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In June, 1917, the California Fish and Game Commission inaugurated scientific investigations of commercially important fishes of southern California. The writer, who is at present in charge of the investigations, has been asked many questions regarding the purpose of the work, and he has come to realize the necessity of an outline to which the various lines of research may be referred and thus understood. However, it is difficult to tell into what fields the pursuit of truth will lead in the case of each investigation, and it will be found that in this paper resort has been had to the statement of aims in terms which are perhaps applicable to fisheries research in general, rather than to that of the albacore in particular, the fish now being studied. The formulation is frankly tentative, due to the chaotic state of the branch of fisheries research concerned, and it is hoped that further experience will correct errors and enable clearer conceptions to arise.

In June, 1917, the California Fish and Game Commission inaugurated scientific investigations of commercially important fishes of southern California. The writer, who is at present in charge of the investigations, has been asked many questions regarding the purpose of the work, and he has come to realize the necessity of an outline to which the various lines of research may be referred and thus understood. However, it is difficult to tell into what fields the pursuit of truth will lead in the case of each investigation, and it will be found that in this paper resort has been had to the statement of aims in terms which are perhaps applicable to fisheries research in general, rather than to that of the albacore in particular, the fish now being studied. The formulation is frankly tentative, due to the chaotic state of the branch of fisheries research concerned, and it is hoped that further experience will correct errors and enable clearer conceptions to arise.

The present paper has two purposes. First, it is an attempt to estimate the economic importance to the state of the bivalves here treated by putting on record the extent and position of the available mollusk producing grounds, the number and abundance of the edible species, and by contributing to a knowledge of their life histories lay the foundation for such protective legislation as may in the future be found necessary. Secondly, it proposes to make available to the camper and amateur naturalist a means of identifying the more common and important bivalves. During the last few years several agencies, chief among which are the development of the automobile and the extension of good roads, have greatly increased the number of people reaching the woods, the mountains and the sea. The campers at the seashore should realize the possibilities of food in the clams, mussels and other bivalves of the California coast, for these animals are at their best when freshly taken. It is hoped that the key and the figures here presented will enable any one to recognize the forms met with on this coast and that the accounts of their habits and use will make it possible to find and to utilize a source of food now distinctly neglected. By directing the attention of the camper to the interesting adaptations and beauties of these little known animals, his pleasure in the great out of doors will be correspondingly increased. Nearly five hundred species of bivalves are known from the west coast of America north of Mexico. Many of these are, of course, too small or too rare to be of possible food value. The following key will serve to identify the forms treated in the present paper, which includes, it is believed, all those to be met with in the markets or likely to be dug for food, but it must be remembered that many others, usually less abundant or less conspicuous, will be found on this coast. As far as known this is the first key to the bivalves of the coast that has been published and

The present paper has two purposes. First, it is an attempt to estimate the economic importance to the state of the bivalves here treated by putting on record the extent and position of the available mollusk producing grounds, the number and abundance of the edible species, and by contributing to a knowledge of their life histories lay the foundation for such protective legislation as may in the future be found necessary. Secondly, it proposes to make available to the camper and amateur naturalist a means of identifying the more common and important bivalves. During the last few years several agencies, chief among which are the development of the automobile and the extension of good roads, have greatly increased the number of people reaching the woods, the mountains and the sea. The campers at the seashore should realize the possibilities of food in the clams, mussels and other bivalves of the California coast, for these animals are at their best when freshly taken. It is hoped that the key and the figures here presented will enable any one to recognize the forms met with on this coast and that the accounts of their habits and use will make it possible to find and to utilize a source of food now distinctly neglected. By directing the attention of the camper to the interesting adaptations and beauties of these little known animals, his pleasure in the great out of doors will be correspondingly increased. Nearly five hundred species of bivalves are known from the west coast of America north of Mexico. Many of these are, of course, too small or too rare to be of possible food value. The following key will serve to identify the forms treated in the present paper, which includes, it is believed, all those to be met with in the markets or likely to be dug for food, but it must be remembered that many others, usually less abundant or less conspicuous, will be found on this coast. As far as known this is the first key to the bivalves of the coast that has been published and

