Summary

IDENTIFICATION

SCIENTIFIC NAME

Paralithodes camtschaticus

SPECIES NAME(S)

Red king crab, Камчатский краб

Stock structure of red king crab is still unclear despite innumerous studies conducted in the North Pacific. Seeb and Smith (2005) found that Bristol Bay, Port Moller and Pribilof Islands populations are genetically distinct from Aleutian Islands and Norton Sound what is coincided with the recent conclusion made by Pengilly et al. (2014) that consider that Adak and Norton Sound differ from the SE Bering Sea population. The existence of this latter population is also justified by Grant and Cheng (2012) that according to genetic studies distinguish three major groups: SE Alaska, W of Alaska and SE Bering Sea. However Grant et al. (2011) detected weak genetic structure among Bering Sea, Central Gulf of Alaska and SE Alaska and strong distinction from the Adak Island sample from the remaining samples. Gene flow rates are moderate within the Gulf of Alaska/Western Alaska region and evidence of multiple and distinct populations is higher in SE Alaska making more appropriate a management at a finer-scale in this area (Vulstek et al., 2013). In lack of a clear distribution and distinction of biological populations here we consider 5 assessment units identified under the 3 management registration areas by the North Pacific Fishery Management Council (Zheng and Siddeek, 2013; NPFMC, 2013):
- Aleutian Islands – 1) Adak and 2) Dutch Harbour;
- Bristol Bay – 3) Bristol Bay;
- Bering Sea – 4) Pribilof Islands and 5) Norton Sound.


ANALYSIS

Strengths

Abundance of mature male and female crab in 2007 is at highest level since 1982. Risk-averse harvest strategy is used. Catches have closely tracked catch limits, reflecting strong in-season monitoring, enforcement and compliance. Population level has generally exceeded Bmsy since the late 1990s. Stock assessments are conducted annually and are reviewed by experts. Potential trawl impacts to crab stocks and habitat are limited by extensive closures to groundfish bottom-trawl fishing and bycatch regulation.

Weaknesses

Eastern Bering Sea crab stocks have shown vulnerability to unfavorable environmental conditions. Cumulative mortality from the Bristol Bay fishery’s own substantial bycatch of non-target king crab (females, undersize males) is not completely understood. A sharp decline in St. Matthew Island blue king crabs in the late 1990s remains unexplained. Habitat needs and effects of climate change on these stocks are not fully understood.

SCORES

Management Quality:

Management Strategy:

8.3

Managers Compliance:

10

Fishers Compliance:

9.7

Stock Health:

Current
Health:

7.9

Future Health:

10


RECOMMENDATIONS

CATCHERS & REGULATORS

1. Start a fishery improvement project to address sustainability issues in this fishery. For advice on starting a FIP, see SFP’s Seafood Industry Guide to FIPs at http://www.sustainablefish.org/publications/2014/04/30/the-seafood-industry-guide-to-fips.
2. Communicate to fishery managers that there are sustainability issues in this fishery that may be affecting the sale of products, and request that they comprehensively evaluate and address such issues.

RETAILERS & SUPPLY CHAIN

1. Encourage your supply chain to start a fishery improvement project. For advice on starting a FIP see SFP’s Seafood Industry Guide to FIPs at http://www.sustainablefish.org/publications/2014/04/30/the-seafood-industry-guide-to-fips.
2. Work with other suppliers and buyers on a pre-competitive basis to start a supply chain roundtable to review improvement needs in this and other similar fisheries, catalyze fishery improvement projects, and monitor progress in improvement efforts.


FIPS

No related FIPs

CERTIFICATIONS

No related MSC fisheries

Fisheries

Within FishSource, the term "fishery" is used to indicate each unique combination of a flag country with a fishing gear, operating within a particular management unit, upon a resource. That resource may have a known biological stock structure and/or may be assessed at another level for practical or jurisdictional reasons. A fishery is the finest scale of resolution captured in FishSource profiles, as it is generally the scale at which sustainability can most fairly and practically be evaluated.

ASSESSMENT UNIT MANAGEMENT UNIT FLAG COUNTRY FISHING GEAR
Bristol Bay US Bristol Bay United States Pots

Analysis

OVERVIEW

Last updated on 3 November 2011

Strengths

Abundance of mature male and female crab in 2007 is at highest level since 1982. Risk-averse harvest strategy is used. Catches have closely tracked catch limits, reflecting strong in-season monitoring, enforcement and compliance. Population level has generally exceeded Bmsy since the late 1990s. Stock assessments are conducted annually and are reviewed by experts. Potential trawl impacts to crab stocks and habitat are limited by extensive closures to groundfish bottom-trawl fishing and bycatch regulation.

