Workshop participants recognized that the prohibitions 

 on the use of drift nets and set nets in certain areas were 

 having an adverse economic impact on some fishermen. They 

 recommended that a feasibility study and, if appropriate, an 

 engineering/assistance program be carried out to assess the 

 potential utility of converting small gill net vessels to 

 alternative types of gear (e.g. , Danish seines) to permit 

 resumption of halibut and other fisheries in areas where set 

 net fisheries have been prohibited to protect sea birds, sea 

 otters, harbor porpoise, and gray whales. Participants also 

 noted that studies should be done to identify factors (e.g. , 

 the length of time that nets are left in the water) that may 

 be causing or contributing to the incidental take of harbor 

 porpoise, harbor seals, and other marine mammals. 



Because of uncertainties concerning the effects of certain 

 fisheries on marine mammals, Workshop participants concluded 

 that survey, reporting, and observer programs should be con- 

 tinued and, in some cases, expanded to provide more reliable 

 information on the species, numbers, ages, and sex of marine 

 mammals being taken, both deliberately and incidentally, in 

 set net, drift net, troll, and other fisheries in California. 

 Participants noted that depredation by California sea lions 

 and harbor seals of fish caught in the party boat, gill net, 

 and salmon troll fisheries could be caused by a small number 

 of "nuisance" animals who have learned that food is easy to 

 find in the vicinity of fishing gear and vessels or by a general 

 cross-section of animals present in fishing areas. Participants 

 pointed out that it might be possible to use non-lethal aversive 

 stimuli to frighten and keep seals and sea lions away from 

 fishing gear and fishing areas. They concluded that additional 

 studies should be done to evaluate this potential. Finally, 

 the participants noted that long-term monitoring of both the 

 affected fisheries and marine mammal populations is necessary 

 to evaluate the relative advantages and disadvantages of 

 measures taken to avoid or reduce interactions. 



Interactions in Areas off Alaska 



The southeastern Bering Sea and other areas off Alaska 

 include some of the world's richest fishing grounds and support 

 a diverse assemblage of marine mammals. The expansion of 

 both domestic and foreign fisheries in these areas beginning 

 in the mid-1960s has increased the potential for marine 

 mammal/ fishery interactions and has focused attention on pos- 

 sible competition between marine mammals and fishermen for 

 the same fish and shellfish resources. Because of the potential 

 interactions, the Marine Mammal Commission and the North Pacific 

 Fishery Management Council initiated cooperative efforts in 

 1980 to develop and implement an ecosystem approach to the 

 management of marine mammals and fishery resources in areas 



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