

30 

 20 

 10 

 "-ZZr 



50 



100 



150 



200 



250 



LENGTH (cm) 



Figure 60. Length composition of samples of bluefin tuna taken along the Libyan coast in 1964 (" 

 than 0.5%). 



' on graph means less 



the landings: one with maturing fish 

 in February, March and April, one 

 with spent fish in July and August, 

 and a lesser one in December. 

 Hovasse believed that the first run 

 was an "arrival" migration into the 

 Black Sea, where spawning took 

 place and the second was a "return" 

 run fi-om the Black Sea. He did not 

 understand the significance of the 

 third maximum. lyigUngor (1957) 

 listed three rather similar runs: 

 March-April, July-autumn, and No- 

 vember-January. Akyuz and Artiiz 

 (1957) specify an "arrival" run simi- 

 lar to Ninni's, from April to early 

 August, and a "return" run from late 

 October into December. These au- 

 thors show the average volume of 

 bluefin tuna sales in the Istanbul mar- 

 ket, by month, for 1935-1955. These 

 show a maximum in March and an- 

 other in July, with good volume in 

 April, February, and August and a 

 minimum in June. The yearly vol- 

 ume of bluefin tuna sales in the 

 Istanbul market varied from 85 to 

 537 tons in 1909-1916 (Ninni 1922), 

 from 15 to 112 tons in 1928-1938 

 and from 40 to 764 tons in 1953- 

 1955 (Akyuz and ArtUz 1957) The 

 allocation of catch by gears is not 

 shown. 



Harpooning is practiced both 

 from the shore and from small boats 

 (Devedjian 1926). Handlining is also 

 practiced from small boats 

 (Devedjian 1926, lyigUngor 1957). 



The hook-and-line fishing seasons are 

 November-Januar>- and March-April; 

 the fish do not take bait July-October 

 (lyigUngor . 1 957). Both of these fish- 

 eries are centered around Istanbul. 



Ninni (1922) concluded that the 

 quantity of bluefin tuna available was 

 much greater than was indicated by 

 the catches of the traps, since the 

 latter did not extend into sufficiently 

 deep water to fish tuna effectively, 

 and also were too weak structurally 

 to hold any considerable quantity of 

 bluefin. He noted that a trial setting 

 of an Italian style trap at Touz 

 Bumum in 1913 had not produced 

 satisfactory results, but did not con- 

 sider this experiment conclusive. 



Evidently most of the bluefin 

 taken near Istanbul are large. Most of 

 the fish examined by AkyUz and 

 Artuz (1957) at the Istanbul market 

 (1955-I956)wereinthe 170-280 cm 

 range, with the smallest 120 cm and 

 the largest 330 cm. Samples exam- 

 ined there in 1967 and 1968 (Hamre 

 et al. 1971) ranged from 85 to 320 

 cm, with most of the fish from 155- 

 290 cm (Figure 62). Lebedeffl 1 936) 

 mentions that hook and line catches 

 in 1 936 included 40 bluefin over 400 

 kg, 10 over 600 kg, and some from 

 700 to 775 kg. He noted that fish 

 over 200 kg were taken only in the 

 fast current, whereas 100 yards away 

 only individuals of 20-50 kg were 

 caught. In early April, the large and 

 small bluefin left, but medium sized 



ones stayed near Prince's Island. Dur- 

 ing a few days of sport fishing, from 

 December 25, 1935 to late March 

 1936, Lebedeff caught tuna of 120, 

 230, 350, 380 and 400 kg. He also 

 lost several large bluefin which broke 

 his lines or leaders. One of these, 

 which was later caught in a net and 

 identified by the hook and leader 

 which had remained attached to it, 

 weighed 450 kg. 



Hovasse (1927) noted that blue- 

 tin tuna occurred in the Aegean Sea- 

 Marmara-Black Sea area in waters of 

 extrenicK different salinities, from 

 1 8.3 o/oo in the Black Sea to 39 o/oo 

 in the southern Aegean. In the vicin- 

 ity of Istanbul tuna are found simul- 

 taneously in deep waters with salin- 

 ity of 38 o/oo and shallow waters 

 with only 17 o/oo to 18 o/oo. He 

 stated that tuna in the area were found 

 in considerable ranges of tempera- 

 ture—as low as 14°C to 19°C, ac- 

 cording to depth — in the Black Sea 

 at the time of the "arrival." These 

 findings conflicted with Roule's 

 (1924) hypothesis of a stenothemiic 

 and stenohaline tuna. 



Small bluefin tuna range along 

 the Mediterranean coasts of Turkey 

 and Syria, and occasionally occur off 

 Cyprus (Carp 195 1. Oren et al. 1959, 

 Sara 1904). Carp reported a Turkish 

 fisher) for bluefin (apparently 10-30 

 kg) along the Anatolian coast and in 

 the Gulf of Mersin. Oren et al. ( 1 959) 

 reported captures of very small (45- 



65 



