Monster Seminar JAM - Accounting for pinniped predation in fisheries stock assessment: implications for the recovery of B.C. inside waters yelloweye rockfish (Sebastes ruberrimus)
Dr. Murdoch K. McAllister, Fisheries Centre, University of British Columbia
Many B.C. rockfish populations have undergone pronounced declines in the last several decades largely due to episodic high fishing mortality rates. In contrast, B.C. pinniped populations have shown marked increases since the implementation of Canadian Marine Mammal Protection Laws in the early 1970s. Strait of Georgia harbour seals (Phoca vitulina richardsi), for example, have increased from about 3,500 animals in the 1970s to currently about 42,000 animals. Diet studies indicate that rockfishes form only a small fraction of the diet of B.C. pinnipeds. However, the high annual total rates of consumption per animal and current high abundance of pinnipeds in B.C. waters suggest that predation rates on B.C. rockfishes may have increased substantially over the last few decades. In this talk, I present adaptations of a stock assessment model for B.C. inside waters yelloweye rockfish (Sebastes ruberrimus) that accounts for variations in predation since the early 1900s and assesses the implications of current trends in pinniped abundance for rockfish population recovery.
Date and Time:
March 11, 2010,
11:00 am - 12:00 pm