626 



Fishery Bulletin 103(4) 



Of the 3771 blue sharks measured, individuals 

 ranged from 40 to 368 cm TL (163.3 cm mean length 

 and 37.7 cm SD). The overall length-frequency dis- 

 tribution is shown in Figure 4. The size distribution 

 by fishing gear varied significantly (Kruskall-Wallis, 

 test statistic=350.2, P=0.000<0.05); larger specimens 

 were caught in the SWO-LL A and DN fishery (Fig. 5). 

 The Levantine basin had larger individuals whereas 

 the Catalonian Sea had smaller ones (Fig. 6). Out of 

 564 blue sharks, 346 were determined to be males 

 and 218 to be females. The sex ratio (males:female) fa- 

 vored males in almost all areas ranging from 1.29-2.50 

 males :1 female. The only exception was in the Alboran 

 Sea where females were predominant (0.61 males:l 

 female). Relationships between TL and FL and dressed 

 weight are given below: 



TL = 4.1+1.176 FL 

 TL = 74.6 DW° 307 



[r-=0.99, ;;=723] 

 [7^ = 0.95, n = 555]. 



The shortfin mako was reported in five out of 

 nine areas examined and represented 3.7% of the 



overall shark catches. This species was caught more 

 often in the swordfish fishery with a mean CPUE of 

 0.07 fish/1000 hooks in SWO-LL A and 0.05 fish/1000 

 hooks in SWO-LL. Shortfin makos were more abun- 

 dant in the Alboran Sea and the Levantine basin 

 (Table 8). 



The total length-frequency distribution for the 257 

 specimens measured is shown in Figure 4. For shortfin 

 makos collected, almost all were juvenile and ranged 

 from 62.5 cm to 272 cm TL (mean length of 120.6 cm 

 and 30.9 cm SD). Each fishing gear caught a statistical- 

 ly significant different average TL size (Kruskall-Wallis, 

 test statistic=23.8, P=0.000006<0.05), and larger speci- 

 mens were observed in the SWO-LL A fishery (Fig. 5). As 

 with the blue shark, larger makos came from the Le- 

 vantine basin and smaller ones from the Catalonian Sea 

 (Fig. 6). Out of 56 shortfin makos, 27 were determined 

 to be males and 29 to be females. Sex ratio was almost 

 equal (0.9 male:l female). The relationship between FL 

 and TL is given below: 



TL = 1.136 FL - 2.5 



[^ = 0.98, n =49]. 



