 for the commercial fishery may during these years were most likely due 1972. This drop is essentially due to the be negatively Lorrelated with popula- to above-average availability of the reduction in activity of the U.S. com- tion size. The most likely explanation dock in relation with exceptionally mercial fishery. the landings of which for the opposite trends in CPUE of warm waters. The equilibrium yield have dropped by borne 50 percent dur- partyboats and commercial vessels is curve derived from the CPUE line ing the same period. The Mexican that theq's forthe twofisheries are non- against effort wggests that the stock is commercial fishery is believed to have linear and oppositely (or at least differ- at present moderately exploited. the remained fairly stable during the whole ently) related to population size. present catches being some 10 percent period. Catches of the U.S. sport below the maximum potential estimated Total stock appraisal fishery and particulary of partyboats by pooling together the various fishery have also regularly decreased during the A preliminary assessment of white sections (Fig. 19). On the other hand. if whole period. Although smallerinabso- seabass was made from overall annual the catchability coeficient is strongly lute terms than the decline experienced catches !Table 20) and commercial negatively related to population size. in the commercial fishery. catches of fishery CPUE ipoundsiboat with annual the maximum potential yield may have partyboats have shown a drop of almost landings I ton). For that purpose. been exceeded. and the population may 90 percent dunng the last two decades. Gulland's ( 1969)approximation method be overfished. Although the overall partyboat has been used. The CPUE figures were Interaction between CPUE of white 3eabass has also de- plotted against average effort during the creased by approximately the same 5 previous years (average duration of fishery segments amount as the catch during this period. exploited phase = 9-10 years). Fishing Procebsing catch and CPUE data by the drop in annual catch and CPUE for power has probably not increased wb- combining the various segments of the partyboats cannot be explained bv a stantially since the early 1950s as boats white seabass fishery may lead to at general reduction in stock abundance have remained fishing about the iame least partly erroneous conclusions since related to fishing activity of the vanous amount of gear. Introduction of nylon the Fegments exploit various age groups fishery sections unless the catchability net material may have had some effect of the stock in different proportions... and since catchability coefficients ofthe w WHITE SEABASS various segments may vary differently. The pier and jetty fishery takes juvenile '.\e3 trout" nenrshore and in estuaries. The U.S. partyboats take large numbers of juveniles but adults are also caught. The U.S. private boat catch IS probably similar to a mixture of the pier and jetty and parryboat fisheries. The U.S. Lommercial fishery operating in both California and Mexican waters fishes with large mesh gill nets (&inch me\h or larger). Although age 4 white

US" -5. 0. ,/- -, ~ ,I .591 -85 z 1; U*ITE SEbBlSS 2

Flgur. 1S.--RH~6onshlp b.1we.n com(~rUa1CPUE and enOn and the em. respcndlmg .Uimal.s ot SU~IY.producllon tor while se.b.U. 1973 (obtained by catch curve analysis) upon effort measured in number of 1 us us PWI boats with an annual catch in excess of ~ge comrnerc~si panyboal iew US us pier a ton. Thomas gave a value ofM = 0.303. ~ge ~omrnercm Panyboal iew Total 0.50 M=O13 NO of Fish For 1973. Z was estimated to be 1 0 0w18 0 0061 2 0 0221 0 0724 0 236 773 1ow from age composition data for the U.S. 0 3 0 0 0123 0 2 0 2361 7727 10088 gill net fishery provided by Rob Collins. 4 0 0029 00123 0 3 0 708 7cB 5 00123 0 223 931 CDFG. These data were also analyzed 0.0164 1 104 6 00123 0 5 1087 1106 2 395 0 0274 to generate values of fishing mortality 1 00656 6 1546 236 1782 00123 0 6 01105 00123 0 1 30% - 3 095 for the various age groups and gear 4416 9 01501 00123 0 6 4 180 236 types (Table 22). This was done by di- 10 03591 00123 0 8 4333 412 4 805 11 04566 00123 0 10 6966 412 7 438 viding total F among the fisheries ac- 12 02MO 00123 0 11 5 5030 412 502 1320 03571 00123 0 12 1703 1703 cording to the proportion of total catch of each fishery. M = 0.20 seabass are caught by gill netters. full Since the estimates ofM are 0.13 and 1 0 0.WW OW31 2 0 00121 0.0398 recruitment appears not to occur until 0.30, the YIR analysis was performed 3 0 OM90 0 age 9 or IO (Table 2 I ). The age composi- forM =0.13.0.20.and0.30. Itwasalso 4 0.0018 o.ow0 0 5 0.0107 00040 0 tion ofthe U.S. commercial fishery may assumed that all undersized fish caught 6 00141 00090 0 be changing since the Mexican compo- 1 O.OU)3 0.W90 0 are released and do not subsequently 8 00852 OM90 0 nent is declining due to a reduction in die. Size limits or alternative fishing in- 9 01206 oowo 0 permits issued by the Mexican Gov- 10 02943 oowo 0 tensities may influence future recruit- 11 03703 oom 0 ernment. ment; unfortunately the analysis could 12 02100 OW90 0 15-20 02910 oowo 0 There has been a minimum size of 28 not take this into account. inches for the sport fishery: however. Results of the analysis indicate that if M = 0.30 1 0 0 Ma3 0 MI1 the bag limit has included one under- a uniform minimum size limit was set 2 0 0 M50 0.0149 sized fish per person except from 1971 3 0 0 W50 0 such that YIR for the entire fishery 4 o mm 0 0050 0 to mid- 1973. Due to the low catch rate. would be maximal. a I2 percent gain in 5 0 W52 0 OM0 0 this one undersized fish essentially 6 0 0152 0 wso 0 YIR would be realized (M = 0.13. 