Part I of this paper uses data from monthly aiiborne infrared tem- 

 perature surveys off central and southern California conducted dur- 

 ing the 5-yr period 1963-68, and catch data from sportfishing boats as 

 collected by the California Department of Fish and Game (CF & G), 

 to determine the temperature at which several important species were 

 caught by the recreational fishery fleet. 



Part II describes the results of a more detailed airborne temperature 

 study which took place at an important recreational fishing area off 

 San Diego from April through October in 1972-74. This second 

 series of airborne surveys used increased survey intensity (weekly 

 vs. monthly) over a high catch rate area for the sportfishing fleet, in 

 order to determine the correlation of catch-per-unit-effort (CPUE) to 

 temperature and the statistical significance of differences in 

 temperature-dependent catch rates. The statistical analysis of the data 

 collected off San Diego is presented in the analysis and conclusions 

 section of Part n. Data presented in Part II apply to the general 

 temperature-catch relationships in Part I. 



PART I— CATCH AND TEMPERATURE OBSERVED 



FOR SEVERAL RECREATIONAL AND 



COMMERCIAL SPECIES OFF CENTRAL AND 



SOUTHERN CALD70RNIA 



In August 1963, the National Marine Fisheries Service (then the 

 U.S. Fish and Wildlife Service, Tiburon Marine Laboratory, 

 Tiburon, Calif.) initiated a program in cooperation with the U.S. 

 Coast Guard to conduct monthly airborne temperature surveys using 

 infrared techniques to measure temperature over three important 

 coastal fishing areas off the west coast. These airborne temperature 

 surveys were continued by the U.S. Coast Guard into 1979. Results 

 of the first 5 yr of surveys (1963-68), in the form of individual survey 

 and monthly average temperature charts for the three areas, were 

 published by Squire (1971). Although those airborne infrared tem- 



perature surveys are useful to many fields of environmental research, 

 they were primarily intended to develop temperature data which 

 could be analyzed with catch data to provide insight into catch tem- 

 perature relationships for some of the more important coastal species. 



The central survey area off the California coast from Point Arena 

 to Point Sur and offshore about 50 nmi (Fig. la), and the survey area 

 off southern California (Fig. lb), supplied the temperature data for 

 this paper. The southern area extended to about 110 nmi offshore at 

 its widest point, and from off the coast of Point Arguello, Calif. , to 

 Point Salsipuedes, Baja California, Mexico. Data from the northern 

 survey area, which covered the coastal waters from Cape Flattery, 

 Wash. , to Cape Lookout, Oreg. , for about 50 nmi offshore, were not 

 included. From the published monthly survey data, the temperature 

 was obtained for each CF & G block area (10' longitude x 10' lati- 

 tude geographical area) by month, and these data were used in the 

 calculations for Part I. 



Monthly catch data recorded by the commercial sportfishing fleet 

 for the period August 1963 through July 1968 were obtained through 

 the cooperation of the CF & G, Marine Resources Laboratory, Long 

 Beach, Calif. Fishes selected for study included two species of 

 salmon (chinook, Oncorhynchus tshawytscha, and silver salmon, 

 Oncorhynchus kisutch), which enter the catch off the San Francisco, 

 Bodega Bay, and Monterey Bay area. Data on these species were 

 combined in the CF & G sportfishing boat catch records. Off south- 

 ern California and northwestern Mexico, catch data were obtained 

 for yeUowtail, Seriola dorsalis; Pacific bonito, Sarda chiliensis; 

 Pacific barracuda, Sphyraena argent ea; albacore, Thunnus ala- 

 lunga; and white seabass, Atractoscion nobilis. All of the latter group 

 are important to the marine sport and/or commercial fishing industry 

 of the United States, and some are important to Mexico. Albacore is 

 taken in substantial quantities by the southern California sportfishing 

 fleet, but most of the catch is taken outside the boundaries of the area 



Figure 1.— Airborne infrared sea surface 

 temperature survey tracks: left, central 

 survey area; right, southern survey area. 



