scholarly journals Feeding habits of harp (Phoca groenlandica) and hooded seals (Cystophora cristata) during late winter, spring and early summer in the Greenland Sea

2000 ◽  
Vol 2 ◽  
pp. 40 ◽  
Author(s):  
Vladimir Potelev ◽  
Kjell Tormod Nilssen ◽  
Vladislav Svetochev ◽  
Tore Haug
Keyword(s):  
Feeding Habits ◽  
Early Summer ◽  
Late Winter ◽  
Polar Cod ◽  
Greenland Sea ◽  
Hooded Seal ◽  
Cystophora Cristata ◽  
Phoca Groenlandica ◽  
Polar Cod Boreogadus Saida ◽  
Seal Diet

Diet data were collected in the Greenland Sea pack ice (the West Ice) from March to June from harp seals (Phoca groenlandica) in 1987, 1990-1992 and 1997, and from hooded seals (Cystophora cristata) in 1992 and 1994, during Soviet Russian commercial sealing and on Norwegian scientific expeditions. The majority of both harp and hooded seal stomachs were empty but intestinal contents were found in most of the seals. The harp seal diet was totally dominated by the amphipods Parathemisto sp. and Gammarus sp., but krlll (Thysanoessa sp.) and polar cod (Boreogadus saida) were also eaten quite frequently. Hooded seals had been feeding mainly on the squid Gonatus fabricii, which was found most frequently in the intestines, but which also dominated in the few stomachs with contents. Polar cod also occurred quite frequently in the hooded seal diet, while crustaceans, such as amphipods and krill, occurred only sporadically.

scholarly journals First independent feeding of harp seal (Phoca groenlandica) and hooded seal (Cystophora cristata) pups in the Greenland Sea

2000 ◽  
Vol 2 ◽  
pp. 29 ◽  
Author(s):  
Tore Haug ◽  
Kjell T Nilssen ◽  
Lotta Lindblom
Keyword(s):  
Interspecific Competition ◽  
Niche Overlap ◽  
Harp Seal ◽  
Minor Importance ◽  
Greenland Sea ◽  
The West ◽  
Hooded Seal ◽  
Cystophora Cristata ◽  
Phoca Groenlandica

Data were collected from harp seal (Phoca groenlandica) and hooded seal (Cystophora cristata) pups belonging to the Greenland Sea (or "West Ice") stocks in 1995-1997. Pups of both species were observed to feed independently shortly after weaning, and their first food was almost exclusively crustaceans. Parathemisto sp., particularly P. libellula, dominated the diet of both the harp and the hooded seal pups, but the diet also contained sympagic amphipods of the genus Gammarus. Krill (Thysanoessa sp.) was of minor importance as food for seal pups in 1995, but occurred more frequentlyin the diet of both species in 1996 and 1997. Considerable niche overlap may suggest some interspecific competition between harp and hooded seal pups in the West Ice.

scholarly journals Morbilliviral Dermatitis in Seals

2001 ◽  
Vol 38 (6) ◽  
pp. 724-726 ◽  
Author(s):  
T. P. Lipscomb ◽  
M. G. Mense ◽  
P. L. Habecker ◽  
J. K. Taubenberger ◽  
R. Schoelkopf
Keyword(s):  
Inclusion Bodies ◽  
Marine Mammals ◽  
Skin Lesions ◽  
Basal Cells ◽  
Hooded Seal ◽  
Cystophora Cristata ◽  
Phoca Groenlandica ◽  
Phocine Distemper Virus ◽  
Intracytoplasmic Inclusion Bodies ◽  
Polymerase Chain

A juvenile female hooded seal ( Cystophora cristata) and a juvenile male harp seal ( Phoca groenlandica) stranded separately on the New Jersey (USA) coast and were taken to a marine mammal rehabilitation center. Both were lethargic and emaciated, had dermatitis, and died. Histologic skin lesions in the seals were similar and consisted of epidermal and follicular epithelial hyperplasia, hyperkeratosis, degeneration, and necrosis. The most distinctive finding was extensive syncytial zones bounded superficially by hyperkeratosis and deeply by hyperplastic basal cells. Eosinophilic intracytoplasmic inclusion bodies were present in epithelial cells. Morbilliviral antigen was demonstrated in the skin lesions by immunohistochemistry. Phocine distemper virus was detected in the skin by reverse transcription polymerase chain reaction and a phocine distemper virus-specific probe using the Southern blot technique. This is the first report of morbilliviral dermatitis in marine mammals.

