Recent test fishing of a halibut excluder device on trawl nets fishing for Pacific cod in the Gulf of Alaska points to a significant reduction of halibut bycatch. The gear modification project was coordinated by the cooperative research program of the Marine Conservation Alliance Foundation (MCAF) in conjunction with Dr. Craig Rose of the National Oceanic and Atmospheric Administration's Alaska Fishery Science Center and the help of Kodiak fishermen.
"This shows what happens when fishermen, scientists, and industry put their heads together to tackle even the most difficult problems," said John Gauvin, cooperative research coordinator for MCAF. "We produced a practical device that reduces halibut bycatch in the Gulf trawl fishery by over 50%. The test shows that the device also reduced the catch of cod by 20-30% but from our preliminary look at the cod size data, the cod that are escaping are mostly smaller fish that are less valuable in the market and best returned to the sea."
Gauvin noted that these results are considered preliminary and more analysis of the data will occur over the coming weeks to identify important factors affecting halibut and cod escapement. This will include a more detailed examination of size gradients for cod escapement and a breakdown of the escapement rate for halibut of different sizes. The researchers are also interested in how tow by tow halibut escapement rates are affected by the cod catch rates for those tows. Once the analysis is complete, the draft report will be reviewed by the North Pacific Fishery Management Council's Scientific and Statistical Committee later this year.
The need for such a device was apparent because of an increase in halibut bycatch in the fall Gulf of Alaska cod fishery. This was due to an increase in halibut abundance around Kodiak and regulations intended to protect sea lions. While cod fishing is best in the winter and spring when the fish are tightly schooled, part of
Contact: John Gauvin
Marine Conservation Alliance