MFR PAPER 1173 tions regarding the course of future ex­ ploitation of southern California fish resources except for the determination of approximate limits of sustainable yields and lower limits on age at first capture (Table I). 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, Engralilis mordax, California The tone of this investigation has future, even under the present fishing barracuda, Sphyraena argenlea, 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, Trachllrlls symmelriclIs , achieving maximum cost-effectiveness, difficult to determine the proportion of white seabass, Cynoscion nobilis, and and identifying areas where further in­ catches coming from northem stocks rel­ yellowtail, Seriola dorsalis, are docu­ vestigation is needed and is likely to be ative to those coming from the southern mented in this report. Brief status re­ 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 s port fish stocks are in var­ japoniclls, and Pacific sardine, rine Fisheries Research Program Plan­ ious states of exploitation. The Sardinops c(lerulells, are included. ning Workshop held 12-15 March 1973 yellowtail resource appears to be lightly These stocks are shared by various in San Clemente, Calif. (proceedings exploited, and has shown an apparent fleets fishing along the coast of southern compiled by Squire, 1973). increase in availability to sport California and the Pacific coast of This work should provide significant fishermen since the cessation of large­ Baja California. The U.S. party boat information for the formulation of posi­ scale commercial fishing in 1954. The fishery , in which fishermen rent space tions and plans for regulatory agencies increase in availability may be due, in aboard a boat for a day or half clay, has managing these resources. We have at­ part, to more favorable ocean tempera­ been popular in southern California tempted to avoid making recommenda- tures. Maximum sustainable yield since the 1920's (Young, 1969). In the (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, 1968). A small round haul fleet Paul Troadec, United Nations White sea bass appear to be somewhat supplies bait dealers with live anchovies Food and Agriculture Organiza­ tion. This study was conducted in depleted. Data from the commercial for fishermen on paltyboats and private cooperation between the Califor­ fleet operating in both Californian and boats to use as bait and chum. nia Department of Fish and Game Mexica'n 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 03-4-208-160. The has declined over the last 2 decades, chovies, jack mackerel, bonito, and authorship is arranged alphabeti­ creating some uncertainty as to the true cally. tuna (Perrin and Noetzel, 1970) and status of the stock. The white seabass Table 1.-Present state of exploitation and estimated potential of major recreational/commercial stocks.

Estimated mean annual catch Present major fishery segments 103 short tons (% 1970/72 totat catch) POlentiat yield Geographical 1940- 1950- 196(}- 1970- U.S.-based U.S. Me)(ican 10' State of Stock range 1949 1959 1969 1973 sport Comm. SportiComm. short tons e)(ploitation Remarks

Northern Southern Cali- 3 18 30 129 55 40 '1,500-2,000 Very lightly Allocation requirements anchovy fomia, northern (bait) exploited may redu ce rates of Baja California e)(ploitation. Pacific California, N. 428 91 10 3 some large '3Q(}-500 Depleted Rehabilitation unlikely sardine Baja California (bait) in near future. Pacific Central Cali- 30 20 16 33 33 34 '30-50 Depleted Rehabilitalion unlikely mackerel lornia to central in near future. Baja California Jack West coast of 34 38 39 24 0.1 89 11 21 (}-450 Probably Size of local stock is mackerel North America lightly indeterminate, but large. exploited California Southern Cali- 2.1 1,9 1,2 0,5 48 2 48 41_2 Depleted Rehabilitation possible barracuda fornia to central in near future. Baja California Yellowtail Southern Cali- 3,1 3.2 1.2 1.5 67 13 20 43-6 Lightly Migration into Calif. fornia and Baja exploited is heavily e)(ploited . California Pacific California and 2.7 1.4 7.6 11 .8 11 87 10-20 Probably mod- Biomass and potential bonito Baja California erately to highly fluctuating with highlyex- recruitment. California ploited residency may be a temporary even\. White Californ ia and 0.5 1,0 0.6 0,5 76 17 0.8 Moderately/ Indices of sea bass Baja California highlyex- abundance conflict. ploited

'At the 1970-1973 population level. 'If rehabilitated to the pre-1944 population level. 'If rehabilitated to Ihe pre-1950 populalion level. AThe 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 barra­ 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 Rockfish 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 party boat 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

2 1950's with respect to abundance of tion of statistical procedures and tests of ceeded, a reduction in fishing effort 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 fleet 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, barra­ justified. The extent to which funda­ timates were based on available infor­ cuda, and white sea bass) 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 1960's, there seems to be little evidence real world, will affect the accuracy of of catches for a particular fishery seg­ tha t either prey or predator biomass the conclusions. ment were estimated by the ratio of shows strong dependence on the abun­ This investiga tion 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 1960'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 weigh t to volume used for the "quick" stock assessment cation of simple fisheries yield models; ratio is approximately constant (15 of some of the more important recre­ moreover, MSY is a likely upper bound pounds/scoop). 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 of the the optimizing criterion be economic Average weights per fish were calcu­ va rious 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 avail­ Stock assessment methods tigation. Thus, we do not wish to imply, able only for a few years in the 1950's in assessing status relative to MSY, that from special studies of the California Stock assessment methods were ap­ catches should necessarily be brought Department of Fish and G a me 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 priority in the face of an Table 2.-Catch data sources. urgent need for information on critical fishery problems. Often the quick solu­ Catch Source Years Availability Units tion will serve as a guide in long-term Commercial California investigation of problems, and can be California waters CDFG 1916-present Published (CDFG Fish Bulletins) Weight considered as a " first cut." Mexican waters CDFG 1916-present Published (CDFG Fish Bulletins) Weight Bait Voluntary (CDFG) 19S1-present Volume Stock assessment procedures have Mexico INP 1962-present Published (FAO Yearbook of Weight three time-consuming operations: I) FAO 1961-present Fishery Statistics)' Weight collection of data, 2) development Sport California and refinement of models, and 3) Local partyboat CDFG 1936-40 Published (CDFG Fi sh Bull. 86) Number justification and elimination of assump­ 1947-present Published (Young . 1969) Number Long range partyboat CDFG 196D-present Number tions. Expedient methods minimize Barge CDFG 1947-present Number these steps. Only available data are Private boat' CDFG 1964 Published (Pinkas et al . t968) Number Pier and jelly' CDFG 1963 Published (Pinkas et al. 1967) Number used; where data are missing, reason­ Shoreline CDFG 1965-66 Published (Pinkas et al. 1968) Number able estimates are made in order to fill the Mexico Partyboat Voluntary (ESFA)' 1961. 1971 Number gaps. Methods tend to be restricted to 'Program in progress 1973. 1974. application of very simple models. 'ESFA-Ensenada Sport Fishing Association. supplied through Instituto National de Pesca (INP). These are further simplified by relaxa- 3Tend to lack sufficient specificity for stock assessment.

3 sampling of sport catches has been Table 3.-Effort unit conversion and area weighting made from more recent data. Individual factor. recently instituted by CDFG. The estimates and assumptions are gener­ 1972 and 1973 length frequencies made ally noted in the sections in which they Area available by it were a great benefit to the weighting occur, but many escape discussion. stock assessments. Where length fre­ Region Conversion' faclor2 Methods quency was lacking, reasonable esti­ San Diego. Mission Bay 1.201 0.19 Dana Harbor, Oceanside 1.318 0.10 mates were again employed. Huntington Beach , Wherever possible, stock status was The second important parameter Balboa 1.121 0.05 determined by a surplus production or San Pedro. Long Beach 1.271 0.12 necessary for stock assessment is an Malibu. Redondo Beach. "Schaefer" model , which in practice index of stock abundance. Traditionally Santa Monica 1.591 011 Santa Barbara. consists of plotting abundance as catch this is obtained by measuring effort Port Hueneme 1.010 0.43 per effort against a mean effort averaged and calculating catch-per-unit-effort Total. over half the fishable lifetime of the fish (CPU E) which is presumably propor­ Southern California 1.215 1.00 (Gulland, 1970). Usually effort (fishing tional to stock abundance I. Effort was 'Anglers/angler day. mortality) is assumed to be related to available for commercial white seabass 'Depth", 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 fishery in 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 Partyboat 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 consistent with effort reported from The presumably steady-state relation­ uni t 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 offishingarea CPU E-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 1960 abundance indices were available to straight line (sometimes not best ap­ were estimated from 1960 and 1961 data verify 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 egg-and-Iarva 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 (F = 56.7, d.f. = 5, 6; P (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 surveys carried out 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-Iarva abundance corresponds to the peak of the yield by annual effort for all areas combined surveys verification of acoustic esti­ curve. Extrapolation 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-Iarva surveys were also tion (particularly toward greater effort) sired, as only total California catch was useful for jack mackerel and sardines. should be interpreted with caution, as available for 1936-40. 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 southern 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 press. 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 were used, or, in the case of white yellowtail and barracuda from their seabass natural mortality, a new esti­ population centers off Baja California 'Recent studies suggest that CPUE may not be linearly proportional to population size. mate (described in more detail later) was into southern California waters is

4 greatly influenced by oceanographic Table 4.-Northern anchovy. biomass estimates and indices of abundance. conditions. The apparent abundance, Overall population Central stock (Southern California and northern Baja California) measured by sport CPUE, depends in part on the extent of this northern mi­ E2~ and larval surveys Acoust ic survey Aerial surveys Spawning biomass Ralio Regression extrapolated gration. The large catches during the anchovy anchovy Annual from regression warm water years of the late 1950's are Year spawning spawning Spawning mean Nighl Day between biomass' biomass' biomass' of surveys2 index3 indexJ (3) and (5) examples. For the purpose of this re­ (10'1) (10'1) (10'1) (10' schools) (10'1) port, the data points for these years are (1) (2) (3) (4) (5) (6) (7) treated as outliers in the surplus produc­ 1940 2.359 1950 279 tion models. 1951 690 637 294 For relatively unfished stocks, where 1952 856 797 410 1953 (1 .404) 1.335 807 biomass is many times larger than 1954 1.937 1.816 855 catch, as in the case of jack mackerel 1955 1.8 55 1.676 1.386 1956 1.307 1.491 919 and northern anchovy, the surplus pro­ 1957 1.869 1.964 1.576 1958 2.875 2.771 1.832 duction model cannot be applied. In this 1959 (2.4 18) 2.299 1.686 case, we have used Gulland's (1970) 1960 3.079 1.918 1961 3.189 1.264 approximation of MSY based on 196 2 6.248 4.362 1.57 0.045 un fished biomass and natural mortality, 1963 6.030 4.861 2.24 0.50 1964 5.121 3.866 3.86 0.5 7 which is itself postulated on surplus 1965 7.771 6.211 4.08 0.71 production concepts. 1966 5.116 4.154 107 3.05 086 1967 174 5.14 202 4.784 The Gulland formula is YpOI = XMB o 1968 (2.167) (2.048) 195 1.35 0.30 1969 3.378 2.993 103 4.39 1.34 POI where Y is potential yield, M is 1970 56 '(7,46) '(6.65) instantaneous natural mortality rate, 1971 101 3.23 1.26 4.166 1972 194 1.41 1.33 3.577 and B" is mean virgin biomass of fish 1973 275 above length at first capture. X is a 1974 (362) M, K coefficient which is determined by 'Alter P. Smith. 1972. lables ~ and 12 and ligUle 13. and A. Vrooman and P. Smilh. 1971.1able 2. Column (1) is (von Bertalanffy growth rater , and derived from a ratio of anchovy larvae to sardi ne larvae relative 10 estimated sardine spawning biomass; column (2) IS derived from the regreSSion of this estimated anchovy spawning biomass on anchovy larvae . length at first capture relative to max­ 'Inlolmalion provided by K. F. Mais. CDFG. imum length. Values for X tend to fall ' After J . Squire. 1972. table 7. compleled wilh recenl yet unpublished data. 4Six months only. 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 sidered here. revised by more precise methods as a not considered for best allocation of re­ Estimates derived from egg-and-Iarva 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 I n fisheries where spawner-recruit re­ Biomass biomass while data from other sources la tionships are obscure and su rplus may include biomass of immature fish. production models give inconclusive Estimates or indices of abundance for Therefore, the estimates are not di­ resu It s, we have attempted to investi­ the northern anchovy have been ob­ rectly comparable. Insufficient infor­ gate yield per recruit (Y/R) as a basis for tained through various independent mation regarding age at first maturity evaluating minimum length restrictions. methods, i.e. , egg-and-Iarva, 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 I year fisheries interaction raised a particular to estimates from eggs and larvae col­ (Knaggs, CDFG3), which also corres­ problem, as in the white seabass, a lected during 16 years, the sUbpopula­ ponds to approximate age of recruit­ complex Y IR 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, spawning biomass is used here This report of northern anchovy, annual values: 40-83 percent) but in as exploitable biomass. If it would be Engraulis mordax , is an overview of the years since 1963 the ratio has been possible to expand exploitation upon relationship between present harvest about 80 percent. Acoustic 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). I ncrease in the Various estimates and indices have central stock accounts for the increase been compared. Correlation coefficients 'The von Benalanffy growlh curve is I, =L", in total biomass of the northern anchovy (I-e-k{t-I,) where II is length al lime I , L ", is since 1950 (Fig. I). Because of this and asymptolic maximum lenglh . k is a growlh rate 'E. Knaggs. CDFG. 350 Golden Shores, Long conslanl, and '0 is hypolhelical age at zero length. its proximity to the California fishing Beach. CA 90802. Pers. commun.

