UC San Diego Library – Scripps Digital Collection

This bulletin is designed as a guide to those marine fishes of California which are likely to be caught by commercial and sport fishermen. While the species included represent only a fraction of the total recorded from the State, those remaining are mostly either deep-sea forms or small fishes of inshore waters which rarely, if ever, enter the fisherman's catch. The guiding precept of likelihood of capture by fishermen results in the inclusion of some species which are actually rather rare in California and the exclusion of some common varieties.

This bulletin provides an in-depth analysis of the California Current Pacific mackerel (Scomber japonicus) fishery. It includes descriptions of the fishery and the species population biology, a cohort analysis, density and environmental-dependent spawner-recruit models, and yield simulations. The cohort analysis (1928–1968), using an instantaneous natural mortality rate of M = 0.5, shows a fluctuating stock size with a maximum total biomass of 965 million pounds (438,000 MT) in 1933 and a minimum of 3.3 million pounds (1500 MT) in 1968. The number of recruits-per-spawner shows large fluctuations with considerable coherence between adjacent years. There was no marked downward trend in recruits-per-spawner over the 1928–1968 period. Density-dependent spawner-recruit models accounted for a maximum of 24 percent of the observed variation in recruitment. Multiple regression models, including both population and environmental variables, were fitted to the data available for two time periods; 1931–68 and 1946–68. The 1931–68 model accounted for 59 percent of the variation in recruitment; increased recruitment was associated with increased sea surface temperature, reduced sea level and reduced atmospheric pressure during the spawning season. The 1946–68 model accounted for 76 percent of the variation in recruitment; increased recruitment was associated with increased coastal upwelling and decreased offshore convergence during the spawning season. Maximum yield-per-recruit occurs with an age at recruitment of 1 or less, and with instantaneous fishing mortalities (F) in excess of 1.0. A dynamic pool model incorporating a Ricker spawner-recruit model predicts that extinction of the stock will occur with the above fishing strategy. Maximum sustained yield (MSY) with the steady state dynamic pool model is above 94 million pounds (41,000 MT). This MSY occurs with an age-at-recruitment of 4 and with an exploitation rate of 0.25. Simulations incorporating the density and environmental-dependent spawner-recruit functions predict that the above MSY cannot be attained when there is serial coherence in the annual recruitment fluctuations. Mean longterm annual yield with the above fishing strategy, under the environmental conditions occurring between 1931–1968, would have been only 56 million pounds (25,000 MT). With an age-at-recruitment of 1, maximum steady state yield (69 million pounds, 31,000 MT) occurs at an exploitation rate of 0.2. Maximum long-term yield with this fishing strategy, under the 1931–68 environmental conditions, would have been 45 million pounds (20,000 MT).

The following two reports, on the sizes of sardines taken by various kinds of fishing gear and caught in different areas of the Monterey and of the San Pedro fishing regions, present the results of an investigation made to determine whether or not the system of sardine sampling as carried on in the past is still adequate since changes have occurred in the fishery. The results are of importance to the industry because they show that lampara, purse seine and ring nets all take the same sizes of fish, that these sizes comprise the sardines available to the fishermen, and that no type of gear exhibits size selection differing from any other type. of greater importance to the industry is the evidence indicating that large fish first appear each winter to the north of Monterey and gradually become disseminated southward throughout the entire Monterey region, whereas in the San Pedro region no consistent distribution of differential sizes within the region is evident. The results are of value to the sardine investigation because of the demonstration of the continual reliability of our sardine sampling system and the furnishing of additional evidence indicating a southward movement of sardines along the California coast during the winter months.

This is the third in a continuing series of marine environment surveys conducted by the California Department of Fish and Game in cooperation with the State's Regional Water Quality Control Boards.

During February and March, 1965, Department scuba diving biologists made an ecological investigation off the western shore of Point Loma, San Diego County (into water depths of 100 feet). Data from this study, conducted for the San Diego Regional Water Quality Control Board, are to be used in evaluating the effects of a submarine outfall discharge on the marine life in the area.

