A Computer Technique for Estimating the Size of Sexual Maturity in Crabs

1980 ◽  
Vol 37 (10) ◽  
pp. 1488-1494 ◽  
Author(s):  
D. A. Somerton
Keyword(s):  
Bering Sea ◽  
Sexual Maturity ◽  
Carapace Width ◽  
Logistic Function ◽  
Body Dimension ◽  
Computer Technique ◽  
Eastern Bering Sea ◽  
Paralithodes Camtschatica ◽  
Chionoecetes Bairdi ◽  
Size Estimates

A new computer technique for estimating the size of 50% sexual maturity from crab morphometric data is described. Using nonhierarchical cluster analysis, crabs are assigned to either of two maturity groups based on the size of one body dimension relative to another. The size of 50% maturity is then estimated by using nonlinear regression to fit a logistic function to percent maturity and size estimates. The size of 50% maturity in the eastern Bering Sea was estimated to be 102.8 and 101.9 mm (carapace length) for male and female Paralithodes camtschatica and 114.7 mm (carapace width) for male Chionoecetes bairdi. These estimates are similar to estimates for these species obtained previously by other techniques.Key words: crabs, growth, sexual maturity, Paralithodes, Chionoecetes

Regional Variation in the Size of Maturity of Two Species of Tanner Crab (Chionoecetes bairdi and C. opilio) in the Eastern Bering Sea, and Its Use in Defining Management Subareas

1981 ◽  
Vol 38 (2) ◽  
pp. 163-174 ◽  
Author(s):  
David A. Somerton
Keyword(s):  
Bering Sea ◽  
Regional Variation ◽  
Carapace Width ◽  
Minimum Size ◽  
Computer Technique ◽  
Eastern Bering Sea ◽  
Commercial Harvest ◽  
Tanner Crab ◽  
Size Limits ◽  
Chionoecetes Bairdi

Minimum size limits for the commercial harvest of tanner crab (Chionoecetes bairdi and C. opilio) are based on the sizes of sexual maturity. Establishing such size limits in the eastern Bering Sea is complicated by a large regional variation in the size of maturity. A computer technique was developed which partitioned the eastern Bering Sea into subareas that were relatively homogeneous with respect to the size of maturity. The best partitioning for C. bairdi was a separation of the eastern Bering Sea into two subareas along 167°15′N longitude. No acceptable partitioning could be found for C. opilio. The size of 50% maturity for male C. bairdi was estimated to be 108.9 mm carapace width in the western subarea and 117.0 mm in the eastern subarea. The size of maturity upon which the current minimum size for C. bairdi is based is nearly the same as the size estimated for the western subarea but significantly less than the size estimated for the eastern subarea.Key words: crabs, size of maturity, Chionoecetes bairdi, Chionoecetes opilio, tanner crab, eastern Bering Sea

Patterns in connectivity and retention of simulated Tanner crab (Chionoecetes bairdi) larvae in the eastern Bering Sea

2015 ◽  
Vol 138 ◽  
pp. 475-485 ◽  
Author(s):  
Jonathan I. Richar ◽  
Gordon H. Kruse ◽  
Enrique Curchitser ◽  
Albert J. Hermann
Keyword(s):  
Bering Sea ◽  
Eastern Bering Sea ◽  
Tanner Crab ◽  
Chionoecetes Bairdi

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
Keyword(s):  
Bering Sea ◽  
Published Data ◽  
Red King Crab ◽  
Sea Temperature ◽  
King Crab ◽  
Recruitment Failure ◽  
Eastern Bering Sea ◽  
Paralithodes Camtschatica ◽  
Size Interval ◽  
Size At Age

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.

scholarly journals Effect of bitter crab disease on rebuilding in Alaska Tanner crab stocks

2010 ◽  
Vol 67 (9) ◽  
pp. 2027-2032 ◽  
Author(s):  
M. Shareef M. Siddeek ◽  
Jie Zheng ◽  
Joseph F. Morado ◽  
Gordon H. Kruse ◽  
William R. Bechtol
Keyword(s):  
Bering Sea ◽  
Potential Effect ◽  
Management Plan ◽  
Reference Points ◽  
Commercial Fishing ◽  
Southeast Alaska ◽  
Control Rules ◽  
Eastern Bering Sea ◽  
Tanner Crab ◽  
Chionoecetes Bairdi

Abstract Siddeek, M. S. M., Zheng, J., Morado, J. F., Kruse, G. H., and Bechtol, W. R. 2010. Effect of bitter crab disease on rebuilding in Alaska Tanner crab stocks. – ICES Journal of Marine Science, 67: 2027–2032. Eastern Bering Sea (EBS) Tanner crab Chionoecetes bairdi stocks were declared overfished in 1996 and were closed to commercial fishing between 1997 and 2004. Subsequent management was based on a rebuilding plan using criteria from the previous US federal fisheries management plan (FMP). Under the revised 2008 FMP, reference points changed for mature biomass (male only vs. total), as well as catch levels (total vs. retained), resulting in different rebuilding criteria. We performed a rebuilding analysis using age-, sex-, and size-structured simulations incorporating recent changes in overfishing definitions. Specifically, we compared the potential effect of additional mortality that bitter crab disease could have on rebuilding performance of lightly infected EBS and heavily infected southeast Alaska Tanner crab stocks. The results suggest that under the assumed recruitment scenario, the new control rules are adequate to rebuild the depleted lightly infected EBS stock, but not the heavily infected southeast Alaska stock.

