1999 

 OUR LIVING OCEANS 



Landings 

 (x 1,000 tl 



Total landings 



I 



_L. 



77 78 79 80 81 82 83 



Figure 19-1 



Landings and abundance of 

 Pacific halibut in metric tons 

 (t). 



86 85 87 88 

 Year 



90 91 92 93 94 95 96 97 



commercial fisheries (39,240 t), recreational fish- 

 eries (S,050 t), personal use (32S t), bycatch in 

 other fisheries (7,975 t), and mortality due to fish- 

 ing by lost gear and discards (1,1 30 t). 



The nature of the commercial fisheries has 

 changed dramatically in recent years. Both Cana- 

 dian and Alaskan halibut fisheries have moved 

 fi'om an open-access fishery with short fishing sea- 

 sons to an individual fishing quota (IFQ) fishery 

 of nearly 8 month's duration. In addition, IFQ 

 share allocations have also been implemented tor 

 Treaty Indian, connnercial, and recreational fish- 

 eries for the Washington-C'alitornia region. Un- 

 der such a tight allocation of quota shares, there 

 has been a decline in overall size of the fishing 

 fleet. Vessels licensed to fish in Canada remained 

 at 435, while 2,000 vessels fished in the U.S. fish- 

 eries in 1997, down from 3,400 vessels in 1993. 



The assessment of Pacific halibut stocks was 



radically revised in 1996 due to a revelation that 

 changes in individual growth rates have affected 

 fishing selectivity by the gear. The new approach 

 (Sulliv.m and P.irma. 1998) takes a model for 

 growth, additional information from surveys and 

 bycatch observations, and brings in commercial 

 catch-at-age and catch-per-unit-effort (CPUE) 

 data to determine the current and historical status 

 of the population. The approach also considers un- 

 certainties with selectivity by age versus length that 

 resulted in two biomass estimates for each year. 

 The IPHC concluded that the true biomass lies 

 between the two estimates. However, tor the pur- 

 pose of being precautionary, the lower of the bio- 

 mass estimates for the main range of Pacific hali- 

 but (Gulf of Alaska, C^anada, and Washington- 

 California) is shown in Figure 19-1. 



The exploitable portion of the Pacific halibut 

 stocks apparently peaked at 360,000 t in 1988 

 (Figure 19-1). The population has since declined 

 slightly to a rather constant biomass level of 

 298,000-305,000 t over the past 5 years. The long- 

 term average reproductive biomass for the resource 

 was estimated at 130,000 t (Parma, 1998). Long- 

 term average yield (equivalent to the long-term 

 potential yield) was estimated by Parma (1998) at 

 29,750 t, round weight. The species is fully uti- 

 lized. The recent average yield (1995-97) was 

 38,180 t for the United States and 7,710 t for 

 Canada, tor a combined total of 45,890 t for the 

 entire Pacific halibut resource. This recent aver- 

 age yield was 6% higher than the estimated long- 

 term potential yield, which reflected good condi- 

 tion of the underlying resource. The values for re- 

 cent average yield and current potential yield 

 shown in lable 1 9- 1 are for all catches — commer- 

 cial, recreational, bycatch, and waste. 



Table 19-1 



Productivity in metric tons 

 and status of Pacific halibut 

 resources. 



202 



