Feeding of ribbon seals (Phoca fasciata) in the Bering Sea in spring

1980 ◽  
Vol 58 (9) ◽  
pp. 1601-1607 ◽  
Author(s):  
Kathryn J. Frost ◽  
Lloyd F. Lowry
Keyword(s):  
Bering Sea ◽  
Arctic Cod ◽  
Main Prey ◽  
Northern Bering Sea ◽  
South Central ◽  
Fresh Food ◽  
Northern Areas ◽  
Pack Ice ◽  
Fish Otoliths ◽  
The Bering Sea

Digestive tracts of 61 ribbon seals (Phoca fasciata) collected in the seasonal pack ice of the Bering Sea during March to June 1976–1979 were examined. Very little fresh food was found in stomachs; however, hard parts of prey, particularly fish otoliths, were found in stomachs and (or) intestines of 28 seals. Based on counts of otoliths, the main prey were pollock in south-central and central Bering Sea, and arctic cod in northern Bering Sea. Weights and lengths of fishes consumed by seals were estimated from measurements of otoliths. On the basis of estimated whole weight of prey consumed, eelpout were a major food of these seals in south-central and central Bering Sea. Comparison of the species composition of fishes caught in trawls and eaten by seals suggests that seals in central and northern Bering Sea select for pollock and arctic cod, and against sculpins and capelin. In contrast, in south-central Bering Sea pollock was the most abundant fish in both seals and trawls. Seals were nonselective with regard to size of pollock consumed but appeared to select for large arctic cod. Our data suggest feeding conditions may be more favorable for ribbon seals in south-central Bering Sea than in more northern areas.

scholarly journals Why does the pollock (Theragra chalcogramma) abundance change

2016 ◽  
Vol 185 (2) ◽  
pp. 31-48
Author(s):  
Vyacheslav P. Shuntov
Keyword(s):  
Bering Sea ◽  
Food Supply ◽  
Global Changes ◽  
Winter Mortality ◽  
Migration Timing ◽  
Northern Bering Sea ◽  
Class Strength ◽  
Strength Dependence ◽  
The Bering Sea

Some common ideas about environmental factors that determine the patterns of migration (including timing) and stock dynamics of walleye pollock are critically analyzed with particular attention to the Bering Sea. There is shown that the conception of the migration timing dependence on food supply in the northern Bering Sea does not represent the real facts, as well as the conception of year-class strength dependence on winter mortality of fingerlings determined by food supply, especially in conditions of its deficiency. Periodicity of the pollock stocks dynamics associated with global changes of climatic and oceanographic factors is also called in question. Role of provincial factors in dynamics of the pollock populations is discussed and emphasized.

Walruses Attack Spectacled Eiders Wintering in Pack Ice of the Bering Sea

ARCTIC ◽  
2010 ◽  
Vol 63 (1) ◽  
Author(s):  
James R. Lovvorn ◽  
Joseph J. Wilson ◽  
David McKay ◽  
Joseph K. Bump ◽  
Lee W. Cooper ◽  
...  
Keyword(s):  
Bering Sea ◽  
Pack Ice ◽  
The Bering Sea

Middle Pleistocene Mollusks from St. Lawrence Island and their Significance for the Paleo-Oceanography of the Bering Sea

1972 ◽  
Vol 2 (02) ◽  
pp. 119-134 ◽  
Author(s):  
David M. Hopkins ◽  
Robert W. Rowland ◽  
William W. Patton
Keyword(s):  
Bering Sea ◽  
Middle Pleistocene ◽  
Pacific Water ◽  
Arctic Water ◽  
Ice Cap ◽  
Northern Bering Sea ◽  
Eastern Bering Sea ◽  
Flow Through ◽  
The Bering Sea ◽  
Arctic Fauna

Drift, evidently of Illinoian age, was deposited on St. Lawrence Island at the margin of an ice cap that covered the highlands of the Chukotka Peninsula of Siberia and spread far eastward on the continental shelf of northern Bering Sea. Underlying the drift on the northwestward part of the island are mollusk-bearing beds deposited during the Kotzebuan Transgression. A comparison of mollusk faunas from St. Lawrence Island, Chukotka Peninsula, and Kotzebue Sound suggests that the present northward flow through Bering and Anadyr Straits was reversed during the Kotzebuan Transgression. Cold arctic water penetrated southward and southwestward bringing an arctic fauna to the Gulf of Anadyr. Warmer Pacific water probably entered eastern Bering Sea, passed eastward and northeastward around eastern and northern St. Lawrence Island, and then became entrained in the southward currents that passed through Anadyr Strait.

