December 8, 2004

  IPHC Staff Recommends Preliminary 2005 Fishery Catch Limits

Totaling 73.67 Million Pounds

The International Pacific Halibut Commission (IPHC) and staff have reviewed results of the 2004 Pacific halibut stock assessment.  The resulting staff recommendations totaling 73.67 million pounds are a 3.7% decrease from the 2004 coast-wide catch limit of 76.51 million pounds.  The following table presents the recommendations for 2005 catch limits for each regulatory area, and the 2004 catch limits for comparison.  The Area 2A recommendation includes all removals (commercial, treaty Indian, sport) allocated by the Pacific Fishery Management Council Catch Sharing Plan.  The Area 2B catch limit recommendation includes totals for the Canadian commercial and sport fisheries.  The catch limit adopted at the Annual Meeting will be allocated between the two user groups by the Canadian Department of Fisheries and Oceans.

In making catch limit recommendations for 2005, the staff has considered the results of the analytic assessment, changes in the commercial and survey results used to monitor the stock, recruitment of incoming year classes, and an updated analysis of an appropriate harvest strategy.  Changes in the relative abundance results from our surveys and the commercial fishery, and the choice of an appropriate harvest rate were the primary factors influencing our recommendations for 2005.

Commercial catch rates in 2004 continued their pattern of relative stability in the central Gulf of Alaska and southward with Areas 2B, 2C, and 3A changing by less than ±3%.  The exception was Area 2A where commercial CPUE declined by 23% from the previous year’s value.  Commercial catch rates in Area 2A are a less reliable index of relative abundance because of the 10-hr fishing periods and gear types used for much of the available catch in the area.  In the western areas, commercial catch rates have been declining for the past half decade and continued to decline from 2003 values by approximately 10% in Areas 3B and 4A.  Slight improvements in commercial CPUE from 2003 were observed in Areas 4B (+5%), 4C (+18%), and 4D (+17%).  It should be noted that although the commercial CPUE in Area 4C improved somewhat, the catch limit in this area was not fully caught, as has been the case for the past several years. 

The IPHC setline survey CPUE values for the central Gulf of Alaska and southward increased by 18-22% for Areas 2A, 2B, and 3A but declined by 22% in Area 2C.  For the western Gulf of Alaska and the Bering Sea , survey CPUE decreased by approximately 10% in Areas 3B and 4A but much more sharply at 30-32% for Areas 4B and 4D.  Area 4B survey CPUE in particular has been declining steadily since 1997. 

There were only minor technical changes in the stock assessment analytic model for 2004. The recruitment of the 1994 and 1995 year classes appears to be relatively strong in most areas although Area 4B is showing a notably low level of recruitment in comparison with other regulatory areas.  Estimates of exploitation rate, hence exploitable biomass, derived from mark-recapture analysis of PIT-tagged halibut are not yet used directly for determining recommended catch limits.  The primary tagging took place in 2003 and there are not yet sufficient recoveries of tagged fish, particularly for the western areas, to determine mixing rates among and exploitable biomass within regulatory areas. 

In 2003, the staff evaluated a range of harvest rates for the halibut stock, in conjunction with changes in the assessment model.  At that time, the staff identified a 25% harvest rate as a candidate target rate pending evaluation using the sex-specific population model.  This updated evaluation has been completed and it indicates that a harvest rate less than 25% would result in a lower probability that the stock would require further reductions in harvest rate.  In particular, a harvest rate lower than 25% would reduce this probability by about one-half.  Accordingly, the staff has used a harvest rate of 22.5% as the baseline harvest rate for the central Gulf of Alaska and southward regulatory areas.  For the western Gulf of Alaska (Area 3B) and the Bering Sea (Area 4), the staff is maintaining a 20% harvest rate due to concerns about the long-term productivity of these areas.

The staff continues to recommend a slow rate of increase in catch limits when biomass is increasing and a more rapid reduction of catch limits when biomass is decreasing.  For Areas 2A, 2B, 3B, 4A, and 4B, the estimated exploitable biomass decreased and we recommend catch limits that are 50% of the difference between the 2004 catch limit and the estimated yield from the stock.  The staff continues to be concerned and exercises caution for the western Gulf of Alaska and the Bering Sea regulatory areas.  Accordingly, the staff uses a 20% harvest rate for regulatory Areas 3B and 4.  For Area 4CDE, the staff recommends adopting one-third of the identified increase, the same procedure as used for Areas 2C and 3A.  The staff is concerned in particular about Area 4B, where the relative strength of incoming recruitment is estimated to be lower than in other regulatory areas.  Area 4B may require further decreases in harvest in the future.

These recommendations, along with public and industry views on them, will be considered by IPHC Commissioners and their advisors at the IPHC Annual Meeting in Victoria BC, Canada , during January 18-21, 2005.  These recommendations are preliminary and, as final data are included in the assessment, may be updated for the Annual Meeting but are not expected to change significantly.

Proposals concerning changes to changes to catch limits should be submitted to the Commission by December 31, 2004.  Catch limit proposals are available on the Commission's web page (http://www.iphc.washington.edu/halcom/default.htm) or from the Commission's office. Additional details about the Annual Meeting can also be found on the web page.

IPHC Staff recommendations for 2005 catch limits, by IPHC regulatory area (million lbs, net weight).  The 2004 catch limits are included for reference.

^a  includes sport, tribal and commercial fishery

^b includes sport and commercial fishery

^c Individual catch limits for Areas 4C, 4D, and 4E are determined by the North Pacific Fishery Management Council Catch Sharing Plan