California Current Pelagic Fish Surveys, 1950-1989, Species Composition

Length frequencies were recorded and total count determined for all other species. Bathythermograph casts and turbidity measurements were made whenever possible. In addition to the trawl stations, from 1950 through 1962 the survey used light to attract fish and dynamite or a blanket net to collect samples in certain locations to provide live sardines for genetic studies and for comparison to midwater trawl results.

Starting in 1963, midwater trawl was the primary sampling tool. (Kenny Mais, Report for the month of January 1964, Marine Resources Operations, CDFG.) However, in the latter half of 1966, the scope and methodology of the cruises changed and the areas covered broadened. These surveys, titled Fisheries Resources Sea Surveys, were accomplished by a line transect method using echo sounder or sonar to detect and determine fish biomass, with a primary focus on northern anchovy.

Mid-water trawling, echogram characteristics, and visual sightings were used to identify fish species. The expanded 'Sea Surveys' were created under a federal aid program (Commercial Fisheries Research and Development Act of 1964, Public Law No. 88-309). Data collected during these cruises from 1950 - 1989 were compiled and presented yearly, in California Cooperative Oceanic Fisheries Investigations (CalCOFI) Data Reports, volumes 1 - 39 (volume 7 contained data for both 1956 and 1957).

These hard copy reports present the basic raw data in tabular form and they were our sole source for this legacy database.