Evaluation of a ship-based unoccupied aircraft system (UAS) for surveys of spotted and ribbon seals in the Bering Sea pack ice

2015 ◽  
Vol 3 (3) ◽  
pp. 114-122 ◽  
Author(s):  
Erin E. Moreland ◽  
Michael F. Cameron ◽  
Robyn P. Angliss ◽  
Peter L. Boveng
Keyword(s):  
Bering Sea ◽  
Large Scale ◽  
The Arctic ◽  
Small Scale ◽  
Ecosystem Responses ◽  
New Class ◽  
Pack Ice ◽  
Low Altitude ◽  
Aircraft System ◽  
The Bering Sea

The remote pack ice of the arctic and subarctic seas is challenging to access, yet extremely important to understand and monitor. The pack ice holds the key to understanding ecosystem responses to climate change and is vital habitat for many species including ice-associated seals. Unoccupied aircraft systems (UAS) are a new class of tools that may overcome the traditional challenges associated with expansive offshore surveys. We conducted UAS flights over the pack ice during a spring 2009 National Oceanic and Atmospheric Administration (NOAA) cruise to the Bering Sea to determine whether advances in UAS technology can enable effective large-scale, systematic ship-based surveys for seals in the seasonal ice of the Bering, Beaufort, and Chukchi Seas. A fixed-wing ScanEagle UAS was successfully launched and recovered from the NOAA ship McArthur II to conduct small-scale transect surveys up to 5 nautical miles (M) from the ship's position. More than 27 000 images were collected from 10 flights over the Bering Sea pack ice and seals were identified in 110 of these images. Review of the images indicated a marked reduction in disturbance to seals when compared to images collected from occupied, low-altitude helicopter surveys. These results suggest that large-scale UAS surveys of arctic and subarctic habitat in United States airspace will be possible with improvements in technology, reduced operational costs, and the establishment of inclusive airspace regulations.

Gray whale feeding on dense ampeliscid amphipod communities near Bamfield, British Columbia

1984 ◽  
Vol 62 (1) ◽  
pp. 41-49 ◽  
Author(s):  
John S. Oliver ◽  
Peter N. Slattery ◽  
Mark A. Silberstein ◽  
Edmund F. O'Connor
Keyword(s):  
Bering Sea ◽  
Benthic Communities ◽  
Gray Whale ◽  
Gray Whales ◽  
Northern Bering Sea ◽  
Amphipod Crustacean ◽  
Different Parts ◽  
Feeding Grounds ◽  
Made In ◽  
The Bering Sea

Gray whales fed on dense populations of ampeliscid amphipods while summering along the west coast of Vancouver Island. These amphipod crustacean communities are ecological analogs of the primary feeding grounds of gray whales in the northern Bering Sea. The same major genera of amphipods dominated the Alaskan and Canadian feeding grounds, including Ampelisca, Photis, Protomedeia, Anonyx, and Orchomene, and comprised 67 to 90% of the number of infaunal crustaceans at the two locations. This is the first documented report of gray whale feeding on benthic infauna south of the Bering Sea. Feeding gray whales observed in Pachena Bay produced an extensive record of feeding excavations in bottom sediments. Excavation patterns suggest that: (i) whales used suction to extract infaunal prey and sediments; (ii) a maximum of six excavations was made in one feeding dive; (iii) excavation size was related to whale size; (iv) small and large whales fed in different parts of the bay; and (v) whales effectively located and worked the densest patches of benthic prey. We estimate that a 6-m whale consumed 116 kg of infaunal prey per 12-h day, and that a 12-m whale consumed 552 kg per 12-h day. Scavenging lysianassid amphipods were attracted to feeding disturbances within seconds and preyed on injured and dislodged infauna. Individual feeding excavations were large, deep valleys in a tube-mat plateau. In addition to the lysianassids, many other infauna undoubtedly colonize these highly modified habitats, resulting in important effects on the structure of benthic communities.

