Temperature-Dependent Growth of Juvenile Red King Crab (Paralithodes camtschatica) and its Effects on Size-at-Age and Subsequent Recruitment in the Eastern Bering Sea

1990 ◽  
Vol 47 (7) ◽  
pp. 1307-1317 ◽  
Author(s):  
Bradley G. Stevens

A temperature-based growth relationship was derived for juvenile red king crab (Paralithodes camtschatica) from published data. Growth of annual cohorts of crab was simulated at various locations in Bristol Bay, AK, using long-term water temperature observations, and the resulting mean sizes were compared with those observed by the annual National Marine Fisheries Service eastern Bering Sea crab survey. Results indicate that mean age-at-recruitment is 3–5 yr greater than previously estimated, and has decreased from 9.5 to 7.5 yr over the past decade as a result of increasing sea temperature. Single year-classes require 3–5 yr for complete recruitment to the 'mature' size interval, and recruitment in any year may consist of crabs from four to five year-classes. The high landings and subsequent crash of the Bering Sea red king crab population during the late 1970's probably originated from one or more adjacent strong year-classes in the late 1960's which recruited over a period of several years, followed by a period of recruitment failure and high mortality. Future stock–recruitment studies should account for the effects of multi-year recruitment and year-class overlap.

1984 ◽  
Vol 41 (1) ◽  
pp. 93-98 ◽  
Author(s):  
David A. Somerton ◽  
Jeffrey June

Red king crab (Paralithodes camtschatica), a prohibited species, are incidentally caught by United States trawl fisheries for yellowfin sole (Limanda aspera) and other groundfish in the eastern Bering Sea. To reduce this incidental catch, we propose a method for determining a king crab conservation zone where trawling would be prohibited. This method considers the gross revenue potentially gained by the yellowfin sole fishery and lost by the king crab fishery by allowing trawling in each of a number of equal-size areas. Utilizing exvessel prices and research survey estimates of species densities, areas are assigned relative values equal to the value of groundfish minus the value of king crab. By including all areas with negative relative values in the conservation zone, the potential gross revenue that could be obtained from the groundfish and king crab resource is maximized.


1993 ◽  
Vol 50 (9) ◽  
pp. 1993-2000 ◽  
Author(s):  
David A. Armstrong ◽  
Thomas C. Wainwright ◽  
Gregory C. Jensen ◽  
Paul A. Dinnel ◽  
Helle B. Andersen

Concerns about possibly heavy impacts of bottom trawl fisheries on red king crab (Paralithodes camtschaticus) pot fisheries in the eastern Bering Sea led in 1987 to an emergency closure of trawling in an area of adult and juvenile crab habitat. We examine the effectiveness of this bycatch refuge in protecting and possibly enhancing the crab resource using three approaches. First, bycatch of crab in trawl fisheries is a small proportion of total estimated abundance throughout the southeastern Bering Sea but may be high relative to stock abundance within the closed area and relative to annual crab landings; recent regulations have diminished this apparent effect. Effects of direct bycatch on the stock are obscured by lack of evidence on indirect effects of trawling, including crushing of crab and degredation of juvenile habitat. Second, surveys inside and outside the refuge before and after closure show no significant changes in abundance of female and prerecruit male crab. Third, important breeding and hatching grounds and juvenile habitat are not protected by the refuge, leaving long-term stock renewal subject to trawl impacts. We suggest that full consideration of the needs of all life history stages could lead to a more effective refuge design.


2011 ◽  
Vol 68 (3) ◽  
pp. 499-506 ◽  
Author(s):  
W. Stewart Grant ◽  
Susan E. Merkouris ◽  
Gordon H. Kruse ◽  
Lisa W. Seeb

AbstractGrant, 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 Science, 68: . Populations of red king crab in the North Pacific and Bering Sea have declined in response to ocean-climate shifts and to harvesting. An understanding of how populations are geographically structured is important to the management of these depressed resources. Here, the Mendelian variability at 38 enzyme-encoding loci was surveyed in 27 samples (n = 2427) from 18 general locations. Sample heterozygosities were low, averaging HE = 0.015 among samples. Weak genetic structure was detected among three groups of populations, the Bering Sea, central Gulf of Alaska, and Southeast Alaska, but without significant isolation by distance among populations. A sample from Adak Island in the western Aleutians was genetically different from the remaining samples. The lack of differentiation among populations within regions may, in part, be due to post-glacial expansions and a lack of migration-drift equilibrium and to limited statistical power imposed by low levels of polymorphism. Departures from neutrality may reflect the effects of both selective and historical factors. The low allozyme diversity in red king crab may, in part, be attributable to adaptive specialization, background selection, ice-age population bottlenecks, or metapopulation dynamics in a climatically unstable North Pacific.


Author(s):  
Cody Szuwalski ◽  
Wei Cheng ◽  
Robert Foy ◽  
Albert J Hermann ◽  
Anne Hollowed ◽  
...  

Abstract Crab populations in the eastern Bering Sea support some of the most valuable fisheries in the United States, but their future productivity and distribution are uncertain. We explore observed changes in the productivity and distribution for snow crab, Tanner crab, and Bristol Bay red king crab. We link historical indices of environmental variation and predator biomass with observed time series of centroids of abundance and extent of crab stock distribution; we also fit stock–recruit curves including environmental indices for each stock. We then project these relationships under forcing from global climate models to forecast potential productivity and distribution scenarios. Our results suggest that the productivity of snow crab is negatively related to the Arctic Oscillation (AO) and positively related to ice cover; Tanner crab’s productivity and distribution are negatively associated with cod biomass and sea surface temperature. Aspects of red king crab distribution and productivity appear to be related to bottom temperature, ice cover, the AO, and/or cod biomass. Projecting these relationships forward with available forecasts suggests that Tanner crab may become more productive and shift further offshore, red king crab distribution may contract and move north, and productivity may decrease for snow crab as the population contracts northward.


1991 ◽  
Vol 48 (4) ◽  
pp. 559-568 ◽  
Author(s):  
Armand M. Kuris ◽  
S. Forrest Blau ◽  
A. J. Paul ◽  
Jeffrey D. Shields ◽  
Daniel E. Wickham

Egg masses of 772 red king crab, Paralithodes camtschatica, were sampled to determine the prevalence, intensity, and patterns of cooccurrence of brood symbionts from 28 Alaskan localities. Carcinonemertes regicides and three other undescribed nemertean egg predators were recovered from many localities, as were an undescribed turbellarian and an amphipod, Ischyrocerus sp. A widespread outbreak of nemerteans occurred in the 1983–84 and 1984–85 red king crab brooding seasons. At some locations, nearly all of the eggs were consumed in the 1983–84 brood season. Feeding of C. regicides on eggs was documented in vitro and these worms caused substantial egg mortality at many locations. The amphipod was also an egg predator and may have had a significant impact at three locations. The turbellarian did not kill eggs. From the seasonal pattern of C. regicides infestation at Kachemak Bay, we postulate an abbreviated life cycle and autoinfection for C. regicides. Such life history features may have contributed to the peak intensities observed late in the 1983–84 and 1984–85 brooding seasons. At some localities, heavy brood mortality may reduce or eliminate recruitment of some year classes to the fishery.


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