ALBERT

Beschreibung: Methods and materials used to tag and recapture jack mackerel, Trachurus symmetricus, off the coast of southern Ca1ifornia and Baja California, Mexico, are described. Tagging, recapture, and movement data resulting from this program are reported. Analysis of these data indicates substantial movement of jack mackerel within the range of the California fishery and suggests a seasonal inshore-offshore movement pattern. (13pp.)

Beschreibung: In 1977 a new fishery began to develop off the coast ofsouthern California. Long gill nets, drifted near the surface in the deep offshore waters, were being used successfully in landing pelagic sharks, primarily threshers. Recent increases in the retail demand for fish had led wholesale buyers to look for new sources of fish protein. Shark meat looked promising to many buyers. Aided by the public's rekindled fascination for sharks, the timing seemed favorable for introducing sharks as food. Word spread that wholesalers were willing to pay a good price for sharks. This created what appeared to many commercial fishermen to be the beginning of a bonanza.The new shark fishery grew rapidly. The number of vesselsengaged in offshore drift gill net operations grew from about 15 in 1977 to approximately 230 by 1984.Fishery biologists have expressed concern over the rapidexpansion of the commercial shark fleet. Historically, sharkfisheries have tended to decline after their initial success, due principally to slow growth and reproductive rates which seem to characterize sharks as a group. Perhaps the new thresher shark fishery might also be subject to a similar decline.Biologists were not the only ones who looked on the newindustry with concern. Among sport fishermen and conservation groups, rumors of marlin, whales, and seals taken by the hundreds became commonplace.Concern spread among the traditional swordfish harpoonfleet that landings by drift gill nets might glut the swordfish markets, driving prices down to the point that harpooners could no longer compete. Some harpooners voiced fears that drift gill nets might even overfish the swordfish stocks, causing serious declines in the availability of fish.Some conservation groups sought to ban the use of all gillnets, feeling that gill nets are inherently indiscriminant in what they catch and that the benefits derived from their use is always over-shadowed by the waste of marine life resulting from their use.In September of 1980, the Legislature enacted Assembly Bill2564 (Kapiloff), which directed the Department of Fish and Game to conduct a study of the drift gill net shark fishery. The purpose of the study was to determine what impact the use of drift gill nets might have on existing fisheries or upon other members of the local marine community such as whales, dolphins, and seals. The final report of that study "Pelagic Shark/Swordfish Drift Gill Net Fishery Management Information Document" was sent to the California Legislature in January 1983.In September 1982, the Legislature enacted Senate Bill 1573(Beverly), directing the Department of Fish and Game to continue monitoring the drift gill net fishery. It also directed, that a further study be conducted on the status of the thresher shark and swordfish resources off California and on the effects of the fishery on other resources. A report on this study would be prepared and delivered to the Legislature on or before January 1, 1985. The study was conducted. This is the report on that work. (77pp.)

Beschreibung: State law requires that the population of Pacificsardines, Sardinops sagax caeruleus, must reach aminimum spawning biomass of 20,000 short tons beforeinitiation of a fishery. Data from ichthyoplanktonsurveys, the anchovy live bait fishery, sea surveycruises, the mackerel purse seine fishery, and a brownpelican food study are discussed concerning evidenceof an increase in population size. The spawningbiomass of the northern stock of sardines appears tobe remaining well below 20,000 tons. (9pp.)

Beschreibung: State law provides for the initiation of a fishery forPacific sardines, Sardinops sagax caeruleus, when thespawning biomass of sardines reaches 20,000 short tons.Data from ichthyoplankton surveys, sea survey cruises,the mackerel fishery sampling program, and the live baitmonitoring program are discussed with regard to an increasein population size. It appears that the spawningbiomass of the northern stock of Pacific sardines remainsbelow 20,000 tons. (7pp.)

Beschreibung: In Tomales Bay, 5-, 6-, and 7-yr-old herring, Clupea harengus pallasi, composed 75% by number of the 1984-85 season's catch. In San Francisco Bay, 2-, 3-, and 4-yr-old herring composed 82% by number of the roundhaul catch, and 5-, 6-, and 7-yr-old herring composed 68% by number ofthe gill net catch.The percent of 4-yr-old herring increased to a record high level in the San Francisco Bay gill net catch.Recruitment of 2-yr-old herring into the San Francisco Bay roundhaul fishery was excellent, with 2-yr-old herring composing 41% of the catch.The growth rate of herring improved in both Tomales and San Francisco Bays, after the period of poor growth during the recent El Nino, when the weight of herring averaged 20% below normal.(23pp.)