This study of the variation in certain commercially important clupeoid fishes of western North America is one of a series by which it is designed to determine the relation which the varying characters of fishes bear toward the physical features of their environment. Although other characters and other environmental factors are receiving attention in these investigations, chief stress is now being laid on the correlation between the average number of vertebrae and the temperature of the water. The average surface temperature of the coast waters of San Francisco Bay (Golden Gate), Monterey Bay (Pacific Grove) and San Diego (off Coronado Beach) is indicated for the whole year by the three curves on Plate I. The marked difference in temperature between the ocean water of southern California and central California is illustrated by the curves for the San Diego region and for Monterey Bay, which is really a very open gulf. The usual maximum temperature for Monterey is lower than the ordinary minimum off San Diego. These is not an even gradation of temperature between these two localities, Point Conception marking the boundary between the cold waters of the central coast and the warmer waters of southern California. In each region, moreover, there is much local variation in temperature conditions, due not only to differences in protection and depth, but also, probably, to the differential upwelling of deep, cold water (McEwen, 1912, 1916). The curve for San Diego is taken from McEwen's 1916 paper; that for Monterey is smoothed from unpublished data supplied by Director Walter K. Fisher of the Hopkins Marine Station at Pacific Grove. The temperature curve at the entrance to San Francisco Bay, constructed by slightly smoothing Davidson's (1886) monthly averages, is intermediate between the San Diego and the Monterey Bay curves. The higher temperatures at San Francisco as compared with the Monterey records are due to the greater warming of the waters in the shallows of San Fr

This study of the variation in certain commercially important clupeoid fishes of western North America is one of a series by which it is designed to determine the relation which the varying characters of fishes bear toward the physical features of their environment. Although other characters and other environmental factors are receiving attention in these investigations, chief stress is now being laid on the correlation between the average number of vertebrae and the temperature of the water. The average surface temperature of the coast waters of San Francisco Bay (Golden Gate), Monterey Bay (Pacific Grove) and San Diego (off Coronado Beach) is indicated for the whole year by the three curves on Plate I. The marked difference in temperature between the ocean water of southern California and central California is illustrated by the curves for the San Diego region and for Monterey Bay, which is really a very open gulf. The usual maximum temperature for Monterey is lower than the ordinary minimum off San Diego. These is not an even gradation of temperature between these two localities, Point Conception marking the boundary between the cold waters of the central coast and the warmer waters of southern California. In each region, moreover, there is much local variation in temperature conditions, due not only to differences in protection and depth, but also, probably, to the differential upwelling of deep, cold water (McEwen, 1912, 1916). The curve for San Diego is taken from McEwen's 1916 paper; that for Monterey is smoothed from unpublished data supplied by Director Walter K. Fisher of the Hopkins Marine Station at Pacific Grove. The temperature curve at the entrance to San Francisco Bay, constructed by slightly smoothing Davidson's (1886) monthly averages, is intermediate between the San Diego and the Monterey Bay curves. The higher temperatures at San Francisco as compared with the Monterey records are due to the greater warming of the waters in the shallows of San Fr

In the last few years, the alleged destructive influence of the purse seine industry on the supply of fish in southern California waters has been much discussed among professional fishermen, as well as among other persons interested in our sea fisheries and their future. Articles to the effect that aliens were destroying the natural supply of fish in this region by means of purse seines have been published repeatedly in the newspapers. To quote from one of these articles: "For many of them [the purse seiners] nothing is more pleasing than to enrich themselves at our expense and risk." The most serious complaint against the purse seine fishermen is that, by killing small barracuda in enormous quantities, they are depleting this fish. Another serious complaint is that these men unsettle the market conditions by landing very large individual catches. There is a rather widespread opinion that purse seining for barracuda, white sea bass, and yellowtail should be prohibited in southern California. Even though it is evident that the complaints are based mainly on hearsay and only to a very little extent on personal and more or less systematic observations, they are too serious to be disregarded. In order to establish the most important facts of the "purse seine problem," the California Fish and Game Commission undertook a preliminary investigation. This was entrusted to me, as a member of the staff of the California State Fisheries Laboratory, and was begun in May, 1922. The present paper is the immediate result of this investigation. The special problems to be examined were as follows: 1. The present economic condition of the purse seine industry. 2. The importance of the purse seiners as a source of supply to canneries and fresh fish markets. 3. The effect of purse seine fishing on the natural supply of fish, with special regard to the barracuda. 4. The possibilities and results of prohibitive or restrictive legislation against the purse seiners. The field to be covered