5 between the independent methods Table S.-Comparlson of biomass estimates and indi· ces 01 availability obtained through various methods. 1970), or when expanded to volume and for years in which the surveys have assigned a packing density of 50 fish/m3 coincided are given in Table 5. Corre­ Correlation Years at Source coefficient observation (Mais, pers. commun.). Considering lations are in general not high and general knowledge on reliability of Acoustic surveys! -0.47 1966.67. positive only in the case between esti­ aerial surveys (nighl) 68. 69,71, and 72 egg-and-Iarva survey methodology, to­ mates derived from egg-and-Iarva sur­ Acoustic surveys! -0.08 1966, 67, gether with the extent of sampling done aerial surveys (day) 68,69,71, and 72 veys and night aerial surveys. The ap­ Egg·and·larva surveys/ +0.30 1962, 63. both in time and space, it is assumed parent contradiction between acoustic aerial surveys (nighl) 64, 65, 66. 68, and 69 that biomass estimates used here pro­ surveys and night aerial surveys may Egg·and·larva surveys/ -0.05 1962.63. vide a picture of the stock sufficiently aerial surveys (day) 64.65,66, resul.t from the fact that these two 68. and 69 accurate for present assessment 'prob­ methods do not actually sample the lems. same portion of the overall biomass. Indices derived from nighttime aerial Acoustic surveys may not suitably de­ Table 6.-Northern anchovy catches In short tons. surveys were regressed on concurrent tect fish occurring close to the surface, U.S. U.S. Mexico estimates of the spawning biomass of while aerial surveys record only fish Year commercial bail commercial Tolal the central stock to estimate the concentrations visible in the upper layer 1973 110.885 (6.000) 10.613 (127.498) biomass in 1967, 1971,and 1972(column of the sea. An important source of error 1972 69,101 (6.000) '(60.000) (135.101) 1971 44,853 6.387 (40,000) ( 91 .240) 7, Table 4) for which no egg-and-Iarva is the fact that sonar-based acoustic 1970 96,243 6.105 (55,000) (157.348) surveys are available. surveys have been employed only since 1969 67.639 5,314 4,258 77.211 1968 15.538 7,177 15,694 38,409 Catches 1969. Data for 1966 and 1967 have been 1967 34 .805 5,387 22, 115 62,307 1966 31,140 6,691 14.567 52,398 inferred from echo-sounding surveys. 1965 2,867 6,148 10,088 19.103 Catch statistics for the 1960-73 period The biomass estimates from the egg­ 1964 2.488 5,191 5.059 12,738 are given in Table 6. These data refer to 1963 2,285 4.442 1.039 7.766 and-larva surveys and indices from the 1962 1,382 6,167 736 8,285 the central stock which is essentially the aerial surveys are in more agreement 1961 3.856 5,9 13 (500) (10.269) only one exploited. The mean lengths of 1960 2.529 4,658 (500) ( 7,687) particularly when night sightings are the catches for successive years have considered. As observed by Squire lEstimated from informal sources. decreased. The trend and year-to-year (1972), this may be due in part to higher fluctuations can be caused by changes in efficienc y of aerial surveys conducted at recruitment and natural mortality rates, Table 7.-Central stock: bloma.s (B), annual catch night as compared with daytime obser­ (C), and IIshlng mortality (F) during Ihe 1968·73 exploitation, and/or size selection of the vations. A correlation coefficient can­ period. fishery. (Average lengths of fish in 4 not be calculated for egg-and-Iarva sur­ Central catch : 123.0 mm in 1965-66; 123.1 mm , slack Estimated vey estimates and acoustic data because Year spawning annual F=g, 1966-67; 120 .5 mm, 1968-69; 120.9 mm, the time series do not overlap enough. biomass catches B 1969-70; 127.5 mm, 1970-71 ; 116.1 mm, On the other hand, acoustic estimates (10' Ions) (10' Ions) 1971-72; and 116.0 mm, 1972-73.) of biomass tend to agree with egg­ 1968 2,048 59 003 1969 2,993 114 0.04 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 (3.577) 135 0.04 a verage value of 17 tons (Smi th , 1973 132 from catch data and biomass estimates (Table 7). The F values confirm that the rate of exploita tion has been very low. Considering that, as mentioned above, biomass estimates do not include the juvenile stages, fishing mortality may be lower than the average value of 0.03 observed from 1968 to 1972. Total mortality has been calculated by MacCal1 ( 1973) from catch curves for 5 different years. The value of Z = 1.1 thus obtained indicates that natural mortality M cannot be smaller than 1.00-1.05. Spratt (1975) gives values of 0.3 and 165.5 mm (standard length) for von Berlalanffy growth curve param­ eters K and L x, respectively. The average size at first capture, Ie, is not exactly known, since recruitment oc­ curs during a rather long period (affect­

YEA R ing individuals from about 85 mm to 115

Figure 1.-Time series comparison of the annual total census esllmates of anchovy larvae as grouped by .\ From Messersmilh (1969) , Collins (1971) , Spratt coa.tal section (Irom Smith, 1972). (1972, 1973 a, b), and Sunada (1975).

6 / '\

a commercial fishery and the mainte­ mm). In the following calculations, the ~>/' ~, , 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 1f available. Here we attempt to assess the Y por = X M B 0 can be used for asses­ present status of the stock. sing the maximum potential yield. With Data /K ...L.QS. Ie 105 .0 ,~ . ~ M -1.. .'". ," !' ~. ; ?~:- =0.3=3.5andc=L =165.5= , \ I .'r Catch records for barracuda are simi­ oo r J'!.i' ',/ r_'_ . ,,; - 0.63, the coefficient X would be about / . lar to those of other recreational 0.6 (Gulland, 1970, p. 3). 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 i commercial fisheries operating in mass. As the latter has shown con­ I I ! California waters and off Mexico, and siderable Ructuations 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 1966. 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 Y/R to implement in footnoted in Table 9. Sport fish catches of northern anchovy can produce a yield California regulatory measures aimed at were converted to weights by using from 10 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 (1953). 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 1958, 1959, senada. If this occurs, such vessels will above 2 million tons. Remembering that 1960, and 1961 (Pinkas, 1966) 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 stock as derived from biomass esti­ larger than in the figures given in Table because undersized fish that were re­ mates for the period 1951-72 and abou t 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 1936-5 I period (Baxter and of the 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 25,000 tons per Ructuations. 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 startofthe warm water years. Mean 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 pounds/fish for 1958, 1959, On the basis of available values of M, ing periods of successive low recruit­ 1960, and 1961 respectively were esti­ K , I", and L oo . 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 pounds/fish based on the 1961 samples gain, if the fishery were unrestricted and The California barracuda, Sphyraena was applied to all following years if juveniles were fully vulnerable to argenlea, fishery has undergone a long through 1970. Because the two under­ fishing gear. For example, with the pres­ decline, beginning in the 1930's and end­ size fish (less than 28 inches) allowance ent rate of exploitation (£ = 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 90 mm instead of the present assumed value of 105 mm, both annual yield and catch Table B.-Biomass and corresponding potential yields for the total population and the central stock for 1) rates would, in theory at least, double. the 20·year period of observation and 2) after the depletion of Pacific sardine .tock. Because of the high rate of natural mor­ Correspondi n9 Biomass polential tali ty of anchovy, even for high rates of Time period Populalion mean and range yields exploitation (e.g., F /Z =- 0.8) maximum (H)' tons) (10' Ions) yields and catch rates would be 1951·69 Total 3.200 (640·7.600) 1.900 (40()'4.700) 1951·72 after sardine collapse Central stock 2.600 (29()'6.200) 1.500 (200·3.700) achieved with sizes at first capture 1965·69 Total 4.600 (2.20()'7.600) 2.600 (1.30()'4.700) below 80 mm. Therefore at the present 1965-72 Central stock 4.000 (2.050·6.200) 2,400 (1 .200·3.700) 7 Table 9.-Catches of California barracuda for various fisheries.

U.S. commercial Sport Total Mexico Partyboat Other Mexican Total commercial California Mexico commerCial Calilornia California waters Total est. weight and sporl Fraction Years (Ib) (Ib) (Ib) (fish) (fish)' (fish)' (fish) (Ib) (Ib) sparl x 1,000 1928 4385.2 2067.2 1929 3925.9 1302.7 1930 3513.6 1250.2 1931 3336.1 841 .5 1932 2505.1 421.7 1933 2912.2 160.8 1934 1801 .3 381.6 1935 2003.9 613.9 1936 2247.9 730.0 492.5 (500) (2450) (5428) 0.45 1937 1799.0 1139.4 598 .5 (600) (2940) (5878) 0.50 1938 1260.8 1269.0 314 .2 (320) (1568) (4098) 0.38 1939 2969.2 1122.8 663.5 (670) (3283) (7375) 0.44 1940 2545.4 1151.9 704 .5 (710) (3479) (7176) 0.48 1941 2971 .3 1230.6 (4202) 1942 2243.2 1211.4 (3455) 1943 2382.8 1392.5 (3775) 1944 2317.3 1330.9 (3648) 1945 1744.6 2110.7 (3855) 1946 1636. 1 1470.4 (3107) 1947 1695.9 969.9 677.4 (10) (10) (697) (3415) (6081) 0.56 1948 1100.1 1025.7 384 .1 (20) (20) (424) (2078) (4204) 0.49 1949 903.6 1570.3 366.4 (30) (30) (426) (2087) (4561) 0.46 1950 890.4 1368.0 (0) 256.4 (33.7) (41.0) (331.1) (1622.4) (3880.8) 0.42 1951 670.0 1438.9 (10) 269.5 (35.4) (51.2) (356.1) ( 1744.9) (3851.8) 0.45 1952 747.7 1346.5 (20) 336.9 (44 .3) (74.1) (455.3) (1365.9) 1953 565.9 872.9 (30) 170.6 (22.4) (37 .5) (230.5) (691.5) 1954 485.9 1076.8 (40) 282.6 (37.1) (79.1) (398.8) (1196.4) 1955 322.8 818.1 (50) 155 .0 (20.4) (48.0) (223.4) (670.2) 1956 50.2 702.4 (60) 87 .6 (11.5) (29.8) (128.9) (386.7) 1957 387.1 295.5 (60) 577.2 (75.9) (213 .6) (866.7) (2600.1) 1958 753.3 162.0 (60) 782.8 (102.9) (313.1 ) (1198.8) (4987.0) (5962.3) 0.84 1959 1110.4 42.2 (60) 1195. 6 (157.2) (478.2) (1831.0) (7086.0) (8298.6) 0.85 1960 1147.8 81.8 (60) 755.4 (99.3) (302.2) (1156.9) (3064.2) (4353.8) 0.70 1961 478.4 231.0 (60) 391 .9 (51.5) 111.4 (554 .8) (1446.3) (2215.7) 0.65 1962 521 .8 224.7 79.5 335.5 (44 .1) ( 134.7) (514.3) (1337.2) (2163.2) 0.62 1963 347.4 31.4 41.4 483.7 (63.6) (193.8) (741 . 1) (1926.9) (2347.1) 0.81 1964 251.0 83.1 99.8 303.1 (39.8) (122.8) (465.7) (1210.8) (1644.7) 0.75 1965 273.0 89.1 603 443 .3 (58.3) (178.3) (679.9) (1767.7) (2190.1) 0.81 1966 233.3 85.8 61.9 892.7 (117.3) (358.4) (1368.4) (3557.8) (3938.8) 0.90 1967 281.2 32.0 32.8 470.5 (61.8) (190.4) (722.7) (1879.0) (2225.0) 0.84 1968 114.5 26.0 14.4 372.2 (48.9) (150.4) (571.5) (1485.9) (1640.8) 0.91 1969 70 .8 3.8 9.2 358.5 (47.1) (149.3) (554 .9) (1442.7) (1526.5) 0.95 1970 22 .5 2.1 3.3 373.8 (49.1) (154 .2) (577.1) (1500.5) (1528.4) 0.98 1971 17.3 0.0 6.6 50.5 (6.6) 194.7 (251 .8) (638.6) (662.5) 0.96 1972 13.9 0.0 (5) 38 .2 (5.0) (154.0) (197.2) (591.6) (610 .5) 0.97 1973 37.6 0.0 (15) 92.5 (12 .2) (370.9) (475.6) (1426.8) (1479.4) 0.96

'Other California sport landings estimated as 0.1315 California partyboat landings. 2Mexican sport landings estimated as long-range partyboat catch plus 0.4 (declining to 0.16 from 1958 to 1950) of California partyboat landings of 3.0 pounds/fish was used for 1971 , in the warm water years of 1957-60 samples from U.S. commercial and 1972, and 1973. Length frequency data (Figure 2). The U.S. commercial from party boat fisheries suggests that are also available for the California fishery landed an annual average of the barracuda stock presently lacks the commercial fisheries for the years 1928 3.800 short tons of barracuda during larger size groups (Figs. 3, 4) . The (Walford, 1932), 1958, 1959. 1960 (Pin­ 1920-25 . These decreased to 1,400 tons length frequencies for the commercial kas. 1966). and 1973 (D. L. Schultze. annually for the years 1932 through fishery may differ somewhat due to CDFG , pers. commun.) 1938. and then increased to 1.900 tons changes in fishing gear. The method of California partyboat records on catch for 1939-45. After 1945 the commercial capture was predominantly purse seines and angler effort provide the only index catches steadily declined to the present 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 (Squire. 1972) recorded too few sight­ beginning of sport fishing records in ples for years 1952 to 1957 do not exist. ings of barracuda to be useful. Egg-and­ 1936. sportsmen consistently landed it is not known if the above trend started larva surveys gather barracuda larvae approximately 1.200 tons annually prior in the early 1950's or early 1960's. The but the data as of yet have nOI been to 1952. During the warm water years. warm water years are associated with processed. It is not known if the obser­ when barracuda were considerably an extensive northward migration of the vations are sufficient to provide an more available. annual sport catches barracuda population. Occurrence of index of abundance. ranged from 1.300 to 3.500 tons. Prior to large fish in these samples may be a 1951 the sport catch amounted to 46 result of this migration. The decline in Historical trends percent of the total landings but since frequency of larger fish may have paral­ Total landings of barracuda have 1968 it has made up more than 90 per­ leled the decline in catch rather than the generally declined since the mid-1930's cent of the total. abrupt change suggested by the length except for short term peaks in 1966 and Examination of the length frequency frequencies available. In any event, the 8 9.0 CALIFORNIA BARRACUDA CALIFORNIA BARRACUDA ao ~ 0 71. 2 em (26" sIZe limit) : \ ,'I I ~ / \ 1958 7.0 1 \ 7"-0 \ 6 I \ I I i ~ 78.7 em J \' \ : X ~ (11t 4 6.0 2 I ~ 0 I .. f \! \. li ? I 5.0 ? 9 I k' \~ I X 1959 I \ 6 I 'b (, I 4.0 4 u I \ ,f.-'rf'\ ,.o...o/~ : >- I \ I ~ \ ~ -¢, 2 >- b..o--o..o-o U '0., Z 0 0·~9LI-5--19-+2-0--19.1-25--1 -I93-0--'9.J,.3""5--1-941-0--' 9...j.4-5--19J,...50:---19:+5:::5--:'9:1::'60::-:--1-:'96::5---'=-19~70~"""":::"975 W :::J 6 196 1 YEAR 0 I ~ 6 6. 7 em W cr 4 u. Figure 2.-Calilornia barracuda U.S. commercial landings (1916-1973) and estimaled lolal landings 2 (1936-1973). 0 6 1972

CALIFORNIA BARRACUDA fishery has harvested the younger age 4 (f ,97, ~ 64.6 em) groups, particularly 2-, 3- , and 4-year 2 71.2 em (28" size limit) old fish in recent years. 0 8 1928 The number of sport-caught under­ 1973 I ~ 78.9 em 6 6 size barracuda permitted per bag has / :63.4 em 4 4 been altered a number of times. Be­ 2 2 tween 1933 and 1949 sport fi shermen were allowed not more than five fish 0 0 I 20 40 100 12 0 1958 I weighing less than 3 pounds each . Be­ 8 tween 1949 and 1957 the undersize al­ LENGTH (em) 6 lowance was five fish less than 28 in­ Figure 4.-Lenglh Irequencles lor Calilornla 4 f('''m ches. These size limits were effectively barracuda Irom U.S. commercial parlyboals lor 1958, 1959, 1960, 1961 (from Plnkas, 1966) 2 identical since a 28-inch barracuda and 1972 and 1973 (D. L. Schulln, CDFG, per•. 0 weighs approximately 3 pounds (age 5 commun.) 19 59 8 years). The allowance was reduced to ~ 6 two undersized fish per bag in 1957 . In only (Fig. 6). For many of the years, the ~ >- 4 March 1971 the possession of barracuda points lie well above the I : I line, which U under 28 inches was prohibited al­ Z 2 means that the sport catch rate was high W ~ together. As it is illegal to possess un­ in the San Diego regi on. yet relatively 0 0 W 1960 dersize barracuda, sport fi shermen re ­ low overall. This suggests that th e ba r­ cr 8 u. lease a large number ofundersize fish as racuda migra tio ns in the ea rly 1950's 6 indicated in length frequency samples 4 for 1972 and 1973 (Fig. 4) . If the re­ 2 leased fi sh have poor survival, the • CPUE l'. mean we iQh.'

