An Assessment of Stock Status of the Greenland Halibut Resource in NAFO Subarea 2 and Divisions 3KLMNO based on Extended Survivors Analysis.

• Main Authors: Jean-claude Mahé, W. R. Bowering
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 2002
• Subjects: Greenland
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.556.317; http://archive.nafo.int/open/sc/2002/scr02-078.pdf

An Extended Survivors Analysis was applied to the commercial catch at age data for Greenland Halibut in NAFO Subarea 2 and Divisions 3KLMNO from 1975-2001 to assess the current status of the stock. The analysis was calibrated using Canadian and European Union research vessel survey data. Stock biomass at ages 5 and older is estimated to have increased during the late 1980's and then declined rapidly during the period of high landings in the early 1990's. Estimated fishing mortality has followed the trend in landings, increasing rapidly in the early 1990's, remaining high as the stock was reduced to its historic lows and then declining to the low levels recorded during 1985–1990. The reduction in exploitation has resulted from both a decrease in the recorded landings and an increase in biomass following the better than average recruitment of the 1993-1995 year-classes. However, the assessment is considered to be very uncertain with respect to absolute estimates of stock size and it does not match the historic trends in the stock as illustrated by the longest survey series. The increasing trend in the late 1990s is believed to be reflective of the stock trajectory during that period, however, the continued increasing trend since then is inconsistent with the trends in stock size from all other major sources. Given these concerns, the assessment in its present form therefore is considered unreliable for projecting future stock trends and potential catch levels. Data