FISHERY BULLETIN: VOL 76. NO 4 



64°40 A 



Figure l. — Northwest Atlantic Ocean partitioned into ICNAF areas. 



regulations in ICNAF were adequate to account 

 for the bycatch. Simulations of 1975 catches were 

 made utilizing bycatch ratios from both 1971 and 

 1973 to assess the sensitivity of the technique to 

 differences in historic bycatch ratios. Brennan 

 ( 1975) found little evidence of a decline in bycatch 

 ratios when examined on a country-gear level over 

 the years 1970-73. We compared the simulated 

 catches and the reported catches on a species basis 

 and on a country basis and examined the results to 

 determine for which countries and species the 

 simulations were successful. 



METHODS AND MATERIALS 



Data Base 



Almost all countries fishing in Subarea 5 and 

 Statistical Area 6 (Figure 1) submitted data on 

 nominal catch (i.e., that reported landed (adjusted 

 to live weight) by the country, not necessarily that 



actually caught — it is the term used in the ICNAF 

 Statistical Records following standard United Na- 

 tions Food and Agricultural Organization proce- 

 dures) and effort for main species (or a species) 

 sought. These data are published each year in 

 tables 4 and 5 in the annual ICNAF Statistical 

 Bulletins. The data of 1971 and 1973 (ICNAF 

 1972b, 1975b) were the sources of the bycatch 

 ratios. Data of these years were reported according 

 to the species categories given in Table 1. The 

 nominal catches do not include fish caught and 

 discarded at sea. 



The nominal catch and effort (days fished) for 

 1971 and 1973 for finfish were summed over 

 months for each target fish of the fishery (the 

 "main species sought") categories reported in ta- 

 bles 4 and 5 of the ICNAF Statistical Bulletin 

 (1972b and 1975b, respectively). Catches made 

 with fixed gear as well as catches of Atlantic 

 menhaden, Atlantic halibut, and large pelagic 

 fishes, i.e., tunas, billfishes, and sharks (other 



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