Status of Stocks & Multispecies Assessment Program
FIT Staff Conduct Successful
Atka Mackerel Tag Release Cruise in the Aleutian Islands
A tagged Atka mackerel ready to be released.
Scientists Peter Munro, Joe Collins, and Lynn Lee tag Atka mackerel and record their lengths.
Fisheries Interaction Team (FIT) staff conducted an Atka mackerel tag release cruise from 15 May to 5 June in the Central Aleutian Islands region. The first objective of the cruise, conducted aboard the chartered fishing vessel Pacific Explorer, was to assess the local abundance and movement of Atka mackerel by tagging and releasing fish in the Central Aleutians (Tanaga Island and Petrel Bank) and at Seguam Pass. Approximately 8,500 fish were tagged and released at Seguam Pass; 9,000 at Tanaga Island; and 10,000 at Petrel Bank; for a grand total of nearly 28,000 tagged fish (Fig. 6). Secondary objectives included conducting a tag-mortality study and other biological projects such as collecting gonads and otoliths. Another objective was to characterize Atka mackerel habitat by taking oceanographic samples and conducting underwater camera tows at each area where fish were tagged and released. Tagged fish will be recovered by the commercial fishery and during a chartered tag recovery cruise in August 2011.
The goal of FIT’s ongoing tag release-recovery studies is to determine the efficacy of trawl exclusion zones as a management tool to maintain prey abundance and availability for Steller sea lions at local scales. Trawl exclusion zones were established around sea lion rookeries as a precautionary measure to protect critical sea lion habitat, including local populations of prey such as Atka mackerel. Localized fishing may affect Atka mackerel abundance and distribution near sea lion rookeries. Tagging experiments are being used to estimate abundance and movement between areas open and closed to the Atka mackerel fishery.
Figure 6. Map showing areas where Atka mackerel were tagged and released: Seguam Pass, Tanaga Island, and Petrel Bank, Alaska.
