May 21, 2010
US study to focus on king salmon decline
Researchers from the University of Alaska Fairbanks (UAF), armed with a US$435,000 grant from the Pollock Conservation Cooperative Research Centre (PCCRC), will embark on a two-year study to address the problem of the decline in king salmon supplies.
Another US$180,000 from the Alaska Sustainable Salmon Fund will augment the study.
"The fishing industry is greatly concerned about recent declines in Western Alaska salmon abundance," said Denis Wiesenberg, dean and director of the UAF School of Fisheries and Ocean Sciences. "As a result, the PCCRC decided to direct significant funding this year to meaningful, focused research into the causes of these declines."
The diminishing king salmon returns are a concern across the state and three fisheries in Cook Inlet were closed May 4 to all types of fishing, including catch-and-release, bringing to five the total of South-central fisheries sharply restricted this year.
From 2003-2005, the state-wide king salmon harvest averaged nearly 700,000 fish per year. From 1990 to 1998, the state-wide harvest averaged 621,667 per year. From 2006-2008, which includes the first season commercial fishing was not allowed in the Yukon district, the state-wide harvest averaged 521,856, a 25.3% decline from the previous three seasons.
King salmon weight is also in decline with the average of 16.1 pounds from 1999-2008, off 9.8% from the 17.9 pounds between 1990 and 1998.
UAF researchers will focus on the ecology of the king salmon freshwater habitat and what effect ichthyophonus, or white spot disease, may be having. White spot disease is a parasitic infection that attacks the organs of fish, reducing endurance and the ability to spawn.
Another potential cause posited is the bycatch of king salmon by pollock fishermen after at least 120,000 were snared by trawlers during 2007. The North Pacific Fisheries Management Council has put hard caps for king salmon bycatch on the pollock industry starting in 2011, requiring the fishery to shut down after 60,000 king salmon are caught.
According to Alaska Department of Fish and Game data, incidental commercial catch of king salmon during chum season was 4,381 in 2008 and 131 in 2009.
Of great concern to the district is the effect on subsistence stocks. The Yukon district typically returns a harvest of more than 50,000 kings for subsistence fishing with the surplus allocated for commercial and sport fishing, but the subsistence harvest was curbed from 55,156 in 2007 to 45,312 in 2008.
During the 2008 season, some reduced fishing periods were implemented on subsistence but escapement goals were not met. That led to even greater restrictions in 2009, including the reduction by half of the Yukon mainstem fishing district and closing fishing for a week to protect the first "pulse" of kings returning.