In the last few years, the alleged destructive influence of the purse seine industry on the supply of fish in southern California waters has been much discussed among professional fishermen, as well as among other persons interested in our sea fisheries and their future. Articles to the effect that aliens were destroying the natural supply of fish in this region by means of purse seines have been published repeatedly in the newspapers. To quote from one of these articles: "For many of them [the purse seiners] nothing is more pleasing than to enrich themselves at our expense and risk." The most serious complaint against the purse seine fishermen is that, by killing small barracuda in enormous quantities, they are depleting this fish. Another serious complaint is that these men unsettle the market conditions by landing very large individual catches. There is a rather widespread opinion that purse seining for barracuda, white sea bass, and yellowtail should be prohibited in southern California. Even though it is evident that the complaints are based mainly on hearsay and only to a very little extent on personal and more or less systematic observations, they are too serious to be disregarded. In order to establish the most important facts of the "purse seine problem," the California Fish and Game Commission undertook a preliminary investigation. This was entrusted to me, as a member of the staff of the California State Fisheries Laboratory, and was begun in May, 1922. The present paper is the immediate result of this investigation. The special problems to be examined were as follows: 1. The present economic condition of the purse seine industry. 2. The importance of the purse seiners as a source of supply to canneries and fresh fish markets. 3. The effect of purse seine fishing on the natural supply of fish, with special regard to the barracuda. 4. The possibilities and results of prohibitive or restrictive legislation against the purse seiners. The field to be covered

There has been a truly marvelous development of the sardine fishery in California. Although it originated as a great fishery during the stress of war, the industry has shown a vitality which augurs well for its permanence so long as the raw material is obtainable. The amount caught exceeds by far that taken of any other species in California, and there appears at present no other which is capable of the tremendous yield, unless it be the unused anchovy. Experience with older fisheries has shown that rational use demands a knowledge of at least two things. There must, above all else, be information from time to time regarding the manner in which the species is withstanding the strain of the fishery. But there must also be an understanding of the natural changes in abundance which inevitably occur, so that these may be distinguished from the effects of overfishing and also may be foretold and understood. Based on such knowledge regulation and exploitation may be rational and restrained. To this end we must concern ourselves principally with the commercial catch, in which lies mankind's major interest. In so doing we meet at once the problem of accurately recording that catch and then of analyzing the complex underlying the biologic and economic conditions. It is hoped that the program which has been adopted for this purpose by the State of California will prove by further experience to be sound and to lead far. Begun as a simple introduction, this paper was at first intended merely to give the background of our investigations. It has been expanded to include a discussion of several things fundamentally important to our purposes, and this discussion portrays rather imperfectly the viewpoint acquired by actual experience with the Pacific sardine. The investigation has, indeed, molded and directed our first ideas and methods. The purposes of the investigation were the seemingly simple ones of detecting depletion caused by overfishing and of following the great natural ch

There has been a truly marvelous development of the sardine fishery in California. Although it originated as a great fishery during the stress of war, the industry has shown a vitality which augurs well for its permanence so long as the raw material is obtainable. The amount caught exceeds by far that taken of any other species in California, and there appears at present no other which is capable of the tremendous yield, unless it be the unused anchovy. Experience with older fisheries has shown that rational use demands a knowledge of at least two things. There must, above all else, be information from time to time regarding the manner in which the species is withstanding the strain of the fishery. But there must also be an understanding of the natural changes in abundance which inevitably occur, so that these may be distinguished from the effects of overfishing and also may be foretold and understood. Based on such knowledge regulation and exploitation may be rational and restrained. To this end we must concern ourselves principally with the commercial catch, in which lies mankind's major interest. In so doing we meet at once the problem of accurately recording that catch and then of analyzing the complex underlying the biologic and economic conditions. It is hoped that the program which has been adopted for this purpose by the State of California will prove by further experience to be sound and to lead far. Begun as a simple introduction, this paper was at first intended merely to give the background of our investigations. It has been expanded to include a discussion of several things fundamentally important to our purposes, and this discussion portrays rather imperfectly the viewpoint acquired by actual experience with the Pacific sardine. The investigation has, indeed, molded and directed our first ideas and methods. The purposes of the investigation were the seemingly simple ones of detecting depletion caused by overfishing and of following the great natural ch