7 0 0281 0 W50 0 eliminates the minimum size require- minimum size = % cm). The expected 6 0 0534 0 m50 0 ment. Also the "sea trout" fishermen 9 0 0803 o ms 0 increase would be only 4 percent ifM = 10 o ma 0 w50 0 often fail to recognize their catch as 0.20 (minimum size = 71 cm), and no I1 0 2294 0 0050 0 white seabass and consequently. fre- 12 o 1420 0 0050 0 gain would be expected if M = 0.30. ism 0 1950 0 00% 0 quently violate the minimum size regu- whereupon no size limit should be im- lation. posed. These changes in yields are in- In order to take into account these dependent of the 20 percent gain in yield Next we examined what might hap- differences and to detect the possible to be expected from increased effort depen to the YIRforthe variousfishenesif interactions between various fishery scribed above. the commercial fishery were to experi- segments. a yield per recruit analysis ence a 50 percent reduction in its fishing was conducted using the computer pro- intensity or a 100 percent increase. The WHITE 5EbBAS5 gram MGEAR (Lenarz et al.. 1974). / conclusions are: This program simultaneously calculates I) A 50 percent reduction should Y!R values for a multiple gear fishery as benefit the partyboat fishery by increas- in the case of the white seabass. The ing YIR in numbers and weight. This following three fisheries were included: increase is due to more large fish being U.S. commercial gill nets. U.S. party- available. The magnitude of the benefit boats. and U.S. pierandjetty. The U.S. decreases ifthe value ofM is larger. The private boat and both Mexican fisheries commercial fishery would obviously were not included because of the experience a decrease in YIR. The op- unavailability of catch and age composi- posite is true for each fishery for the 100 tion data. Therefore. it is implicit that percent increase (Fig. ZOa. b). they are a component of natural mortal- 2) The trends for all three fisheries ity. If they fluctuate they can affect the combined were similar to those of the results of the analysis. commercial fisheries (Fig. ZOa). The necessary growth and mortality 3) The curves in Figure 21 were es- parameters were taken from Thomas sentially unaltered if the fishing inten- (1968). His estimates for instantaneous 4ry for the pier and jetty fishery were mortality coetlicients were reexamined actually twice the original value. and a new value of 0.13 was estimated 4) Since the pier and jetty fishery was for M. based on a regression of total assumed to harvest only age I and 2 fish. mortality rates for 1958. 1959. and 1960 its YIR was unchanged by the variations (obtained by cohort analysis) and for in the commercial fishery. Second. we examined what might 0.20. and by 0-2 percent if M = 0.30 -estimates were made from infor- happen if the commercial fisheries not (Fig. 21). mation on their relative importance in only experienced a change in fishing in- YELLOWTAIL certain years and from likely trends in tensity but also if a strict ?&inch their development. The importance of minimum size were to be imposed on The yerlowtail. Seriokr dorsalis. is these estimated catches appears to be the three fisheries equally. The conclu- probably the most imponant single rather small compared to that of sions were: species to the southern California documented 3ections (about I percent I) A 50 percent reduction in com- partyboat fishery. both in economics of estimated total catches for the period mercial fishing plus a 38-inch size limit and angler preference. A large commer- 1948-53 and between 15 and 36 percent should benefit the sport fishery if naturai cial fishery for yellowtail has existed in for the 1966-73 period). The assump mortality were less than 0.20. If. on the the past. and could be expanded at any tions made. though probably inaccurate other hand. the commercial fishery re- time both off U.S. and Mexican shores. in details. should provide a fair picture mains unchanged or increases 100 per- Therefore. it is essential to determine of actual trends (Table 23). cent. YIR for the partyboats should be the present status of exploitation. max- Annual catch per angler for the reduced because of the elimination of imum sustainable levels of yield. and Coronado Islands (Mexico) area young age groups from the catch due to probable interactions with the sport (CDFG statistical block 916) was cho- enforcement of the size limit. The larger fishery. sen as the best available index of abun- M is. the -greater this reduction in YIR Data dance. The Coronado Islands are the (Fig. ?IC). Data on yellowtail fisheries suffer the closest well-sampled area to the center 2) The size limit should improve same shortcomings as do other primar- of the yellowtail population and tend to commercial YIR at all levels of fishing ily recreational species. Long time be the mainstay of local yellowtail intensity except at the higher levels ofM series catch records are available for sportfishing in southern California. near 0.30. The improvement increases California commercial landings in which exploits the fringe ofa population with lower M (Fig. 31b). weight and for the California partyboat which is centered off southern Baja 3) Trends in the fishery as a whole catch in numbers of fish. Mexican California. Partyboat effort forpre- 1960 are similar to those for the commercial commercial landings in weight are years was calculated using the conver- fishery. known since 1966. The only length dis- sion I.0073 anglecangler day based on 4) Thepierandjettyfishery wouldbe tributions available allowing transfor- the meanof 1960and 1961 observations. eliminated if the size limit is enforced. mation of catches in numbers to catches Panyboat catch. in number of fish 5) If the pier and jetty fishery were in weight refer to partyboat catches in caught. was transformed to weight actually double the estimated size. a 1973 and to individual samples occa- caught using the average weights of fish :&inch size limit should cause the Y.R sionally taken from various U S. caught for the two periods (10.86 for all fisheries to increase by 5- IO per- catches (sport. commercial. and re- pounds for 1947-34and 12.78 pounds for cent if M = 0.13. by 2-5 percent if M = search) during the period 1951-44. Since 1966-73). Overall standard effort was size composition of catches is known to estimated by dividing total catch in vary between fishery segments (see Fig. .NHITE SEbBASS weight for all fisheries by the Coronado ,- 22) and with time in relation to changes lslarida CPUE thus obtained. in the amount of fishing. these two sets Indices of apparent abundance de- of data are notably insufficient to build rived from aerial surveys have also been up the sport fishery catch (in weight) published, but because yellowtail are -2ot r*,OZObj//l during the whole period considered. \ridom observed from planes. the Despite these limitations. annual 30L ..a3Qd method probably does not provide a re- catches by fleets have been tentatively liable index of relative abundance for xconstructed for two periods- 1947-54 such species (Squire. 1972). Therefore. mu 1966-72 respectively-selected for ,,,' , this source of data was not used in the ihe following reasons: I) Availability of M.013/,,' ,, COUHERCIAL FISHERY present analysis. 0 -to1 m ,I length frequency distributions (and length/weignt relationship): and 2) The Historical trends relative stability ofthe amount offishing During the warm water years of 1957 taken as a whole during each of these through i959. yellowtail appeared in two periods. unusual abundance in southern Califor- For such conditions of fishing stabil- nia waters and angler success reached ity. the >port fish catches were con- record Levels. The warm water verted to weight by applying the corre- phenomena aroused interest in the ef- rponding average weight of fish in the fects of ocean temperature on fish dis- hize composition samples to all years tribution and availability. and Radovich within the respective time series. ( 1963)presenteda hypothesis that warm For the vanous fishery segments for oceanic conditions may bring about a which no dataare available-essentially northward shift ofthe yellowtail popula- U.S. sport fisheryotherthan partyboats tion. and as southern California is nor-

