Carter and others 



Chapter 27 



Mortality in Gill Nets 



and Hood Canal. Common Murres and Rhinoceros Auklets 

 were the most frequently caught species. On 25 August 1993, 

 two murrelets were captured at 0657 hrs in the same purse 

 seine set about 500 m off Village Point, Lummi Island, in the 

 San Juan Islands. Both birds were captured alive and released 

 within 10-15 minutes. Almost all seabirds captured during 

 this program also were released shortly after capture. A 

 similar program is envisioned for 1994. 



Point Roberts Tribal Fishery - In February and March 

 1993, a small tribal fishery (involving 10 boats) for herring 

 occurred in the Point Roberts/Semiahmoo Bay area. 

 Observers reported no entanglements or mortalities of 

 murrelets (BIA 1993). 



Beached Birds - Kaiser ( 1 993 ) reported two dead juvenile 

 murrelets and hundreds of other seabirds, especially Common 

 Murres and Rhinoceros Auklets, washed ashore in Boundary 

 Bay. British Columbia, in August 1993. Boundary Bay is 

 located just across the border from areas where high numbers 

 of murrelets and gill-net fishing areas co-occur. 



Grays Harbor - No Marbled Murrelets have been recorded 

 as killed in gill nets in Grays Harbor during observer programs 

 in summer and fall 1991, 1992, and 1993 for non-tribal 

 fisheries ( Jefferies and Brown 1993, WDFW 1994). Between 

 4 and 10 percent of nets were monitored each season and 

 year. Bycatch included Common Murres, Rhinoceros Auklets, 

 and loons. Some unidentified alcids and birds were recorded 

 which may have included murrelets. 



Willapa Bay - No Marbled Murrelet bycatch was observed 

 in Willapa Bay during observer programs in summer and fall 

 1991. 1992. and 1993 for non-tribal fisheries (Jefferies and 

 Brown 1993. WDFW 1994). Between 1 and 13 percent of 

 nets were monitored each season and year. Bycatch included 

 Common Murres. cormorants, loons, grebes, and other alcids. 

 Some unidentified alcids and birds were recorded which 

 may have included murrelets. 



Columbia River - No Marbled Murrelets have been 

 recorded as killed in gill nets in the Columbia River during 

 observer programs in winter 1991, 1992 and 1993 (Jefferies 

 and Brown 1993). Bycatch included Common Murres, 

 cormorants. Western and unidentified grebes, and Surf Scoters 

 (Melanina perspicillata). Some unidentified alcids and birds 

 were reported which may have included murrelets. 



With available information, it is not yet possible to 

 accurately determine the extent of mortality on Marbled 

 Murrelets in Washington. U.S. Fish and Wildlife Service 

 (1993b,c) stated in a biological opinion that a mortality of 

 less than ten murrelets recovered from nets during the 

 observer programs would not jeopardize the continued 

 existence of the Marbled Murrelet in Washington. Additional 

 information on mortality must be derived from tribal and 

 non-tribal fisheries, especially within and north of the San 

 Juan Islands, northern Puget Sound, along the northern side 

 of the Olympic Peninsula, and in the Cape Flattery area. 



It is likely that significant mortality of murrelets is 

 occurring and has occurred in northern Puget Sound and 

 around the San Juan Islands. The large amount of fishing 



effort that occurs throughout this area is likely to cause 

 mortality on the scale of tens to hundreds of murrelets at a 

 minimum. Mortality extrapolations using 1979-1980 

 mortality rates in relation to fishing effort and murrelet 

 densities from Trevor Channel in Barkley Sound, British 

 Columbia (Carter, unpubl. data; Carter and Sealy 1984), in 

 association with murrelet densities and fishing effort in 

 various fishing areas in northern Puget Sound and around 

 the San Juan Islands (Speich and others 1992; Speich and 

 Wahl, this volume; Wahl and others 198 1 ), yielded potential 

 annual mortality estimates in the high hundreds (Wilson, 

 pers. comm.). However, fishing effort is more intensive 

 and murrelet densities are lower in northern Puget Sound 

 which may act to produce different mortality rates than 

 observed in Barkley Sound. Observer programs should be 

 continued and augmented to better describe gill-net mortality 

 in northern Washington. 



Oregon 



Gill-net fishing has been prohibited in estuaries, bays 

 and along the outer coast of Oregon since 1942 (Nelson and 

 others 1992). No net-caused mortalities of murrelets are 

 known in Oregon. 



California 



Nearshore gill- and trammel-net fisheries have existed 

 in Central and Southern California since the early 1900s, 

 and increased dramatically in size during the 1970s and 

 1980s. These fisheries have targeted a wide array of fish, 

 including halibut and flounder (Bothidae and Pleuronectidae ). 

 croaker (Sciaenidae). shark, rockfish (Scorpaenidae), and 

 others. The catch from these fisheries peaked during the 

 1980s and early 1990s, but has since declined because of 

 regulations aimed at reducing mortality of marine birds and 

 mammals. These fisheries are managed primarily by the 

 California Department of Fish and Game (CDFG) which 

 operated a bycatch monitoring program from 1983 to 1989. 

 This observer program has been continued by NMFS from 

 1990 to 1994. These fisheries are managed through a series 

 of CDFG fishing regions (fig. 5). 



Northern California - Gill-net fishing is prohibited north 

 of Point Reyes, Mann County. 



Central California - Small numbers of birds were killed 

 in gill nets before the late 1970's (Sowls and others 1980). 

 From 1979 to 1987, more than 70,000 Common Murres were 

 killed in regions 3 and 4 (fig. 5), mainly in the summer and 

 fall, which contributed to a severe decline in the local breeding 

 population (Carter and others 1992, DeGange and others 

 1 993, Takekawa and others 1 990). Thousands of other seabirds 

 including Marbled Murrelets, and marine mammals also were 

 killed. Carter and Erickson (1988, 1992; also see Sealy and 

 Carter 1984) summarized known evidence of mortality of 

 murrelets from this fishery. Three birds were noted in the 

 monitoring program: (1) two birds in Monterey Bay on 3 



USDA Forest Service Gen. Tech. Rep. PSW-152. 1995. 



281 