A Cost-Benefit Method for Determining Optimum Closed Fishing Areas to Reduce the Trawl Catch of Prohibited Species

1984 ◽  
Vol 41 (1) ◽  
pp. 93-98 ◽  
Author(s):  
David A. Somerton ◽  
Jeffrey June
Keyword(s):  
Bering Sea ◽  
Cost Benefit ◽  
King Crab ◽  
Research Survey ◽  
Eastern Bering Sea ◽  
Yellowfin Sole ◽  
Survey Estimates ◽  
Paralithodes Camtschatica ◽  
Limanda Aspera ◽  
Trawl Fisheries

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.

Relation of Number of Eggs and Egg Length to Carapace Width in the Brachyuran Crabs Chionoecetes bairdi and C. opilio from the Southeastern Bering Sea and C. opilio from the Gulf of St. Lawrence

1976 ◽  
Vol 33 (11) ◽  
pp. 2592-2595 ◽  
Author(s):  
Evan Haynes ◽  
John F. Karinen ◽  
Jeffrey Watson ◽  
Daniel J. Hopson
Keyword(s):  
Bering Sea ◽  
Carapace Width ◽  
Reproductive Potential ◽  
Relative Number ◽  
Chionoecetes Opilio ◽  
Adult Females ◽  
Brachyuran Crabs ◽  
Chionoecetes Bairdi ◽  
First Time ◽  
The Bering Sea

The number of eggs attached to pleopods of Chionoecetes bairdi and C. opilio from the southeastern Bering Sea increased at a rate proportional to about the 3.4 and 2.7 power of carapace width, respectively, but for C. opilio from the Gulf of St. Lawrence it increased to the 4.2 power. The range in carapace width and number of eggs for crabs from the Bering Sea of a given carapace width were considerably greater for C. bairdi than for C. opilio. In the southeastern Bering Sea, the reproductive potential for adult females of C. bairdi with mixed spawning history is approximately 4 times greater than that of C. opilio spawning for the first time. Chionoecetes opilio females with mixed spawning history in the Gulf of St. Lawrence carry more eggs for a given carapace width than first-time spawners from the southeastern Bering Sea. Our data were not sufficient to resolve the question of relative number of eggs for crabs of various ages.

The physiological adaptations and toxin profiles of the toxic Alexandrium fundyense on the eastern Bering Sea and Chukchi Sea shelves

Harmful Algae ◽  
2017 ◽  
Vol 63 ◽  
pp. 13-22 ◽  
Author(s):  
Masafumi Natsuike ◽  
Hiroshi Oikawa ◽  
Kohei Matsuno ◽  
Atsushi Yamaguchi ◽  
Ichiro Imai
Keyword(s):  
Bering Sea ◽  
Chukchi Sea ◽  
Alexandrium Fundyense ◽  
Eastern Bering Sea ◽  
Physiological Adaptations

scholarly journals Predicted shifts of groundfish distribution in the Eastern Bering Sea under climate change, with implications for fish populations and fisheries management

2020 ◽  
Author(s):  
Christopher N Rooper ◽  
Ivonne Ortiz ◽  
Albert J Hermann ◽  
Ned Laman ◽  
Wei Cheng ◽  
...  
Keyword(s):  
Bering Sea ◽  
Marine Species ◽  
Species Distribution Modelling ◽  
Fish Populations ◽  
Trawl Survey ◽  
Climate Scenarios ◽  
Important Species ◽  
Eastern Bering Sea ◽  
Northern Latitudes ◽  
Distribution Shifts

Abstract Climate-related distribution shifts for marine species are, in general, amplified in northern latitudes. The objective of this study was to predict future distributions of commercially important species in the eastern Bering Sea under six climate scenarios, by incorporating predictions of future oceanographic conditions. We used species distribution modelling to determine potential distribution changes in four time periods (2013–2017, 2030–2039, 2060–2069, and 2090-2099) relative to 1982–2012 for 16 marine fish and invertebrates. Most species were predicted to have significant shifts in the centre of gravity of the predicted abundance, the area occupied, and the proportion of the predicted abundance found in the standard bottom trawl survey area. On average the shifts were modest, averaging 35.2 km (ranging from 1 to 202 km). There were significant differences in the predicted trend for distribution metrics among climate scenarios, with the most extensive changes in distribution resulting from Representative Concentration Pathway 8.5 climate scenarios. The variability in distributional shifts among years and climate scenarios was high, although the magnitudes were low. This study provides a basis for understanding where fish populations might expand or contract in future years. This will provide managers’ information that can help guide appropriate actions under warming conditions.

The Food of Fur Seals in the Eastern Bering Sea

1957 ◽  
Vol 21 (2) ◽  
pp. 237 ◽  
Author(s):  
Ford Wilke ◽  
Karl W. Kenyon
Keyword(s):  
Bering Sea ◽  
Eastern Bering Sea ◽  
Fur Seals
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