Lack of Genetic Stock Discretion in Pacific Cod (Gadus macrocephalus)

1987 ◽  
Vol 44 (3) ◽  
pp. 490-498 ◽  
Author(s):  
W. Stewart Grant ◽  
Chang Ik Zhang ◽  
Tokimasa Kobayashi ◽  
Gunnar Ståhl
Keyword(s):  
Pacific Ocean ◽  
Bering Sea ◽  
Yellow Sea ◽  
North Pacific ◽  
Gene Diversity ◽  
North Pacific Ocean ◽  
The Yellow Sea ◽  
Pacific Cod ◽  
Pacific Cod Gadus Macrocephalus ◽  
Gadus Macrocephalus

We examined the ocean-wide genetic population structure of Pacific cod (Gadus macrocephalus) using electrophoretically detectable population markers at 41 protein loci. Samples were collected at 11 locations extending over most of the species's range from the Yellow Sea, Korea, to Puget Sound, Washington. Seven loci (17%) were polymorphic using the 0.05 criterion of polymorphism. Sample heterozygosities ranged from 0.018 to 0.041 and averaged 0.025 (±0.013). Two major genetic groups were detected: a western North Pacific Ocean (Asian) group and an eastern North Pacific group (including Bering Sea stocks). The UPGMA Nei genetic distance, D, (based on 41 loci) between samples from these two groups was 0.025, and this subdivision accounted for 18.9% of the total gene diversity. Genetic differentiation between these two groups appears to reflect the barrier effects of coastal Pleistocene glaciation. Morphological and tagging data from other studies suggest that Pacific cod are subdivided into several independent stocks. In this study, significant allele-frequency differences were detected between samples within the eastern North Pacific Ocean, the Bering Sea, and the western North Pacific Ocean, but not between stocks on a larger geographic scale. The average Nei genetic distance (based on 41 loci) between samples was only 0.0007, and a gene diversity analysis indicated that within-region differences represented only 3.1% of the total gene diversity. There was a slightly greater amount of differentiation between the Yellow Sea and the Sea of Japan (D = 0.0041), which reflects geographic isolation of the Yellow Sea stock not found in other areas. From theoretical considerations, little genetic divergence between stocks of Pacific Cod is expected because random genetic drift in large population sizes is insignificant and because migration between areas prevents genetic differentiation.

scholarly journals Do Pacific cod (Gadus macrocephalus) and walleye pollock (Theregra chalcogramma) lack a herding response to the doors, bridles, and mudclouds of survey trawls?

2004 ◽  
Vol 61 (7) ◽  
pp. 1186-1189 ◽  
Author(s):  
David A. Somerton
Keyword(s):  
Pacific Ocean ◽  
North Pacific ◽  
North Pacific Ocean ◽  
Walleye Pollock ◽  
Pacific Cod ◽  
The North ◽  
Pacific Cod Gadus Macrocephalus ◽  
Gadus Macrocephalus ◽  
The North Pacific ◽  
Trawl Surveys

Abstract Pacific cod and walleye pollock were subjected to herding experiments in which trawl hauls are conducted repeatedly in an area with the bridles varied among three distinct lengths. For the flatfishes in these studies, catch per unit of area swept (cpue) by the trawls increased greatly with increasing bridle length, indicating that flatfish are stimulated to herd into the path of the net by the action of the bridles. In contrast, the cpue of Pacific cod and walleye pollock did not increase significantly with increasing bridle length. This lack of significance indicates that these two species respond only weakly to any herding stimuli produced by the 83–112 Eastern and Poly Nor'eastern trawls used to conduct groundfish trawl surveys in the North Pacific Ocean.

Genetic isolation by distance and localized fjord population structure in Pacific cod (Gadus macrocephalus): limited effective dispersal in the northeastern Pacific Ocean

2009 ◽  
Vol 66 (1) ◽  
pp. 153-166 ◽  
Author(s):  
Kathryn Maja Cunningham ◽  
Michael Francis Canino ◽  
Ingrid Brigette Spies ◽  
Lorenz Hauser
Keyword(s):  
Population Structure ◽  
Pacific Ocean ◽  
Isolation By Distance ◽  
Spatial Scales ◽  
Puget Sound ◽  
Pacific Cod ◽  
Genetic Population ◽  
Pacific Cod Gadus Macrocephalus ◽  
Gadus Macrocephalus ◽  
Northeastern Pacific

Genetic population structure of Pacific cod, Gadus macrocephalus , was examined across much of its northeastern Pacific range by screening variation at 11 microsatellite DNA loci. Estimates of FST (0.005 ± 0.002) and RST (0.010 ± 0.003) over all samples suggested that effective dispersal is limited among populations. Genetic divergence was highly correlated with geographic distance in an isolation-by-distance (IBD) pattern along the entire coastal continuum in the northeastern Pacific Ocean (~4000 km; r2 = 0.83), extending from Washington State to the Aleutian Islands, and over smaller geographic distances for three locations in Alaska (~1700 km; r2 = 0.56). Slopes of IBD regressions suggested average dispersal distance between birth and reproduction of less than 30 km. Exceptions to this pattern were found in samples taken from fjord environments in the Georgia Basin (the Strait of Georgia (Canada) and Puget Sound (USA)), where populations were differentiated from coastal cod. Our results showed population structure at spatial scales relevant to fisheries management, both caused by limited dispersal along the coast and by sharp barriers to migration isolating smaller stocks in coastal fjord environments.