0 be neficial effect on the stock may be CPUE RECONSTR UC TED FROM 12 1973 140 ... LENGTH FREOUENCY INFORMATION reduced and/or retarded. 'i 12..0 10 The C PUE ( L catch in weight! L § , CALIFORNIA BARRACUDA 8 anglers) for the U.S. partyboats has two periods of extreme highs , the years 6 prior to 1948 and the warm water years 4 V (Fig, 5) . If these extremes are elimi­ !: ········ ~ Es l 1 ." r. T£s l 2 nated, the two remaining sequences are 3 ." '!:.::~:~ ,;~" [ • 0 j r 20 40 60 80 100 120 somewhat level. On the other hand each 20 .....& LENGTH (em) segment shows a decline in itself. 194() 1950 1960 1970 Figure 3.-Lenglh frequencies lor Calilornia The C PUE index in numbers of fi sh YE AR barracuda Irom U.S. commercial Iishery lor 1928 for all regions combined was compared (Wallord, 1932), 1958, 1959,and 1960 (Plnkas, 1966) Figure 5.-Calilornla barracuda parlyboal CPUE and 1973 (D. L. Schultze, CDFG, pers. commun.) to the C PUE for the San Diego region lor year. 1936-1970. 9 1.8 Figure 5.-Compari· trends in the catches, nor do they indi­ _ 59 son of partyboat CPUE for San Diego cate the present status of the stock. In 1.6 region with CPUE in· order to ascertain recent levels of ex­ dex for all regions _ 58 combined for Call· ploitation with regard to catch and ef­ i" fornla barracuda, 1.4 fort, Schaefer model analysis was at­ ~ 1947·70. Q) tempted. C> c _65 0 1.2 Valious indices of CPUE were ex­ "- -67 -66 1:: amined for application to the model. As U) -68 ;;: -63 previously discussed, distribution pat­ 1.0 70 •• 69 W .64 terns have varied , with the migration ;:) a. not extending much north of San Diego u 0.8 50 • • 52 .61 0 .57 in some years. Thus we have calculated (!) .51 .62 W CPU E as total annual partyboat catch 0.6 ·53 48. ·60 i5 of barracuda divided by total annual Z .49 O 55 60 65 Four groups are apparent, correspond­ YEARS Pinkas' ( 1966) study on the California Figure 7.-Commercial ex-yessel prices tor ing to different, presumably homoge- barracuda adjusted by wholesale price Index, barracuda utilized a Beverton and Holt 1941·71. 16 dynamic pool model to investigate op­ CALI FORNIA BARRACUDA

(.)36 timum minimum size in relation to yield Before the mid-1950's the undersize fish 14 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 12 .3. .40 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 (oU7 stliction also should have helped in sure ably in abundance. By the late 1960's (et47 . 38 the reproductive capacity of the stock however, the sport fishery accounted (e)58 as the onset of sexual maturity occurs at for more than 90 percent ofthe landings, ::J'" 6 a. u age 2 for most individuals (Walford, and fish larger than 28 inches had be­ ('.~ 49 60 1932) . come relatively scarce, so that the bulk ...66 (e173 Commercial fishing has observed a of the landings was composed of fish 6'.~ .00 .51 70~6e·.~ 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 EFFORT ( 106 onQler standard units -3 year meon) tain number of undersized fish could be timum size limit effective once again. Figure 8.-Callfornla barracuda party boat CPUE kept (five under-sized fish from 1933 to Yield per recruit considerations, (pounds/angler) versus nominal effort (standard angler units) for 1936·73 (see text for calcula· 1957 , and two under-sized fish to 1970). however, do not explain the observed tion of effort for 1971·73).

10 neous, periods in the fishery. Data points Table lO.-Annual calche_ of Pacilic bonito by main fl_hery segmenls. for the late 1930's comprise a loose group included primarily for the pur­ U.S. commercial S(!Orl Total Mexico' Partyboats Other Mexican Cornm. poses of establishing a basic relation- Calil. Mexico commercial Calif. Calif' waters] Total Total and sport ship between catch and effort for the ______Year (1()3 Ib) (10' Ib) (10'Ib) (10' fish) (10' fish) (10' fish) (10' fish) (10' Ib) (10' Ib)_ earlier years of the fishery . Tentative 1950 33 662 (0) 2.4 (2.1) (0.1) (4 .6) (14) (709) values for 1936 and 1937 are shown. 1951 54 723 (0) 14.5 (13. I) (0.8) (28.4) (85) (862) 1952 8 2,135 (0) 7.6 (6.9) (0.5) (15.0) (45) (2,188) Presumably an effective minimum 1953 19 3,084 (0) 6.3 (5.7) (0.5) (12.5) (38) (3,141) 1954 219 2.100 (0) 70.1 (63.4) (6.1) (139.6) (419) (2.738) length of 28 inches was in effect during 1955 40 100 (0) 22.4 (20.3) (2.2) (44.9) (135) (275) the late 1930's (mean annual catch = 1956 22 105 (0) 61.4 (55.5) (6.0) (122.9) (369) (496) 1957 110 109 (25) 258.6 (233.7) (30.3) (522.6) (1.568) (1.812) 3,000 short tons). A second group, 1958 4.805 742 (50) 422.6 (382.0) (49.4) (854.0) (2.562) (8.159) comprised of years 1947 to 1951, is 1959. 3,003 9 (75) 776.4 (701 .1) (90.8) (1 .568.3) (4.705) (7.792) 1960 1,220 31 (100) 1.199.9 (1.083.5) (140.4) (2.423.0) (7.270) (8,621) characterized by declining catches 1961 8.439 74 (163) 849.4 (767.0) (119.7) (1 ,736.1) (5.208) (13,884) 1962 2.072 63 67 798.7 (730.2) (94.3) (1 .623.2) (4 .870) (7,072) = (mean annual catch 2,300 tons) and 1963 4.014 9 1.118 775.7 (662.4) (91.7) (1 .529,8) (4 ,589) (9.730) probablY a minimum effective size limit 1964 2.606 6 1.125 1.298.8 (1.172.8) (152.7) (2.624.3) (7.873) (11 .610) 1965 5.633 6 735 806.3 (728.1) (96.0) (1 .630.4) (4 ,891) (11 .265) of about 28 inches. The third group is 1966 18.308 840 2.044 644 .4 (581 .9) (76.2) (1.302.5) (3.908) (25,100) composed of observations from the 1967 17.842 3.378 1.343 350.0 (316.0) (42.3) (708.3) (2.125) (24,688) 1968 14.903 19 779 1.102.9 (996 .0) (131.6) (2.230.5) (6,692) (22.393) 1960's, a fairly stable period in effort 1969 13.175 4.027 147 1.130.2 (1 ,020.6) (139.9) (2.290.7) (6.872) (24.221) and landings (mean annual catch = 1970 8.794 399 (163) 651 .9 (588.7) (78.3) (1.318.9) (3.957) (13.313) 1971 10.476 9,793 (325) 152.8 (137.8) ( 16.7) (307.3) (922) (21 .516) 1,200 tons), however, with an effective 1972 15,600 6,712 (325) 419.0 (377.8) (53.6) (850.4) (2,551) (25.188) minimum length considerably shorter ______1973 18.477 12,263 710 472.5 -.:.._-=---...... :_..:...--....:...._..:...--....:...... :...-..:...-...-:.:...... ;.:---'. (426.1) (60.5) (959. 1) (2,877) (34 .327) __ than 28 inches. The higher CPUE for 'Source: FAO Yearbook of Fishery Statistics, and catch data furnished by Instituto Nacional de Pesca. 'Estimated by Thayer (1973, table 3) less reported partyboat catch. 1960 may be the result of successful 'Sum of eslimated Ensenada party boat catch (est. catch ~ 0.117 California partyboat catCh, based on mean of 1961 local spawning in previous years as sug­ and 1971 reported catches. with smalier ratio lor earlier years: linearly decreasing from 1958 to '/5 of ralio in 1950) and gested by the large numbers of small California long range partyboat catch. barracuda in the 1960 length frequency Although it is possible to draw a nia waters in the latter half of 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 probably not be a valid equilibrium checked. Knowledge of potential sus­ in a sharp drop in reported party boat curve because of the changing nature of tainable yields and fisheries interactions catch, although the number of anglers the fishery. From the examination of the 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 1930's 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% I Mexican commercial catches are of younger fish, which takes the form California waters, almost certainly ac­ regularly reported in the F AO of reduced "effort" in Figure 8, ac­ celerated the decline in the 1960's. It Yearbook of Fishery Statistics and cording to the formula:}" = C / CPUEest , may take several years for the stock to catches for 1%2-69 and 1973 were fur­ where!' 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 (lNP). 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 CPUEest 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 10) 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, and!, 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 creasing mean weight. This should in­ PACIFIC BONITO with distinction made between catches crease CPU E, and simultaneously in­ taken off California and off Baja crease the proportion oflegal fish to fish After an absence of several years, the California-were regularly sampled caught, which will increase "effort" as Pacific bonito, Sarda 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 weight/length relationships long-range partyboat catch, while tak­ The CPUE (in numbers offish caught (Campbell, in press) were used for ing considerably larger fish, accounts per angler) data are also available for the convel1ing 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 pounds/fish (1973 calculation. Lack of length frequency I) Annual (~~) for all southern pal1yboat average weight was 2.87 information for earlier years necessi­ Cali fornia areas combined. pounds), which has been the usual con­ tates the use of a constant mean weight 2) Weighted mean, (or CPUE index) version used by CDFG. Also. the estimate. PACIFIC BONITO L [aj (ij) ] , with weighting factor 15 u.s. COMMERCIAL 1973 2; aj MEXICO CALIFORNIA rl proportional to the area (0-20 fathoms), N=365 10 N-I,502 I \ /' ai, of six respective statistical divisions ii= 6.45 lb •. I I. \ W=7.70 lb •. I \ (described in Table 3). I \ Indices of apparent abundance, de­ J '\ 5 I I rived from aerial surveys, are available I \ I \ for the period 1962-72 (Squire, 1972). / \. / _ / ..... --_1 r O~~~~~~~~~~~~~----~~~---=--~~~--~~~~~ Trends of fishery segments u MEAN LENGTHS OF AGE GROUPS I Z W As illustrated in Figure 10, until about :::>o 1957-58 , catches as a whole were at a w u.s. PARTYBOATS I~ rather low level-although showing [E 15 LOCAL marked oscillations. They subsequenlly i \ LONG RANGE OFF MEXICO (_/ I (\ N = 1,235 N=1I6 increased in two steps. The first, from w- 2.B7 lb •. ! \/ \ late 1950's to mid-1960's, corresponded 10 I \ I \ to the development, both in Mexico and I " I \ California, of sport catches. The sec­ I \ 5 I " ond, beginning in the mid-1960's, cor­ I \ I \ responded to an expansion of U.S. I _/ commercial landings (Table 10). From length frequency distributions of U.S. catches sampled in 1973 (Fig. LENGTH (em.) 9), it is clear that the various fishery Figure 9.-Paclflc bonito length frequency distributions lor U.S. catches by fleet and location for 1973. sections exploit different parts of the popUlation. Such segregation in sizes caught reflects an uneven geographical distribution of various age groups. PACIFIC BONITO Roughly , older fish are more available • COMMERCIAL CALIFORNIA WATERS offshore and in Mexico, although large fish are taken in the Santa Barbara area D. COMMERCIAL CALIFORNIA and MEXICAN WATERS 30 in the fall. The local U.S. sport fishery • ALL including SPORT essentially takes individuals less than 60 cm (age I). Long-range U .S. party boats harvest older fish. but make a small con­ \I) Q tribution to the sport catch. Commer­ )( ~ 20 cial vessels tend to take larger fish: I year old and above off California. 2 years old and above off Mexico.