This investigation under the authority of the Bureau of Commercial Fisheries, Division of Fish and Game of California, was started in the fall of 1927. The paper, while all on the general subject of Sacramento salmon, is in three parts, each of which is a separate problem. The first part, "Historical and Statistical Review of the Sacramento-San Joaquin Salmon Fishery," takes into consideration the early investigations, history, and statistics of the fishery, artificial propagation, legislation, water supply, prices, and the causes of depletion, with suggested remedies. The second problem, "Survey of Salmon Spawning Grounds in the Sacramento-San Joaquin River Systems," shows the available salmon spawning grounds in the systems as contrasted with the extent of the grounds in the early days. Each stream in the systems is taken up individually to show runs, spawning time and beds, obstructions to the fish, and abundance. The last part is on the "Determination of the Age of Maturity of the Sacramento-San Joaquin Salmon (Oncorhynchus tschawytscha)," and deals with the methods of age determination, the age of maturity, and age classes in relation to sex and types.

This investigation under the authority of the Bureau of Commercial Fisheries, Division of Fish and Game of California, was started in the fall of 1927. The paper, while all on the general subject of Sacramento salmon, is in three parts, each of which is a separate problem. The first part, "Historical and Statistical Review of the Sacramento-San Joaquin Salmon Fishery," takes into consideration the early investigations, history, and statistics of the fishery, artificial propagation, legislation, water supply, prices, and the causes of depletion, with suggested remedies. The second problem, "Survey of Salmon Spawning Grounds in the Sacramento-San Joaquin River Systems," shows the available salmon spawning grounds in the systems as contrasted with the extent of the grounds in the early days. Each stream in the systems is taken up individually to show runs, spawning time and beds, obstructions to the fish, and abundance. The last part is on the "Determination of the Age of Maturity of the Sacramento-San Joaquin Salmon (Oncorhynchus tschawytscha)," and deals with the methods of age determination, the age of maturity, and age classes in relation to sex and types.

The goal striven for was to find all works written previous to the close of 1929, dealing in any way with the five large tunas: Thynnus thynnus, Neothunnus macropterus, Germo alalunga, Euthynnus pelamis, and Sarda chiliensis. As one would expect, other names and species have been included for reasons which are made clear by an examination of these papers. The rule followed in puzzling questions of synonymy in the index was this: when in doubt as to what fish was being considered, the exact name was used as given in the paper. The synonyms about which there was no doubt are all given a place in the index as "see also" references and all author citations are listed under the accepted name. However, it was thought best to retain the names and spelling used by each author in the résumé of each paper. The titles fall mainly into the following groups: systematic, morphologic, biologic, commercial, the latter concerned with local conditions of fisheries of the world, and with fishing methods and gear.

The goal striven for was to find all works written previous to the close of 1929, dealing in any way with the five large tunas: Thynnus thynnus, Neothunnus macropterus, Germo alalunga, Euthynnus pelamis, and Sarda chiliensis. As one would expect, other names and species have been included for reasons which are made clear by an examination of these papers. The rule followed in puzzling questions of synonymy in the index was this: when in doubt as to what fish was being considered, the exact name was used as given in the paper. The synonyms about which there was no doubt are all given a place in the index as "see also" references and all author citations are listed under the accepted name. However, it was thought best to retain the names and spelling used by each author in the résumé of each paper. The titles fall mainly into the following groups: systematic, morphologic, biologic, commercial, the latter concerned with local conditions of fisheries of the world, and with fishing methods and gear.

This report is presented to aid directly the administrators of the Division of Fish and Game in their conservation program. Herein is given an account of the California halibut fishery and a detailed analysis of the catch in the Los Angeles Harbor district by means of the catch per unit of effort expended. The paper is so arranged that the general and fundamental aspects of the fishery and the results of a catch analysis are briefly given in the first part. For those who may be interested in the details of the fishery some of its life history and methods of boat catch analysis employed, the balance of the paper will be of importance.