22 mally at the extreme edge of the population. this movement considerably increases the local abundance. Exam- ination of data from more recent years supports the hypothesis (Radovich. 1975) and a scatter diagram of CPUE in - numbers perangler day at the Coronado 1947 1037 98491 6 95 (934) (10.046) 1948 2466 101381 1303 1192.21 110 577) Islands versus annual mean sea surface 1949 159 73016 17 71 1232.41 17.5501 19% 57 35242 assumed 697 I9231 13.822) temperature at Scripps Pier in La Jolla 1951 145 46553 10be 2372 1309 51 14.979 shows a distinct relationship (Fig. 23). 1952 51 1 939G9 negligible 59 26 177651 l10.224) 1953 144 51960 27 70 (363.8) (5.577) On the other hand. the temperature re- 1954 118 le449 40 87 (54301- (2.2W)- lationship is not as pronounced for the 1955 56 1588 - 3647 1956 186 3523 - 29 20 - - common range of water temperatures. 1957 1509 358 1 - 24269 1568) (2995) - - It is still worthwhile to examine the ef- 1958 1055 641 - 12338 (296) (15301 - - 1959 2072 241 - 45735 111211 ,5896) - fects offishingin more "normal" years. 1961 807 3001 - 42.12 (10.8) 152.91 - - The period 1948-54 corresponds to 1962 371 151 4 611 1 21 79 (57) (27.5) - - the end of a stable era of high exploita- 1963 254 443 261.3 41.68 11131 15861 - - 1954 259 842 14814 38.w i115i id951 - - tion by U.S. commercial boats operat- 1965 12.5 115.3 9383 116% 1113) 1234 - - ing mainly near Magdalena Bay, Baja 1986 359 2093 7616 7294 129.01 1102.01 l1.30361 (2.310) 1967 132 1375 642.7 1600 (240) 140.01 151121 (1.305) California. During this period. initiated 1 968 22.5 1407 1.9011 3501 I3941 1745) 19520 13.0161 in 1935. commercial landings fluctuated 1969 117 2224 6712 4470 (573) 102.01 11.303.61 (2.209) 1970 58 3 1279 528.0 72.55 (534) 128.01 I1 610.31 12,3231 between4and IOmillionpounds withan 1971 310 3595 308 1730 (40.7) 158.01 (74121 (1,163) 1972 96.1 163.0 '1740.01 31.08 I4601 (7701 I984 1) (1.9831 average of 6.3 million pounds. Between 1973 82.5 152.8 18692 18989 l100.11 (2900) 13.80721 15,712) 1948 and 1954. U.S. commercial land- - ings and sport catches amounted to about 92 percent and 8 percent of total catches respectively. Cannery demand for yellowtail ceased after 1954. causing a considerable drop in U.S. commercial yellowtail fishing operations. As a consequence, their landings have fluctuated around 230.000 pounds since 1955. Since then a commercial fishery has developed in Mexico. and sport catches from Cali- fornia and Mexican boats have more than doubled. Yet these overall landings remain far below the previous level. During the 1966-72 period total catches have averaged 7 I percent below the 1947-54 level. Simultaneously the catch per angler (partyboat) increased by about two-thirds above the 1948-54 YELLOWTAIL LENGTH lcml level and the overall effort is now at IO percent of its level at the end of the period of intensive fishery (1948-50) (Table 24). The result of such changes in participation in this fishery is well illustrated by the following percentages (of total catches):

US Mexico Sport ----PBnOd commercid ~ommer~tal tlShen86 194854 95% Negligible 5% 1966172 11% 37% 52% Reported mean weights of fish caught (about IO pounds in 1935 according to Fry( 1973). I0.86poundsin 1952-54. and 12.78 pounds in 1973) are in agreement with the general reduction in the amount of fishing deduced from trends in total 23 catch. Length composition shows an in- YELLOWTAIL crease in the proportion of older fish I between 1952-54 and 1973. I En Present state of exploitation

Using Gulland's ( 1969) approximation method for assessing equilibrium curve. yellowtail CPUE dataITdble 24) I5 for partyboat anglers *ere plotted against average total effort (average of past3yearsinordertotakeintoaccount the approximately 6 years duration of exploited phase). Since data are only available for the periods of 1948-51 and 1966-72. respectively. the number of points is small: however. they appear to give a fair picture of the above trend in responding effort is not essential. Al- regulations are not justified on biologi- recent history of the fishery. A slightly though the data used suffer from various cal grounds. curved line describes the relationship limitations. it seems reasonable to con- In addition. a 28-inch size limit has between CPUE and total effort (Fig. clude that stock abundance increased been introduced for the California 24). and the derived equilibrium yield following the reduction in the amount of commercial fishery. Apparently such a curve shows a maximum of about 8.5 fishing since 1955. The stock appears to measure has been based on size of first million pounds for a corresponding total be in very good health. Sport catches maturity (alltish are said to be mature as effort of2.5 to 3 x IO6 Coronado Islands have improved under the present level 3 years old. or 27.8 inches). However. partyboat angler standard units. Le.. since exploitation has been iar from there is no scientific evidence. either in roughly 8 to IO times the 1966-72 level. maximum sustainable levels. The stock yield per recruit or in recruitmenb' Estimated MSY is slightly above the is capable of producing much higher parental stock to justify such regula- average catch for the 1935-54 period of yields (3-4 times or more). however. at tion. Although .M LS not known. the high fishing. the cost of a corresponding decrease in present low level of exploitation Under the present conditions of ex- sport CPUE (Fig. 24). It shouldalso be strongly ruggests that the maximum ploitation. determination of the exact noted that neither the southwardexten- yield per recruit would be achieved positions of the potential and of the cor- sion of the stock nor its relationship for a ,mailer size at first capture with other stocks located in the Gulf of than the legal one which represents California and more southern waters. is ahout 0.55 the maximum sizes of fish very well known. It is. at