UC San Diego Library – Scripps Digital Collection

During January 1952, California Department of Fish and Game marine biologists developed history's first successful tuna tag. It resembles a piece of spaghetti and has been employed as a research tool for studying the populations of important tuna species. Using these tags Department scientists discovered: that albacore migrate northward up the west American coast averaging at least six nautical miles per day; that they perform a transpacific migration between the American mainland and the Hawaiian Islands and Japan; that their growth rate is relatively rapid, averaging seven pounds per year for the catch-dominating 13-pound fish; that the natural size groups in the fishery are successive year classes; that individuals and perhaps the same schools return to the American fishing grounds during several seasons; and that there is but one population in the North Pacific.

In addition Department scientists have determined the ages of albacore by studying rings on the scales; have obtained valuable data on the time and place of albacore spawning; and have determined their size at maturity.

Data obtained from research cruises and specially designed fishermen's logbooks disclosed that albacore abundance is greatest where sea-surface temperatures are 60–68 degrees F. This information led to our discovery of the albacore coastward migration routes and the successful prediction of vast migration route changes in 1958, 1959, and 1960.