scholarly journals Radiocesium in the western subarctic area of the North Pacific ocean, Bering Sea, and Arctic Ocean in 2015 and 2017

Polar Science ◽  
2019 ◽  
Vol 21 ◽  
pp. 228-232 ◽  
Author(s):  
Yuichiro Kumamoto ◽  
Michio Aoyama ◽  
Yasunori Hamajima ◽  
Shigeto Nishino ◽  
Akihiko Murata ◽  
...  
Keyword(s):  
Pacific Ocean ◽  
Arctic Ocean ◽  
Bering Sea ◽  
North Pacific ◽  
North Pacific Ocean ◽  
The North ◽  
The North Pacific

Single-nucleotide polymorphisms reveal distribution and migration of Chinook salmon (Oncorhynchus tshawytscha) in the Bering Sea and North Pacific Ocean

2013 ◽  
Vol 70 (1) ◽  
pp. 128-141 ◽  
Author(s):  
Wesley A. Larson ◽  
Fred M. Utter ◽  
Katherine W. Myers ◽  
William D. Templin ◽  
James E. Seeb ◽  
...  
Keyword(s):  
Pacific Ocean ◽  
Chinook Salmon ◽  
Bering Sea ◽  
North Pacific ◽  
Oncorhynchus Tshawytscha ◽  
North Pacific Ocean ◽  
Nucleotide Polymorphisms ◽  
Single Nucleotide ◽  
And Migration ◽  
The Bering Sea

We genotyped Chinook salmon (Oncorhynchus tshawytscha) from the Bering Sea and North Pacific Ocean for 43 single-nucleotide polymorphisms (SNPs) to investigate seasonal distribution and migration patterns. We analyzed 3563 immature fish from 22 spatiotemporal strata; composition analyses were performed using genotype data from spawning stocks spanning the species range. Substantial variation in stock composition existed among spatial and seasonal strata. We inferred patterns of seasonal migration based upon these data along with data from previous tag, scale, and parasite studies. We found that stocks from western Alaska and Yukon River overwinter on the Alaska continental shelf then travel to the middle and western Bering Sea during spring–fall. Stocks from California to Southeast Alaska were distributed in Gulf of Alaska year-round, with a substantial portion of this group migrating northward to the eastern Bering Sea during spring–fall. Proportions of Russian stocks increase when moving east to west in both the Bering Sea and North Pacific Ocean. These data can be used to better understand the impacts of fisheries and climate change on this valuable resource.

scholarly journals Twentieth century <i>δ</i><sup>13</sup>C variability in surface water dissolved inorganic carbon recorded by coralline algae in the northern North Pacific Ocean and the Bering Sea

2011 ◽  
Vol 8 (1) ◽  
pp. 165-174 ◽  
Author(s):  
B. Williams ◽  
J. Halfar ◽  
R. S. Steneck ◽  
U. G. Wortmann ◽  
S. Hetzinger ◽  
...  
Keyword(s):  
Pacific Ocean ◽  
Bering Sea ◽  
North Pacific ◽  
Dissolved Inorganic Carbon ◽  
North Pacific Ocean ◽  
Coralline Algae ◽  
Aleutian Low ◽  
Ambient Seawater ◽  
Δ13c Values ◽  
The 1960S

Abstract. The oxygen isotopic composition and Mg/Ca ratios in the skeletons of long-lived coralline algae record ambient seawater temperature over time. Similarly, the carbon isotopic composition in the skeletons record δ13C values of ambient seawater dissolved inorganic carbon. Here, we measured δ13C in the coralline alga Clathromorphum nereostratum to test the feasibility of reconstructing the intrusion of anthropogenic CO2 into the northern North Pacific Ocean and Bering Sea. The δ13C was measured in the high Mg-calcite skeleton of three C. nereostratum specimens from two islands 500 km apart in the Aleutian archipelago. In the records spanning 1887 to 2003, the average decadal rate of decline in δ13C values increased from 0.03‰ yr−1 in the 1960s to 0.095‰ yr−1 in the 1990s, which was higher than expected due to solely the δ13C-Suess effect. Deeper water in this region exhibits higher concentrations of CO2 and low δ13C values. Transport of deeper water into surface water (i.e., upwelling) increases when the Aleutian Low is intensified. We hypothesized that the acceleration of the δ13C decline may result from increased upwelling from the 1960s to 1990s, which in turn was driven by increased intensity of the Aleutian Low. Detrended δ13C records also varied on 4–7 year and bidecadal timescales supporting an atmospheric teleconnection of tropical climate patterns to the northern North Pacific Ocean and Bering Sea manifested as changes in upwelling.

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