present. as- caught. Examination of yield per recruit sumed that such stocks do not contrib- tables (Beverton and Holt. 1966) indi- ute substantially to the California cate that ifMiK = I.50(K = 0.136). and fisheries. If this assumption is not to be fishing mortality is low (less than .M). confirmed. expansion of fishing in more yield per recruit could potentially be in- 1947 a 229 southern waters might provide higher creased from 6 to 16 percent by lowering 1 948 0 232 1949 a 290 yields. minimum size from 28 inches. If M!K = 1950 a 174 0.75 only a 1-4 percent increase would 1951 a 451 Analysis, discussion of 1952 a 620 be expected, as 28 inches is nearer 1953 a 3e4 present management measures 1954 0 664 proper minimum size for low mortality I955 a 644 Between May and August the U.S. rates. Stock recruitment relationship 1956 a 489 1957 1913 commercial yellowtail fishery is now should not raise particular problems at 1958 1315 subject to several limitations: Catches the present level of fishing. and even for 1959 4312 1418 per trip are limited to 500 pounds per wbstantially higher ones. since the long 1961 a559 Asherman and 2.500 pounds per boat: life span of >ellowtail and the cubse- 1962 a 518 I963 0 869 use of purse seine and round haul nets I\ quem high number of year classes pres- 1964 0716 prohibited. and gill nets must have a 1965 a 304 ent in the population should make it less 1968 0 886 minimum mesh size of 3.5 inches. Simi- vulnerable to successive low recruit- 1967 0 380 1988 a682 8460 357 larly. a daily bag limit of IO fish is ap- ments. It shouldalso be mentioned here 1969 0452 5779 3~2 plied to the sport fishery which tires that the minimum mesh size does not 1970 0633 8092 207 '971 0319 4082 285 only hook and line. Considering the appear to correspond to the legal 1972 a455 5802 309 present low level of exploitation of the 1971 1441 ,8114 315 minimum size and sublegal size tish may stock and the fact that 50-60 percent be captured. Such a situation is inap- of the total catches are taken in unregu- propriate both on hiological and lated waters off Baja California. such economic grounds. 24 It can be concluded that at present no limitation appears to be necessary in the yellowtail fishery. However. the limited potential of the stock would require early formulation and implementation of proper management measures. should the fishery expand in the future. INTERACTIONS Fisheries seldom act in the absence of important interactions from other fisheries. species composition and trophic relationships. and exogenous environmental influences. These interactions are complex in southern California waters. Here we have selected some relevant aspects for USSR quick investigation. Fisheries interac- High UI~ Ollshore USSR tions are an important aspect of the (US northern anchovy exploitation con- troversy. andare bnefly discussed. with emphasis on the live bait anchovy supply. Species composition of both commercial wetfish Reet and partyboat catches have undergone large changes in recent years. A strong argument against large-rcale exploitation of the northernanchovy has been basedon the necessity of this species as forage for Unfortunately. each fishery is presently Live bait anchovy fishery game fish. Discussion of these topics regulated by a different agency and it The southern California live bait may be of use in gaining perspective on will be impossible to manage the stock fishery is the supplier of bait for the status of the individual stocks dis- scientifically or efficiently unless the sport fishermen. The bulk of the bait cussed in this report. various agencies are able to establish a goes to partyboat utilization. Thus. the common basis for discussion and op- live bait fishery operates under two Northern anchovy fisheries timization of anchovy exploitation. simultaneous sets of constraints. Sup- interaction and allocatlon Presently there is a healthy cooperation ply is limited by availability (CPUE) of Three separate Reets presently ex- and communication at lower levels. as is anchovies. while demand is determined ploit the northern anchovy. Engruirlis necessary for formulation of manage- by sport fishing activity. Fortunately. rnordax: The southern California live ment alternatives. Cooperation. how- analysis of these relationships is possi- bait Reet: the southern California ever, must occurat the highest levels of ble due to the availability of voluntary wetfish fleet: and the Mexican wetfish State. Federal. and foreign govern- live bait catch and effort logbook data Reet based in Ensenada (Table 25). To ments so that coordinated and respon- and extensive partyboat effort data col- these may be added the possibilityof the sive management is implemented. lected by CDFG. entry of Russian vessels as evidenced Establishment of such a forum will Supply was approached as a problem by recent experimental offshore trawl- be difficult. in CPUE. with catch measured in ing for northern anchovy. These An initial attempt at establishing suit- scoops (about 15 pounds of fish) and fisheries must be expected to show both able criteria for allocation might be effort in boat trips. The CDFG Statisti- short- and long-term interactions. and basedonpricepaidpertonoffish(Tab1e cal regions 6.7. and 8. corresponding to the nature of these interactions should 3),which tends to reilect the value Santa Barbara. Los Angeles. and San be a major input to plans for allocation consumers put on the fishery product. Diego areas respectively. were investi- of the anchovy resource to the various Such an index could be improved by gated separately. users. including other factors such as yield rel- Annual CPUE values were calcu- The problem of allocation has gener- ative to maximum (or optimum) sus- lated as annual catch divided by annual ally been avoided since simple. conser- tainable yield and variations in price trips. This glosses over seasonal varia- vative management has been acceptable with supply, or these factors could be tion. but gives a good view of the long- to the interested parties. Future de- included as components in a general al- term trend (Fig. 25). Assuming fishing velopments may alter present attitudes location model. By this simple price vessels have not changed in fishing toward the fishery in California. and ex- index. the live bait fishery far outweighs power. and neglecting sardine catches. ploitation by foreign fleets will certainly the reduction fishery in importance and there has been a large increase in avail- undergo expansion in the near future. should be given full consideration. ability of anchovies in recent years.