Twenty diving and four intertidal stations were occupied along four transects run perpendicular to shore. A modified transect-quadrat method of survey was employed to sample the biota both quantitatively and qualitatively. In addition, three orange-peel grab samples were taken near the outfall terminus (200-foot depth) primarily to determine sludge build-up.

The animal and plant assemblages were both lush and varied. The recorded species, numbers and diversities appeared typical for this general area, water depth, and bottom type. Bathymetrically, the greatest species diversity occurred in the 60- to 80-foot depths—the least in the 20. Geographically, species diversity was greatest in the central portions of the study area, and the least diverse in the northern. This correlated with the height of the bottom relief.

Although it is difficult to make comparisons with prior studies, because of different sampling techniques, the area's general biotic assemblages appeared similar, and except for the occurrence of Capitella capitata (a "pollution-tolerant" polychaete worm) at the outfall terminus, no adverse changes, directly attributable to outfall operations, were apparent in 1965. Five plants and 14 animals are deemed particularly hardy; these index species should be closely monitored in future studies to detect changes in their abundance relative to associated species.

Similar ecological studies should be carried out at least annually to record biotic changes which may be relative to the outfall's operation.

This report discusses in detail findings and observations made during more than 4 years of study on three experimental multi-component man-made reefs, and one "production" model reef, in Santa Monica Bay, California (August 1960–January 1965). The multi-component replication reefs were each constructed of 333 tons of quarry rock, one streetcar, 14 automobile bodies, and 44 concrete shelters. The "production" model reef was 1000 tons of quarry rock. The study was designed to investigate various aspects of man-made reef ecosystems and to determine the optimum material for reef construction in southern California.

Observations made and sampling conducted at each reef included: (i) enumeration (by estimate) of the fishes, invertebrates, and plants, (ii) sediment analysis, (iii) water temperature, (iv) water clarity, and (v) encrusting growths on each reef material.

Quarry rock was determined to be the preferred reef building material (based upon cost and ease of handling), even though the concrete shelters attracted the largest number of fishes. Further, quarry rock disturbed the bottom sediments less than the other three materials.

True succession, not seasonal progression, was recorded for the various encrusting organisms. During the first year, a barnacle-hydroid phase was closely followed by mollusk-polychaete, ascidian-sponge, and finally encrusting ectoproct stages. Subsequent stages involve aggregate anemones, gorgonians, and stony corals.

More than 200 invertebrates (protozoans to tunicates) were recorded during this study. Notations concerning each species occurrence, growth, importance on the reef, ecological niche, and known predatorprey relationships are presented.

Fish populations around each reef, and material, were assessed by: (i) species enumeration, (ii) estimates of size ranges, (iii) feeding habits, and (iv) general behavioral traits. Underwater tagging techniques were developed and employed to determine fish movements. In all, 78 species (35 families and 60 genera) were recorded. Embiotocid perches and serranids were dominant during the first two years of reef life. In time they decreased in dominance while resident species (e.g., cottids, gobies, damselfish, etc.) increased.

Observed fishes were classified as reef associated or non-reef associated, based upon their requirements or association to our reefs: a reef biotype being required to satisfy one or more life processes of a reef oriented species. We further subdivided the reef associated species into semi-resident (which periodically leave the reef) and resident forms (which consistently remain on the reef).

Fishing success on the reefs was two to three times that recorded for nearby natural reef areas. In some instances, due to the fish concentrating effect of these structures, angler success may be even higher.

Man-made reefs can turn "non-productive" areas of the nearshore into "productive" fishing areas. Initially, these structures attract fishes from surrounding areas. With time (about 5 years in our area) a natural situation is reached and the plant and animal populations exhibit fluctuations typical of reef ecosystems.

