4- 



3- 



1- 



0- 



□ NUMBER OF FlSH/lO* 



■ metric tons/io' 



1958 



Figure 27. Annual catches of small and some medium size bluefin tuna from the 

 northwest Atlantic purse seine fisheries, 1958-1973, in tens of thousands offish 

 and thousands of tons. 



era! seasonal distribution pattern, 

 based on Japanese catch rates for 

 1956-1969, is illustrated by Figure 

 32 (Wise and Davis 1973). This fig- 

 ure, however, includes southern blue- 

 fin, Thunnus maccoyii, as well as the 

 Atlantic bluefin, 7" thynnus thytmus. 

 The records south of latitude 2()°S, 

 and perhaps also the one in the first 

 quarter centered at 12°S, 2°E, are 

 probably of southern bluefin. Catch 

 rates for individual years and areas 

 (Table 8, Figure 35) (J P Wise, 

 personal communication. Wise and 

 IDavis 1 973) suggest that the abun- 

 dance has varied considerably over 

 the years. The catches declined pre- 



Figure 28. Lengths of bluefin tuna captured in the Atlantic tail.sidc the 2(K) meter amtour north of 35°N and west of 40° W 

 ("+" on graph means less than 5%) 



31 



