Megalofonou et al.: Incidental catch and estimated discards of pelagic sharks in the Mediterranean Sea 



629 



100 



90 



13 80 



a. 

 o 



70 



60 



50 



-•- Xiphias gladius 

 -•- Sharks 



25 



2.0 



o 



15 2 



•■ 1 



■■05 



00 



Jan Feb Mar Apr May 



Jun Jul 

 Months 



Aug Sep Oct Nov Dec 



Figure 2 



Monthly variation in sharks and swordfish longline CPUE (catch in num- 

 bers/1000 hooks) in the swordfish longline fishery of the Mediterranean Sea 

 during 1998-99. 



05 



00 



Xiphias gladius 

 Sharks 



Jan Feb Mar 



Aug Sep Oct Nov Dec 



Figure 3 



Monthly variation in sharks and swordfish CPUE (catch in numbers/1000 m net) 

 in the driftnet fishery of the Mediterranean Sea during 1998-99. 



in local markets. The very low discard rate of shark — 

 about 1% of the sharks caught during onboard sampling 

 was discarded — confirmed that sharks contribute to 

 fishermen's income and may become target species with 

 future increases in their market value. That discard- 

 ing was observed only in the Greek swordfish fleets is 

 probably due to the low market prices of shark meat 

 compared to the high price of swordfish in this country. 

 Sometimes during long trips fishermen are reluctant to 

 retain them onboard and loose cool storage space for 

 more valuable species such as swordfish or tuna. 



The analysis of catch composition by gear and areas 

 indicated that the various gears used in the swordfish 



and tuna fisheries affect the shark populations dif- 

 ferently and that the proportion of shark catches is 

 related both to the type of fishing gear and the sam- 

 pling area. This finding is consistent with previous 

 findings for the Mediterranean Sea where incidental 

 shark catch in the swordfish fisheries varied from in- 

 significant to dominant, depending on the area studied 

 (De Metrio et al., 1984; Di Natale, 1998; Filanti et al., 

 1986; Buencuerpo et al., 1998; Mejuto et. al., 2002). 

 The highest shark incidental catches were found in 

 the Alboran Sea and were probably related to their 

 location (Alboran Sea), adjacent to the Atlantic Ocean. 

 Shark bycatch in the Atlantic swordfish fishery is one 