This bulletin presents results of several studies related to marine sportfish in central and northern California. Since 1957, Dingell-Johnson funds have been used in central California to conduct life history studies of blue rockfish and lingcod, several sportfishing assessment studies, a reef ecology study, and a pilot kelp canopy harvesting study. Results of a blue rockfish study were published in 1967, however, important additional life history and catch data have been collected subsequently and a collation of all blue rockfish findings is presented.

Lingcod data have been collated with published lingcod life history data collected in British Columbia and Washington. Our studies emphasized maturity, age and growth, food analyses, and evidence of a vertical spawning migration.

In the reef ecology study, 727 underwater fish transect tallies were made over a 3 year period yielding seasonal variations, relative abundance between stations, and relative abundance between years from 1968 through 1970 of larger species in the kelp bed area.

Pilot kelp harvesting experiments included kelp frond growth and plant life expenctancy, effects of canopy harvesting on haptera growth, kelp standing crop estimates, and effects of canopy removal on kelp bed fish populations.

A thorough literature search of kelp-invertebrate-sea otter interactions was conducted and no valid documentation was found to substantiate reports that the apparent increase in Macrocystis canopy densities since 1958 in central California resulted from sea otter predation on sea urchins.

The word mackerel is a common one in every day conversation. Everywhere we can hear such expressions as, "holy mackerel," "dead as a mackerel," and "cold as a mackerel." Undoubtedly the fish called mackerel, from which these terms have arisen, must be universally popular and well known. It is hoped that the following pages will give some idea of the popularity and economic importance of this fish.

The irregular habits and the unheralded periods of scarcity or abundance of the common Atlantic mackerel are subjects of great concern to the fishermen of Europe and America. The occasional failure of the mackerel to appear spells hardship and privation for many fishermen and dealers, and when its does appear in the vast shoals that are eagerly awaited each spring, adverse economic conditions sometimes prevent the fishermen from making a living. In California the mackerel is always present, summer and winter, year in and year out, but because of economic factors the fishery is subject to sudden ups and downs.

As might be expected, the habits of the Atlantic mackerel have long been the subject of speculation and study, both by fishermen and scientists. Many stories are current about how the mackerel spends the winter, the time when it is absent from the Atlantic coasts of Europe and North America. One of the most common stories is that the fish bury themselves in the mud at the bottom of the sea and that during this hibernation a film comes over their eyes so they are rendered blind. Some people claim that the mackerel go into the Arctic Ocean to spend the winter; others say that they go south into the tropics. The only certain fact is that nobody really knows where the majority of the mackerel spend the winter and that one guess is as good as another.

Mackerel occasionally appear in shoals so dense and extensive that the ocean is colored with them for miles. At these times it is said to be dangerous to enter the water. A story is told of a Norwegian fisherman who fell overboard into a school of mackerel and was torn to pieces by the savage fish before his comrades could pull him out. This story is probably somewhat exaggerated, but the thought of that luckless fellow would suffice to keep most people from diving into a swarm of hungry mackerel.

The idea has arisen in some places, notably Australia, that the flesh of the mackerel and mackerel-like fishes is poisonous. As a matter of fact, no food is more wholesome than fresh or properly preserved mackerel, tuna or bonito. However, all these fish spoil readily if not cared for, and stale fish can cause illness, and the illness can cause stories about poison.

The scombroid or mackerel-like fishes are of very great commercial importance throughout the world. The four most important groups of fishes are those comprising the herring, salmon, codfish and mackerel families. Of the mackerel family, the two mackerels (Scomber and Pneumatophorus) are among the most widespread and universally important, although the tunas, bonitos, seerfishes, and Spanish mackerels help to keep the family Scombridae in a leading position.

The fishermen of nearly every maritime nation in the temperate zones catch mackerel in large numbers. The annual catch (1928–1929) off the North Sea and Atlantic coasts of Europe amounts to 100,000,000 pounds. The fishermen of the Atlantic coast of North America catch 40,000,000 to 60,000,000 pounds of mackerel every year (1924–1930). The California fishery accounts for 15,000,000 to 60,000,000 pounds annually (1928–1931). Japan, with an annual (1923–1925) catch of about 150,000,000 pounds, is the largest consumer of mackerel in the world. In addition to the foregoing, there are important mackerel fisheries in the Mediterranean and Black seas, and lesser fisheries in Australia, New Zealand and South America.

