scholarly journals Survey estimates of king crab (Paralithodes camtschaticus) abundance off Northern Norway using GLMs within a mixed generalized gamma-binomial model and Bayesian inference

2012 ◽  
Vol 69 (8) ◽  
pp. 1416-1426 ◽  
Author(s):  
C. Hvingel ◽  
M. C. S. Kingsley ◽  
J. H. Sundet

Abstract Hvingel, C., Kingsley, M.C.S., and Sundet, J.H. 2012. Survey estimates of king crab (Paralithodes camtschaticus) abundance off Northern Norway using GLMs within a mixed generalized gamma-binomial model and Bayesian inference. – ICES Journal of Marine Science, 69: . A trawl survey provides information on number and biomass of introduced king crab (Paralithodes camtschaticus) to the management of a fishery off the coast of Northern Norway; the annual catch quotas are largely set as a percentage of the survey estimate. A specially built sledge trawl was designed for the survey. It needs only small areas of trawlable bottom, performs well on a wide range of bottoms, and appears to have good catchability for benthic organisms. Many survey hauls catch no crabs and the non-zero catches have a highly skewed distribution. Data were therefore analysed with a compound model, in which separate predictors were fitted for the proportion of zero catches and for the catch size of the non-zero catches. The compound model was fitted by Bayesian methods using WinBUGS. The distribution of non-zero catches fitted well to a generalized gamma distribution, but with parameter values that made it approximate a lognormal distribution. Numbers of fishable crabs peaked in 2003, and total numbers in 2010 were about two-fifths of the 2003 maximum.

2010 ◽  
Vol 41 (3) ◽  
pp. 467-479 ◽  
Author(s):  
Eivind Oug ◽  
Sabine K. J. Cochrane ◽  
Jan H. Sundet ◽  
Karl Norling ◽  
Hans C. Nilsson

2011 ◽  
Vol 68 (3) ◽  
pp. 479-488 ◽  
Author(s):  
Jannike Falk-Petersen ◽  
Paul Renaud ◽  
Natalia Anisimova

Abstract Falk-Petersen, J., Renaud, P., and Anisimova, N. 2011. Establishment and ecosystem effects of the alien invasive red king crab (Paralithodes camtschaticus) in the Barents Sea – a review. – ICES Journal of Marine Science, 68: . Since its introduction to the Barents Sea from the North Pacific in the 1960s, the red king crab (Paralithodes camtschaticus) has become invasive. The crab represents an important source of income, but also a potential threat to the highly productive fisheries in the region through its ecosystem impacts. A literature review was conducted, identifying factors contributing to the success of the crab as well as its interactions with native biota. Characteristics of the Barents Sea and the crab itself that may explain its success include suitable habitat for settlement and growth of the larvae; the wide range of habitats occupied throughout its life history, high mobility, generalist prey choice, low fishing pressure during establishment, and the lack of parasites. Being a large, bottom-feeding omnivore of great mobility, the king crab can significantly impact the ecosystem. Reduced benthic diversity and biomass have been registered in invaded areas. Important prey items include large epibenthic organisms whose structures also represent important habitat. Impacts on commercial and non-commercial fish species, through egg predation or indirect interactions, are difficult to detect and predict.


2021 ◽  
Vol 240 ◽  
pp. 105964
Author(s):  
Cory Lescher ◽  
Noëlle Yochum ◽  
Brad Harris ◽  
Nathan Wolf ◽  
John Gauvin

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.


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