Fatty-acyl esters of retinol (vitamin A) in the liver of the harp seal (Phoca groenlandica), hooded seal (Cystophora cristata), and California sea lion (Zalophus californianus)

1992 ◽  
Vol 70 (9) ◽  
pp. 809-813 ◽  
Author(s):  
Mark D. Ball ◽  
Christopher P. Nizzi ◽  
Harold C. Furr ◽  
James A. Olson ◽  
Olav T. Oftedal
Keyword(s):  
Fatty Acid Composition ◽  
Vitamin A ◽  
Zalophus Californianus ◽  
Sea Lion ◽  
California Sea Lion ◽  
Liver Lipids ◽  
Hooded Seal ◽  
Cystophora Cristata ◽  
Phoca Groenlandica ◽  
Retinyl Esters

The fatty-acid composition of retinyl esters in the livers of two species of phocid seal, the harp seal (Phoca groenlandica, n = 20) and the hooded seal (Cystophora cristata, n = 15), and one species of otariid seal, the California sea lion (Zalophus californianus, n = 6), was determined. Vitamin A ranged in concentration from 4 to 1024 nmol retinol/g liver for the phocids and from 381 to 979 nmol/g liver for the otariids. In most of the livers, retinyl palmitate was not the principal ester, and the palmitate + stearate + oleate trio of retinyl esters represented less than 50% of the total. In all samples, the retinyl esters contained 20:1, 20:4, 20:5, and 22:6 in unusually large amounts. Retinyl esters tended to be richer than whole-liver lipids in 20:5 + 22:6, whereas whole-liver lipids were richer in 18:0 and 18:2. Therefore, the pool of acyl donors used for the esterification of retinol may be distinct from that used for other lipids. Birth-to-weaning changes were seen only in the harp seals. In the pups, the hepatic vitamin-A concentration increased 454%, while the proportion of 18:0 and 20:1 in the retinyl esters rose and that of 14:0 + 16:1 and 20:4 fell. Concomitantly, in their mothers, the proportion of 20:4 increased but that of 16:0 and 18:0 decreased.Key words: fatty-acid composition, pinniped liver, retinyl esters, vitamin A.

Levels of non-essential elements in muscle from harp seal (Phagophilus groenlandicus) and hooded seal (Cystophora cristata) caught in the Greenland Sea area

2006 ◽  
Vol 366 (2-3) ◽  
pp. 784-798 ◽  
Author(s):  
Linn Anne Brunborg ◽  
Ingvild Eide Graff ◽  
Livar Frøyland ◽  
Kåre Julshamn
Keyword(s):  
Essential Elements ◽  
Harp Seal ◽  
Greenland Sea ◽  
Hooded Seal ◽  
Cystophora Cristata ◽  
Sea Area

Estimation of hooded seal (Cystophora cristata) pup production in the Greenland Sea pack ice during the 2005 whelping season

Polar Biology ◽  
2008 ◽  
Vol 31 (7) ◽  
pp. 867-878 ◽  
Author(s):  
Arnt-Børre Salberg ◽  
Tore Haug ◽  
Kjell Tormod Nilssen
Keyword(s):  
Greenland Sea ◽  
Hooded Seal ◽  
Cystophora Cristata ◽  
Pack Ice

scholarly journals Distribution, abundance and biology of ringed seals (Phoca hispida): an overview

1998 ◽  
Vol 1 ◽  
pp. 9 ◽  
Author(s):  
Randall R Reeves
Keyword(s):  
Polar Bear ◽  
Late Summer ◽  
Early Summer ◽  
Ringed Seal ◽  
Late Spring ◽  
Late Winter ◽  
Polar Cod ◽  
World Population ◽  
Phoca Hispida ◽  
Ringed Seals