w Sport fishery and recruitment ~ to commercial fishery ~ 10 Indices of apparent abundance have ..J :::> been derived by Squire (1972) from ~ :::> tonnages of bonito estimated during u aerial surveys (Table II). Day and night indices have been calculated sepa­ rately. Since the 1962 source data cov­ 30 40 50 60 70 ered the last period of the year only, YEAR indices for that year were discarded in Figure 10.-Hlstorlcal development 01 the Pacific bonito fishery: total catches of major fishery segments. the following analyses. The aerial sur- 12 vey indices have been recalculated to Table 11 .-Aerlal survey Indices, partyboat CPUE, and correlations between various combinations of CPUE and aerial Indices. exclude the area north of Pt. Concep­ tion in order to correspond with other Aerial survey Part~boa l CPUE index Day Nighl biomass estimates, particula rly south­ Year; index i ndex CPUEi CPUEi· , CPUE j., ' CPUE j., CPUEj., A B 'c ern California partyboat CPUE for 1963 1.71 0.85 1.53 1.63 1.73 1.87 1.20 0.95 0.65 0.38 bonito. 1964 1.80 0.31 2.41 1.53 1.63 1.73 1.87 0.90 0.62 0.37 1965 1.48 0.22 1.53 2.41 1.53 1.63 1.73 1.21 0.76 0.44 A number of correlations between 1966 1.49 0.37 0.96 1. 53 2.41 1.53 1.63 1.00 0.7 1 0.41 aerial survey indices and partyboat 1967 1.03 0.49 0.50 0.96 1.53 2.41 1.53 0.71 0.53 0.34 1968 0.54 0.31 128 0.50 0.96 1.53 2.41 0.43 0.34 0.23 CPUE-with vaJ;ous yearly lag times 1969 0.28 0.18 1.46 1.28 0.50 0.96 1.53 0. 61 0.38 0.23 a nd combination-were calculated 1970 0.01 0.10 0.74 1.46 1.28 0.50 0.96 0.75 0.48 0.26 1971 0.56 0.21 0.23 0.74 1.46 1.28 0.50 0.54 0.41 0.24 (Table II). Highest values of the corre­ 1972 1. 11 0.20 0.59 0.23 0.74 1.46 1.28 0.28 0.24 0.17 lation coefficient (r) were found with in­ r day 0.58 0.50 0.39 0.60 0.69 0.26 0.56 0.64 0.71 dices derived from daytime observa­ r night 0.58 0.20 0.15 0.44 0.66 0.07 0.30 0.40 0.46 ti ons. Squire (1972) felt that daytime ae rial observations were more efficient A :. ~ CPUEj.j e·j 1 ~ 1 than night observations for estimating , . B: V, CPU Ej _ e + l: CPU E,_je-j bonito abundance. The highest correla­ 1 j => 2 , , , ~ C: CPUE _ Ie + 1/2 CPUE _ e CPUEj_je -I tion was observed between party boat 'f, j j 2 + j = ' C PUE and daytime aerial index 3 years 'These are plotted in Figure 3. later (Fig. II). Taking into account age 2These are plotted in Figure 4. composition of catches made by sport 2.5 0. ' and commercial fisheries respectively . 1967 (Fig. 9) and th e fact that airplanes are mainly assisting the commercial fishery • 19G ~ and therefore likely concentrate their . ,...... , 0.4 surveys over commercial fishing ,go. , grounds, it is reasonable to assume th a t ..., ... . .1961 aerial surveys mainly reflect changes t9!2 · 1966 occurring in that part of the bonito stock 1. 5 0.3 _) 1970 exploited by commercial vessels, while . 1971 / . 197. partyboat C PU E provides an index of · 1968 0.2 prerecruit abundance before th ey start '.0 . 1969 to be exploited by the commercial fleet. . 1972 However, there is not an exact 3-year lag in age composition of party boat and 0 5 _1 1970 D. ' commercial catches. Moreover, while party boats may essentially exploit a single age group, commercial vessels exploit several age groups. In order to 1.0 I.' 0'bl':.o,.----...,o':-.,---...J,.':-o ---...JI.,:--- account for mortality, plus selectivity AERIAL SURVEY DAY INDEX AERIAL SURVEY DAY INDEX by commercial fishing, various reason­ Figure 11.-Regresslon of aerial survey day Figure 12.-Regresslon of aerial survey day Index against partyboat CPUE Index 3 year. Index against CPUE adjusted for mortality and able combinations of pa rtyboat CPUE earlier. recruitment. (in numbers) over years were te ntatively correlated with daytime aerial survey pies from the partyboat catch are domi­ Annual catches of 1,000-4 ,000 tons of indices. The highest correlation (r = nated by a single age group, this may not bonito were taken commercially from 0.71) was found for the combination: have been the case in earlier years. California waters between 1926 and Consequently, partyboat C PUE may 1941 , but information on the effort re­ Day Alia: V cruitment since 1960, the stock appears 0- 1.0 U to be intensively exploited. In fact, the 1973 catch of 34 million pounds appar­ ently is substantially above the MSY suggested by the analysis. Given that recent partyboat CPU E values do not 0.OL--19I3-S.=:lI19L4-=-0---!:"""'1"'95"'0""""-.!---I...l9S:-:0:------:I:l:97=-=0-- indicate any strong year classes in the YEAR present population, this high catch may For unknown reasons, bonito became sure of apparent abundance of the prove to be disastrous to the bonito scarce sometime during the early biomass exploited by commercial stock. Determination of equilibrium 1940's. This disappearance of the re­ boats, and similarly party boat CPUE abundance and yields are confounded source was independent of fishing, index is probably proportional to by a possibly density-independent de­ which was curtailed during World War biomass exploited by sportsmen. Since crease in recruitment, highly variable II. Subsequently, bonito catches on sport and commercial fisheries exploit availability due to behavioral changes party boats were dependent on migra­ different age groups and commercial ef­ (Collins, CDFG5) and generally low tory fish until 1956, when large quantities fort data do not exist, a combination of precision and coverage of available of bonito moved into California waters the above two indices provides the only data. Nonetheless it appears likely that and became reestablished as a locally means for stock evaluation using a sur­ fisheries take an appreciable share of spawning population. Management of plus production model. each year class. In the absence of information on mor­ the resource will assume different forms The combined index for each year tali ty rates (or even comparative mortal­ according to whether the resource is was an average of the two indices stan­ ity rates for similar species) yield per migratory or permanent. It is here as­ dardized by their respective means for recruit analysis was not attempted. sumed that the resource is sufficiently the 10-year time series (excluding 1970) Moreover, lack of mortality rate esti­ permanent to attempt management on and weighted by their respective annual mates preclude analysis of the interac­ the basis of sustainable yield. None­ catches (Table 12). The ratio of total tion between sport catch and commer­ theless, there is no evidence that catch (C) to this mean index should vary cial yield or rates of exploitation. residency is other than a temporary . I' fi h' f" (Catch C Comparison of numbers of fi sh caught event. 10 re atlOn to s 109 e lort [ndex a: Ii = by sport and commercial vessels re­ K). The units of measurement for this spectively (Table 13) , and observations Stock assessment ratio or f are abstract. The mean index made above suggest that the sport rate The present state of the bonito re­ for biomass (8) 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 of the sport fishery will catch and a combination of partyboat I n 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 consequently affect their catches. discussions suggested that aerial 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 exploits younger fish . However, Table 12.-lndex of exploited biomass, total catch, and calculated eHort for Pacific bonito, 1963 to 1972. decrease in sport CPUE could result Effort from a reduction of parental stock to a Aerial index survey Comm. Partyboat Sport Weighted Total Effort 2-year point where recruitment is significantly day landings CPUE catch mean catch index mean reduced. Up to now this has most likely Year lQ3 Ib lQ3 Ib index 103 Ib (103) index index (103) not occurred; however, the 1973 fishing 1963 1.71 5.141 1.53 4.589 1.43 9.730 6,782 season appears to have been consider­ 1964 1.80 3.737 2.41 7.873 1.93 11 .610 6.031 6.406 1965 1.48 6.374 1.53 4.891 1.33 tl .265 8.496 7.264 ably in excess of equilibrium yield and 1966 1.49 21.192 0.96 3.908 1.26 25 .100 19.860 14.178 may have severely affected the re­ 1967 103 22.563 0.50 2.125 0.89 24 .688 27. 843 23.852 1968 0.54 15.701 1.28 6.692 0.67 22 .393 33 .424 30.634 source. Although such events cannot be 1969 0.28 17.349 1.46 6.872 0.54 24 .221 45.152 39.288 1970 0.01 9.356 0.74 3.957 -, 13.313 neglected. their occurrence is very 1971 0.56 20.594 0.23 982 0.49 21 .576 43.900 1972 1.11 22 .637 0.59 2.551 0.95 25.188 26.464 35.182 ' R. Collins, CDFG, 350 Golden Shores, Long lAerial survey data for 1970 incomplete. Beach, CA 90802. Pers. commun. 14 difficult to determine for a stock subject Table 14.-Catches of jack mackerel for various fisheries to large natural fluctuations in recruit­ Sport ment, as is the Pacific bonito. Commercial All other California Total JACK MACKEREL United Siaies Mexico Parlyboal plus Tolal commercial Cannery Bail cannery California MexicoJ sporl and sport The jack mackerel, Trachurus sym­ Year 1()3Ib 10" Ib 10' Ib 10" tish 10' fish 10" Ib' 10" Ib me/riClts (Ayres), fishery has been one 1950 133.2558 0.4 '(7,000) 0.6 (1.8) (2.4) (140,259) of the mainstays of the southern 1951 89,838.1 0.0 (4.000) 0.2 (0.6) (0.8) (93,839) 1952 146,521.7 33.1 (3.000) 4.4 (13.2) (17.6) (149.572) California wetfish fleet since the decline 1953 55.750.9 1.4 (3,000) 196.3 (588.9) (785.2) (59.538) of the Pacific sardine. On rare occasions 1954 17,333.6 0.4 440 19.4 (58.2) (77.6) (17 .852) 1955 35,754.7 0.0 13,300 39.5 (118.5) (158.0) (49,213) large sport catches are made but jack 1956 75,762.1 0.0 14.200 23.5 (70.5) (94.0) (90.056) mackerel remains primarily of com mer­ 1957 82,011.8 0.0 1(8,000) 6.9 (20.7) (27.6) (90.039) 1958 22,065.8 6.2 (2.000) 27.9 (83.7) (111.6) (24.184) cial interest. 1959 37.507.2 40.0 (500) 11 .8 (35.4) (47.2) (38,094) 1960 74.945.5 4.0 (5 ,000) 8.5 (25.5) (34.0) (79.984) Catches 1961 97,606.3 0.0 3.934 28 .9 (86.7) (115.6) (101,656) 1962 89,978.9 0.0 6.978 9.0 (27.0) (36.0) (96.993) Long time series of landings in weight 1963 95.442.3 15.0 30.153 9.3 (27.9) (37.2) (125.648) 1964 89.692.9 0.0 6.871 6.6 (19.8) (26.4) (96.590) are available for the main segments of 1965 66 .666.4 0.0 8,420 25.6 (76.8) (102.4) (75,189) 1966 40,862.4 25.0 12.919 19.0 (57.0) (76.0) (53.882) the fishery: California cannery land­ 1967 38,180.5 0.0 4.285 16.2 (48.6) (64.8) (42.530) ings, Mexican cannery landings , and 1968 55,667.7 158.0 3,549 136 (40.8) (54.4) (59.429) 1969 51.921 .2 103.0 3,336 11.3 (33.9) (45.2) (55,405) California live bait landings (Table 14) . 1970 47,746.5 0.0 '(5,000) 15.7 (47.1) (62.8) (52,809) A similar time series in numbers of fish 1971 59,883.0 9.0 (5,000) 10.6 (31 .8) (42,4) (64,934) 1972 51 ,117.6 5.0 (5,000) 5.9 (17.7) (23 .6) (56,146) landed is available for the California 1973 20,615.8 438 15.8 (47.4) (63.2) (21,117) party boat fishery, and landings for other 'Estimated from reported catch of PaCific and jack mackerel combined. sport fisheries were estimated by means 21nformalion not available-rough maximal estimate. 'Estimaled as parlyboal calch x 3.0. of a simple ratio to party boat landings 'Estimated from assumed weight of 1 pound per fi sh. (3 .0 fish/partyboat fish) . Sport-caught fish were arbitrarily assigned a weight of I pound apiece in the calculation of total landings. In the year of largest sport landings, 1953 , sport-caught fish com­ prised only 1.3 percent of total landings, and the percentage for most years falls far below this value. 3.0 30 Commercial landings have been PACIFIC BONITO strongly influenced by the availability of more lucrative species. Landings during 72 2.5 .66 25 the 1950's tend to be inversely related to ·67 .69 sardine availability. The slight decline .68 .71

2.0 20 Table 13.-Paclflc bonito-number of fish caught (In 64 thousands) by commercial fleets and sport fishery. x w .; Commercial 0 ~ US· Sporl ~ .. Year Calif. Mexico MexiCO TOlal total w \ Q t) 1.5 15 z \ ~ 1950 5 86 0 91 5 .. :J: 0 1951 8 94 0 102 28 Z 70 t) 1952 1 277 0 278 15 ::> .... ID .. 1953 3 401 0 404 13 .. t) 1954 34 273 0 307 140 1955 6 13 0 19 45 1.0 10 1956 3 14 0 17 123 ,\72 1957 17 14 3 34 523 67 \ 1958 745 96 6 847 854 \ 1959 466 1 10 477 1.568 \ 1960 189 4 13 206 2.423 • CATCH 68 \ 1961 1.308 10 1 1.319 1.736 69 5 1962 321 8 9 338 1.623 ABUNDANCE 1963 622 1 90 713 1.530 • 1964 404 146 551 2.624 1965 873 1 95 969 1.630 1966 2.838 109 266 3.213 1.303 1967 2.766 439 174 3,379 708 ~--~--~--~ __~~ __~ __~~~~ __~ __-L __ ~O 1968 2.311 2 101 2,414 2.231 2.0 3.0 ' .0 5.0 1969 2.043 523 18 2.584 2.291 EFFORT INDEX (x 107) 1970 1,363 52 21 1,438 1.319 1971 1.624 1.272 42 2,938 307 1972 2,419 872 42 3.333 850 Figure 14.-Relatlonshlp between combined CPUE and effort and the cor­ 1973 2.685 1.593 92 4,370 959 responding estimates of surplus production for Pacific bonito.

15 Table lS.-lndlces and estimates of biomass. The present level of fishing is very Larvae Aerial survey Biomass low, with an F of 0.02-0,04 (Table 16), Year CalCOFI area' index estimate indicating that the yield could be in­ ( 109) Nighl Day 106 tons creased manyfold. Applica tion of 1950 6,846 1951 4,233 Gulland' s quick calculation of potential 1952 3,921 yield (Y = 0.5 x M x Bo) gives 1953 1,484 p 0 1 1954 2,413 210 ,000 to 450,000 tons, assuming 1955 2,635 M = 0.6 and using the 1972 estimates 1956 1,372 } 0,35 (Spawning biomass, local area based 1957 2,876 on eggs and larvae' ) of biomass, B o. Yield values will vary 1958 830 1959 545 according. to the biomass, and would 1960 655 be proportionately larger if the stock 1961 981 1962 2,516 were at the 1964-66 level of abundance. 1963 3,122 2.98 1.41 There are indications that estimation 1964 3,045 2.18 1.62 } 1965 2,681 1,36 0.71 1,4-2.2 (Spawning biomass, CalCOFI area based of MSY may not be so simple. Knaggs 1966 6,288 1.94 0,28 on eggs and larva"') and Barnett (1975) have noted a de­ 1967 1.41 0.20 1966 2,25 0,30 crease in average age of the catch, 1969 0.65 0.11 which suggests the possibility ofa much 1970 0,58 0.16 1971 0,92 0.04 higher totaJ mortality rate or smaller 1972 0.74 0.13 0.7-1 .5 (Exploiled bi o mass, based on tagging') stock size than generally believed , ' Uncorrected for tempera1ure . 1957·59 are probably underestimated. Fishermen are of the opinion that jack 'MacGregor (1964). ' Ahlstrom (1968), mackerel abundance has decreased ' Knaggs (1973) . considerably (E. Knaggs, pers. com­ mun,). Comparative biology and ex­ in landings since 1965 has been primar­ and-larva surveys show the stock to be ploitation of simiJar Trachurlls species ily due to expansion of fisheries on the extremely widespread. Ahlstrom (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 sponse of the California stock to appar­ 1.4 and 2.4 x 106 tons, based on egg and Status of the stock ently very low fishing mortality, and its explOitation larval occurrences in 1964-66. Knaggs (1973) estimated from tag returns that Aged landings of jack mackerel were PACIFIC MACKEREL not completed in time to be included in between 0.7 and 1.5 x 10 6 tons were this report; however, they are now available to the fi shery in 1972. These Inception of Pacific mackerel, available (Knaggs, 1974 and Knaggs and estimates are in agreement with trends Scomber japoniclIs, canning in the late Barnett, 1975) . This information will af­ in the aerial survey index (Squire, 1972) . 1920's caused a sudden rise in landings, ford a n opportunity for detailed analysis This suggests that jack mackerel are which, augmented by what was the of the fishery by use of cohort analysis now about half as abundant as they were strongest year class (1932) in the docu­ (Murphy method); the present discus­ in the mid-1960's. However, egg-and­ mented history of the fishery, peaked at sion is restricted to very simple and larva estima tes of spawning biomass do a record 146 million pounds in the general terms, not necessarily correspond to exploit­ 1935-36 season, Subsequently, the Various indices of abundance (Table able biomass. Juveniles are exploited, catches went through a long, fluctuating 15) show that the resource tends to be while old fish emigrate from the fishing decline , ending with a severely depleted highly variable in magnitude and egg- grounds. stock in 1933 (Fig. 15). However the 1953 spawning was highly successful , PACIFIC MACKEREL leading to a resurgence of the stock and 200 o TOfa! Biomass the fishery , which remained healthy (C oho,! onolys i ~ MaO.6 ) throughout the decade, Beginning in • Ca tch 1963. a sequence of six exceptionally

15 0 severe recruitment failures resulted in '"Q extinction of the commercial fi shery. (f) z The Pacific mackerel remains a rather 0 >-- popular and sufficiently abundant target >-- 0: tOO 0 of sport fishermen , although lacking the I (f) esteem given to the larger game fish. ExplOitation and dynamics 50 The Pacific mackerel has been sub­ ject to severe and rather unpredictable fluctuations in recruitment, although a 6-year cyclic pattern has been de­

