Method of Predicting Tuna Catch by Using Coastal Sea - Surface Temperatures

,:From its start nearly 60 years ago the California tuna fishery has ',own into the state's largest fishery, both in val)le and in pounds "nded (Power, 1960). Yellowfin tuna (Neothunnus macropterus) and ~, ,'pjack (][atwwonus pelarnis) now are the two most important species , nd comprise the bulk of the California tuna landings. These are topical tunas and seldom enter California waters in commercial quanties, the greatest portion of the catch being made by large bait boats 'f ,'d purse seiners operating off Mexico, Central America and South :f 'i erica. ;~ }In contrast to the distant fishery supported by yellowfin and skipjack w., t the fishery for the temperate tunas, albacore (Th7tnnUS geTmo) and ),; ~luefin (TJwnnus saliens). During the summer and fall, both of these ., 'ecies occur off the California and Baja California coasts where they i ~ .:re taken by many boats incapable of making the long trips to the ~"opics. Baitfishing and trolling produce the major portion of the :i "bacore catch, whereas the bluefin is almost exclusively a purse-seine !/i,hery. For detailed accounts of these methods see Godsil (1938) and , himada and Schaefer (1956) on baitfishing, Scofield (1956) on troll','g, and Whitehead (1931), Scofield (1951) and Oi.'ange and Broadhead ,'.1959) on purse seining. ;The catches from the California albacore and bluefin fisheries have . hried markedly from year to year. The author, and other researchers, , ~el that some of this variation has been attributable to changes in the , . eean climate off the California coast. The present study attempts to elate fluctuations in the temperate tuna catch (bluefin and albacore) .' environmental conditions as measured by sea-surfl'.ce temperatures at " 0 shore stations in southern California.