This report is presented to aid directly the administrators of the Division of Fish and Game in their conservation program. Herein is given an account of the California halibut fishery and a detailed analysis of the catch in the Los Angeles Harbor district by means of the catch per unit of effort expended. The paper is so arranged that the general and fundamental aspects of the fishery and the results of a catch analysis are briefly given in the first part. For those who may be interested in the details of the fishery some of its life history and methods of boat catch analysis employed, the balance of the paper will be of importance.

The two papers herein presented comprise further results from a continuous study of the California sardine. The program of investigation was inaugurated in 1919 and has been carried on by a staff of numerous workers.1) DOMINANT SIZE-GROUPS AND THEIR INFLUENCE IN THE FISHERY FOR THE CALIFORNIA SARDINE (Sardina caerulea)2) THE COMMERCIAL CATCH OF ADULT CALIFORNIA SARDINES (Sardina caerulea) AT SAN DIEGO

The two papers herein presented comprise further results from a continuous study of the California sardine. The program of investigation was inaugurated in 1919 and has been carried on by a staff of numerous workers.1) DOMINANT SIZE-GROUPS AND THEIR INFLUENCE IN THE FISHERY FOR THE CALIFORNIA SARDINE (Sardina caerulea)2) THE COMMERCIAL CATCH OF ADULT CALIFORNIA SARDINES (Sardina caerulea) AT SAN DIEGO

The present paper is a digest of the work accomplished in a salmon investigation conducted under the authority of the Bureau of Commercial Fisheries of the California Division of Fish and Game. Active work was begun in 1919, and is still in progress. At the outset the investigation was so planned as to contribute as directly as possible to the solution of certain questions relating to the conservation of the fishery. The work has progressed in a fairly satisfactory way in some directions as will appear, while in others the results are not so good. The information now most needed relates to the seaward migration of young salmon, and to the relative contribution of natural and artificial propagation to the population of the river.It may seem that the matter of depletion is overstressed in this report, since its progress has been evident for years. A condition of increasing depletion was not sufficiently evident on the Klamath however, to be convincing to those most interested. In fact, opinions to the contrary were commonly held, some asserting that the "run" was not only maintaining itself but that it was gradually building up. There is very little exact information concerning fishing operations on Klamath River previous to 1912, and no really dependable statistics are available relating to the catch before that time. During the period of placer mining on the river, large numbers of salmon were speared or otherwise captured on or near their spawning beds, and if credence is given to the reports of old miners, there then appeared the first and perhaps major cause of early depletion. In 1912 three plants operated on or near the estuary and the river was heavily fished, no limit being placed on the activities of anyone. A resume of commercial fishing near the mouth or the river appears on page 88.In the collection of statistical data relating to the ocean catch of salmon, the state authorities have not been able to separate the different species. Four occur in the state

The present paper is a digest of the work accomplished in a salmon investigation conducted under the authority of the Bureau of Commercial Fisheries of the California Division of Fish and Game. Active work was begun in 1919, and is still in progress. At the outset the investigation was so planned as to contribute as directly as possible to the solution of certain questions relating to the conservation of the fishery. The work has progressed in a fairly satisfactory way in some directions as will appear, while in others the results are not so good. The information now most needed relates to the seaward migration of young salmon, and to the relative contribution of natural and artificial propagation to the population of the river.It may seem that the matter of depletion is overstressed in this report, since its progress has been evident for years. A condition of increasing depletion was not sufficiently evident on the Klamath however, to be convincing to those most interested. In fact, opinions to the contrary were commonly held, some asserting that the "run" was not only maintaining itself but that it was gradually building up. There is very little exact information concerning fishing operations on Klamath River previous to 1912, and no really dependable statistics are available relating to the catch before that time. During the period of placer mining on the river, large numbers of salmon were speared or otherwise captured on or near their spawning beds, and if credence is given to the reports of old miners, there then appeared the first and perhaps major cause of early depletion. In 1912 three plants operated on or near the estuary and the river was heavily fished, no limit being placed on the activities of anyone. A resume of commercial fishing near the mouth or the river appears on page 88.In the collection of statistical data relating to the ocean catch of salmon, the state authorities have not been able to separate the different species. Four occur in the state