Weaknesses

Eastern Bering Sea crab stocks have shown vulnerability to unfavorable environmental conditions. Cumulative mortality from the Bristol Bay fishery’s own substantial bycatch of non-target king crab (females, undersize males) is not completely understood. A sharp decline in St. Matthew Island blue king crabs in the late 1990s remains unexplained. Habitat needs and effects of climate change on these stocks are not fully understood.

RECOMMENDATIONS

Last updated on 28 June 2016

Improvement Recommendations to Catchers & Regulators

1. Start a fishery improvement project to address sustainability issues in this fishery. For advice on starting a FIP, see SFP’s Seafood Industry Guide to FIPs at http://www.sustainablefish.org/publications/2014/04/30/the-seafood-industry-guide-to-fips.
2. Communicate to fishery managers that there are sustainability issues in this fishery that may be affecting the sale of products, and request that they comprehensively evaluate and address such issues.

Recommendations to Retailers & Supply Chain

1. Encourage your supply chain to start a fishery improvement project. For advice on starting a FIP see SFP’s Seafood Industry Guide to FIPs at http://www.sustainablefish.org/publications/2014/04/30/the-seafood-industry-guide-to-fips.
2. Work with other suppliers and buyers on a pre-competitive basis to start a supply chain roundtable to review improvement needs in this and other similar fisheries, catalyze fishery improvement projects, and monitor progress in improvement efforts.

1.STOCK STATUS

Stock Assessment

Last updated on 9 August 2013

Length-based stock assessments are conducted annually, using multiple data sources, including fishery-independent annual surveys, catch, observer and processing reports, and cooperative research. Assessments are reviewed by independent experts and the model was updated in 2011. Bycatch mortality from the fishery’s own bycatch of undersized and female crabs (estimated at 4.58% of total removals) is incorporated in TAC recommendations. Bristol Bay is managed and assessed separately from red king crab populations in other parts of the Bering Sea and in the Aleutian Islands. Assessments are conducted by Alaska Department of Fish and Game in consultation with NMFS and scientific advisors to the North Pacific Fishery Management Council.

Current model suffers from a retrospective bias.This bias results in an overestimate of biomass in the terminal year. As such stock status is likely worse then predicted

Scientific Advice

Last updated on 3 November 2011

A conservative harvest control rule reduces exploitation rates when spawning biomass diminishes, and a Minimum Stock Size Threshold (MSST) protects the stock during periods of low abundance. Threshold to open the fishery at low abundance is 8.4 million female crabs and minimum guideline harvest level of 4 million pounds. Several recent studies suggest potentially important future impacts from climate change and ocean acidification (a chemical consequence of anthropogenic CO2 mixing from the atmosphere into seawater), but research to better delineate these risks has not yet been funded.

Reference Points

Last updated on 3 November 2011

Harvest strategy has become more conservative through repeated adjustments since 1990. Several biological thresholds are used for Bristol Bay red king crab.
Minimum effective spawning biomass to open fishery: 14.5 million pounds. Minimum GHL/TAC of legal males to open fishery: 4 million pounds.

Minimum Stock Size Threshold (MSST) = 50% of average spawning biomass for the period 1983-1997, e.g. 44.8 million pounds. Below this level, the stock would be considered overfished.

Target harvest rate on mature male biomass: the rate is stair-stepped according to abundance. Rate is 0% below 14.5 million pounds of Effective Spawning Biomass (ESB), 10% when abundance is above that threshold, 12.5% at when ESB exceeds 34.75 million pounds, and 15% when ESB exceeds 55 million pounds.

Fishing mortality at MSY (Fmsy) functions as a Maximum Fishing Mortality Threshold, and is defined as 0.2 for king crab, with Maximum Sustained Yield (MSY) estimated from the same base period as MSST. This threshold is set to equal a conservative estimate of natural mortality rate.

Current Status

Last updated on 9 August 2013

Current biomass is slightly below target, but substantially above limit reference points.

Trends

Last updated on 9 August 2013

Abundance trends for red king crab reflect sharp fluctuations typical of many invertebrates, but the Bristol Bay stock has been more stable than other crab stocks in the U.S. Bering Sea. However, stock is currently in a downward trend. While exploitation at recent levels is projected not bring the stock to it’s limit reference point, this assumes median recruitment.Over the past 6 years recruitment has been well below average.

It should be noted that projections are based on the current estimate of biomass; which may be more optimistic that actual due to the retrospective bias in the assessment.

