scholarly journals Contrasting coastal and shelf nursery habitats of Pacific cod in the southeastern Bering Sea

2014 ◽  
Vol 72 (2) ◽  
pp. 515-527 ◽  
Author(s):  
Thomas P. Hurst ◽  
Daniel W. Cooper ◽  
Janet T. Duffy-Anderson ◽  
Edward V. Farley
Keyword(s):  
Bering Sea ◽  
Gulf Of Alaska ◽  
Size Distributions ◽  
Pacific Cod ◽  
Coastal Embayments ◽  
Nursery Habitats ◽  
Subsurface Waters ◽  
Shallow Subtidal ◽  
Surface And Subsurface Waters ◽  
The Bering Sea

Abstract Shallow, subtidal waters of coastal embayments are the primary nursery habitats of juvenile Pacific cod through much of their range. However, the importance of these habitats to the Bering Sea population is poorly understood as the Bering Sea offers relatively little of this habitat. In this study, we examined the use of demersal and pelagic habitats in the southeast Bering Sea by age-0 Pacific cod. In 4 years of demersal beam trawling on the shelf at depths of 20–146 m, fish were most abundant along the Alaska Peninsula (AKP) at depths to 50 m. In addition, 1 year of spatially intensive beam trawl sampling was conducted at depths of 5–30 m in a nearshore focal area along the central AKP. In this survey, age-0 cod were more abundant along the open coastline than they were in two coastal embayments, counter to patterns observed in the Gulf of Alaska. Demersal sampling in 2012 was conducted synoptically with surveys of surface and subsurface waters over the continental shelf. Age-0 cod were captured in pelagic waters over the middle and outer shelf, with maximum catches occurring over depths of 60–80 m. The similar size distributions of fish in coastal-demersal and shelf-surface habitats and the proximity of concentrations in the two habitat types suggests that habitat use in the Bering Sea occurs along a gradient from coastal to pelagic. While capture efficiencies may differ among trawl types, trawl-based estimates of age-0 cod density in demersal waters along the AKP was 10 times that observed in the highest density pelagic-shelf habitats, demonstrating the importance of coastal nursery habitats in this population. Despite representing a much smaller habitat area, the coastal waters along the AKP appear an important nursery area and support a significant fraction of the age-0 Pacific cod in the Bering Sea.

Migration and Feeding of the Gray Whale (Eschrichtius gibbosus)

1962 ◽  
Vol 19 (5) ◽  
pp. 815-838 ◽  
Author(s):  
Gordon C. Pike
Keyword(s):  
British Columbia ◽  
Bering Sea ◽  
Chukchi Sea ◽  
Close Contact ◽  
Gulf Of Alaska ◽  
Bering Strait ◽  
Visual Contact ◽  
Gray Whales ◽  
Baleen Whales ◽  
The Bering Sea

Observations of gray whales from the coasts of British Columbia, Washington, and Alaska are compared with published accounts in order to re-assess knowledge of migration and feeding of the American herd. Source of material is mainly from lighthouses and lightships.The American herd of gray whales retains close contact with the shore during migration south of Alaska. Off Washington and British Columbia the northward migration begins in February, ends in May, and is at a peak during the first two weeks in April; the southward migration occurs in December and January, and is at a peak in late December. Northward migrants stop occasionally to rest or feed; southward migrants are travelling faster and appear not to stop to rest or feed during December and January. Gray whales seen off British Columbia, sometimes in inside protected waters, from June through October, probably remain in this area throughout the summer and fall months.Available evidence suggests that gray whales retain contact with the coast while circumscribing the Gulf of Alaska, enter the Bering Sea through eastern passages of the Aleutian chain, and approach St. Lawrence Island by way of the shallow eastern part of the Bering Sea. Arriving off the coast of St. Lawrence Island in May and June the herd splits with some parts dispersing along the Koryak coast and some parts continuing northward as the ice retreats through Bering Strait. Gray whales feed in the waters of the Chukchi Sea along the Siberian and Alaskan coasts in July, August and September. Advance of the ice through Bering Strait in October initiates the southern migration for most of the herd. In summering areas, in northern latitudes, gray whales feed in shallow waters on benthic and near-benthic organisms, mostly amphipods.There is no evidence to indicate that gray whales utilize ocean currents or follow the same routes as other baleen whales in their migrations. Visual contact with coastal landmarks appear to aid gray whales in successfully accomplishing the 5000-mile migration between summer feeding grounds in the Bering and Chukchi Seas and winter breeding grounds in Mexico.Reconstruction of the migration from all available data shows that most of the American herd breeds and calves in January and February, migrates northward in March, April and May, feeds from June through October, and migrates southward in November and December.