2s Both the San Diego and Los Angeles regions show this trend. The Santa Bar- bara regjon appears to have experienced an increase in availability up to NO"rBd"C1IM 1969. but it sutfered a severe decline in 60-61 - 1576 1664 4621 0906 3'95 7916 0907 61-62 1510 2656 0505 2669 4077 0351 7"S3 5167 -03.2 CPUE in 1970. 1971. and 1972. 62-63 '426 1959 0316 2413 3515 0376 4760 5718 0179 63-64 1175 2024 0544 1929 4544 0657 2039 6401 1144 Separation of short-term fseasonal) 64-65 1301 '917 0328 2320 4253 Om 2436 5484 0.908.. and long-term trends in availability. 6' 98 2505 1414 -0572 9406 5746 -0493 3601 5810 0456 vis-a-vis the reduction fishery, was ac- 1600 1925 0236 3467 4460 0434 3869 6083 0531 complished by separating CPUE ob- 0 5209 4315 0467 2933 7449 0510 1641 9853 5535 servations into long-term groups (re- RedUCliOn 65-66 208 2436 00s) 2961 4779 1419 2878 .135 u7a duction fishing seasons of 1%5, 1966, 6667 1380 2296 3539 3341 5136 0430 3497 13U38 1316 1%8. 1969. 1970. and 1971. and non- 66-69 2258 2¶46 .967 465 1 7264 0449 4694 6990 0398 6k70 1415 1636 ,146 3198 7739 3884 5470 6674 0484 reduction seasons of 1960. 1961. 1962. '0 '0 71 696 1335 046 5140 0263 0024 6734 9302 0323 1%3. 1974. and 1967). and into short- 71 12 838 in0 07- 7173 8~10175 7043 20311 0952 term groups (reduction period. 1466 2071 0403 4411 6477 3407 5166 10758 0702 winter-November. December. Jan- I 6591 595 0271 1609 1591 0295 '895 5266 031 uary. and March: non-reduction period. summer-June. July. and Au- gust). The long-term availability has likely increased since the mean CPUE's for all three geographical regions for the summer period were higher for the reduction years than for the previous non-reduction years (Table 26). Winter availability shows a similar trend for Los Angeles and San Diego. but a slight decrease for Santa Barbara. particularly for the most recent years. The tendency for increased availability in recent years. despite the reduction fishery. presumably has been a result of an increase in anchovy abundance (we have assumed an increase in vulnerabil- OY"" """" '" " ity or fishing power has not occured). 951 1955 1960 '965 em YEARS Values of anchovy bait CPUE (Fig. 25) Flpur. 21.-Anshow Ih. ball CPUE (annud scwpdup). show a weak correlation with egg-and- larvae indices of abundance of the central stock of anchovies lr San Diego = 0.65. r Los Angeles = 0.51. r Santa Barbara = 0.45). Offsetting the years to account for the younger age of bait an- i chovies did not give significant increases in correlation coefficients. Short-term changes in anchovy bait availability. presumably caused by decrease in winter availability due to reduction fishing. were examined by comparing summer/winter ratios (in natural logarithms) of CPUE during years of reduction fishing with ratios for years in which there was no reduction fishery (Table 26). Mean relative winter availability decreased 11 percent in the Santa Barbara region and I2 percent in the San Diego region during years of reduction fishing, but in the Los Angeles region. in which reduction fishing was presumably the heaviest. the mean of ratios showed an 8.6 per-

26 cent increase in relative winter availability. The variance of the log ratios is 0 Region 8 (SonDlego) large so no tests of significance were 4 Region 7 (Lor Angalen) attempted. Region 6 (Sonto Barbara) It is concluded that bait anchovy availability has not shown either long. or short-term decreases connected with the anchovy reduction fishery up to the 1971-72 level of reduction catch. The San Diego and Los Angeles bait regions appear healthy. but the Santa Barbara region shows a large anomaly startingin 1970. The live bait fishery is also highly d influenced by bait demand. with com- * mitments to bait users varying with - amount of sport fishing effort. Letting or I I 1 I I 1 1 I 1 J the number of partyboat anglers be an 1960LL 1962 1964 1966 1968 1970 1972 index of demand (as we have no values YEARS for private boat utilization of bait) and flQu" 27.4nchW Iln ball MnIMPS.). letting the bait catch indicate the supply for that market. an index of bait supply to the sport fishermen can be calculated. The trend of live bait catch per partyboat angler shows a fluctuating. but 0 REGION 8 (SonOieggo) .e2 fairly constant. supply to the angler for lo- A REGION 7 (Lor Angelor) .61 the San Diego and Los Angeles regions. REGION 6 (Sonto Barbara) but the Santa Barbara region shows a long downward trend since I%2 (Fig. 26). The years 1969 through 1972 show extremely poor bait supplies in Santa Barbaraand the 1%9 point is unusual in that CPUE was the highest on record for the Santa Barbara area (Fig. 25). Examinationoftrendsineffort showthe expected reduction in effort for San Diego and Los Angeles areas where CPUE increased. but shows a decrease in effort for Santa Barbara when CPUE also decreased (Fig. 17). This suggests that either commitments to the fishermen decreased. or it became economically unfeasible to fish at the low level of bait availability. which is unlikely as the price of bait can be ad- Possible relationships are K = 0.85 justed accordingly. The anomalous be- scoops/angler for 1969-72. again sug- havior of the Santa Barbara fishery in gesting a reduction in level of commitment for recent years. 1969 supports the former hypothesis. OT = K CPUE-' $ Levels of commitment can presum- The ratio of bait catch to partyboat J% anglers was auggested as a measure of ably change due to changes in the rela- commitment above. Letting K beacon- A plot of&,

27 low availability in the Santa Barbara

t 0 BONITO area is a condition which has existed at b ANCHOVY, BONITO !east since 1951. and is probably not the result ofthe anchovy reduction fishery. A JACK MACKEREL, ANCHOVY, Moreover. there is some evidence that BONITO the Santa Barbara bait fishery has estab- A PACIFIC and JACK MACKEREL, lished lower commitments rather than 200 increasing etTon to maintain the supply ANCHOVY, BONITO to the sport fisheries. Lack of further 0 ALL plus SARDINE information on the Santa Barbara bait Heet and fishery prevents a definite con- clusion. and there may be other factors !- which explain this anomalous behavior. a Southern California ? wetfish fishery 0 W Species caught by the wetfish fleet L include Pacific sardines. Pacific mack- G erel. jack mackerel. Pacific bonito. and -I northern anchovy. and small amounts 3 z of a vanety of other species. The major- 3 V ity of the commercial catch is landed in the Santa Barbara. Los Angeles. and Tan Diego regions with the San Pedro wetfish fleet accounting for most of the fishingeffort. Priorto the collapseofthe sardine stock. almost the entire effort was directed toward sardines. Since the 1951 collapse. the catches of the four other species have sustained the fishery but have Huctuated for various reasons (Fig. 29). Documentation of the fishery interactions between wetfish species is useful in the assessment of any one of the stocks. After the vlnual collapse of sardines in 1951 and until 1963. the total catch of the five species varied between 80,OOO and 130.ooO tons annually. When sardine catches temporarily improved, catches of the others usually dropped. The anchovy uas canned for human consumption and made up from one- quarter to one-third ofthe fishery until 19%. Jack mackerel catches sustained the fishery when sardine5 were low and dfter the demand for canned anchovies declined. Pacific mackerel catches were consistent from 1954 until the collapse of the stock in the mi-19Ws. Bonito catches were low because of low stock \izes in the early 1950's and lack of pro- cecsorc' demand. The combined catch of 311 five cpecies reached a low of J3.ooO tons in 1965. Beginning in 1966 the composltion of the wetfish catch changed. Sardine and 1970 973 Pacific mackerel catches failed to recover and fishing moritoria were im- po\ed In 1967 and 1971 for the two stocks respectively. Bonito catches jumped in 1966 and have since fluctuated depending somewhat on pro- 1, WlTE SEA 8155 YELLOWTAIL cessor demand (Perrin and Noetzel. WHITE SEA EA55 1970). The jack mackerel catch has dropped apparently as the result of effort being redirected toward anchovies. This new interest in anchovies is due to the California Fish and Game Commis- sion allowing anchovy reduction for fish meal in the fall of 1965. Recent high catches are a result of high prices paid for fish meal brought on by the collapse of the Peruvian anchoveta fishery.

