RESOURCE ASSESSMENT &
CONSERVATION ENGINEERING (RACE) DIVISION (cont.)

MIDWATER ASSESSMENT AND CONSERVATION ENGINEERING (MACE) PROGRAM:

Preliminary Results of the Gulf of Alaska EIT Pollock Survey (cont.)

Pollock was the most abundant species caught in midwater trawl hauls, comprising 82.3% and 51.8% of the total catch by weight and numbers, respectively. In bottom trawls, several of which were conducted in midwater, Pacific ocean perch was the most abundant species caught, accounting for 46.6% by weight and 44.4% by numbers. Pollock was the next most abundant species caught by weight (21.6%). Capelin was the only species caught in the single Marinovich trawl haul. Most pollock echosign was detected in the vicinity of Kodiak Island in Barnabas and Chiniak Troughs, in the Shelikof Strait sea valley, and Marmot and Alitak Bays (Fig. 2 above). Pollock were also concentrated in near-shore basins of deep water off Renshaw Point in the Shumagin Islands and off Nakchamik Island. Diffuse midwater layers of pollock were occasionally observed along the shelf break between about 300- and 500-m bottom depths. Virtually no pollock echosign was detected over bottom depths less than 100 m except in Alitak Bay, where fish were detected just outside the mouth of the bay over bottom depths of 60-70 m. Pollock were usually observed in aggregations within 20 m of the seafloor or as discrete schools located throughout the water column during daylight hours and tended to disperse throughout the water column at night.

In addition to the EIT survey work, a marine mammal sighting survey was conducted by National Marine Mammal Laboratory (NMML) scientists along the eastern EIT survey track (see NMML’s Cetacean Assessment and Ecology Program report in this issue).

By Sarah Stienessen.


Trawl Modifications To Reduce Salmon Bycatch In Pollock Trawls

RACE division scientists teamed up with industry specialists to study ways to reduce salmon bycatch in trawl fisheries for pollock. During the first 2 weeks of September video recordings and sonar observations were made of pollock and salmon behavior using the Vesteraalen. The observations were used to improve several modifications allowing salmon escapes and to select one for subsequent testing.

From 13 to 19 September, the bycatch reduction device was tested under an exempted fishing permit aboard the F/V Auriga. Full-scale pollock trawling was conducted using modified trawl with an auxiliary recapture net to enumerate the number of ‘escaping’ fish. Preliminary results indicate that salmon bycatch was reduced by approximately 12% with less than 2% loss of the targeted pollock. Development and testing will be continued during trials in the winter pollock fishery in January.

By Craig Rose.



RECRUITMENT PROCESSES:

The fall Recruitment Processes cruise was conducted aboard the Miller Freeman during 7-21 September 2003. The cruise was designed to address biological and methodological questions regarding juvenile walleye pollock and other forage fishes in the western Gulf of Alaska.

By Kevin Bailey.


Staff Volunteer at Fishermen’s Festival

RACE and REFM staff members Bob Lauth, Chris Wilson, Sarah Gaichas, Lyle Britt, Jerry Hoff, Ned Laman, Steve Barbeaux, Eric Brown, Rachel Cartwright, Gary Stauffer, and Mark Wilkins each spent Saturday, 13 September, at the Fishermen’s Fall Festival at Fishermen’s Terminal in Seattle, Washington, displaying examples of groundfish species to the festival-goers. For several years the AFSC has teamed with the Deep Sea Fishermen’s Union to bring real fish to the festival. The Center’s booth has been one of the more popular at the event and gives staff a chance to introduce the public to what groundfish are, and to answer questions about the fish and our work to monitor and manage the stocks.

AFSC Quarterly
Research Reports
July-Sept 2003