YEAR scribed. Parrish (1974) showed that the Figure 15.-Pacific mackerel annual catches and biomass estimates. fishery has depended largely upon occa- 16 Table 16.-Blomass, catches, and tlshing mar· thresholds, the adopted regulation en­ PACIFIC SARDINE lalily 01 jack mackerel. sures that the maximum amount of The purpose of this report on Pacific Bi omass Catch fishing is controlled and that it will Years (10' tons) (10' tons)' F ~ C/B sardine, Sardinops eaeruleus , is not to gradually increase, tending towards an 1.4-2.2 37 .3 0.02·0.03 discuss the population dynamics of the 1964·66 asymptote of F = 0.3 as the stock gains 1972 0.7· 1.5 28.1 0.02· 0.04 stock but only to document the total in size. 13--yr average. 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, (NMFS), pers. year classes. As the spawning biomass sequent fishable biomass. This aspect is commun.), and a moratorium on fishing was reduced, variance in spawning suc­ 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 of large amplitude. How­ the stock. ducing the mean age and number of age ever the practical difficulties involved in We are interested though in the sar­ classes in the population to a point 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 mentioned advantages. 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 . Also, the pres­ not the only cause responsible for such while quota limitation alone is ent wetfish fleet is the remnant of the collapse. insufficient to prevent economic sardine purse seine fleet. During the col­ As for most stocks where similar overtishing, enforcement of quotas ad­ lapse of the sardine fishery the events were experienced, the respec­ justed on early estimates of the recruits fishermen began redirecting their effort tive roles of natural causes and of those should dampen year-to-year oscilla­ towards other pelagic species, including due to fishing have not been satisfactor­ tions in the fishable biomass and thus Pacific mackerel, jack mackerel, and ily explained. Long-term fluctuations in 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 California sponse of the sardine resource to fi~hi .ng pelagic community have been observed Present state of pressure is now mainly of academiC in­ since the late 1950's and early 1960's, exploitation terest and is discussed by Clark and e.g., waters generally warmer 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 predominance of anchovy over the sar­ tremendous decline in the stock from 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 population of Pacific bonito, a likely 2,000-5,000 tons at present (Table 18 , mackerel in California (Table 17). Fish­ competitor with the Pacific mackerel. Fig. 16) . Sardine biomass combined ing mortality is at present low (F = with anchovy biomass estimates show 0.06), indicating that it is not necessary Management an interesting cycle with the lowest to implement further restrictions on the amount at I million tons in 1950 increas­ I n 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. tune, as the spawning biomass is so more comprehensive management bill Such cycles in biomass are appar­ small that local environmental was passed by the California legislature ently common events in history as dem­ fluctuations may have a large influence which provides for the rehabilitation onstrated by occurrence of fish scales on spawning success. Moreover, poten­ and subsequent regulation of a sus­ in ocean bottom sediments examined by tial response of the stock in the present tained and controlled commercial Soutar and Isaacs (1974) . Their work environmental regime is unknown. fishery should the stock recover and in­ suggests that for the Santa Barbara Based on knowledge of present biomass crease over a minimum biomass. In es­ Basin the level of anchovy stock over and recent recruitment, it is unlikely sence, the law provides for a harv~st the past 150 years has been relatively that a fishery will develop in the next 5 equivalent to 20 percent of the spawmng constant. The level since about 1920 , years. biomass in excess of 10,000 tons and to though, appears to be below average 30 percent of the spawning biomass above 20,000 tons. The closure of the Tobie 17. Recenl biomass, calches, and fishing mortailly rales 01 Pacific mackerel. commercial fishery for spawning Biomass' Sport catch' Commercial catch Tolal biomass below 10 ,000 tons-the pres­ Year Spawning TOlal Number Weight' Cali I. Mexico ca tch F ~ C/B ent situation-aims at ensuring that a 10' Ib 10' Ib 10' 10' Ib 10' Ib 10' Ib 10' Ib minimum parental stock is maintained 1972 10,000 15,772 495.1 415.9 108.0 (400) 924 0.06 1973 11,000 15,224 376.5 425.4 56.7 438 920 0.06 and a minimum sport fishing stock is provided. 'Knaggs CDFG pers. commun. h ' Estimal~ trom'known parlyboat and barge catches, all other sport estimated as 0.826 parlyboat catc . Above the 10,OOO-ton and 20,000-ton 'Weight conversions: 1972-0.84 pounds/fish, 1973-1 .13 pounds/fish, based on 1970 year class.

17 Table 18.-Biomass estimates: anchovy and sardine (AHer P. Smith, 1972, Table 12 and Figure 13). (Fig. 17). During the same period the Ratio Regression Murphy Regression Anchovy and sediments reveal cyclic occurrences of anchovy anchovy sardine sardine sardine Year spawner spawner Mean spawner spawner Mean spawner sardines. Sardines probablY peaked biomass biomass (1,2) biomass biomass (4 .5) biomass during 1854 to 1864, 1889 to 1899, and (lQ3t) (lO't) (10't) (tQ3t) (3+6) 1914 to 1924 (Fig. 17). Just prior to the (1) (2) (3) (4) (5) (6) decade of 1870, sardines apparently de­

1940 2.359 2.359 1.296 1.296 3.655 clined to a very low level but the stock 1941 2.871 2.871 2.001 2.001 4.872 had rebounded by 1890. During the last 1942 1.913 1.913 1943 1.647 1.647 150 years sardine scale deposits only 1944 1.142 1.142 1945 691 691 exceeded those of the anchovies in four 1946 412 412 5-year periods. Scale deposition rate for 1947 387 387 1948 524 524 anchovies, however, seems to be higher 1949 682 682 per unit of biomass than for sardines. 1950 279 279 716 716 995 1951 690 637 664 570 553 562 1,226 Despite this, it seems that, on the 1952 856 797 827 554 542 548 1.375 average, the anchovy biomass has ex­ 1953 (1.404) 1.335 1.370 709 450 1.159 2,529 1954 1.937 1,816 1.877 668 658 1.326 3.203 ceeded that of the sardine. Therefore, 1955 1.855 1.676 1.768 425 404 829 2.595 1956 1.307 1,491 t ,399 293 351 322 1.721 since anchovies may usually be the dom­ 1957 1,869 1.964 1.917 212 234 223 2,140 inant species, if the sardine stock does 1958 2.875 2.771 2,823 281 299 290 3.113 1959 (2,418) 2.299 2.359 190 117 154 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 1964 5.121 5.121 104 104 5.225 WHITE SEABASS 1965 7.771 7.771 226 226 7.997 1966 5.116 5.116 151 151 5.267 1967 The white seabass, Cynoscion 1968 (2.167) (2.167) nobilis, is one of the most highly es­ 1969 (3,378) (3.378) 27 27 3.405 1970 teemed game fishes found in southern 1971 2-5 2-5 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 stock. This study attempts, with the lim­ Table 19.-Whlte seabass-catches by year and by main fishery segments. ited information available, to assess Commercial (10' Ib) Sport (10' Fish) the present condition of the stock, in­

u.s. Other Shore- teractions between the fisheries seg- open line, Calif. Mexico Mexico Party­ water pier. Total Total Est. boats (U.S .. jetty. sport sport total 8 Calil. Mex.) bay catch catch catch Year waters est.3 est.4 (10' Ib) (103 Ib)

1950 1.123 408 '(74) 54.7 4.7 (9.0) (68.4) (532) (2.137) 1951 955 578 (74) 44.4 5.2 (9.0) (58.6) (445) (2.052) 1952 692 455 (74) 41.0 6.0 (9.0) (56.0) (423) (1 .644) 1953 471 402 (74) 28.2 5.8 (9.0) (43.0) (288) (1.235) 6 1954 434 772 (74) 41.6 7.9 (9.0) (58.5) (445) (1.725) 1955 545 370 (74) 30.1 7.6 (9.0) (46.6) (341) (1.330) 1956 414 667 (74) 19.8 7.1 (9.0) (35.9) (246) (1,401) ., c 1957 1.262 245 (74) 19.0 7.5 (9.0) (35.5) (243) (1.824) 2 5 1958 2,751 99 (74) 34 .0 10.2 (9.0) (53.2) (398) (3.322) .. 1959 3.386 38 (74) 10.6 6.7 (9.0) (26.3) (161) (3.659) g 1960 1.087 149 (74) 15.7 7.7 (9.0) (32.4) (215) (1 .525) 1961 458 236 (74) 14 .1 7.5 (9.0) (30.6) (199) (967) 1962 209 366 158 14.6 7.8 (9.0) (31.4) (125) (858) 1963 372 519 47 19.8 9.0 (9.0) (37.8) (262) (1.200) 1964 551 840 82 14.9 8.1 (9.0) (32.0) (211) (1.684) 1965 578 851 87 9.8 7.1 (9.0) (25.9) (157) (1,673) 1966 675 663 69 4.0 5.6 (9.0) (18.6) (93) (1.500) 1967 508 715 36 3.4 5.5 (9.0) (17 .9) (87) (1.346) 1968 210 652 18 4.1 5.7 (9.0) (18.8) (95) (975) 1969 251 848 93 4.1 5.8 (9.0) (18.9) (94) (1.286) 1970 426 675 (92) 4.4 6.5 (9.0) (19.9) (98) (1.291) 1971 552 272 (62) 5.3 6.5 (9.0) (20.8) (164) (1.050) 1972 548 227 '(157) 3.9 5.7 (9.0) (18.6) (133) (1.065) 1973 581 228 (100) 7.1 7.0 (9.0) (23.1) (130) (1,039)

'1950-1961 catches estimated as 1962-1969 mean. other Mexican data courtesy of Instituto Nacional de Pesca. 2PreHminary estimate based on information through September and mean catches for October, November, and Oecember. 'InCludes long-range partyboats. private boats (tinear interpolation: 1964-0.225 partyboat catch. 1950-0.05 YEARS partyboat catCh) and Mexican partyboats (linear interpolation: 1971 catch ~ 4.338, 1961 catch ~ 4.901. 1950-1956 increasing from 2,000). Figure lB.-Combined spawning biomass 01 41963 pier and jetty catch ~ 8.551 (Pinkas et aI., 1967), 196&-66 shoreline catch ~ 699 (Pinkas et al.. 1968). anchovies and sardines lor years 1940-69.

18 ments. and the possible effects of vari­ Table 20.-Whlte seabss8-CPUE available for the commercial flsheryl and for the par· tyboats and estimated total eHort derived from estimated total catch (Table 19) and commer- ous management alternatives. cial CPUE (pounds/boat with catches > 1 ton). Data available Estimated Commercial Parlyboats TOlal effort Catch and CPUE data available for Commercial Ib/boat Pounds fish/angler standard Year Ib/boat (C > 1 ton) landing day' uniP the various fishery segments suffer from 1947 0.0428 similar limitations as described for other 1948 0.0451 sport species. Long time series of catch 1949 0.0654 1950 0.0603 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 4,498 9.369 380 0.0585 179.6 1953 4,456 6,417 501 0.0360 201.7 the U .S. and Mexican commercial 1954 6.348 16,243 751 0.0533 108..6 1955 4,597 8.081 484 0.0516 169.4 fisheries (only since 1966 for the latter). 1956 7,508 16.689 772 0.0314 86.3 Annual numbers of fish caught by 1957 5.057 11,491 417 0.0243 162.1 1958 6.521 23,712 572 0.0547 141.7 party boats have also been regularly re­ 1959 13,916 29,918 552 0.0170 123.6 ported for the whole period under re­ 1960 7,631 12,136 293 0.0340 128.9 1961 4, 157 7,074 278 00264 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 ,033 377 0.0493 114.7 1964 8,917 19,405 633 0.0340 88.4 few occasional years. On the basis of 1965 10.274 18.199 567 0.0196 93.4 such information and on known or as­ 1966 10.213 16,738 473 0.0089 92.6 1967 8,734 16.284 556 0.0066 87.0 sumed trends in the history of their re­ 1968 6,113 14,606 578 0.0060 69.3 1969 9,391 19,294 844 0.0068 69.9 spective developments, annual catches 1970 8,408 17,839 794 0.0049 75.2 ha ve been recons tructed for 1971 6,242 13,426 409 0.0109 80.1 1972 5,015 10,818 394 0.0065 106.5 insufficiently documented fishery sec­ 1973 0.0087 tions. Assumptions made are given in lCommercial effort information courtesy of R. Collins and C. Hooker, CDFG. footnotes on Table 19. Catches in num­ 28ased on angler CPUE index as described in text. bers of fish have been converted to 'Standard unil is boat (C > 1 ton). catches in weight using the following PACIFIC SARlJ If\E, SN'lTA 8~!lRA e.... SIN 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.g., 5, 5,6, and Ilpercentin1968, 1969, 1970,and 1971, t970 1$0 respectively) estimated total catches should not depart significantly from ac­ tual figures. C( The CPU E data for white seabass are >- 30·"" N' available for the period considered for :E

20 and in Figure 18. 60· 00 Historical trends in 30·00 annual catches and CPUE 15-00

Information presented in Figure 18 0·00 shows tha t total white seabass catches 1970 1960 1950 l ~ 1'330 1'£1 1910 1900 l a30 1.8EK) IB70 l.a5O 1B5O 1840 lB30 L820 1B1O have decreased during the period under YEAR S review, i.e., from 1950 to 1972. If year­ Figure 17.-Hlstogram plot of the scale-deposition rate of the Pacific sardine, the northern anchovy. and to-year fluctuations in fishing activity, the Pacific hake In sediment of Santa Barbara Basin, 1810-1969 (from Soutar and Isaacs, 1974).

19 recruitment. and availability (in particu­ coefficient, q, is posi tively correia ted on fishing power (R. Collins and C. lar the sudden increase observed in wi th popUlation size. The positive trend Hooker, CDFG, pel'S . commun.). The 1958-59 and said to be associated with in U.S. commercial fishery CPUE, 1958 and 1959 values have been deleted exceptionally warm waters) are ne­ which has seen an average increase of in the fitting because of abnormally high glected, total catches regularly de­ 27 percent between 1951 and 1972, sug­ catches. Subsequent CPUE observed creased by 42.5 percent from 1950 to gests q for the commercial fishery may during these years were most likely due 1972. This drop is essentially due to the be negatively correlated with popula­ to above-average availability of the reduction in activity of the U.S. com­ tion size. The most likely explanation stock in relation with exceptionally mercial fishery, the landings of which for the opposite trends in CPU E of warm waters. The equilibrium yield have dropped by some 50 percent dur­ partyboats and commercial vessels is curve derived from the CPUE line ing the same period. The Mexican that the q 's for the two fisheries are non­ against effort suggests 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 20 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 smaller in abso­ seabass was made from overall annual the catchability coefficient 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 CPU E (pounds/boat with annual the maximum potential yield may have party boats have shown a drop of almost landings > 1 ton) . For that purpose, been exceeded, and the population may 90 percent during the last two decades. Gulland's (1969) approximation method be overfished. Although the overall partyboat has been used. The CPUE figures were Interaction between CPU E of white seabass has also de­ plotted against average effort during the fishery segments creased by approximately the same 5 previous years (average duration of amount as the catch during this period, exploited phase = 9-10 years). Fishing Processing catch and CPUE data by the drop in annual catch and CPUE for power has probably not increased sub­ combining the various segments of the party boats cannot be explained by a stantially since the early 1950's as boats white seabass fishery may lead to at general reduction in stock abundance have remained fishing about the same least partly erroneous conclusions since related to fishing activity of the various amount of gear. Introduction of nylon the segments 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 of the W WHITE SEABASS ::l w_ various segments may vary differently.