Southern California 50 55 En m partyboat fishery The status of the partyboat fishery is largely the result of the satisfaction obtained from the angling experience: however. angler satisfaction is a difficult concept with which to work. It is generally not quantifiable as is profit in the case of commercial fisheries. It varies widely between anglers. and generalizations are likely to result in overlooking the variety of individual experience. In view of these problems. the following discussion attempts to assess the status of the partyboat fishery in simple terms with enough quantifications to allow rough comparisons between years. The partyboat catch is composed of a multitude of species of varying interest to the angler. Total CPUE regardless of species, in number of fish per angler- trip. shows an upward trend since 1950. having doubled the overall catch rate since that time (Fig. 30). Such a trend in CPUE of combined species has a limited meaning in assessing angler satisfaction. however. as species composition of the catch is of prime importance to the sport fisherman. Nine species compnse the bulk of the landings (Fig. 30). These species were divided into three groups based on a subjective classification. The first group is composed of large sport fish: white seabass. yellowtail. and albacore (Fig. 31). The tecond group is composed of smaller ‘,port fish: barracuda, bonito. ao1 50 and Pacific mackerel (Fig. 32). The YEAR third group is composed of ”food” species: kelp and sandbass. rockfish and halibut (Fig. 33). The CPUE was calculated as total partyboat catch divided by total anglers. which in this case includes long-range partyboat data.

29 Both the large and small sport fish was later ignored in favor of the highly In summation. the partyboat fishery groups show large increases in catch available sport fish species in the warm experienced an increase in availability rate during and following the warm water years. With the slow decline of of medium and large sport fish during water years. Catch rates for these func- sport fish availability to previous levels. and following the warm water years. tional groups have tapered off more re- the "food" species were again sought. Catch rates for these groups of fish are cently and appear to have returned to It appears likely that the period of high now returning to levels similar to those levels comparable to the early 1950's. \port fish abundance caused an increase of the early 1950,. The fishery appears The species composition within these in the catch level necessary for angler to be producing an angler experience groups has changed considerably since satisfaction. This need for more fish has comparable to or better than that of the that time. however. been filled mostly by rockfish. which early 1950s and therefore must be con- The biggest change that has occurred furnishes the expected catch. but angler sidered to be fulfilling angler expecta- in the partyboat fishery is the increased satisfaction falls short of that provided tions no poorer than they did in the early effort directed toward the "food" by the livelier sport fish. The ability of 1950's. group. particularly rockfish. The the rockfish resource to withstand in- rockfish resource appears to have been creased harvesting is unknown and Sport fish-anchovy "discovered" in the mid- 1950's. hut should be seriously investigated. relationships The trophic relationships are complex between forage species such as anchovies and sardines and predatory game fish species such as yellowtail. barracuda. bonito. white seabass. and albacore. An attempt to descnbe the food webs and to quantify energy flows between trophic levels for the last 20 years is beyond the scope ofthis report. Furthermore. necessary estimates of I growth rates. daily food rations. and predator biomass do not exist. On the other hand. biomass estimates for sar- 42 dines and anchovies and partyboat CPUE provide enough information for $1 a supeficial examination of the relationship between biomass of these for- 'I age species and the availability of the major game fish. A plot of anchovy and sardine biomass estimates for all stocks versus combined partyboat CPUE (pounds/ angler) for yellowtail. barracuda. white seabass. bonito, and albacore for the years 1950-69 tend to support 600r rhe general theory of Brocksen. Davis. - dnd Warren (1970) (Fig. 34). They 00- 1953 - W hypothesize that if forage is limiting, then a negative relationship would WIn 1956 ' 5 400- he expected between forage biomass A and predator biomass such that high P levels of predators should reduce forage z to low levels, and at low levels of pred- +0 ators. forage would grow to high 5 200- !evels. If the system becomes more 4 a a productive as result of environmental 0- events. the relationship still holds ex- :: cept at much higher levels of both prey and predator biomass. 01 2.0 40 6.0 80 The data for southern California sug- ANCHOVY AND SARDINE BIOMASS i106 tons) gest three time periods. The first is the years 1950-56 when forage biomass and game fish index were both relatively low. The second. 1957-60. appears to be ability in southern California nor does it 1950-53 and 1961-65. This contradicts a transitional period during which for- support the contention that game fish the suggestion that the forage supplies age biomass remained low but the index influence anchovy stock as much as in 1950-53 were influenced by game fish ofgame fish increased greatly as a result suggested in Figure 35. Examination of to the same extent as those in 1961-65 as of the warm water. the time series in Figure 35 suggests that suggested by similar slopes and scatter The third period. 