On exchange of water between the Gulf of Alaska and the Bering Sea through Unimak Pass

1982 ◽  
Vol 87 (C8) ◽  
pp. 5785 ◽  
Author(s):  
J. D. Schumacher ◽  
C. A. Pearson ◽  
J. E. Overland
Keyword(s):  
Bering Sea ◽  
Gulf Of Alaska ◽  
The Bering Sea

scholarly journals Modeling connectivity of walleye pollock in the Gulf of Alaska: Are there any linkages to the Bering Sea and Aleutian Islands?

2016 ◽  
Vol 132 ◽  
pp. 227-239 ◽  
Author(s):  
Carolina Parada ◽  
Sarah Hinckley ◽  
John Horne ◽  
Michael Mazur ◽  
Albert Hermann ◽  
...  
Keyword(s):  
Bering Sea ◽  
Gulf Of Alaska ◽  
Walleye Pollock ◽  
Aleutian Islands ◽  
The Bering Sea

The occurrence of Anisakis sp. type I larvae (Oshima 1972) (Nematoda: Anisakidae) in fishes from the Gulf of Alaska and the Bering Sea

1983 ◽  
Vol 61 (1) ◽  
pp. 266-268 ◽  
Author(s):  
G. J. Munger
Keyword(s):  
Bering Sea ◽  
Feeding Habits ◽  
Gulf Of Alaska ◽  
Type I ◽  
Intermediate Hosts ◽  
Bristol Bay ◽  
The Bering Sea

Of 33 species of fish examined for Anisakis larvae, 12 (36%) were infected. Larvae were identified as Anisakis type I larvae (Oshima 1972) and were found in fish from all localities surveyed: Bristol Bay, Unimak, Chirikof, Chiniak, and Cape St. Elias. The small size and feeding habits of some fish infected suggests that small fishes or very small invertebrates rather than euphausids may be the intermediate hosts for Anisakis type I larvae.

scholarly journals STATE OF STOCKS AND MODERN FISHERY OF ATKA MACKEREL PLEUROGRAMMUS MONOPTERYGIUS (PALLAS, 1810) IN THE OLYUTORSKY-NAVARINSKY AREA OF THE BERING SEA

2020 ◽  
Vol 200 ◽  
pp. 38-57
Author(s):  
A. O. Zolotov ◽  
O. G. Zolotov ◽  
Yu. K. Kurbanov
Keyword(s):  
Bering Sea ◽  
Gulf Of Alaska ◽  
Aleutian Islands ◽  
Commander Islands ◽  
Spawning Grounds ◽  
Spawning Stock ◽  
Atka Mackerel ◽  
Pleurogrammus Monopterygius ◽  
Commercial Stock ◽  
The Bering Sea

Atka mackerel Pleurogrammus monopterygius is one of the mass species of fam. Hexagrammidae that inhabits the boreal and subarctic waters of the North Pacific and forms two large populations in its western and eastern parts. Reproductive range of the eastern, Aleutian population extends from the Gulf of Alaska, along Aleutian Islands to Commander Islands, with the main spawning grounds at the Aleutians and in the southeastern Bering Sea. From these areas, the fish at early stages of ontogenesis spread widely in system of the Bering Sea currents to the western-southwestern Bering Sea, where the atka mackerel aggregations are formed on the external shelf at prominent capes, as Cape Olyutorsky. Dynamics of the atka mackerel stock in the Olyutorsky-Navarinsky area in 1994–2019 is presented on the base of bottom trawl surveys, fishery statistics, and open NOAA data. After the period of low stock in the middle 1990s, the atka mackerel abundance increased sharply to the maximum in 2006–2008, when the spawning stock in this area was about 9.5 . 103 t and the commercial stock about 14.0 . 103 t. Since that time, trend to decreasing is observed, with the spawning stock 3.6 . 103 t and the commercial stock 5.6 . 103 t in 2013, and recent stabilization at the low level with slight decline continuing. A possible reason of the sharp increase in 2000s could be the intensive transport of the atka mackerel juveniles from the main spawning grounds at Aleutian Islands to the area at Cape Olyutorsky. The catches of atka mackerel in the Olyutorsky-Navarinsky area in 1994–2018 corresponded well with its stock dynamics.

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