WHITE SEA8ASS ~ ~ .. 3.0 .: '0 " c 1.0 0 :J 20.000 -69 -64 .J 0 W Q. w .70 ·65 ::> >= .. a. • -66 _56 u 7 Q :J 2.0 .J · 68 ·71 "ii' " U 60- 51 CD :I: 0:" . 72 - 63 :J Q5 5 Ll w 10.000 a ~ " ·55 w Ll 1.0 8" vi :J MEXICAN COMMERCIAL presenl level o.oL-----....;· .:.-..:.-:..::· -.:.:· -:.;;· -:;.· :..:-· .::.;..:.='---'==~=::::..-....:..... 00~---=50~.0 ---L~IOO~. 0~--~I~~.0~--2~O~0.O~-:--2~50~ 1940 1950 1960 1970 YEAR EFFORT (5 year overage)

Figure 18.-Catches and CPUE lor the various segments 01 the white seabass Figure 19.-Relatlonshlp between commercial CPUE and effort and the cor­ fishery. responding estimates of surplus production for while seabass. 20 Table 21.-Whlte seabass age composition of 1973 (obtained by catch curve analysis) Table 22.-Estlmate. of F for three segments olthe catches In 1973 for three fishing segments. white seabass fishery, for M = 0.13, 0.20, and 0.30. upon effort measured in number of boats with an annual catch in excess of I U.S. U.S. Pier & Age commercial partyboat jetty u.s. U.S. Pier & ton. Thomas gave a value of M = 0.303. Age commercial partyboal jelly TOlal For 1973, Z was estimated to be 0.50 M ~ 0.13 No. of Fish 1 0 0.0018 0.0061 1 0 236 773 1.009 from age composition data for the U.S. 2 0 0.0221 0.0724 2 0 2.3 61 7.727 10.088 gill net fishery provided by Rob Collins, 3 0 0.0123 0 3 0 708 708 4 0.0029 0.0123 0 4 223 708 931 CDFG. These data were also analyzed 5 0.0164 0.0123 0 5 1.087 1.108 2.195 to generate values of fishing mortality 6 0.0274 0.0123 0 6 1.546 236 1.782 7 0.0656 0.D123 0 7 3.095 3.095 for the various age groups and gear B 0.1105 0.0123 0 9 0.1501 0.0123 0 8 4.180 236 4.416 types (Table 22). This was done by di­ 9 4.333 472 4.805 10 0.3591 0.0123 0 10 6.966 472 7.438 viding total F among the fisheries ac­ 11 0.4566 0.0123 0 11 5.030 472 5.502 12 0.2600 0.0123 0 12 1.703 1.703 cording to the proportion of total catch 13-20 0.3577 0.0123 0

of each fishery. M ~ 0.20 seabass are caught by gill netters, full Since the estimates of Mare 0. 13 and 1 0 0.0009 0.0031 recruitment appears not to occur until 2 0 0.0121 0.0398 0.30, the Y/R analysis was performed 3 0 0.0090 0 age 9 or 10 (Table 21). The age composi­ for M = 0.13, 0.20, and 0.30. It was also 4 0.0018 0.0090 0 tion of the U.S. commercial fishery may 5 0.0107 0.0090 0 assumed that all undersized fish caught 0.0191 0.0090 0 be changing since the Mexican compo­ are released and do not subsequently 7 0.0483 0.0090 0 8 0.0852 0.0090 0 nent is declining due to a reduction in die. Size limits or alternative fishing in­ 9 0.1206 0.0090 0 permits issued by the Mexica n Gov­ 10 0.2943 0.0090 0 tensities may influence future recruit­ 11 0.3703 0.0090 0 ernment. ment; unfortunately the analysis could 12 0.2 100 0.0090 0 There has been a minimum size of28 not take this into account. 13-20 0.2910 0.0090 0 inches for the sport fishery ; however, Results of the analysis indicate that if M ~ 0.30 the bag limit has included one under­ 0 0.0003 0.0041 a uniform minimum size limit was set 0 0.0050 0.0149 sized fish per person except from 197 I such that Y /R for the entire fishery 0 0.0050 0 to mid-1973 . Due to the low catch rate, 0.0008 0.0050 0 would be maximal , a 12 percent gain in 0.0052 0.0050 0 this one undersized fish essentially Y/R would be realized (M = 0.13, 0.0152 0.0050 0 eliminates the minimum size require­ 7 0.0281 0.0050 0 minimum size = 96 cm). The expected 8 0.0534 0.0050 0 ment. Also the "sea trout" fishermen 9 0.0803 0.0050 0 increase would be only 4 percent if M = 10 0.2020 0.0050 0 often fail to recognize their catch as 0.20 (minimum size = 71 cm) , and no 11 0.2294 0.0050 0 white seabass and consequently, fre­ 12 0.1420 0.0050 0 gain would be expected if M = 0.30, 13-20 0.1950 0.0050 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 de­ pen to the YI R for the various fisheries if 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 gram MGEAR (Lenarz et aI. , 1974) . WHITE SEABASS .'" (0.) conclusions are: This program simultaneously calculates .20 I) A 50 percent reduction should Y /R values for a multiple gear fi shery as " 0 benefit the party boat fishery by increas­ in the case of the white seabass. The ENTIRE FI SHERY ing Y/R in numbers and weight. This following three fisheries were included: -10 -20 increase is due to more large fish being U.S. commercial gill nets, U.S. party­ -30 M-0.30 available. The magnitude of the benefit boats, and U.S. pierandjetty. The U.S. a:: decreases if the value ofM is larger. The ~ +30 (b.) private boat and both Mexican fisheries commercial fishery would obviously were not included because of the experience a decrease in Y /R . 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. 20a, 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. M ~O.l3· ...... • 20 commercial fisheries (Fig. 20a). The necessary growth and mortality M s O.20 ...... +10 3) The curves in Figure 21 were es­ M-0.30 ...... , ... ~ ... parameters were taken from Thomas O ~------~~~~~-'PWAR~T ~YB~OA~T'F~I~~ER~Y sentially unaltered if the fishing inten­ (1968) . His estimates for instantaneous -1 0 ~~-::-:.-:: sity for the pier and jetty fishery were mortality coefficients were reexamined - 20 -30 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 fIOO% CHANGE IN COMMERCIAL F assumed to harvest only age I and 2 fish , mortality rates for 1958, 1959, and 1960 Figure 20.-Changes In VIR for white seaba •• If its YI R was unchanged by the variations (obtained by cohort analysis) and for only F for commercial fishery Is changed. in the commercial fishery. 21 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 28-inch their development. The importance of minimum size were to be imposed on The yellowtail , S erioLa dorsalis , is these estimated catches appears to be the three fisheries equally. The conclu­ probably the most important single rather small compared to that of sions were: species to the southern California documented sections (about I percent I) A 50 percent reduction in com­ party boat fishery , both in economics of estimated total catches for the period mercial fishing plus a 28-inch size limit and angler preference. A large commer­ 1948-53 and between 15 and 36 percent should benefit the sport fishery ifnatural 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, Y/R 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 abu n­ M is, the greater this reduction in Y/R Data dance. The Coronado Islands are the (Fig.2Ic). 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 Y/ R at all levels of fishing ily recreational species. Long time be the mainstay of local yellowtail intensity except at the higher levels of M 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. 2Ib) . weight and for the California party boat which is centered off southern Baja 3) Trends in the fishery as a whole catch in numbers of fish. Mexican California. Party boat effort for pre-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 1.0073 angler/angler day based on 4) The pierandjetty fishery would be tributions available allowing transfor­ the mean of 1960 and 1961 observations. eliminated if the size limit is enforced. mation of catches in numbers to catches Partyboat 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 28-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 5-10 per­ catches (sport, commercial, and re­ pounds for 1947-54 and 12.78poundsfor cent if M = 0. 13 , by 2-5 percent if M = search) during the period 1952-54. 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. WHITE SEABASS weight for all fisheries by the Coronado 30 (0) 22) and with time in relation to changes Islands CPUE thus obtained. 20 in the amount of fishing, these two sets Indices of apparent abundance de­ 10 of data are notably insufficient to build rived from aerial surveys have also been 0'~~M~~~0.~13~~S7~~~~~~~ up the sport fishery catch (in weight) -10 published, but because yellowtail are -20 during the whole period considered. seldom observed from planes, the -30 Despite these limitations, annual method probably does not provide a re­ a: catches by fleets have been tentatively liable index of relative abundance for ;: 30 (b.) reconstructed for two periods-1947-54 ~ 20 such species (Squire, 1972) . Therefore, ~ 10 and 1966-72 respectively-selected for this source of data was not used in the ~ 0 ~~M~'0~.1·3~~~~~~~~~~ the following reasons: I) Availability of present analysis. I U -10 length frequency distributions (and ~ -20 length/weight relationship); and 2) The Historical trends ~ -30 a: w 0----0 AT ESTIMATED F PIER relative stability of the amount of fishing During the warm water years of 1957 a. AND JETTY 30 (c.) '- .-.. DOUBLE THE ESTIMATEO taken as a whole during each of these through 1959, yellowtail appeared in M=O.13 " F FOR PIE RAND JE TTY 20 "" two periods. unusual abundance in southern Califor­ 10 " For such conditions of fishing stabil­ nia waters and angler success reached 0~~M~'0~.2~0~~~'~~~~--~M~R~TY~B~0~~C-­" -10 FISHERY ity, the sport fish catches were con­ record levels. The warm water -20 verted to weight by applying the corre­ phenomena aroused interest in the ef­ -30 sponding average weight of fish in the fects of ocean temperature on fish dis­ -50% 0 size composition samples to all years tribution and availability, and Radovich CHANGE IN COMMERCIAL F within the respective time series. (1963) presented a hypothesis that warm For the various fishery segments for oceanic conditions may bring about a Figure 21.-Changes in VIR for while aeabass which no data are available-essentially northward shift of the yellowtail popula­ If F for commercial fishery Is changed and allhe same lime a 28-lnch size IImllls enforced. U.S. sport fishery other than partyboats tion , and as southern California is nor-

22 mally at the extreme edge of the popula­ Table 23.-Yellowtall: estimated annual catches. tion, this movement considerably Other increases the local abundance. Exam­ U.S. commercial sport combined Total Total3 Estimated ination of data from more recent years Mexico U.S. (U .S. + Mex.) sport sport lo tal supports the hypothesis (Radovich, Year California Mexico commercial partyboat estimate' catch catch catch (10' Ib) (10' Ib) (103 Ib) (10' fish) (103 fish) (10' lish) (10' Ib) (10' Ib) (975) and a scatter diagram ofCPUE in 1947 103.7 9.849.1 6.95 (1.6) (8.6) (93.4) (10.046) numbers per angler day at the Coronado 1948 246.6 10.1381 13.03 (4 .7) (17 .7) (192.2) (10.577) Islands versus annual mean sea surface 1949 15.9 7,301 .8 17.71 (3.7) (21.4) (232.4) (7 .550) 1950 5.7 3,524.2 assumed 6.97 (1 .5) (8.5) (92.3) (3.622) temperature at Scripps Pier in La Jolla 1951 14.5 4.655.3 to be 23.72 (4 .8) (28.5) (309.5) (4 ,979) shows a distinct relationship (Fig. 23). 1952 51.1 9.395.9 negligible 59.26 (12.2) (71.5) (776.5) (10.224) 1953 14.4 5,198.0 27.70 (5.8) (33.5) (363.8) (5 .577) On the other hand, the temperature re­ 1954 11 .8 1,644.9 40.87 (9.1) (50.0) (543.0) (2,200) 1955 5.6 158.8 36.47 (8 .0) (44.5) lationship is not as pronounced for the 1956 18.6 352.3 29.20 (6 .8) (36.0) common range of water temperatures. 1957 150.9 358.1 242.69 (56.8) (299.5) 1958 105.5 64.1 123.38 (29.6) (153.0) It is still worthwhile to examine the ef­ 1959 207.2 24.1 457.35 (112.1) (569.5) fects offishing in more " normal" years. 1960 156.5 92.1 254.97 (63.5) (318.5) 1961 80.7 300.1 42.12 (10.8) (52.9) The period 1948-54 corresponds to 1962 37.1 151.4 611 .1 21.79 (5.7) (27 .5) the end of a stable era of high exploita­ 1963 25.4 44 .3 261 .3 41 .68 (11 .3) (56.6) 1964 25.9 84.2 1.481.4 38.00 (11.5) (49.5) tion by U.S. commercial boats operat­ 1965 12.5 115.3 938.3 11.68 (11 .3) (23.0) ing mainly near Magdalena Bay, Baja 1966 35.9 209.3 761 .6 72.94 (29.0) (102.0) (1 ,303.6) (2,310) 1967 13.2 137.5 642.7 16.00 (24 .0) (40.0) (511 .2) (1 ,305) California. During this period, initiated 1968 22.5 140.7 1,901 .1 35 .01 (39.4) (74.5) (952.1) (3,016) 1969 11 .7 222. 4 671.2 44.70 (57.3) 102.0) (1 ,303.6) (2,209) in 1935 , commercial landings fluctuated 1970 56.3 127.9 528.0 72.55 (53.4) 126.0) (1,610.3) (2,323) between 4 and 10 million pounds with an 1971 31 .0 359.5 30.8 17 .30 (40.7) (58 .0) (741.2) (1 .163) 1972 96.1 163.0 '(740.0) 31 .08 (46.0) (77.0) (984.1) (1 .983) average of 6.3 million pounds. Between 1973 82.5 152.8 1,869.2 189.89 (100.1) (290.0) (3,607.2) (5,712) 1948 and 1954 , U.S. commercial land­ 'Mean between maximum and minimum guesses, calcula ted as following: (8) Ratio Mexican party boat catch to U.S. ings and sport catches amounted to parlyboat catch: max ~ 0.23 (1961), min = 0.03(1971): (b) Ratio U.S. private boat catch to U.S. partyboat catch : constant about 92 percent and 8 percent of total = 0.13 (1964), increasing = 0.0 1l(year-1950): (c) Long range partyboat catch as reported. 'Preliminary estimate based on 550.000 Ib caught in 9 months and average catch/quarter from 1966 to 1971, other catches respectively. Mexican data courtesy of Instituto Nacional de Pesca. 3Based on mean weights of samples taken from partyboats (w - 12.78Ib) in 1973 and from sport. commercial. and Cannery demand for ye 1I0wtaii research boats. (w = 10.86 Ib) in 1952-54. ceased after 1954, causing a consider­ able drop in U.S. commercial yellowtail fishing operations. As a consequence, 1952-54 Figure 22.-Yellowtall length their landings have fluctuated around frequency distributions for 20 ALL SAMPLES COMBINED 1973 IN. 3,377) 1952-54 and 1973. 230,000 pounds since 1955 . Since then a LOCAL PA RTY BOATS commercial fishery has developed in (N- 3,109) 15 Mexico, and sport catches from Cali­ >­ u z ~,., 1973 fornia and Mexican boats have more w " " LONG RANGE PARTY BOATS ::> than doubled. Yet these overall land­ o 10 I \ (N. 541) W 0:: ings remain far below the previous LL level. During the 1966-72 period total ca tches have averaged 71 percent below the 1947-54 level. Simultaneously the °3~0--~~~~~7-~~--~--~9~0~~" '~~~~~=-~ catch per angler (party boat) increased 40 50 60 70 BO 100 110 120 130 by about two-thirds above the 1948-54 YELLOWTAIL LENGTH (cm) level and the overall effort is now at 10 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 illus­ - 7 • Y=5.013 JI 10 JI (2.484) trated by the following percentages (of g r= 0.7588 total catches): Figure 23.-Yellowtail CPUE I In number per angler at the ~4 Coronado 'slands plolted ..J U.S. Mexico Sport against annual mean sea sur· ~ Period commercial commercial fisheries face temperature at Scripps - of fishing deduced from trends in total ~4 ~ ~ 17 18 S I 0 SURFACE TEMPERATURES IN 'c 23 catch. Length composition shows an in­ . 68 YELLOWTAIL crease in the proportion of older fish \ . 70 i' 8.0 B.O between 1952-54 and 1973 . '\ g- \ .54 o \ Figure 24.-Relationshlp be­ , .52 Present state of ~ tween Coronado Is1ands ~ CPUE and ellort and the cor­ c 72 ~ exploitation &. 6.0 " 6.0 responding estimates of sur­ "69 " "Q plus production lor yellow­ W ::. Using Gulland's (1969) approxima­ tail. :J J: "­ u tion method for assessing equilibrium U >-- o 4.0 .71 4.0 u Z "'" curve, yellowtail CPUE data (Table 24) ::; ...J :J !Q"'" 1i: for partyboat anglers were plotted ID :::i against average total effort (averagc of g S z 2.0 0 past 3 years in order to take into account o"'" w '"o the approximately 6 years duration of u exploited phase). Since data are only 0 available for the periods of 1948-54 and 1.0 2.0 3.0 4.0 1966-72, respectively, the number of EFFORT (lI[ 106 angler standard units - 3 yeor mean) 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 a mount 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 (all fish are said to be mature as 6 effort of2.5 to 3 x 10 Coronado Isla nds have improved under the present level 3 years old, or 27.8 inches). However, partyboat angler standard units, i.e., since exploitation has been far from there is no scientific evidence, either in roughly 8 to 10 times the 1966-72 level. maximum sustainable levels. The stock yield per recruit or in recruitment! 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 is 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 should also be strongly suggests that the maximum ploitation, determination of the exact noted that neither the southward exten­ yield per recruit would be achieved positions of the potential and of the cor- sion of the stock nor its relationship for a smaller size at first capture with other stocks located in the Gulf of than the legal one which represents Table 24.- Yellowtail: CPUE and estimated total California and more southern waters, is about 0.55 the maximum sizes of fish ellort. very well known. It is, at present, as­ caught. Examination of yield per recruit Party boat CPUE Estimated sumed that such stocks do not contrib­ tables (Beverton and Holt. 1966) indi­ total elfort catethatifMIK = I.50(K =0.136),and Coronado 1.000 ute substantially to the California Islands Estimated standard fisheries. If this assumption is not to be fishing mortality is low (less than Y:J M), 1 Year fish/angler Ib/angler units confirmed, expansion of fishing in more yield per recruit could potentially be in­ 1947 0.229 2.490 4035 southern waters might provide higher creased from 6 to 16 percent by lowering 1948 0.232 2.521 4197 1949 0.290 3.146 2400 yields. minimum size from 28 inches. If M IK = 1950 0.174 1.891 1914 0.75 only a 1-4 percent increase would 1951 0.451 4.903 1016 Analysis, discussion of 1518 be expected, as 28 inches is nearer 1952 0.620 6.734 present management measures 1953 0.364 3.948 1413 proper minimum size for low mortality 1954 0.664 7.211 305 1955 0.644 Between May and August the U.S. rates. Stock recruitment relationship 1956 0.489 commercial yellowtail fishery is now 1957 1.913 should not raise particular problems at 1958 1.315 subject to several limitations: Catches the present level of fishing, and even for 1959 4.312 1960 1.418 per trip are limited to 500 pounds per substantially higher ones, since the long 1961 0559 fisherman and 2,500 pounds per boat; life span of yellowtail and the subse­ 1962 0.518 1963 0.869 use of purse seine and round haul nets is quent high number of year classes pres­ 1964 0.716 prohibited, and gill nets must have a ent in the population should make it less 1965 0.304 1966 0.886 11 .325 204 minimum mesh size of3.5 inches. Simi­ vulnerable to successive low recruit­ 1967 0.380 4.860 268 larly, a daily bag limit of 10 fish is ap­ 1968 0.662 8.460 357 ments. It should also be mentioned here 1969 0.452 5.779 382 plied to the sport fishery which uses that the minimum mesh size does not 1970 0.633 8.092 287 1971 0.319 4.082 285 only hook and line. Considering the appear to correspond to the legal 1972 0455 5.802 309 present low level of exploitation of the minimum size and sublegal size fi sh may 1973 1.441 18.414 315 stock and the fact that 50-60 percent be captured. Such a situation is inap­ 'Slandard efforl unil is Coronado Island angler day. Tofal efforl is the hypothetical amount of standard of the total catches are taken in unregu­ propriate both on biological and effort units necessary fa take the entire catch. lated waters off Baja California, such economic grounds. 24 It can be concluded that at present no Table 25.-Anchovy fisheries. limitation appears to be necessary in the Present Ex-vessel Probable Regulat· Age of Present catch price catch ing yellowtail fishery . However, the limited Geographic area recruit- catch value index in 5·10 yr agency potential of the stock would require Exploiter of exploitation men! (llJ.:llons) ($1IJ.:l) $/Ion (10' Ions) Southern Inshore, near San early formulation and implementation California Pedro and Port 100 '5,000 3()'50 1O()'200 Calif. of proper management measures, wettish Hueneme facif- Fish . fleet ilies (Sa n Diego Game should the fishery expand in the future. (reduction) in future) Comm.

