Science Advisory Report  2011/011

Assessment of Newfoundland and Labrador Snow Crab

Summary

• Total landings increased by 22% from 44,000 t in 2005 to 53,500 t in 2009, but then decreased to 52,200 t in 2010, primarily due to a decrease in Div. 3K.
• The multi-species trawl surveys indicate that the exploitable biomass increased from 2003-2007 due to recovery in the south (Div. 3LNOPs) while the north had decreased (Div. 2HJ3K).  There has since been little change.
• Recruitment increased from 2003-2008 and has since changed little.
• Longer-term recruitment prospects are uncertain.

Division 2H

• Landings declined by 63% from 190 t in 2007 to 70 t in 2010.
• CPUE decreased from 2006-2009 and was unchanged in 2010.
• The exploitable biomass changed little from 2008-2010.  The post-season trawl survey exploitable biomass index peaked in 2006, decreased by 68% to 2008, and remained unchanged in 2010.
• Recruitment has decreased since 2004 and is expected to be low over the next several years.  There were no pre-recruit males captured in the 2010 post-season trawl survey.
• Maintaining the current level of fishery removals would likely result in little change to the exploitation rate in 2011, but would increase the exploitation rate in future years.

Division 2J

• Landings increased by 60% from 1,500 t in 2005 to 2,400 t in 2008.  They decreased by 14% to 2,100 t in 2010.  Effort increased by 27% in 2009 and changed little in 2010.
• CPUE increased from 2004-2007 and changed little until it decreased sharply in 2010.
• The exploitable biomass has decreased in recent years.  The post-season trawl survey exploitable biomass index peaked in 2006, declined to 2009, and changed little in 2010.
• Recruitment has recently declined and is expected to remain low in the short term.  The post-season trawl survey pre-recruit index was exceptionally high in 2004 and has otherwise fluctuated without trend since 1999.
• The exploitation rate index declined between 2003 and 2007 but has since gradually increased.  The pre-recruit fishing mortality index declined sharply between 2003 and 2005, and has since remained low.
• Maintaining the current level of fishery removals would likely have little effect on the exploitation rate in 2011.

Division 3K Offshore

• Landings more than doubled from 6,000 t in 2005 to 12,600 t in 2009 but decreased by 24% to 9,600 t in 2010 (13% below the TAC).  Meanwhile effort changed little until it increased by 73% in 2009 before decreasing by 15% in 2010.
• CPUE declined sharply since 2008.
• The exploitable biomass, as indicated by the post-season trap and trawl survey indices, declined by about half since 2008.
• Recruitment decreased in 2010 and is expected to change little in 2011. Prospects remain poor in the short term. Post-season pre-recruit biomass indices from both trap and trawl surveys have declined by 34-52% respectively since 2008.
• The trawl survey exploitation rate index declined sharply between 2006 and 2009 and has since increased back to the 2006 level.  The pre-recruit fishing mortality index increased from 2006-2009 and changed little in 2010.
• Maintaining the current level of fishery removals would likely result in an increase in the exploitation rate and high mortality on soft-shelled immediate pre-recruits in 2011.

Division 3K Inshore

• Landings increased by 33% from 2700 t in 2005 to 3,600 t, in 2009, but dropped by 22% to 2,800 t in 2010 (16% below the TAC).  Effort has increased by 67% since 2008. 
• CPUE increased sharply from 2005 to a record high level in 2008, but has since declined by half.
• The exploitable biomass, as indicated by the post-season trap survey index, decreased gradually between 2007 and 2010 but there is considerable variability among management areas. 
• Recruitment prospects, as indicated by the post-season trap survey index, have improved slightly, but there is considerable variability among management areas. 
• It was not possible to estimate the exploitation rate index in 2010 because of uncertainty concerning the 2009 exploitable biomass index. Data are insufficient to estimate the pre-recruit fishing mortality index.
• It is not possible to infer how maintaining the current level of removals would affect the exploitation rate in 2011.  However, it would likely result in increased wastage of soft-shelled immediate pre-recruits in 2011.

Division 3LNO Offshore

• Landings remained at 22,000-25,000 t since 2000.  Effort increased steadily from 2000-2008 and has since declined by 16%.
• CPUE declined steadily from 2000-2008, to the lowest level since 1991, but has increased during the past two years.
• The exploitable biomass has recently increased.  Both the trap and trawl survey exploitable biomass indices increased sharply in 2009.  The trap survey index increased further in 2010, while the trawl survey index decreased.  However, both indices remain above 2005-2008 levels.
• Both post-season surveys indicate that recruitment has been recently increasing.  Prospects remain promising for the next two to three years, as both the trap and trawl survey pre-recruit biomass indices have remained at high levels since 2007.
• Both the exploitation rate index and the pre-recruit fishing mortality index peaked in 2008 and have since declined.  The latter index was near its lowest level in 2010.
• Maintaining the current level of removals would likely have little effect on the exploitation rate in 2011.