The mackerel is everywhere primarily a fresh fish, that is to say, the greatest part of the world catch is consumed in a fresh state. Nevertheless, really enormous quantities are canned, salted or dried in many parts of the world. The canning industry is a recent development, dating back no farther than the nineteenth century. Salting and drying, however, are ancient methods of preserving fish so they can be sent to distant markets or held over from periods of abundance to times of scarcity. Before modern refrigeration methods made possible the transportation or holding of fresh mackerel in quantities, salted mackerel was by far the most important product of the world's mackerel fishery.

Although there are at least fifteen kinds of barracuda distributed in all the warm seas of the world, the California barracuda (Sphyraena argentea) is the only one which may be considered of sufficient commercial importance to constitute a distinct "fishery." If one may judge by the available statistics, the barracuda of the west coast of Mexico and Central America, those of the Atlantic coast of North America, of the tropical Atlantic, of the coasts of southern Europe, of Africa, and of the seas of Asia, are to the countries which exploit them but little more than incidental additions to the usual landings of other species. It is not surprising, therefore, in the absence of economic necessity, that studies on the biology of any of these fishes have been neglected for those on more important species. Although from Aristotle down, a fairly voluminous literature exists on the nomenclature, the habitats, the voraciousness, and the food value of the various species, practically nothing has been written about the habits or the life histories. As for the California barracuda, a number of scattered notes on the distribution is all that has added to our knowledge of its biology since Girard first named the species in 1854.

Notwithstanding the fact that within the range of California fishing activities, there are two species of barracuda, Sphyraena argentea and Sphyraena ensis, only the former has yet reached the California markets. Sphyraena ensis is known to occur from the Gulf of California to Panama Bay, but possibly because of the availability of Sphyraena argentea farther north, possibly because of the smaller size or the inferior quality of Sphyraena ensis, it has not been taken by our fishermen. Although Sphyraena argentea is distributed from Cape San Lucas, Lower California, north to Puget Sound, it is important commercially only south of Ventura County, California.

The classification of the tunas throughout the world has remained unsatisfactory for many years due chiefly to the difficulties involved in comparing large specimens from many localities. On the eastern side of the Pacific are found several species which have not been clearly separated from those of the Western and Mid-Pacific. of these forms four play an important role in the fisheries of California, Mexico and Central America. The present study was undertaken in March 1940, to determine the geographical range of these species and the relationships between them and similar ones occurring in the Central, Western and Equatorial Pacific. This was the first essential step in a comprehensive investigation of the tuna populations supporting the California industry. In particular, it was necessary to explore the differences between the bluefin and the oriental tuna and to know whether or not the yellowfin tuna, the skipjack and the albacore are of the same species as those taken in Japanese and Hawaiian waters. If such proved to be the case additional studies would be required to determine if any intermingling occurred between the populations in the different localities. If on the other hand, the species proved to be distinct the Eastern Pacific population might be exploited without regard to the fisheries of Hawaii and Japan.

The only comprehensive work on the systematics of the Pacific tunas was published by Kishinouye. He found that separation of the various species required a careful study of the anatomy of these fish. To follow the approach laid down in his paper, a similar detailed anatomical treatment of the problem was required to compare those species supporting the California fishery with Kishinouye's descriptions. Although this work appears to be principally morphological, the great detail in which the anatomy of the Eastern Pacific tunas has been studied will form a firm foundation upon which investigations may be extended into lines more directly applicable to conservation.

Concerning the skipjack, this work has demonstrated that within the entire fishing area in the Eastern Pacific extending along the Central and North American coastline from the Equator to California and off-shore to include all the outlying islands, there is but a single species, and specimens from all these areas are furthermore individually indistinguishable from those obtained from Japan and the Hawaiian Islands and described as Katsuwonus pelamis.