INTERACTIONS Soulhern Shallow inshore 2direc i Calil. California near sp ortfishing 10 5.000 '660+ 10·15 legis- Fisheries seldom act in the absence of live bait ports in southern Ji ndirect lature fleet California 5.000- important interactions from other Total fisheries, species composition and 10.000- Mexican Inshore Mexico trophic relationships, and exogenous wetlish near Ensenada (U.S. environmental influences. These in­ fleet 1-2 30 41.000+ '25-35+ 5()'200 GOY!' (reduclion) has au- teractions are complex in southern Ihority lor nego- California waters. Here we have liation) selected some relevant aspects for USSR quick investigation. Fisheries interac­ High seas Offshore USSR tions are an important aspect of the trawler! (U.S. faclory 3 0 0 0 ()'100 Gov'!, northern anchovy exploitation con­ ships may have (canning) strong troversy, and are briefly discussed, with control) emphasis on the live bait anchovy sup­ ply. Species composition of both com­ '100,000 tons @$50/ton (price generally lower). 21.000,000 scoops @$5/scoop. mercial wetfish fleet and partyboat '600.000 partyboat angler-trips @$8/trip.assuming the partyboal industry is completely dependent on live bait. True indirect value will be less. catches have undergone large changes '30,000 tons @$33/ton. Economic value to Mexico nol comparable with U.S. values. in recent years. A strong argument sBased on $5! 15 pound scoop. Inclusion of indirect value would increase index. 6Economic worth to Mexico may be greater than U.S. dollar value suggests . against large-scale exploitation of the northern anchovy has been based on 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 Northern anchovy fisheries common basis for discussion and op­ live bait fishery operates under two timization of anchovy exploitation. simultaneous sets of constraints. Sup­ interaction and allocation Presently there is a healthy cooperation ply is limited by availability (CPU E) of Three separate fleets presently ex­ and communication at lower levels, as is anchovies, while demand is determined ploit the northern anchovy, Engraulis necessary for formulation of manage­ by sport fishing activity. Fortunately, mord{lX: The southern California live ment alternatives. Cooperation, how­ analysis of these relationships is possi­ bait fleet; the southern California ever, must occur at 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 fleet based in Ensenada (Table 25). To ments so that coordinated and respon­ and extensive partyboat effort data col­ these may be added the possibility of 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 based on price paid per ton offish (Table cal regions 6, 7, and 8, corresponding to the na ture of these interactions shou Id 25), which tends to reflect 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 CPU E 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. Tabte 26.-Anchovy belt fishery-long end short term elfects of reduction fishing. Both the San Diego and Los Angeles

Region 6 (Santa Barbara) Region 7 (Los Angeles) Region 8 (San Diego) regions show this trend. The Santa Bar­ bara region appears to have experi­ Years Winter' Summer2 In (s/w) Winter' Summer2 In (s/w) Winter' Summer2 In (s/w) enced an increase in availability up to Nonreduction 6(}'61 157.6 186.4 462.1 0.908 319.5 791 .6 0.907 1969, but it suffered a severe decline in 61-62 151 .0 265.8 0.565 286.9 407.7 0.351 708.3 518.7 -0.312 CPUE in 1970, 1971, and 1972. 62-63 142.8 195.9 0.316 241.3 351 .5 0.376 478.0 571 .8 0.179 63-64 117.5 202.4 0.544 192.9 454.4 0.857 203.9 640.1 1.144 Separation of short-term (seasonal) 64-65 138.1 191.7 0.328 232.0 425.3 0.606 243.6 546.4 0.808 and long-term trends in availability, 67-68 250.5 141.4 -0.572 940.8 574.8 -0.493 368.1 581.0 0.456 vis-a-vis the reduction fishery, was ac­ x 160.0 192.5 0.236 346.7 446.0 0.434 386.9 608.3 0.531 complished by separating CPUE ob­ 52.09 43.15 0.467 293.3 74.49 0.510 184.7 98.53 0.535 servations into long-term groups (re­ Reduction 65-66 220.8 243.6 0.098 296.1 477.9 0.479 287.8 603.5 0.740 duction fishing seasons of 1965, 1966, 66-67 138.0 229.6 0.509 334.1 513.6 0.430 349.7 1.303.8 1.316 1968, 1969, 1970, and 1971, and non­ 68-69 225.8 294.8 0.267 465.1 728.4 0.449 469.4 699.0 0.398 69-70 141 .5 163.8 0.146 319.8 773.9 0.884 547.0 887.4 0.484 reduction seasons of 1960, 1961, 1962, 70-71 69.8 133.5 0.648 514.0 526.3 0.024 673.4 930.2 0.323 1963, 1974, and 1967), and into short­ 71-72 83.8 177 .0 0.748 717.3 854.1 0.175 784.3 2.031.1 0.952 term groups (reduction period, 146.6 207.1 0.403 441.1 647.7 0.407 518.6 1.075.8 0.702 winter-November, December, Jan­ 65.91 59.5 0.271 160.9 159.1 0.295 189.5 526.6 0.381 uary, and March; non-reduction per­ I); cl L , for November. December. January. and March. iod, summer-June, July, and Au­ ,); clL , for June. July. and August. gust). The long-term availability has likely increased since the mean 1400 CPUE's for all three geographical re­ o Region 8 (San Diego) gions for the summer period were higher 1200 ~ Region 7 (Los Angeles) for the reduction years than for the pre­ • Region 6 (Santo Borboro) vious non-reduction years (Table 26). Q. 1000 Winter availability shows a similar 0:: I- trend for Los Angeles and San Diego, -.... 800 (f) but a slight decrease for Santa Barbara, Q. o o particularly for the most recent years. u 600 (f) The tendency for increased availability

400 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 ~9~5-1~~~1~95~5-L-L~~-19~6LO-L-L~~-I~96L5~-L-L~-19~7~0-L~ ity or fishing power has not occured).

YEARS Values of anchovy bait CPUE (Fig. 25) Figure 25.-Anchovy live bait CPUE (annual scoops/trip). show a weak con'elation with egg-and­ larvae indices of abundance of the cen­ tral stock of anchovies (r San Diego = 0.65 , r Los Angeles = 0.51, r Santa a Region 8 (San Diego) Barbara = 0.45). Offsetting the years to 3.0 c. Region 7 (Los Angeles) account for the younger age of bait an­ • Region 6 (Santo Barbara) chovies did not give significant In­ creases in correlation coefficients. 0:: 1J.J Short-term changes in anchovy bait ..J (!) Z availability, presumably caused by de­ - I- 0:: natural logarithms) of CPUE during 'it years of reduction fishing with ratios for ..... years in which there was no reduction C/l 0.o fishery (Table 26). Mean relative winter 8 availability decreased 12 percent in the C/l Santa Barbara region and 12 percent in the San Diego region during years of reduction fishing, but in the Los Q?9L60--~----19~6-2--~---I964~--~--~I966~--~--~I96~8--~--~19=70~~L-~1972 Angeles region, in which reduction YEARS fishing was presumably the heaviest, Figure 26.-Anchovy live bait catch per partyboat angler (scoops/angler). the mean of ratios showed an 8.6 per-

26 cent increase in relative winter avail­ 3000 ability. The variance of the log ratios is o Region 8 (Son Diego) large so no tests of significance were '" Region 7 (Los Angeles) attempted . • Region 6 (SonIa Barbara) It is concluded that bait anchovy availability has not shown either long­ ~ 2000 or short-term decreases connected with II> the anchovy reduction fishery up to the E 1971-72 level of reduction catch. The r­ a: San Diego and Los Angeles bait regions o lJ... appear healthy, but the Santa Barbara lJ... region shows a large anomaly starting in W 1000 1970. The live bait fishery is also highly influenced by bait demand, with com­ mitments to bait users varying with amount of sport fishing effort. Letting o~--~--~----~--~--~----~--~--~--~----~--~--~ the number of partyboat anglers be an 1960 1962 1964 1966 1968 1970 1972 index of demand (as we have no values YEARS for private boat utilization of bait) and Figure 27.-Anchovy live bait eftort (trips). letting the bait catch indicate the supply for that market, an index of bait supply CPUE SCOOPS/BAIT TRIP to the sport fishermen can be calculated. 12 r-~2,~~~I~~ ____~ ~~o ____~~~r~ ____ ~2T~~ __~ 2~OO~ ____~'6~ 7 ____~I'r~~ ______The trend of live bait catch per par­ tyboat angler shows a fluctuating, but o REGION 8 (San Diego) . 62 fairly constant, supply to the angler for 10 1:::,. REG/ON 7 (Los Angeles) · 6' the San Diego and Los Angeles regions, • REGION 6 (SonIa Barbara) (/) a:: but the Santa Barbara region shows a w ..J 8 long downward trend since 1962 (Fig.

