COLLECTING AND PROCESSING DATA ON FISH EGGS 

 AND LARVAE IN THE CALIFORNIA CURRENT REGION 



By 



David Kramer, Mary J. Kalin, Elizabeth G. Stevens, 

 James R. Thrailkill, and James R. Zweifel 



National Marine Fisheries Service 

 Southwest Fisheries Center 

 La Jolla, California 92037 



ABSTRACT 



Descriptions are given for the methods used by the California Cooperative Oceanic 

 Fisheries Investigations to collect and process plankton. These include details of the 

 design of the station pattern in the survey area, the gear and methods used for plankton 

 hauls, measuring plankton, and sorting plankton for fish eggs and larvae; some pro- 

 cedures for identifying fish eggs and lai-vae; details of "hand" processing data for 

 standardization of numbers of organisms collected in all plankton hauls; calibration 

 of flowmeters; and some new procedures for automatic data processing. 



INTRODUCTION 



For more than 20 years the California Coop- 

 erative Oceanic Fisheries Investigations (Cal- 

 COFI) have conducted a program of intensive 

 research in the California Current region in a 

 designated area of approximately 500,000 square 

 miles from the California-Oregon border to the 

 tip of Baja California. The investigations were 

 originated in 1949 to determine the reason for 

 the decline of the Pacific sardine fishery. Since 

 then, the data have contributed a wealth of in- 

 formation from which it has been possible to 

 study the effects of the biological, physical, and 

 chemical environment on all the resources in the 

 area. 



The chief participants in CalCOFI in ships, 

 personnel, equipment, shoreside facilities, and 

 data collection, processing and analyses are the 

 California Department of Fish and Game (CF- 

 &G) on the evaluation of resources by census 

 of young and adult fishes, the University of Cal- 



ifornia, Scripps Institution of Oceanography 

 (SIO), on the studies of the physical and chem- 

 ical data and selected groups of invertebrates, 

 and the National Oceanic and Atmospheric Ad- 

 ministration (NOAA), National Marine Fish- 

 eries Service (NMFS), formerly the Bureau of 

 Commercial Fisheries, on the evaluation of re- 

 sources by censuses of fish eggs and larvae. 

 Other participating groups are the California 

 Academy of Sciences and the Stanford Univer- 

 sity, Hopkins Marine Station, chiefly in labora- 

 tory research. 



It is the purpose of this report to describe the 

 methods and gear used by the CalCOFI for col- 

 lecting and processing data on fish eggs and lar- 

 vae. Some of these have been described in vary- 

 ing detail (Ahlstrom, 1948, 1950) but none with 

 the full treatment that we feel is warranted, as 

 now reported here, in view of the requests for 

 greater detail by visitors to our laboratory and 

 some investigators who have cooperated with us 

 in data collection at sea. 