1961-66. appears to the increased availability of game fish of points in the anchovy-sardine be a regime of greater productivity in during warm water years did not reduce biomass and game fish CPUE relation- general. An examination of CalCOFl anchovy-sardine biomass as theory ship (Fig. 35). data from Thrailkill (1969) suggests a would suggest. Either the productivity In summary. the trends in forage slight increase in plankton volumes for of forage increased simultaneously or biomass and game fish availability are the 1960's over the 1950's if 1953 and the predator species being considered probably coincidental. The evidence is 1956 are ignored (Fig. 35). This trend did not influence forage biomass too incomplete at this time to demon- may be more significant if salps are significantly. The high CPUE values for strate the degree of dependency of game eliminated from the volume means. If the third period are not the result of a fish on forage supplies. the first and third periods are treated composite of similar increases for the five species but result mainly from in- separately. assuming levels of produc- ACKNOWLEDGMENTS tivity are indeed different. it might be creased catch of bonito which appar-.. concluded for each that forage biomass ently established a larger population in This study has been made possible by is influenced by the abundance of these the southern California bight during the the cooperation of many people. Much game fish. warm water years. Whereas the CPUE ofthe data contained in this report were Unfortunately this analysis is an declined during the mid-l96O's while unpublished and were made available oversimplification of the relationship forage supplies increased. the abun- through Isadore Barrett. NMFS: Gail and is not supported by a more detailed dance of game fish is not obviously de- Campbell. CDFG: Harold Clemens. examination of the evidence. First of all pendent on forage supplies. CDFG: Robson Collins. CDFG: Ig- the food web is much more complex The biomass of anchovles and sar- nacio Felix Cota. the Instituto Nacional than suggested by the analysis. The dines lost to natural mortality each year de Pesca (INP); Charles Hooker. number of forage species is greater than can be estimated by ZiiM,B, where in- CDFG: Eric Knaggs. CDFG; Kenneth two. Squid, for example, are also impor- stantaneous rate of natural mortality Mi Mais. CDFG: Leo Pinkas. CDFG; tant but annual estimates of biomass are is assumed to equal 1 .O and 0.8 for an- Patricia Powell. CDFG: Donald not available. The abundance of forage chovies and sardines respectively. and Schultz. CDFG: Paul Smith. NMFS: species in any one year may be more where Bi is the annual average biomass James Squire. Jr.. NMFS; and James dependent on recruitment than on graz- of each species. The estimates average Thrailkill. NMFS. Bruce Wahlen and ing by predators. Information from 1.0. 3.0. and 6.0 million tons from total William Altland spent many weeks col- MacCall (1973) suggests that anchovy stocks of anchovies and sardines for the lating these source data. We wish to recruitment has been relatively con- years 1950-53. 1954-60. and 1961-65 re- thank the INP for its contribution of stant for years 1960-65. Thc partyboat spectively. The proportion of this vital Mexican catch data. and the CPUE does not include all the major natural loss due to predation by game southern California live bait fishermen predators: birds and marine mammals fish can be estimated by making as- and the Ensenada Sport Fishing As- must account for a large proportion of sumptions on feeding rates and game sociation for their voluntary submission the annual mortality. Albacore has been fish biomass. To find likely maximum of catch and effort information. We included in the CPUE index for two values for these ratios, it was assumed would like to thank Norman Abramson. reasons. First. the original CDFG par- that combined rates of exploitation on NMFS: Clark Blunt. CDFG: William tyboat statistics includes albacore trips game fish for all fisheries were near 5 Fox. NMFS: David Kramer. NMFS: and. second. stomach samples of alba- percent annually, that game fish con- William Lenarz. NMFS: John Rado- core collected in southern California sume 5 percent of their body weight per vich. CDFG: and Brian Rothschild. have contained 55 percent anchovies by day in anchovies and sardines. and that NMFS for their review and criticism volume(Pinkas. Oliphant. and Iverson. game fish feed 200 days per year on the of the manuscript. We wish to extend 197 I). The species of game fish included anchovies and sardines. The estimated our thanks to Roy Allen for preparing in the CPUE index are highly migratory proportions of mortality are 100 per- the illustrations and the SWFC typists so that the quantity of game fish present cent. 50 percent and 25 percent for the for typing the manuscript. in any one year is most likely due to periods 1950-53, 1954-60. and 1961-65 This cooperative study was sup- contemporary conditions of the ecosys- respectively. For the earlier years. food ported by the California Department of tem rather than population dynamics of supply may have indeed been a limiting Fish and GameiNational Marine the game fishes. Furthermore. par- factor. The assumptions and absolute Fisheries Service contract entitled tyboat CPUE may not be proportional values of the ratios are relatively unim- Stock Assessment. Fishery Evaluation to biomass of game fish. portant. invariably leading to the con- and Fishery Management of Southern Additional evidence does not support clusion that the influenceofgame fishon California Recreational and Commer- the contention that increases in forage forage supply should have decreased cial Fisheries. No. 03-4-208-160 and biomass will increase game fish avail- rather significantly between the penods 03-5-208-60.

