

20 



SO 



20 

 10 







30 



20 



10 





 SO 



20 



iO - 



\95B 



-a- 



1937 



1968 



-a- 



30 r 



«59 



10 - 







so 



20 - 

 10 

 



1960 



**- 



SO 



100 



«96t 



-a- 



1967 



1966 



-a- 



1969 



■»T r 



1 r 



^^ 



50 100 150 ZOO 250 300 



LENGTH (cm) 



LENGTH 



Figure 38. Lengths of bluefin tuna captured off Norway (north of 63°N) ("+" on graph means less than 0.5%). 



dium sized and large bluefin in the 

 eastern Atlantic Considerable num- 

 bers of medium sized (32-122 kg) 

 and some large bluefin have also been 

 taken in the Bay of Biscay (Le Gall 

 1954, Shinguet al 1975) 



French tuna landings from this 

 bay began about 1840, when pilot 

 boats from La Rochelle began taking 

 considerable catches of tuna by tioll- 

 ing while waiting for ships Tuna fish- 

 ing did not become important there 

 commercially, however, until a crisis 

 in the sardine fishery about 1860 

 caused the French fishermen to turn 

 their attention to tuna. The success of 

 the trials exceeded expectations, and 

 the fleet of sailing trollers increased 

 year by year (Grandbesan(;on 1 909) 

 The major catch of this fishery was 

 albacore, Thunnus alalunga, with 



bluefin usually being taken inciden- 

 tally. The introduction of the live bait 

 method in Spain and France in the 

 years 1947-1949 (Navaz 1950a, 

 1950b, dc la Tourrasse 1951), how- 

 c\cr, resulted m a specialized fishery 

 for bluefin The catches of this spe- 

 cies consequently increased greatly 

 in the 1950s, but were much lower 

 through most of the 1 960s and have 

 remained at intermediate levels in the 

 1970s (Figure 41) Statistics for this 

 fishery are VC17 confusing, but it ap- 

 pears that the landings varied between 

 1,000 and 1.500 tons m 1945-1949, 

 then rose to between 2,700 and 5,500 

 tons in 1949-1959. The catches in 

 the 1960s were much smaller, gener- 

 ally varying between 1 ,000 and 1 ,900 

 tons, but attained 2,100 and 3,300 

 tons in 1965 and 1966, respectively. 



Catches in the early 1 970s have evi- 

 dently been somewhat over 2,000 

 tons per year. 



Bluefin tuna apparently occur in 

 the Bay of Biscay in every month of 

 the year (J. LeGall 1950. 1954; 

 Navaz 1950b), but the active fishing 

 season has usually extended from 

 May or early June into October or 

 November Individuals weighing 

 more than 30 kg are usually taken 

 between mid-July and early Septem- 

 ber (llamre and Tiews 1964, Hamre 

 et al. 1966, 1968, 1971, Aloncle et 

 al, 1974), 



Research on bluefin tuna m the 

 Bay of Biscay has been divided be- 

 tween two periods — 1 949-1 954 and 

 from 1972 to the present This divi- 

 sion of research effort leaves a gap of 



39 