Division 3L Inshore

• Landings increased by 19% from 6100 t in 2005 to 7,300 t in 2010.  Meanwhile, effort decreased by 23% from 2005-2008, and has subsequently increased by 21%.
• CPUE has changed little during the past four years and remains near the long-term average.
• The post-season trap survey index indicates the exploitable biomass has changed little over the past 7 years.
• Overall, recruitment prospects have recently improved, but there is considerable variability among management areas.
• The exploitation rate index from the post-season trap survey has varied without trend since 2005.  Data are insufficient to estimate pre-recruit fishing mortality index.
• Maintaining the current level of fishery removals would likely result in little change in the exploitation rate, but may increase mortality on soft-shelled immediate pre-recruits in some areas in 2011.

Subdivision 3Ps Offshore

• Landings increased by 70% from 2,300 t in 2006 to 3,900 t in 2010.  Meanwhile effort decreased from 2006 to 2008 and increased slightly to 2010.
• CPUE increased from 2005-2009 and changed little in 2010.
• The exploitable biomass, as indicated by both the spring trawl survey and the post-season trap survey indices, increased steadily from 2006-2009 and decreased slightly in 2010.
• Recruitment appears promising for 2011 but is expected to decline thereafter.
• Exploitation and pre-recruit fishing mortality rates, as indicated by spring trawl survey indices, decreased from 2007-2009 but increased in 2010.
• Maintaining the current level of fishery removals would likely have little effect on the exploitation rate in 2011.

Subdivision 3Ps Inshore

• Landings increased from 700 t in 2005 to 2,200 t in 2010 while effort declined slightly.
• CPUE has increased steadily from 2005 to its highest level since 1996.
• The exploitable biomass, as indicated by the post-season trap survey index, increased substantially between 2006 and 2008 and has since changed little.
• Recruitment has recently increased and prospects for 2011 and 2012 are promising.
• The post-season trap survey-based exploitation rate index changed little during 2008-2010.  Data are insufficient to estimate a pre-recruit fishing mortality index.
• Maintaining the current level of fishery removals would likely have little effect on the exploitation rate in 2011.

Division 4R Offshore

• Landings declined by 83% from 190 t in 2007 to a historical low of 30 t in 2010, while effort declined by 91%.  The TAC has not been taken since 2002.
• CPUE declined slightly from 2006-2009 but increased sharply in 2010.  However, the 2010 increase was associated with a record low level of both landings and effort.
• The exploitable biomass is low as reflected by virtual abandonment of the fishery in recent years. The post-season trap survey index decreased in 2009 and was unchanged in 2010.
• Recruitment has been low in recent years and prospects for the short term are poor.
• The time series of information from the post-season trap survey is insufficient to interpret any trend in the exploitation rate index.  Data are insufficient to calculate a pre-recruit fishing mortality index.
• Maintaining the current level of fishery removals would likely result in little change to the exploitation rate in 2011. 

Division 4R Inshore

• Landings and effort were at historical lows in 2010. Landings declined by 90% from 950 t in 2003 to 190 t in 2010, while effort declined by 60%.  The TAC has not been taken since 2002.
• CPUE declined steadily from 2002 to its lowest level in 2008 and has changed little since.
• The post-season trap survey exploitable biomass index changed little between 2005 and 2009 but increased in some management areas in 2010.
• Recruitment has recently increased.  Prospects remain promising for the next two to three years, but there is considerable variability among management areas. 
• The post-season trap survey exploitation rate index has changed little since 2005.
• Increased fishery removals would not likely increase the exploitation rate in 2011, but may increase mortality on soft-shelled immediate pre-recruits in some management areas.

This Science Advisory Report is from the Fisheries and Oceans Canada, Canadian Science Advisory Secretariat, Regional Advisory Meeting of February 28 – March 4 and March 7 – 11, 2011 on Snow Crab in NAFO Divisions 2HJ3KLNO, Subdivision 3Ps and Division 4R.  Additional publications from this process will be posted as they become available on the DFO Science Advisory Schedule .

Complete document (PDF, 403 KB)

Accessibility Notice

This document is available in PDF format. If the document is not accessible to you, please contact the Secretariat to obtain another appropriate format, such as regular print, large print, Braille or audio version.