The ringed seal (Phoca hispida) has a circumpolar Arctic distribution. Because of its great importance to northern communities and its role as the primary food of polar bears (Ursus maritimus) the ringed seal has been studied extensively in Canada, Alaska, Russia, Svalbard and Greenland as well as in the Baltic Sea and Karelian lakes. No clear-cut boundaries are known to separate ringed seal stocks in marine waters. Adult seals are thought to be relatively sedentary, but sub-adults sometimes disperse over long distances. Stable ice with good snow cover is considered the most productive habitat although production in pack ice has been little studied. Populations appear to be structured so that immature animals and young adults are consigned to sub-optimal habitat during the spring pupping and breeding season. Annual production in ringed seal populations, defined as thepup percentage in the total population after the late winter pupping season, is probably in the order of 18-24%. Most estimates of maximum sustainable yield are in the order of 7%.The world population of ringed seals is at least a few million. Methods of abundance estimation have included aerial surveys, dog searches and remote sensing of lairs and breathing holes, acoustic monitoring, correlation analysis by reference to sizes of polar bear populations, and inference from estimated energy requirements of bear populations. Aerial strip survey has been the method of choice for estimating seal densities over large areas. Adjustment factors to account for seals not hauled out at the time of the survey, for seals that dove ahead of the aircraft, and for seals on the ice within the surveyed strip but not detected by the observers, are required for estimates of absolute abundance.Male and female ringed seals are sexually mature by 5-7 years of age (earlier at Svalbard). Pupping usually occurs in March or early April and is followed by 5-7 weeks of lactation. Breeding takes place in mid to late May, and implantation is delayed for about 3 months. In at least some parts of their range, ringed seals feed mainly on schooling gadids from late autumn through early spring andon benthic crustaceans and polar cod (Boreogadus saida) from late spring through summer. Little feeding is done during the moult, which takes place in late spring and early summer. Pelagic crustaceans offshore and mysids inshore become important prey in late summer and early autumn in some areas. Ringed seals have several natural predators, the most important of which is the polar bear in most arctic regions. Arctic foxes (Alopex lagopus) kill a large percentage of pups in someareas.From a conservation perspective, the ringed seal appears to be secure. Levels of exploitation of arctic populations have usually been considered sustainable, except in the Okhotsk Sea. Large fluctuations in production of ringed seals in the Beaufort Sea and Amundsen Gulf are thought to be driven by natural variability in environmental conditions. While concern has been expressed about thepotential impacts of industrial activity and pollution on ringed seals, such impacts have been documented only in limited areas. Because of their ubiquitous occurrence and availability for sampling, ringed seals are good subjects for monitoring contaminant trends in Arctic marine food chains. 

Feeding habits of harp seals (Phoca groenlandica) during early summer and autumn in the northern Barents Sea

Polar Biology ◽  
1995 ◽  
Vol 15 (7) ◽  
Author(s):  
K.T. Nilssen ◽  
T. Haug ◽  
V. Potelov ◽  
Y.K. Timoshenko
Keyword(s):  
Barents Sea ◽  
Feeding Habits ◽  
Early Summer ◽  
Phoca Groenlandica

scholarly journals Volume capacity and contraction control of the seal spleen

1997 ◽  
Vol 82 (6) ◽  
pp. 1989-1994 ◽  
Author(s):  
Arnaud Cabanac ◽  
Lars P. Folkow ◽  
Arnoldus Schytte Blix
Keyword(s):  
Body Mass ◽  
Total Blood Volume ◽  
Volume Changes ◽  
Venous Outflow ◽  
Total Blood ◽  
Hooded Seal ◽  
Cystophora Cristata ◽  
Phoca Groenlandica ◽  
Stimulation Of

Cabanac, Arnaud, Lars P. Folkow, and Arnoldus Schytte Blix.Volume capacity and contraction control of the seal spleen. J. Appl. Physiol. 82(6): 1989–1994, 1997.—Volume changes in the spleens of hooded seals ( Cystophora cristata) and harp seals ( Phoca groenlandica) were measured plethysmographically in vitro in response to epinephrine, norepinephrine, isoprenaline, phentolamine, and acetylcholine. Dilated spleens contracted forcefully within 1–3 min of α-adrenoceptor activation with 1.0–5.0 μg epinephrine/kg body mass, whereas stimulation of β-adrenoceptors and cholinergic receptors had little effect. The mass of dilated hooded seal spleens corresponded to 2–4% ( n = 7) of body mass, with volume (V; ml) relating to body mass (M; kg) as follows: V = 12.0M + 910 ( r 2 = 0.96, n = 4). Thus the spleen of a 250-kg hooded seal maximally expels 3.9 liters, or 13%, of its estimated total blood volume. Average hematocrit in splenic venous outflow from dilated spleens was 90 ± 3% ( n = 3) in hooded seals and 85% ( n = 2) in harp seals. From these data we have estimated that the aerobic diving limit of a 250-kg hooded seal increases only 105 s, at the most, if complete emptying of the spleen occurs during diving, while the corresponding estimate for a 112-kg harp seal is 80 s.

Organochlorines in mother and pup pairs in two Arctic seal species: Harp seal (Phoca groenlandica) and hooded seal (Cystophora cristata)

1997 ◽  
Vol 44 (3) ◽  
pp. 315-330 ◽  
Author(s):  
Oscar Espeland ◽  
Lars Kleivane ◽  
Signe Haugen ◽  
Janneche Utne Skaare
Keyword(s):  
Harp Seal ◽  
Hooded Seal ◽  
Cystophora Cristata ◽  
Phoca Groenlandica
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