31 LITERATURE CITED regulauon for Atlantic yellowtin CUM. Thunnui biomass of northern anchovy. Engroulis albarorrs. Fish. Bull.. U.S. 7237.61. rnordox Fish. Bull.. U S. 70849.876. Ahlstmm. E. H. 1%8. An evaluation of the VacCall. A. D 1973. The monality rate of Soutar. A.. and 1. D. Isaacs. 1974. Abundance of fishery resources available to California Engrnulis mordax m southern Calrfomra. Calif. pela@c fish during the 19th and 20th centunea as fishermen. Umv. Wash.. Publ. Fish.. New Ser. Dep. Fish Game. Mar. Res. Tech. Rep. 4.23 p recorded in anaerobic sediment off the Califor- .1:65-80. MaGregor. I. 1964. Average biomass estimates nias. Fish. BuU.. US. 72257.274. Baxrer. J. L.. and P. H.Young. 1953 Anevalua- forrhe years 1955-57 In Caltf. Mar. Res. Comm. Sprau. J. D. 1972. Ageand lengthcompor1tionof tion of the manne rponfishig record sysrem !n Mm.6 Mar. 1%. Doc. 6. northern anchovies. Enproulis rnordar. In the California. Calif. Fish Game 39:343-353 Mersersmah. 1. D 1969. The nonhern anchovv California anchovy reduction fishery for the Bevenon. R. J. H..and S. I. Holt. 1965. Manual 1Ensraulir mordml and rts fishery l%5-1%8'. 1%9-70 season. Calif. Fish Game 58:1?1-1?6. of methods for fish stock assessment. Pan Calif. Dep. Fish Game. Fish BuU. 147. 102 D. __ 1973a. .Age and length cornpositton of :-Tables of yield functtons. FA0 (Food Agnc. Murphy. G-. I, 1966. Population biology of ihr nonhern archowes (Enprorlis mordaxl landed Organ. U.N.) Fish. Tech. Pap. 38. 77 p. Pacific sardine (Sardmops caerulco,. Pm. In California for reduction dunng the 1970-71 Erocksen. R. W.. G. E. Daw. andC. E. Warren. Calif. .Acad. Sa.Ser. 4341-84. season. Calif Fi5h Game 59l?l-I25. 1970 Analyr!~ of trophic pmcesser on the Parnsh. R. 1974 Explotmiton and recruitment 01 -. 1973b. ARCand lenmh comwsition bas86 of den,ity-dependent functions. In J H. Pacific mackerel. Scombcr ~(lpmtcu.In !he of northern anchowe;. Enyrouli; mord&. tn the Stcele leditor). Manne food chams. p. 168498. nonheart Pacific. Calif. Coop. Oceamc Fish. Calrfornra reduction fishery for the 1971.71 sea- Unw. Calif. Press. Bcrkely and Los Ang.. Calif. Invest. Rep. 17.:3&IM. >on.Calif. Fi5h Game 59:?93-298. Campbell. 0. In press. The age and growth of the Perm. W. F.. and B. G. Noetzel. -. 1975 Growth rate of northern an- Pacific bonita.Sordo rhdienns. Cahf. Dep. Fish 1970. Economc study ofthe San Pedm wcrfish chovy. Engrauiis mordar. in southern Califorma Game. Fish Bull. boats. Fish. Id. Res. 6105-138. waters. calculated from otohthr. Call. Fish Clark. F. N.. and J C. Mar. 1955. Population Pinkas. L. 1966. A managcment srudy of thc Game 61:1161?6. dynamics of the Pacific Fardine. Calif. Coop Cahfornta barracuda Sphwoenn orqcnim Squrre. J. L.. Jr. 1972. Apparent abundance of Oceanic Fish. Invest. Rep. 1953-55: 11-48. Girard. CaM. Dep. Fish Game. Fish BuU. 134. some pela@c marine fishes off the southern and Collins. R. A. 1971. Sire andaee commsition of 58 p. Central California coast as surveyed by an ur- nunhern mchovic3 !Enyroul,; mumor) m the Pinkas. L.. M. S. Oliphant. and C W. Haugcn. borne monitoring program. Fish. Bull.. U.S Cdaiornta reductnun and .mnmg nshenes 1968. Southern Califorma manne rponfishrng 7OIWS-1119 W-h9 season Calif Fi\h Game i' 33-39 survey: pnvate boats. 1W. shoreline. 1%5-66. ___ 1973 Proceedinns of the Slue- Fry. H..Jr 1937. YeUowtail. In Srdiof Bureau Calif. Dep. Fish Garre. Fish Bull. 143. 43 p. Federal Manne Fishenes Research Program of Commercial Fisheries. The commercd fish Pinkas. L.. M. S. Oliphant, and 1. L. K. Iversan. Planning Workshop. March 12-15, 1973. Sa" catch of California for rhe "ear 1935. 0. 33-36. 1971. Food habits of albacore. bluefin tuna. and Clemente. Cnlrf. Calif. D~D.Fish Game and Calif Dep Fish Game Fish Bull 49' botuto in California waters. Calif. Dep. Fish Natl. Mar. Fish. Sew.. 327'p. Gulland. J A 1969 Manual of methods for hsh Game Fish Bull. 152. 105 I). Sunada. J. 1975 Age and length composition of rtock assessment Pan I Fish Dooulation Pinkas. L . J. C. Thomas. and J. A. Hanron. nonhern anchovies. Enpraulis mordor. the analysis. FAO(F~AFC. Organ. U.N.) an. I%7. Manne rponfishmg wwey of southern 1972-73 season. Califorma anchovy reduction Fish. Sa. 4. 154 p. California mers and ietties. 1%3 Calif. Fiih tirhery. Calif Fish Game 61:133-143. 1970. ___. Preface. in 1. Gulland(edi1or). Game 53:SE-lOa. Thavcr. B. D. 1973. The S~PIUE of the Pacific The fish rcsourccs of the oceans. P. 14. FA0 Radovich. J. 1%3 Effects of water temperature bdnito resou~ccand its utilization. Calif. Dep. IF& Agnc. Organ. U.N.1 Fish. Tkch Pap.97. on the distribution of some scombnd fishes alone Fish Game. Mar. Res Tech. Rep. 7. 16 p. Knagg5.E. H. 1973. Thestaturofthejackmack- the Pactfic Coast of Nonh America. FAO(F& Thomas. J. C. 1968. Management of the white ere1 resource and its management. Calif. Dep. 4gnc. Om. U.N.) Fish. Rep. 3(6):1459-1475 reabasr (Cvno~rmnnobilir 1 in California waters. Fish Game. Mar. Res. Tech. Rep. 11. 12 p. - 1975 Ocean temDemtures and Calif. Dep. Fish Game. Fish Bull. 142. 34 p. Knaggr, E. H.. and P. A. Barnett. 1974. The southern California angling success. A paper Thmlkl. J. R. 1959. Zoodankton volumesoffthe southern California jack mackerel fishery and prescntedattne Symp.on FirheriesScicnce held Pacific coast IW U S-Flsh Wild1 Sew Spec age composition of the catch for the 1947-48 at the Higher School of Marine Sciences of the Scr. Rep. Fish 518. 50 p. rhrough 195657 seasons. Calif. Dep. Fish Autonomous Univ of Baja California. En- Vrooman. A. M..and P. E. Smith. 1971. Biomass Game. Mar. Res. Tech. Reo. 22. 47 D. senada. &a@ Calif.. Mexico. February 1622. of the subpopulations of nonhern inihovy ___. 1975. The southern Cahfornia jack 1975. Enproulrs mordax Girard. Calif. Coop. Oceansc mackerel fishery and age composition of the Smith. P. E. 1970. The horiionlaldimcnsionsand Fish. Invest. Rep. IW9.51 catch for the 1%2-63 through 196667 %ea..ons. abundance of 6sh schools an the upper mixed Walford. L A. 1932. The Califorma barracuda Calif. Dep. Fish Game. Mar. Res. Tecn. Rep. layer as measured by sonar. In G. B. Farquhar ISphvraena arqenieui. Calif. Dep. Fish Game. 28. 28 p. (editorl. Proc. Int. Symp. Bioi. Sound Scattenng Fish BuU. 37. I21 Lenarz. W. H..W. W. Fox. Jr.. 0. T. Sakagawa. in the Ocean. p. 563-591. Maury Center for Young. P H 1969P' The California panyhat and B. J. Rothschild. 1974. An examinabonof Ocean Science. De of Navy. Wash.. D.C. fishery. 197-1967, Calif. Dep. Fish Game. Frrh the yield per i-e~~itbasis for a mnimum size ~. 197: &e increase tn rpawnmg Bull. 145. 91 p.

MFR Paper 1173 From Marine Fisheries Review Vol 38 No 1 January 7976 Copies of fhis paper m limired numbers are available from DE25 Technical Inlormarion Division Environmenhl Science Informaiton Cenrer. NOAA. Weshingion OC20235 Copies of Manne Flsherles Review are available from rhe Supennrendent of Documenrs US Government Prinrrng Offrce Washmgron. DC 20402 for Sl 10 each