In the case of the yellowfin tuna a similar conclusion was reached. A single species, Neothunnus macropterus, exists throughout this fishing area, and these fish are individually indistinguishable from the specimens obtained from the Hawaiian Islands, from Japan and from Peru. Here again the range of the species spans the Pacific and extends southward to Callao, on the Peruvian coast. Within this large area distinct populations may exist, but conclusions concerning this must await the analysis of all the data collected.

The albacore obtained from Japan and from the Hawaiian Islands likewise proved to be similar to the fish of the North American coastline. All must be considered of the same species, Thunnus germo, with a geographical distribution extending across the north temperate Pacific. The authors agree with Kishinouye that the albacore belongs in the genus Thunnus, and should not be separated therefrom.

The bluefin tuna from Southern and Lower California are essentially one species, and until adequate descriptions are available from all localities, must be assigned to the same species as Thunnus thynnus of the Atlantic. Similarly, lacking material from Japan with which to compare directly the local specimens, it was necessary to base this comparison upon these findings and Kishinouye's description of Thunnus orientalis. Although very similar to Thunnus thynnus, T. orientalis (the oriental bluefin) as described by Kishinouye, differs in several respects from the local bluefin, and pending a direct comparison it must be concluded, tentatively, that the two are different, and that the local species is limited in distribution in the Pacific to the Eastern, temperate waters.

Lack of time prevented similar studies on the bonito, Sarda velox and S. lineolata, and on the black skipjack, Euthynnus lineatus. It is hoped that these forms may be investigated at some future date. These species are not reported, however, from Mid- and Western Pacific waters and their distribution does not present as great complexities as the other four species mentioned above.

Reports from fishermen and an observation by Kishinouye concerning the occurrence of Parathunnus mebachi, in the Eastern Pacific have been confirmed. This fish is very similar to the yellowfin tuna, but differs from it in outline, in the length of the pectoral and the size of the head and eye. The body and head are deeper than in the yellowfin, the pectoral is longer and the eye is conspicuously larger. For this reason, and because the specific name means, in Japanese, "big-eye," we suggest as a common name for this fish, the "big-eyed tuna." The name is descriptive, and is, moreover, commonly applied by fishermen to this fish. The species was first described by Kishinouye from Japanese waters. Except that it is taken occasionally at the Galapagos Islands and sometimes at Guadalupe Island (Mexico) and in the vicinity, nothing is known of its habitat on this coast. Kishinouye states, p. 444, that it is: "probably widely distributed in the deeper layer of the subtropical region of the Pacific Ocean."

The existing literature does not permit a positive identification of the Pacific tunas. Thus, Jordan and Evermann separate the yellowfin into two species on the basis of the height of the "dorsal and anal lobes," and the length of the pectoral fin. Neothunnus macropterus, with higher dorsal and anal lobes and a longer pectoral, is supposedly abundant "along the coast of tropical Mexico from Cape San Lucas to the Galapagos * * *," whereas N. catalinae, "* * * the northern representative of Neothunnus macropterus, is like the latter in almost all respects except that the fins are less developed." However, there is no justification for this separation and it is impossible to classify any given specimen on this basis.

Kishinouye's monograph, "Contributions to the Comparative Study of the So-called Scombroid Fishes," contains the most complete descriptions extant of the Pacific tunas. When, however, specimens of yellowfin tuna from the American coast were compared with his description of N. macropterus, a number of important differences were found superimposed upon a general, fundamental similarity. To identify positively the yellowfin of this coast, and thus determine the geographical range of the species, it was necessary to secure specimens from Japan for a direct comparison. The results of this comparison indicated a number of discrepancies in Kishinouye's work. These will be discussed when necessary in the text.

