Scripps Institution of Oceanography Library 

About: Scripps Institution of Oceanography Library is an academic journal. The journal publishes majorly in the area(s): Fishing & Population. Over the lifetime, 139 publications have been published receiving 5235 citations.

Fish Bulletin 152. Food Habits of Albacore, Bluefin Tuna, and Bonito In California Waters

Abstract: The authors investigated food habits of albacore, Thunnus alalunga, bluefin tuna, Thunnus thynnus, and bonito, Sarda chiliensis, in the eastern North Pacific Ocean during 1968 and 1969. While most stomach samples came from fish caught commercially off southern California and Baja California, some came from fish taken in central California, Oregon, and Washington waters. Standard procedures included enumeration of food items, volumetric analysis, and measure of frequency of occurrence. The authors identified the majority of forage organisms to the specific level through usual taxonomic methods for whole animals. Identification of partially digested animals was accomplished through the use of otoliths for fish, beaks for cephalopods, and the exoskeleton for invertebrates. A pictorial guide to beaks of certain eastern Pacific cephalopods was prepared and proved helpful in identifying stomach contents. This guide is presented in this publication. The study indicates the prominent forage for bluefin tuna, bonito, and albacore in California waters is the northern anchovy, Engraulis mordax.

Fish Bulletin 157. Guide To The Coastal Marine Fishes of California

Abstract: This is a comprehensive identification guide encompassing all shallow marine fishes within California waters. Geographic range limits, maximum size, depth range, a brief color description, and some meristic counts including, if available: fin ray counts, lateral line pores, lateral line scales, gill rakers, and vertebrae are given. Body proportions and shapes are used in the keys and a statement concerning the rarity or commonness in California is given for each species. In all, 554 species are described. Three of these have not been recorded or confirmed as occurring in California waters but are included since they are apt to appear. The remainder have been recorded as occurring in an area between the Mexican and Oregon borders and offshore to at least 50 miles. Five of California species as yet have not been named or described, and ichthyologists studying these new forms have given information on identification to enable inclusion here. A dichotomous key to 144 families includes an outline figure of a representative for all but two families. Keys are presented for all larger families, and diagnostic features are pointed out on most of the figures. Illustrations are presented for all but eight species. of the 554 species, 439 are found primarily in depths less than 400 ft., 48 are meso- or bathypelagic species, and 67 are deepwater bottom dwelling forms rarely taken in less than 400 ft. depth. The deepwater forms included are those taken in commercial trawling gear or that occasionally occur near the surface. An illustrated glossary is included to facilitate use of the identification keys and species descriptions. A comments section presents in detail reasons for certain taxonomic choices and to acknowledge personal communications. Original data presented include a ventral sensory pore pattern key for the skates, 170 geographic range limit extensions, and several depth range and maximum size records. Many of the family keys have been revised to incorporate recent taxonomic changes and to clarify previously ambiguous terminology.

Fish Bulletin No. 98. The Life Histories of the Steelhead Rainbow Trout (Salmo gairdneri gairdneri) and Silver Salmon (Oncorhynchus kisutch) with Special Reference to Waddell Creek, California, and Recommendations Regarding Their Management

Abstract: The Steelhead Rainbow Trout, Salmo gairdneri gairdneri Richardson, and Silver Salmon, Oncorhynchus kisutch (Walbaum), are two of the most important fishes found along the Pacific Coast of North America. A considerable amount of published material regarding their biology, distribution, systematic status, propagation, and management already exists. However, up to the present time, and especially to the start of the experiments described in the present paper, there has been a notable lack of quantitative data regarding both species, particularly with regard to their life histories. Because of this lack of quantitative data, so necessary for sound regulatory, stocking, and other management programs, the California Trout Investigations, a cooperative unit of the California Division of Fish and Game (now the California Department of Fish and Game) and the U. S. Bureau of Fisheries (now a part of the U. S. Fish and Wildlife Service) in 1932 initiated a program of study at Waddell Creek, a typical coastal stream in Santa Cruz County, California. Upon the termination of the formal cooperative agreement in 1937, these studies were conducted independently by the California Division of Fish and Game. The plan of the experiment was to study the steelhead and the silver salmon in their natural habitat. Since both fishes are anadromous, the logical approach was to construct a dam or weir at which both the upstream and downstream migrants could be counted. In the process of counting, observations could be made on the migrants (measurements, scale samples, sexual maturity, parasites, etc.), fluctuations of populations determined from the counts, and the counts complemented by observations made on the fishes in the stream (spawning activities, feeding habits, etc.). Waddell Creek was chosen for the following reasons: It was a stream under as nearly natural conditions as could be found in California at the present time and was still reasonably accessible; it was large enough to possess a full biota and small enough to be dammed at reasonable cost and to permit complete counts of at least all upstream migrants, and thus avoid errors that might result from sampling; it was so situated that it could be kept under observational and legal control as a unit, with the general public excluded. Waddell Creek in its general characteristics is typical of the great majority of California coastal streams of like size. Moreover, in miniature it is almost a replica of the larger stream systems, such as the Klamath and the Eel. This fact is of great importance in that the habits and ecology of the trout and salmon in the small streams and the large ones are similar. Consequently, the conclusions regarding the proper management of these fishes derived from the present study are applicable, at least in the broader aspects, to the coastal streams in general. Obviously, certain limitations are imposed by a program that consists of studying the natural fluctuations of a population in a limited area. Large-scale sampling involving the killing of specimens cannot be carried on without danger of disturbing the natural balance. Thus, it is not possible to make various measurements such as egg counts and pyloric caeca counts, stomach analyses, etc. The very great advantage of Waddell Creek in this respect was that its drainage basin is adjacent to that of Scott Creek, a stream of comparable size, with comparable environmental conditions and a similar fauna, in which the lacking data could be gathered. Scott Creek had the advantage of being the location of a State egg collecting station and a State hatchery (the latter situated on a tributary, Big Creek) and of being set aside as a State Fish Refuge. Consequently, it was possible not only to gather data on egg production and to secure measurements but also, through marking of the naturally-spawned fish in Waddell Creek and the artificially-spawned and hatchery-reared fish in Scott Creek, to carry out a comparative study of two adjacent streams, one under natural conditions and the other under artificial management, and to study the amount of homing and straying between the two streams. As will be discussed further in this paper, certain conditions already existed or were created by the experiment which altered natural conditions to varying degrees, especially in the direction of making difficult a true evaluation of population fluctuations under natural conditions, but the essential quantitative picture of the life histories of the species concerned has remained a correct one.

Fish Bulletin 131. The Structure, Development, Food Relations, Reproduction, and Life History of the Squid Loligo opalescens Berry

Abstract: The squid, Loligo opalescens Berry, is abundant along much of the west coast of North America. They often congregate where a light is suspended over the water at night, and at certain seasons, individuals that are spent by spawning may be seen swimming aimlessly near the surface. Great schools spawn in shallow waters like those adjacent to Monterey, California, where they support a valuable fishery. This squid is also important as food for many fishes, sea birds, and marine mammals.

Fish Bulletin 158. Summary of Blue Rockfish and Lingcod Life Histories; A Reef Ecology Study; And Giant Kelp, Macrocystis Pyrifera, Experiments In Monterey Bay, California

Abstract: 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.