1.25 20 



IE 



nr 



1.00 16 



0.75 12 — 



■ 0.50 8 



025 4 — 



10 20 30l 40 50 60l 70 80 901 



3 6 9 







^ol 130 140 I50l I60-»LENGTH V4 CMS. 

 12 15 -•^ LENGTH INCHES 



I n n nz iinsni-*^ — age group 



Figure 7. — Weight-length-age relation for Pacific mackerel (fig. 15 of Fitch, 1951). 



3.5 Behavior 



3.51 Migrations and local movements 



The California Division of Fish and Game 

 (Fry and Roedel, 1949) devised a tagging pro- 

 gram in 1935, intensified it in 1940-41, and 

 concluded it in 1943. Mackerel were tagged at 

 several localities in central and southern 

 California and as far south as Magdelena Bay, 

 Baja California. 



The Fisheries Research Board of Canada 

 also tagged a few fish off the Oregon coast 

 near the Columbia River. 



Tag returns showed that the fish migrated 

 throughout the region covered by the tagging 

 program. One of the fish tagged off Oregon 



was caught again off southern California, Fish 

 tagged off central California were recovered 

 in large numbers at Los Angeles and Newport 

 Beach canneries, and one was caught at San 

 Diego and another at Ensenada, Baja Cali- 

 fornia. Mackerel tagged off southern California 

 were recaptured at Monterey and San Fran- 

 cisco. Fish tagged at northern and central 

 Baja California were recovered at San Diego, 

 Newport Beach, Los Angeles, Monterey and 

 San Francisco, Calif. No fish tagged south of 

 San Roque Bay, Baja California, were re- 

 covered. 



3.52 Schooling 



The Pacific mackerel schools by size. It is 

 found in pure schools and mixed schools with 

 jack mackerel and Pacific sardine. 



10 