Specimens of yellowfin tuna, skipjack and albacore were obtained from Japan and the Hawaiian Islands. Specimens of yellowfin tuna only were obtained from Peru. In regard to the origin of these fishes, the Hawaiian specimens were taken in the vicinity of Honolulu, and the Peruvian yellowfin were shipped from, and probably caught in the proximity of, Callao; but of the Japanese specimens it is known only that they were shipped by freight from Japan. This material was compared directly with a large collection of local specimens collected in the course of research trips aboard the "N. B. Scofield" to all parts of the extensive local fishing grounds. All specimens were frozen and retained in cold storage until needed. A comparison of the bluefin tuna from California and from Lower California was also made, and the big-eyed tuna is described for the first time from this coast.

Preparatory to this work a study was made of the literature and in particular of Kishinouye's monograph, and a list of all characters used in the classification of the tunas was compiled. Preliminary dissections of local specimens were then made and characters offering little promise and those not amenable to routine examination were rejected, and others added. The final list was then organized into a procedure standard for the dissection of each species, and a corresponding blank was prepared for every specimen. The method proved very satisfactory and is heartily recommended because it insures continuity and comparability of observations throughout. The comparisons were made as exhaustive as circumstances permitted, in the hope that this publication might serve as a basis for a thorough and permanent classification of the Pacific tunas.

Foreseeing the necessity of a more detailed population study of some species, a large number of both external and internal measurements and counts was added to the routine. These, however, will be reserved for a biometrical analysis in a future publication and not discussed herein. In addition routine sketches were made of every organ system examined and the final illustrations were prepared from these without embellishment. of the five species investigated, a representative specimen from each widely separated area (Japan, Hawaii, local, etc.), was photographed.

This publication presents the total landings of commercial fish and shipments into California in the year 1951.

All catch statistics are influenced by economic demand as well as by the abundance of the supply. In using and interpreting the statistics of 1951, at least two economic factors must be considered.

The year 1951 was one of crises in the tuna industry. The phenomenal growth in the post-war years of the tuna fleet with its augmented catch, in conjunction with increased imports of canned and frozen tuna from abroad, gradually piled up a surplus of unsold goods. Early in 1951 the industry was forced to call a halt, and throughout the year the local fleet was either idle or fishing on a rotation basis. Whereas 193 regular tuna boats made 887 deliveries in 1950, 227 tuna boats in 1951 made only 818 deliveries. The average number of deliveries in 1951, 3.6 per boat, compares with 4.6 per boat in 1950. The decrease in catch was not proportionate. The explanation is that when in 1951 a vessel was released to fish, it stayed out until it filled its holds, knowing that it would be tied up again when it returned; whereas in 1950 it was often more productive to return to port with a partial load. These factors must be considered when interpreting the catch of 1951.

While the tuna fleet was idle, the industry was active in attempting legislative curbs on foreign imports. The common threat to the domestic plants and fleet forced concerted action on the part of all concerned. Such effort may have a profound effect upon the future of the tuna fishery.

Meanwhile in the sardine industry the year witnessed the culmination of a trend, associated with the decline in the fishery, from reduction to canning. Although 84 permits were issued to reduce a total of 150,000 tons of sardines, only 1,022 tons of this amount were used. The reasons were largely economic. The season's catch was roughly only 35 percent of that of the preceding year and the price per ton went up accordingly. This high price coupled with a strong demand for canned sardines took the incentive and the profit out of reduction, and everything that could be packed went into the cans.

The failure of the sardine fishery was absolute in northern California, and almost so at Monterey. This stimulated wholesale trucking of fish both north and south. of the 25,000 tons processed in Monterey plants, only 878 tons were landed there by fishing boats. The balance was received by truck and originated almost entirely in southern California. At the same time, so great was competition for sardines, that many of the canners in the Los Angeles region trucked loads to their plants from Santa Barbara and Port Hueneme.

These are but two of the economic factors which influenced the catch of 1951. Numerous others were operative, and must be evaluated in any analyses of the detailed catch statistics.