Pacific Halibut Bycatch in IPHC Area 2A

Abstract

This report updates the estimates of Pacific halibut bycatch and mortality in the portion of the limited-entry groundfish bottom trawl fishery that operates between 48˚.667 and 40˚.667 degrees through the calendar year 2008. The estimates of halibut bycatch and mortality in the bottom trawl fishery are based upon the method developed in the report for 1999 (Wallace, 2000). The current report uses halibut bycatch rates observed during the 2008 calendar year by the West Coast Groundfish Observer Program (WCGOP). These rates are stratified by season, depth, latitude, and amount of arrowtooth flounder catch, and then multiplied by the amount of 2008 trawl effort (hours towed) in each stratum determined from Oregon and Washington trawl logbooks. Estimated halibut bycatch and mortality from other gear types targeting groundfish has not been updated for 2008 at this time. As was done for the first time last year, this analysis continues to use the WCGOP observations of the viability of discarded halibut for determining the mortality rates used in calculating the amounts of mortality. In 2008, the amount of bottom trawl effort increased by 23 % relative to 2007, and effort continued to shift to depths seaward of the RCA. The total amount of halibut bycatch (437,689 lb) represents a 35 % increase over 2007