A change in the way researchers count halibut has upped the 2001 catch quota for Gulf of Alaska commercial fishers.
Last year, 15.3 million pounds of halibut -- 28 percent of Alaska's commercial landings -- were delivered to Kenai Peninsula ports. Homer led the state with 9.6 million pounds, followed by Kodiak with 9.3 million, Dutch Harbor with 7.9 million and Seward with 5.5 million.
The news could be even better following last week's meeting in Vancouver, British Columbia, of the International Pacific Halibut Commission, a U.S. and Canadian treaty organization.
The commission recommended raising the Gulf of Alaska quota from 18.3 million pounds last year to 21.9 million pounds this year. It recommended raising the Alaska Peninsula quota from 15 million pounds to 16.5 million pounds and raising the Southeast quota from 8.4 million pounds to 8.8 million pounds.
It recommended raising the coastwide quota, from the Bering Sea through British Columbia and the U.S. West Coast, from 67.5 million pounds last year to 73.2 million pounds this year. Its recommendations go to the U.S. and Canadian governments.
The 2001 Alaska fishery runs from March 15 to Nov. 15.
Bruce Leaman, commission director, said biologists expect a gradual decline in the North Pacific halibut stock. However, research last summer suggested there may be more pounds of halibut in the North Pacific than previously thought. That opened the door for the increased quotas.
The new assessment of halibut biomass -- the total weight of the halibut on the grounds -- stems from a reevaluation of how changes from one bait to the next affect annual halibut surveys.
Like commercial fishers, the biologists catch halibut by laying longlines on the sea floor. Each longline has hundreds of hooks. From 1982 through 1986, biologists baited alternating hooks with salmon and herring. There were no surveys from 1987 to 1992. When they resumed in 1993, biologists used only salmon for bait.
Then, in 1999, they decided to test longlines baited with squid and herring in case salmon was not always available. It turned out longlines baited only with salmon caught twice as many halibut as those baited only with herring.
That suggested that surveys using only salmon for bait might over-estimate the halibut biomass, Leaman said. As a precaution, researchers lowered their 1999 biomass estimates by 20 to 30 percent. That led to cuts in commercial fishing quotas.
However, Leaman said, biologists still had not compared longlines baited only with salmon to those baited with salmon and herring on alternating hooks. They did that last summer and found little difference between the two. So, the salmon-only surveys probably do not over-estimate the halibut biomass, after all, they concluded.
Commissioner Drew Scalzi of Homer said on top of that, the 2000 survey catches were strong, commercial catch rates were up and the halibut seem to be growing faster. So, the commission set higher catch quotas for 2001.
Leaman said the halibut biomass now is near a long-term peak. However, it appears to be headed for a decline, based on the estimated abundance of age groups still too small for commercial fishers to keep. Leaman said there are less-than-average numbers of halibut spawned from 1989 to 1993. While there are good numbers of halibut spawned in 1994 and 1995, oceanographic conditions were unfavorable for halibut spawned from 1998 through 2000.
Even so, he said, rising halibut growth rates could slow the decline in harvestable biomass.
Due to environmental conditions or because there have been so many halibut on the sea floor -- biologists do not know which -- the growth rate of young halibut has been slowing, Leaman said. So, it has taken longer for halibut to reach the minimum 32-inch length at which commercial fishers are allowed to keep them. As a result, he said, there have been more age groups in sub-legal sizes.
In 2000, though, the growth rate increased, Leaman said. If that trend continues, halibut will reach legal size sooner, and there will be more age classes above the 32-inch limit. That would slow the decline in harvestable biomass, he said, though the decline will not end until there are new strong age classes to replace those that now support the fishery.
Peninsula Clarion ©2014. All Rights Reserved.