Murray: Magnitude and distribution of sea turtle bycatch in the sea scallop dredge fishery 



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mated bycatch of turtles in the Virginia Beach area was 

 five animals in 2001 and zero animals in 2002. 



Across both areas, the highest bycatches occurred in 

 summer (128 turtles; 76%), followed by spring (23 tur- 

 tles; U7 ( ) and fall (18 turtles; 10%) (Table 5). One hun- 

 dred thirty-two (78%) (CV=49.6) sea turtles were caught 

 in the mid-depth zone from 49 to 57 m, whereas 37 (22%) 

 (CV=59.6) sea turtles were caught in waters deeper 

 than 57 m. One-hundred fifty-eight (93%) (CV=51.2) sea 

 turtles were caught in waters warmer than 19°C, and 11 

 (7%) (CV=74.9) in waters cooler than 19°C. 



Discussion 



Use of bycatch models 



Generalized linear and generalized additive models 

 help to identify environmental variables or fishing 

 practices that influence the probability of sea turtle 

 bycatch. In estimating total mortality, bycatch rates can 

 then be stratified according to these factors, reducing 

 unexplained variability in the total estimate. More- 

 over, understanding factors that lead to a high or low 



