Monitoring Update of the Roughhead Grenadier Stock Assessment in NAFO Subareas 2 and 3

The revised catch history after 1987 is presented, total SA 2+3 roughhead grenadier catch in 2000 was 4767 tons. The trends in biomass estimates from four survey series are examined: Canadian fall, Canadian spring, Spanish spring 3NO and EU summer 3M. Only the Canadian fall surveys are considered to...

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Bibliographic Details
Main Authors: Junquera, Susana, Murua, Hilario, Patterson, Kenneth
Format: Report
Language:English
Published: 2001
Subjects:
Online Access:http://hdl.handle.net/10508/883
http://hdl.handle.net/10261/328647
Description
Summary:The revised catch history after 1987 is presented, total SA 2+3 roughhead grenadier catch in 2000 was 4767 tons. The trends in biomass estimates from four survey series are examined: Canadian fall, Canadian spring, Spanish spring 3NO and EU summer 3M. Only the Canadian fall surveys are considered to cover adequately the species distribution range. The biomass index from this survey in 2000 was 29139 t , 36 % of it in Div. 3L. Commercial catch include mainly ages between 5 and 10, with a peak at age 6. An age structured production model has been performed as a trial. The result of it indicate a moderate decrease in the total biomass but a sharp decrease in SSB. The F reference obtained is 0.41. The C/ B index using data from the Canadian fall survey is 0.16 (C/B1999 = 0.27).