Diet and body condition of spectacled eiders wintering in pack ice of the Bering Sea

Polar Biology ◽  
2003 ◽  
Vol 26 (4) ◽  
pp. 259-267 ◽  
Author(s):  
James R. Lovvorn ◽  
Samantha E. Richman ◽  
Jacqueline M. Grebmeier ◽  
Lee W. Cooper
Keyword(s):  
Body Condition ◽  
Bering Sea ◽  
Pack Ice ◽  
The Bering Sea

scholarly journals Diet and body condition of spectacled eiders wintering in pack ice of the Bering Sea

Polar Biology ◽  
2003 ◽  
Vol 26 (5) ◽  
pp. 358-358 ◽  
Author(s):  
James R. Lovvorn ◽  
Samantha E. Richman ◽  
Jacqueline M. Grebmeier ◽  
Lee W. Cooper
Keyword(s):  
Body Condition ◽  
Bering Sea ◽  
Pack Ice ◽  
The Bering Sea

Historical Changes in the Beaufort–Chukchi–Bering Seas Surface Winds and Waves, 1971–2013

2015 ◽  
Vol 28 (19) ◽  
pp. 7457-7469 ◽  
Author(s):  
Xiaolan L. Wang ◽  
Yang Feng ◽  
Val R. Swail ◽  
Andrew Cox
Keyword(s):  
Wave Height ◽  
Bering Sea ◽  
Surface Wind ◽  
Surface Wind Speed ◽  
Wave Period ◽  
Historical Changes ◽  
Wind Speeds ◽  
The North ◽  
Northern Bering Sea ◽  
The Bering Sea

Abstract This study characterizes historical changes in surface wind speed and ocean surface waves in the Beaufort–Chukchi–Bering Seas using Environment Canada’s Beaufort Wind and Wave Reanalysis for the period 1970–2013. The results show that both the significant wave height () and mean wave period () have increased significantly over the Bering Sea in July and August and over the Canadian Beaufort Sea westward to the northern Bering Sea in September, and that the 1992–2013 trends in September mean agree well with satellite-based trend estimates for 1993–2010. Most outstandingly, the regional mean has increased at a rate of 3%–4% yr−1 of the corresponding 1970–99 climatology; it has more than tripled since 1970. Also, the regional mean has increased at a rate of 0.3% to 0.8% yr−1. The trends of lengthening wave period and increasing wave height imply a trend of increasing wave energy flux, providing a mechanism to break up sea ice and accelerate ice retreat. The results also show that changes in the local wind speeds alone cannot explain the significant changes in waves. The wind speeds show significant increases over the Bering Sea to the north of Alaska in July and over the central part of the domain in August and September, with decreases in the region off the Canadian coasts in August. In the region west of the Canadian coast, the climatological mean wind direction has rotated clockwise in July and August, with the climatological anticyclonic center being displaced northeastward in August.

scholarly journals Assessment of stock, spatial distribution, and recruitment of walleye pollock in the northern and eastern Bering Sea

2016 ◽  
Vol 185 (2) ◽  
pp. 16-30
Author(s):  
Mikhail A. Stepanenko ◽  
Elena V. Gritsay
Keyword(s):  
Bering Sea ◽  
Late Summer ◽  
Walleye Pollock ◽  
Zooplankton Abundance ◽  
Mean Values ◽  
The North ◽  
Northern Bering Sea ◽  
Favorable Conditions ◽  
Fish Survival ◽  
The Bering Sea

Abundance and biomass of walleye pollock Theragra chalcogramma in the Bering Sea exceeded the mean values in 2015 owing to the high-abundant year-classes of 2008 and 2012 and several medium-abundant year-classes (of 2006, 2009-2011, 2013, and 2014). In contrast to rather stable distribution on its spawning grounds, distribution of feeding pollock in the northern Bering Sea is very variable and depends on both biomass of the population and long-term and short-term variations of environments, as water temperature and zooplankton abundance. In some years including recent times (2005-2007 and 2010-2014), the pollock migrated earlier and faster into the northwestern Bering Sea and returned back to the eastern shelf also early: in late summer - early autumn. This scenario is supposedly conditioned by low zooplankton abundance over the Bering Sea that forces pollock to active feeding migrations, particularly a deficit of preferable food (large-sized zooplankton) on the north-western feeding grounds could be a reason for its leaving this area in late summer. Strength of pollock year-classes is highly variable, too, and depends mostly on young-of-the-year fish survival in winter. As usual, favorable conditions for reproduction and progeny survival, when strong year-classes appear, are observed in the years or short periods of transition from one state of marine environments to another, whereas long periods of either «warm» or «cold» regime are not favorable for forming of high-abundant year-classes of the Bering Sea pollock.

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