1.0 Background

• Main Author: Christopher M. Legault
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Garm; Northwest Atlantic
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.224.8184; http://nefsc.noaa.gov/publications/crd/crd1206/at.halibut.pdf

Atlantic halibut (Hippoglossus hippoglossus) is the largest species of flatfish in the northwest Atlantic Ocean. It is a long-lived, late-maturing species distributed from Labrador to southern New England (Bigelow and Schroeder 1953). Within the Gulf of Maine-Georges Bank region (NAFO Divisions 5Y and 5Z, Figure M1) halibut have been exploited since the early 1800s, with major abundance declines noted as early as the 1870s (Goode 1884, Grasso 2008). Atlantic halibut was assessed in 2002 and 2005 using index-based methods (Brodziak 2002, Brodziak and Col 2005). Northeast Fisheries Science Center (NEFSC) autumn weight per tow survey indices were expanded to swept-area biomass estimates (assuming a catchability coefficient of one), and the 5-year average biomass index was compared to BMSY proxy reference points for status determination (Col and Legault 2009). Based on the 2005 Groundfish Assessment Review Meeting (GARM) assessment of Gulf of Maine-Georges Bank Atlantic halibut, the stock was overfished (B2004 was 5 % of BMSY proxy) and it was unknown whether overfishing was occurring (Brodziak and Col 2005). During the 2008 GARM, halibut was assessed using a simple production model called Replacement Yield Model (Col and Legault 2009) enabling overfishing status to be determined for the first time. The fishing mortality