2.MANAGEMENT QUALITY

Managers' Decisions
US Bristol Bay

Last updated on

Managers have recently set quotas well below scientific recommendations as a precautionary measure. Bristol Bay red king crab is managed largely by Alaska Department of Fish and Game under a federal fishery management plan maintained by the North Pacific Fishery Management Council (NPFMC) in cooperation with the U.S. National Marine Fisheries Service (NMFS). Most routine management responsibilities are delegated to the State of Alaska, which sets seasons and catch limits. NMFS and the Council retain certain authorities to establish a license limitation program, protect essential fish habitat, and to assure that state harvest rules prevent overfishing. Catch limits are coupled with minimum size limits, a ban on fishing during molting and mating periods, and gear rules to improve survival of discarded crab.
Although bycatch of crabs in trawl gear has been a persistent source of conflict between gear groups, this bycatch is constrained by multiple bottom-trawl closures and typically amounts to 5-10% of the number of king crabs incidentally caught and released by crabbers themselves in the Bering Sea. In 2004 crabbers’ own bycatch accounted for 2,470,000 red king crabs; trawl bycatch was 78,742 (Witherell, Stram, and Pengilly, in 2005 BSAI crab SAFE, p. 5-1).

Recovery Plans

Last updated on 9 August 2013

As the stock was never declared overfished, there is no federal rebuilding plan. However, owing to depressed stock condition, in 1996, a stock rebuilding plan was implemented by the State’s Alaska Board of Fisheries with a rebuilding target of 25,000 tonnes of effective spawning biomass, the biomass of mature females estimated to have been mated in a given year. Key elements of the rebuilding plan include a fishery threshold (6,600 tonnes) – a level of effective spawning biomass (15% of estimated pristine level) below which no fishing is allowed – and a conservative stair-step harvest strategy that established a 10% to 15% exploitation rate of mature males, depending on stock abundance. Concurrent ecosystem-based management approaches by the North Pacific Fishery Management Council included a prohibited species catch limit that constrains king crab bycatch by groundfish trawl and scallop dredge fisheries and a ban of mobile bottom-contact gear from two habitat areas – the Nearshore Bristol Bay Closure Area that protects juvenile crabs and their rearing habitat and an offshore Red King Crab Savings Area that protects adult crabs.

Compliance

Last updated on 9 August 2013

While total harvest has not exceeded scientific recommended removals, Harvesters regulatory exceed the TAC (ACL) by small amounts.

3.ENVIRONMENT AND BIODIVERSITY

ETP Species

Last updated on 3 November 2011

This fishery is not known to have a significant rate of encounters with endangered or protected species. For bowhead whales, an average annual of 0.2 animals per year were reported as entangled in crab gear during 1999-2003 (Alaska Marine Mammal Stock Assessments, NMFS, 2005, p. 196), but it is not known which crab fishery they encountered.

Other Target and Bycatch Species

Last updated on 3 November 2011

In the king crab fishery, bycatch of non-targeted crabs includes females and sub-legal male king crab, and other non-target crabs as well as fish and invertebrates.

Habitat

Last updated on 3 November 2011

Trawl closures and other measures in the eastern Bering Sea have reduced fishing impacts on crab habitat in the area of this fishery. However, Eastern Bering Sea crab stocks have shown vulnerability to environmental variability and climate forcing that can affect survival, especially of young crabs. A depleted blue king crab population west of Bristol Bay at St. Matthew Island and the Pribilof Islands has not recovered, despite directed-fishing closures since 1999 and a trawl closure around the Pribilofs. Possible future effects of climate change and ocean acidification are emerging concerns.

Marine Reserves

Last updated on 2 March 2009

No MPAs, but there are extensive trawl and bottom trawl closures within and around the fishing area.

FishSource Scores

MANAGEMENT QUALITY

As calculated for 2012 data.

This measures the F at low biomass as a percentage of the F management target.

The F at low biomass is 0.140 (from management plan). The F management target is 0.320 .

The underlying F at low biomass/F management target for this index is 43.8%.

As calculated for 2011 data.

This measures the Set TAC as a percentage of the ABC.

The Set TAC is 3.55 ('000 t). The ABC is 7.17 ('000 t) .

The underlying Set TAC/ABC for this index is 49.5%.

As calculated for 2011 data.

This measures the Catch as a percentage of the Set TAC.

The Catch is 3.61 ('000 t). The Set TAC is 3.55 ('000 t) .

The underlying Catch/Set TAC for this index is 102%.

STOCK HEALTH:

As calculated for 2012 data.

This measures the Abundance as a percentage of the 35%B0.

