412 



Fishery Bulletin 105(3) 



interactions were observed during 1996-98. Interaction 

 rates for both pilot whales and Risso's dolphins peaked 

 during the late summer and fall (Fig. 2B). 



Types of serious injury 



Of the 94 observed serious injuries, there were 60 cases 

 where marine mammals were released with hooks 

 remaining in the mouth. In 49 of these cases, monofila- 

 ment line (typically 15-60 feet in length) remained with 

 the animal (Table 3). In the remaining 11 cases, the 

 animal was released with less than five feet of monofila- 

 ment line and with the hook remaining in the mouth. In 

 four of the 11 documented mortalities, the animal was 

 hooked in the mouth. 



There were 34 serious injuries in which the animal 

 was released entangled with fishing gear that did not 

 involve ingestion of a hook (Table 3). The majority 

 of these cases were injuries to animals that became 



entangled in the mainline which typically consists of 

 700-lb test monofilament. In most of these cases, the 

 animal was released with multiple wraps of mainline 

 around its tail or body, and the gear remained with 

 the animal after the line was cut. In five of the 10 

 documented mortalities, the animal was entangled 

 in the mainline. Fishermen were typically able to cut 

 the mainline away from entangled animals. Thus, the 

 majority of animals entangled in the mainline were 

 released without entangling gear, and these animals 

 were not considered to be seriously injured. 



Logistic regression results: Pilot whales 



Geographic area (MAB vs. other areas; chi-square=31.24, 

 df=l, P<0.0001), distance from the 200-m isobath (chi- 

 square=11.31, df=l, P=0.0008), and observed damage to 

 the swordfish catch (chi-square=7.26, df=l, P=0.0071) 

 were significant factors correlated with the occurrence 