Letting Cb be bait catch, higher commitment than does Los chum are used. This partly explains the Angeles (K = 1.65 scoops/angler). lower levels of commitment in the Santa Santa Barbara is again anomalous in not Barbara area where bottom fishing pre­ showing any well-defined relationship. dominates. It must be concluded that

2' 250 low availability in the Santa Barbara \ , I I 0 BONITO area is a condition which has existed at , I I least since 1951, and is probably not the 6 ANCHOVY, BONITO Q • result of the anchovy reduction fishery. l':,. JACK MACKEREL, ANCHOVY, Moreover, there is some evidence that BONITO the Santa Barbara bait fishery has estab­ lished lower commitments rather than 200 ... PACIFIC and JACK MACKEREL, increasing effort to maintain the supply III ANCHOVY, BONITO to the sport fisheries . Lack or" further oC 0 information on the Santa Barbara bait rt) ALL plus SARDINE o- fleet and fishery prevents a definite con­ >< clusion, and there may be other factors which explain this anomalous behavior. I <.) 150 Southern California I­ ,t « , wetfish fishery <.) , I;;l " I /I :," Species caught by the wetfish fleet w , II :, > I ·Q : \ include Pacific sardines, Pacific mack­ P \ I ~ f; Q !: erel, jack mackerel, Pacific bonito, and !;t " '0 ~ :, .....J ~ \ :, northern anchovy, and small amounts ::J I I /:j I ' of a variety of other species. The major­ ~ 100 , I ::J I , ~ ,,:" .:,:'1 ity of the commercial catch is landed in I I . II:· I <.) I ,I j : ~ ~/ : the Santa Barbara, Los Angeles, and .1 , 6 I .1 I .. San Diego regions with the San Pedro ;,,:. I I T I , wetfish fleet accounting for most of the I I I I fishing effort. Prior to the collapse of the II 1/ 1/ 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 • I but have fluctuated for various reasons "" (Fig. 29). Documentation of the fishery • interactions between wetfish species is useful in the assessment of anyone of

O~~~~~~~~~~~~~~L-L-L-~~ the stocks. After the virtual collapse of sardines 1940 50 60 70 in 1951 and until 1963, the total catch of YEAR the five species varied between 80,000 Figure 29.-Total commercial catch of fish species exploited by purse seine wettish fleet, 1941·73. and 130,000 tons annually. When sar­ dine catches temporarily improved, 8 catches of the others usually dropped. The anchovy was canned for human 7 consumption and made up from one­ ~ quarter to one-third of the fishery until 0- TOTAL CPUE c 6 o 1958. Jack mackerel catches sustained "- .c the fishery when sardines were low and ;;:'" 5 after the demand for canned anchovies declined. Pacific mackerel catches were ALL SPECIES EXCEPT ROCKFISH consistent from 1954 until the collapse of the stock in the mid-1960's. Bonito catches were low because of low stock sizes in the early 1950's and lack of pro­ cessors' demand. The combined catch of all five species reached a low of OTHER SPECIES CPUE EXCEPT ROCKFISH, YELLOWTAI ,WHITE 43,000 tons in 1965. SEA BASS , ALBACORE, BONITO, BARRACUDA, PACIFIC MACKEREL, KELP a SAND BASS, .Beginning in 1966 the composition of AND HALIBUT ",---,_..--<1 O~~~~-L~~=±~~~~~~-L~~-L~ the wetfish catch changed. Sardine and 1948 1950 1955 1960 1965 1970 1973 Pacific mackerel catches failed to re­ YEAR cover and fishing moritoria were im­ posed in 1967 and 1971 for the two Figure 30.-Total partyboat CPUE (fish/angier) for southern California. 28 stocks respectively. Bonito catches 0.9 jumped in 1966 a nd have since o WHITE SEA BASS, YELLOWTAIL, ALBACORE fluctu ated depending somewhat on pro­ 0.6 cessor demand (Perrin and Noetzel, ... WHITE SEA BASS. YEL LOWTAIL • WHITE SEA BASS 1970). The jack mackerel catch has i 0.7 ~ dropped apparently as the result of ef­ ~ 0.6 fort being redirected toward anchovies. '" This new interest in anchovies is due to w Q5 u5' the California Fish and Game Commis­ OA 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 . O.oL..-!:-"--"--'--'-:'::-'-.:...... :r:;:r:::r::=::::::r:=o=>===-==- Southern California ~ ~ ~ ~ ro partyboat fishery YEAR

The status of the partyboat fishery is Figure 31 .-Large sport fish partyboat CPUE. largely the result of the satisfaction ob­ tained from the angling experience; however, angler satisfaction is a 4.0 o BARRACUDA , BONITO. PAC IF IC MACKEREL difficult concept with which to work. It ... BARRACUDA, BONIT O is generally not quantifiable as is profit • BAR RACUDA ~ in the case of commercial fisheries. It ! 3.0 varies widely between anglers. and £ generalizations are likely to result in w 5' overlooking the variety of individual u 2.0 experience. In view of these problems. the following discussion attempts to as­ sess the status of the party boat fi shery in s imple terms with enough quantifications to allow rough compari­ sons between years. 50 55 60 65 70 The party boat catch is composed of a YEAR multitude of species of varying interest Figure 32.-Small and medium sport fish partyboat CPUE. to the angler. Total CPU E 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 lim­ ited meaning in assessing angler satis­ 5.0 o ~:~~~~S~~L:O~:~~SH faction, however, as species composi­ ... HALIBUT, KELP and SAND BASS tion of the catch is of prime importance ~ 4.0 to the sport fisherman. f ~. Nine species comprise the bulk of the '" 3.0 w landings (Fig. 30). These species were ::> 0. divided into three groups based on a u 2.0 subjective classification . The first group is composed of large sport fish : white seabass. yellowtail , and albacore (Fig. 1. 0 31) . The second group is composed of 0.0 smaller :;port fish: barracuda, bonito, 50 55 60 65 70 and Pacific mackerel (Fig. 32) . The YEAR third group is composed of "food" species: kelp and sand bass, rockfish Figure 33.-"Food" fish partyboat CPUE. and halibut (Fig. 33). The CPUE was calculated as total partyboat catch di­ vided by total anglers, which in this case includes long-range party boat data. Both the large and small sport fish was later ignored in favor of the highly In summation, the party boat 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. sport fish abundance caused an increase of the early 1950's. 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 1950's 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 party boat 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 Sport fish-anchovy rockfish resource appears to have been creased harvesting is unknown and "discovered" in the mid-1950's, but should be seriously investigated. relationships The trophic relationships are com­ plex between forage species such as an­ 8 chovies and sardines and predatory '"c game fish species such as yellowtail, 2 7 barracuda, bonito, white seabass, and '"Q ~_.--,.1962 albacore. An attempt to describe the If) 6 If) food webs and to quantify energy flows « ::;: 1966 between trophic levels for the last 20 0 5 iIi years is beyond the scope of this report. ILl Furthermore, necessary estimates of Z 4 is growth rates, daily food rations, and a: « 1954 1958 '"--_1960 predator biomass do not exist. On the If) 3 other hand, biomass estimates for sar­ Cl 1953 z dines and anchovies and partyboat « 2 >- CPUE provide enough information for >0 1951------1952 I I 1950 a superficial examination of the rela­ <.) Z tionship between biomass of these for­ « age species and the availability of the 00 2 4 6 8 10 12 14 16 18 20 22 major game fish. CPUE IN POUNDS/ANGLER INCLUDES; YELLOWTAIL, A plot of anchovy and sardine BONITO, BARRACUDA, ALBACORE, WHITE SEABASS biomass estimates for all stocks versus combined party boat CPUE (pounds/ Figure 34.-Relalionshlp between anchovy plus sardine biomass and game fish party· boat CPUE lor 195()'69. angler) for yellowtail, barracuda, white seabass, bonito, and albacore for the years 1950-69 tend to support 600 the general theory of Brocksen, Davis, and Warren (1970) (Fig. 34). They <.> 1953 <.> hypothesize that if forage is limiting, then a negative relationship would (/) W be expected between forage biomass ;:!; 400 => and predator biomass such that high ....J 0 > levels of predators should reduce forage Z 1964 to low levels , and at low levels ofpred­ 0r- ators, forage would grow to high :lC Z 200 1963 levels. If the system becomes more

31 regulation for Atlantic yellowfin tuna. Thullllus biomass of northern anchovy. Engralilis LITERATURE CITED albacares. Fish . Bull. , U .S. 72:37·61. mardax. Fish. Bull .. U .S. 70:849-874. Ahlstrom, E, H , 1968, An evaluation of the MacCali . A. D. 1973 . The mortality rate of Soutar. A ., and J. D . Isaacs . 1974. Abundance of fishery resources available to California Engrllulis rn ordax in southern California. Calif. pelagic fish during the 19th and 20th centuries as fishermen. Univ. Wash" Publ. Fish" New Ser. Dep. Fish Game. Mar. Res. Tech. Rep. 4, 23 p. recorded in anaerobic sediment off the Califor­ 4:65-80. MacGregor, J . 1964 . Average biomass estimates ni as. Fish. Bull., U.S. 72:257-274 . Baxter, J. L. , and p, H , Young, 1953. An evalua­ forthe years 1955-57.ln Calif. Mar. Res. Comm . Spratt, J . D. 1972. Age and length composition of tion of the marine sportfishing record system in Min, . 6 Mar. 1964. Doc. 6. northern anchovies, Engratllis m ord(lX. in the California. Calif. Fish Game 39:343-353. Messersmith, J . D . 1969. The northern anchovy California anchovy reduction fi shery for the Beverton, R.J, H"andS.J. HolL 1966, Manual (Engraulis ltI ordax) and its fishery 1965- 1968. 1969-70 season. Calif. Fish Game 58:121 -126. of methods for fish stock assessmenL Part Calif. Dep. Fish Game. Fish Bull. J47 . 102 p. ____ . 1973a. Age and length composition of 2-Tables of yield functions, FAO (Food Agric. Murphy, G. l. 1966. Population biology of the northern anchovies (En/iralilis rnordox) landed Organ. U. N ,) Fish. Tech. Pap. 38, 77 p. Pacific sardine (Sardillops caerulea). Proc. in California for reduction during the 1970-7 I Brocksen. R. W., G. E, Davis. and C. E. Warren. Calif. Acad. Sci. Ser. 434: 1·84. season. Calif. Fish Game 59:121-125. 1970. Analys is of trophic processes on the Parrish. R. 1974. Ex ploitation and recruitment of _-:-_-:-. 1973b. Age and length composition basis of density-dependent functions. III J. H. Pacific mackerel . Scomber japonicus . in the of n0l1hern anchovies, EnR",uli" ltI ordax . in the Steele (editor), Marine food chains. p. 468-498. northeast Pacific . Calif. Coop. Oceanic Fi sh. California reduction fishery for the 1971-72 sea­ Univ. Calif. Press, Berkely and Los Ang., Calif. Invest. Rep. 17 :136-140. son. Calif. Fi sh Gamc 59:293-298. Campbell. G. In press. The age and growth of the Perrin, W . F .• and B. G. Noetzel. ____ . 1975. Growth rate of northern an­ Pacific bonito, Sardo chiliellsis . Calif. Dep. Fish 1970. Economic study of the San Pedro wetfish chovy. Engralilis rnordax. in southern California Game, Fish Bull. boats. Fish. Ind . Res. 6:105-138. waters. calculated from otoliths. Calif. Fish Clark, F. N ., and J . C. Marr, 1955. Population Pinkas. L. 1966. A management stud y of the Game 61: I 16-126. dynamics of the Pacific sardine. Calif. Coop. California barracuda Sphyraella argelliea Squire. J . L .. Jr. 1972 . Apparent abundance of Oceanic Fish, Invest. Rep. 1953-55: 11-48. Girard. Calif. Dep. Fish Game. Fish Bull. 134 . some pelagic marine fishes off the southern and Collins, R. A. 1971. Size and age composition of 58 p. Ccntral California coast as surveyed by an ai r­ northern anchovies (Ellgraulis rnordax) in the Pinkas. L.. M. S. Oliphant. and C. W. Haugen. borne monitoring program. Fish. Bull ., U .S. California reduction and canning fisheries. 1968 . Southern California marine sportfi shing 70: 1005- 1119. 1968-69 season. Calif. Fish Game 57:283-289. survey: private boats, 1964; shoreline , 1965-66. _ ::--:--:-. 1973. Proceedings of the State­ Fry, H" Jr. 1937. Yellowtail. In Staff of Bureau Calif. Dep. Fish Game. Fish Bull. 143 . 42 p. Federal Marine Fisheries Research Program of Commercial Fisheries. The commercial fish Pinkas, L" M. S. Oliphant, and I. L. K. Iverson. Planning Workshop. March 12- 15 . 1973 . San catch of California for the year 1935. p. 33-36. 197 I. Food habits of albacore. blue fin tuna. and Cle mente. Calif. Calif. Dcp. Fish Game and Calif. Dep. Fi sh Game. Fish Bull. 49. bonito in California waters. Calif. Dep. Fish Natl. Mar. Fish. Serv., 327 p. Gulland, J . A. 1969. Manual of methods for fish Game. Fish Bull. 152 , 105 p. Sunada. J . 1975. Age and length composition of stock assessment. Part I. Fish population Pinkas, L. . J . C. Thomas. and J . A. Hanson. northern anchovies, Ellgralilis mordllx. in the analysis. FAO(Food Agric. Organ. U .N.) Man. 1967. Marine sportfishing survey of sOllthern 1972-73 season, California anchovy reduction Fish. Sci. 4. 154 p. California piers and jetties. 1963 . Calif. Fish fishery. Calif. Fish Game 61: 133-143. ---=:::---=-:-. 1970. Preface. III J . Gulland (editor), Game 53:88-104 . Thayer, B. D. 1973 . The status of the Pacific The fish reSO urces of the oceans. p. 1-4. FAO Radovich. J. 1963 . Effects of water temperaturc bonito resource and it s utilization . Calif. Dep. (Food Agric. Organ. U .N .) Fish. Tech. Pap. 97 . on the distribution of some scombrid fi she s along Fish Game. Mar. Re s. Tech. Rep. 7. 16 p. Knaggs, E. H . 1973 . The status of the jack mack­ the Pacific Coast of North America. FAO (Food Thomas, J . c:. 1968. Manage ment of the white erel resource and its management. Calif. Dep. Agric. Organ. U.N.) Fish. Rep. 3(6): 1459-1475 . seabass (Cl'lIoscion nobilis) in California waters. Fish Game, Mar. Res . Tech. Rep. II. 12 p. _ _ -:-_. 1975. Ocean temperatures and Calif. Dcp. Fish Game. Fish Bull . 142. 34 p. Knaggs, E. H" and P. A, BarnetL 1974. The southern California angling success. A paper Thrailkill. J . R. 1969. Zooplankton volumes off the southern California jack mackerel tishery and presented at the Symp. on Fisheries Science held Pacific coast. 1960. U .S. Fish Wild\. Serv .• Spec. age composition of the catch for the 1947-48 at the Higher School of Marine Sciences of the Sci. Rep. Fish 518 , 50 p. through 1956-57 seasons. Calif. Dep. Fish Autonomous Univ. of Baja California, En­ Vrooman. A. M., and P. E. Smith. 197 I. Biomass Game, Mar. Res. Tech. Rep. 22 . 47 p. senada, Baja Calif. , Mexico. February 16-22 . of the subpopulations of northern anchovy ___---,. 1975. The southern California jack 1975. Engraulis moulllx Girard. Calif. Coop. Oceanic mackerel fishery and age composition of the Smith, P. E. \970. The horizontal dimensions and Fish. Invest. Rep. 15:49-5 I. catch for the 1962-63 through 1966-67 seasons. abundance of fi sh schools in the upper mixed Walford, L A . 1932. The California barracuda Calif. Dep. Fish Game, Mar. Res. Tech. Rep. layer as measured by sonar. In G. B. Farquhar (Sphyraella argenlell) . Calif. Dep. Fish G ame. 28,28 p. (editor). Proc. Int. Symp. BioI. Sound Scattering Fish Bull. 37, 122 p. Lenarz, W. H ., W. W. Fox, Jr .• G. T. Sakagawa. in the Ocean, p. 563-591. Maury Cent er for Young. P. H. 1969. The California partyboat and B. J . Rothschild. 1974 . An examination of Ocean Science, Dep. of Navy. Was h., D.C. fishery, 1947-1967. Calif. Dep. Fish Game, Fish the yield per recruit basis for a minimum size ____. 1972 . The increase in spawning Bull. 145,91 p.

MFR Paper 1173. From Marine Fisheries Review . Vol. 38. No. 1. January 1976. Copies of this paper. in limited numbers. are available from 0825. Technical Information Division. Environmental Science Information Center. NOAA. Washington. DC 20235. Copies of Marine Fisheries Review are available from the Superintendent of Documents. U.S. Government Printing Office, Washington. DC 20402 for $1 .10 each.

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