The Abundance is 26.3 (M individuals). The 35%B0 is 27.3 ('000 t) .

The underlying Abundance/35%B0 for this index is 96.4%.

As calculated for 2011 data.

This measures the F as a percentage of the F management target.

The F is 0.130 (age-averaged). The F management target is 0.320 .

The underlying F/F management target for this index is 40.6%.

HUMAN RIGHTS ABUSE RISK

High Medium Low

This indicates the potential risk of human rights abuses within this fishery.

No data available for recruitment
Data notes

Data and landings are on the fishing rather than the calendar year

SSB as Mature Male Biomass

TAC and catch are actually TAL (Total Allowable Landings) and landings. Estimate of discards are available, total catch (landings and discards) have not exceeded the ABC

Download Source Data

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Fishery Improvement Projects (FIPs)

No related FIPs

Certifications

Marine Stewardship Council (MSC)

No related MSC certifications

Sources

Credits
  1. 2006, 2007 BSAI Crab Stock Assessment and Fishery Evaluation reportshttp://www.fakr.noaa.gov/npfmc/SAFE/2007/CRABSAFE07.pdf
  2. Grant, W. S. and Cheng, W. 2012. Incorporating deep and shallow components of genetic structure into the management of Alaskan red king crab, Evol Appl. 5(8): 820–837http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3552400/
  3. Grant, W. S., Merkouris, S. E., Kruse, G. H., and Seeb, L. W. 2011. Low allozyme heterozygosity in North Pacific and Bering Sea populations of red king crab (Paralithodes camtschaticus): adaptive specialization, population bottleneck, or metapopulation structure? – ICES Journal of Marine Sciencehttp://icesjms.oxfordjournals.org/content/early/2011/01/04/icesjms.fsq184.full
  4. Harvest and TAC data from Alaska Department of Fish and Game websitehttp://documents.cf1.adfg.state.ak.us/AdfgDocument.po?DOCUMENT=3350
  5. North Pacific Fishery Management Council, (NPFMC), 2008. Fishery Management Plan for Bering Sea/Aleutian Islands King and Tanner Crabs. North Pacific Fishery Management Council. December 2008. Anchorage, Alaska. 118 pp.http://www.fakr.noaa.gov/npfmc/PDFdocuments/fmp/CRAFMP2008.pdf
  6. North Pacific Fishery Management Council (NPFMC), 2013. Stock Assessment and Fishery Evaluation Report for the king and tanner crab fisheries of the Bering Sea and Aleutian Islands Regions, 2013 Final Crab SAFE, 827pp.http://www.npfmc.org/wp-content/PDFdocuments/resources/SAFE/CrabSAFE/CrabSAFE2013.pdf
  7. Persselin, S, Blue King Crab Ocean Acidification Research, AFSC Quarterly Report of the Resource and Conservation Engineering Division, April-May-June 2007, NMFShttp://www.afsc.noaa.gov/Quarterly/amj2007/divrptsRACE10.htm
  8. Vulstek, S.C., Linderoth, T.P., Guyon, J.R. Tallmon, D.A. 2013. Spatio-temporal population genetic structure and mating system of red king crab (Paralithodes camtschaticus) in Alaska, Journal of Crustacean Biology 33(5): 691–701http://booksandjournals.brillonline.com/content/journals/10.1163/1937240x-00002173
  9. Zheng, J. and Siddeek, M.S.M., 2011. Bristol Bay Red King Crab Stock Assessment in Fall 2011. In: North Pacific Fishery Management Council (ed.) Stock Assessment and Fishery Evaluation Report for the king and tanner crab fisheries of the Bering Sea and Aleutian Islands Regions. Anchorage. p. 169-284.http://www.fakr.noaa.gov/npfmc/PDFdocuments/resources/SAFE/CrabSAFE/CrabSAFE2011.pdf
  10. Zheng, J. and Siddeek, M.S.M., 2012. Bristol Bay Red King Crab Stock Assessment in Fall 2012. In: North Pacific Fishery Management Council (ed.) Stock Assessment and Fishery Evaluation Report for the king and tanner crab fisheries of the Bering Sea and Aleutian Islands Regions. Anchorage.http://alaskafisheries.noaa.gov/npfmc/PDFdocuments/resources/SAFE/CrabSAFE/912Chapters/BBRKC.pdf
  11. Zheng, J. and Siddeek, M.S.M. 2013. Bristol Bay red king crab stock assessment in Fall 2013, Alaska Department of Fish and Game, 174 pp.http://www.npfmc.org/wp-content/PDFdocuments/membership/PlanTeam/Crab/September13/BBRKC.pdf
References

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