Beschreibung: In Tomales Bay, 4-, 5-, and 6-yr-old herring, Clupea harengus pallasi, composed 85% by number of the 1986-87 season's catch. In San Francisco Bay, 2-, 3-, and 4-yr-old herring composed 88% of the roundhaul catch, and 4-, 5-, and 6-yr-old herring composed 86% by number of the gill net catch.The age composition of both the Tomales Bay and San Francisco Bay gill net catch has shifted to primarily 4-, 5-, and 6-yr-old herring.Recruitment of 2-yr-old herring into the San Francisco Bay roundhaul fishery was good, with the 1985 yr class composing 37% of the catch.The mean length of herring in the San Francisco Bay roundhaul catch decreased to 174 mm BL, and the mean length of the gill net catch decreased to 194 mm BL. The mean length of the Tomales Bay catch also decreased to197 mm BL.Average weight at age of Tomales Bay herring is below average for the fourth consecutive year. In San Francisco Bay the average weight at age is above average, even though length at age declined slightly. (20pp.)

Beschreibung: Herring schools were surveyed hydroacoustically and sampled in San Francisco Bay from late October 1986 to March 1987. Eight large schools (greater than 1000 tons each) spawned from December to February and seven smaller schools were detected throughout the spawning season. Total acoustic biomass estimate using a "visual integration" technique was 40,930 tons, and it was determined from spawn escapement and commercial landings that an additional 2240 tons were not detected. This is a slight increase from last season's total of approximately 42,200 tons. For the first time, biomass was also estimated using echo integration equipment. A total biomass was obtained of 33,050 tons, including herring not detected acoustically. This estimate must be considered preliminary and subject to revision after target strength of San Francisco Bay herring is determined.Eighty-seven samples, containing a total of 13,125 herring, were collected with variable-mesh gill net and midwater trawl or obtained from the roundhaul and gill net fisheries. Mean body length (BL) of sampled herring decreased by about 20 mm from the beginning to the end of the spawning season. A combination of variable-mesh gill net and midwater trawl samples for a particular school closely approximates mean BL and age composition data from unbiased roundhaul samples.Age-weight and age-length relationships were average to above average compared with those of the previous two seasons. The 1982 year class exhibited unusually good growth, with a mean BL of 202.8 mm for herring aged from stratified random samples.The 1982 through 1985 year classes (5- through 2-yr olds)contributed 97% by number and 95% by weight to the total 1986-87 spawning biomass in San Francisco Bay. Good recruitment has occurred during the past four seasons. The weak 1981 year class contributed little to the total biomass as 6-yr olds.Average catch per tow of young-of-the-year (YOY) herring is a potential index of abundance for recruitment 18 months later as 2-yr olds. Estimated recruitment has only varied by 15% during the past three seasons and does not reflect the magnitude or trend in YOY catches in the bay. (85pp.)

Beschreibung: Field intercept Marine Recreational Fisheries Statistics Survey (MRFSS) data for central and northern California, collected in April to June of 1983, is presented in a data report format. Data in this quarterly report are subdivided into three categories: primarily by five geographical areas;secondarily by fishing modes and gear types within each area; and finally by catch definition for each area, mode, and gear type. Tables are presented for these categories, each with three sections: sampled effort, ranked catch, and catch-per-unit-effort (CPUE). Also, within each area, length-frequency histograms and tables are presented for select species. (149pp.)

Beschreibung: Field intercept Marine Recreational Fisheries Statistics Survey (MRFSS) data for central and northern California, collected in January to March 1984, is presented in a data report format. Data in this quarterly report are subdivided into three categories: primarily by five geographical areas;secondarily by fishing modes and gear types within each area; and finally by catch definition for each area, mode, and gear type. Tables are presented for these categories, each with three sections: sampled effort, ranked catch, and catch-per-unit-effort (CPUE). Also, within each area, length-frequency histograms and tables are presented for select species. (141pp.)

Beschreibung: Field intercept Marine Recreationa1 Fisheries Statistics Survey (MRFSS) data for central and northern California, collected in July to September 1983, is presented in a data report format. Data in this quarterly report are subdivided into three categories: primarily by five geographical areas;secondarily by fishing modes and gear types within each area; and finally by catch definition for each area, mode, and gear type. Tables are presented for these categories, each with three sections: sampled effort, ranked catch, and catch-per-unit-effort (CPUE). Also, within each area, length-frequency histograms and tables are presented for select species. (159p.)