346 



Alaska — Our Living Rt'soiirtes 



Pink salmon 



79 81 83 85 87 



Sockeye salmon 



91 93 



d. Chinook salmon 



250- 



BB. K, Y 



Or-r 



73 



76 79 



82 



Yeat 



85 88 91 



Fig. 3 a-d. Salmon escapements 

 over time in select areas of Alaska. 

 (BB— Bristol Bay; CI— Cook 

 Inlet; K— Kodiak: PWS— Prince 

 William Sound; Y — Yukon.) 



about 1 2% of the catch in the central region and 

 about 33% in southeastern Alaska (Wertheimer 

 in press). 



Chum sahnon escapements (1979-93) in 

 central and western Alaska (Fig. 3b) have gen- 

 erally declined, as have the escapements of fall- 

 run chum salmon in the Yukon River. These 

 declines have directly affected western Alaska 

 commercial and subsistence users who depend 

 on the chum salmon resource. Several factors 

 could be responsible for this decline, including 

 oceanographic change, density-dependent com- 

 petition at sea with large numbers of chums 

 released by hatcheries in Russia and Japan 

 (Ishida et al. 1993). and interception by high 

 seas drift-net fisheries (Olsen 1994). In addi- 

 tion, fishing effort has increased in recent years 

 from expanding in-river commercial and subsis- 

 tence chum salmon fisheries. 



Sockeye Salmon 



A trend summary was possible for sockeye 

 salmon in all regions of Alaska. Most popula- 

 tions were either stable or increasing (Table). 

 Statewide sockeye salmon harvest is at a record 

 level (Fig. 2c). and the catch throughout Alaska 

 has risen substantially since the early 1970"s 

 (Wertheimer in press). Escapement also appears 

 to be increasing for most populations (Fig. 3c). 

 In addition to the few stocks in southeast Alaska 

 that have declined, a decline in Cook Inlet sock- 

 eye salmon is predicted over the next 2 years. 

 After many spawning adults escaped harvest 

 when fisheries were closed in 1989 because of 

 the Exxon Valdcz oil spill, too many fry were 

 produced to be supported by their habitat (D. 

 Schmidt, Alaska Department of Fish and Game, 

 personal communication). The resulting 

 increase in fry mortality will probably be a fac- 

 tor in the abundance of Cook Inlet sockeye 

 salmon in the immediate future. 



Chinook Salmon 



The trend summary for chinook salmon sug- 

 gests that most populations are either stable or 

 increasing (Table). Although present commer- 

 cial harvest of chinook salmon statewide is 

 slightly lower than the average historical level 

 (Fig. 2d), the catch appears to be more stable 

 than for all species combined (Fig. 1 ). A recent 

 decrease in the quota for southeastern Alaska 

 troll fisheries may be a factor in the stable catch 

 of chinook salmon. Sport harvest of chinook 

 salmon has increased substantially over the past 

 several years (Mills 1993) and now exceeds 

 10% of the commercial catch (Wertheimer in 

 press). Catches of chinook salmon declined in 

 nearly all regions of Alaska in the early 1970's, 

 rebounded through the early 1980"s. and have 

 begun to decrease since that time. High seas 

 drift-net and trawl fisheries that target other 



Sockeye salmon return to spawn in numerous Alaskan 

 streams each summer 



species may be factors in the minor decline in 

 chinook salmon harvest in western Alaska 

 (Olsen 1994; Table). When actual e.scapements 

 are plotted for several areas of Alaska, however, 

 the trends are generally increasing (Fig. 3d). 



Coho Salmon 



A trend summary was possible for coho 

 salmon stocks only in the southeastern and cen- 

 tral regions of Alaska (Table). Overall, fewer 

 data have been collected for coho than for other 

 species of salmon because of their late run tim- 

 ing, smaller population sizes, and use of remote, 

 heavily vegetated watersheds. Most populations 

 analyzed in southeastern Alaska showed no 

 trend: some increased and some decreased 

 (Table). Of the eight populations examined 

 from central Alaska, half increased and none 

 decreased. 



Statewide harvest of coho salmon is at a 

 record level (Fig. 2e). as is the catch in all 

 regions of Alaska (Wertheimer in press). Data 

 were insufficient to plot coho salmon escape- 

 ments in key areas of Alaska. Based on catch 

 data alone, abundance of coho salmon is gener- 

 ally increasing (Wertheimer in press). For some 

 of the populations that are declining in south- 

 eastern Alaska (Table), habitat effects associat- 

 ed with logging may be a factor; however, an 

 equal number of declining populations in south- 

 east Alaska are in pristine areas (C. Halupka, 

 U.S. Forest Service, personal communication). 



Conclusions 



The population trends and escapements of 

 pink, sockeye. chinook, and coho salmon in 

 Alaska are generally stable or increasing based 

 on the data analyzed. A recent decline in chum 

 salmon escapements has occurred in central and 

 western Alaska, the cause of which may be 

 related to density-dependent factors and ocean- 

 ic change in the marine environment. In many 

 Alaskan streams, salmon abundance has not 



