scholarly journals Comparative Feeding of Grey (Halichoerus grypus)and Common Seals (Phoca vitulina) in Coastal Waters of Iceland, with a Note on the Diet of Hooded (Cystophora cristata) and Harp Seals (Phoca groenlandica)

1997 ◽  
Vol 22 ◽  
pp. 125-135 ◽  
Author(s):  
E Hauksson ◽  
V Bogason
Keyword(s):  
Coastal Waters ◽  
Phoca Vitulina ◽  
Halichoerus Grypus ◽  
Cystophora Cristata ◽  
Phoca Groenlandica

Susceptibility of Grey (Halichoerus grypus) and Harp (Phoca groenlandica) Seals to the Influenza Virus and Mycoplasma of Epizootic Pneumonia of Harbor Seals (Phoca vitulina)

1984 ◽  
Vol 41 (1) ◽  
pp. 151-156 ◽  
Author(s):  
J. R. Geraci ◽  
D. j. St. Aubin ◽  
I. K. Barker ◽  
V. S. Hinshaw ◽  
R. G. Webster ◽  
...  
Keyword(s):  
Influenza Virus ◽  
New England ◽  
Influenza A ◽  
Phoca Vitulina ◽  
Lung Homogenate ◽  
Halichoerus Grypus ◽  
Harbor Seals ◽  
Eastern Canada ◽  
Cystophora Cristata ◽  
Phoca Groenlandica

Six grey, Halichoerus grypus, and 12 harp, Phoca groenlandica, seals were inoculated intratracheally with lung homogenate containing influenza virus A/seal/Mass/1/80 and mycoplasma from harbor seals, Phoca vitulina, which had died in an epizootic of pneumonia. The grey seals were refractory to infection, whereas some of the harp seals developed mild pneumonia. Virus was recovered from 4 of 10 harp seals necropsied, and antibodies were produced in 2 survivors. The mycoplasma given alone to 2 grey seals did not replicate or produce infection and was recovered from only 1 of 12 harp seals inoculated. We examined 99 grey, 102 harp, 14 harbor, and 7 hooded seals (Cystophora cristata) from eastern Canada and found antibodies to avian influenza A/seal/Mass/1/80 in 3 adult male grey seals from Sable Island, N.S.; this virus is apparently adaptable to other seal species. Related forms of the virus are highly suspect as the cause of past epizootics, and one is currently responsible for a new outbreak of pneumonia in New England harbor seals.

Mercury in Seals from Eastern Canada

1973 ◽  
Vol 30 (6) ◽  
pp. 843-846 ◽  
Author(s):  
D. E. Sergeant ◽  
F. A. J. Armstrong
Keyword(s):  
Phoca Vitulina ◽  
Halichoerus Grypus ◽  
Eastern Canada ◽  
Small Pelagic Fish ◽  
Marine Food Web ◽  
Cystophora Cristata ◽  
Pagophilus Groenlandicus ◽  
Harbour Seals ◽  
Order Of Magnitude ◽  
Marine Food

Mercury concentrations in the tissues of four species of seals from individual localities in eastern Canada were highest in liver (usually 1–100 ppm) but up to 387 ppm and lowest in blubber (usually 0.1 ppm). Levels in muscle ranged from < 0.16 to 2.35 ppm. Values similar to those in muscle were found in the few specimens of heart, intestine, and lungs analyzed, and higher values in kidney and hair. Ratios of mercury in the liver to that in the muscle for adult seals were much greater than those found in two species of freshwater fish and three species of domestic animals exposed to wide ranges of mercury concentrations in their food. The ratios for seal pups, however, resembled those in the other animals.Mercury in seals increased with age and appeared to vary with the position in the marine food web of the organisms which they eat. Harp seals (Pagophilus groenlandicus), which feed on small pelagic fish and crustaceans, accumulated an order of magnitude less mercury than grey (Halichoerus grypus) and harbour (Phoca vitulina) seals, which live on large pelagic and benthic fish and cephalopods. However, grey and harbour seals are resident in eastern Canadian waters, which presumably contain higher mercury levels than arctic waters, where harp seals spend about half the year. Yet hood seals (Cystophora cristata), which spent more than half the year in arctic waters but feed on large fish and cephalopods, had mercury levels as high as grey and harbour seals.

Host specificity and abundance of parasitic nematodes (Ascaridoidea) from the stomachs of five phocid species from Newfoundland and Labrador

1993 ◽  
Vol 71 (11) ◽  
pp. 2156-2166 ◽  
Author(s):  
John Brattey ◽  
Garry B. Stenson
Keyword(s):  
Newfoundland And Labrador ◽  
Phoca Vitulina ◽  
Halichoerus Grypus ◽  
Parasitic Nematodes ◽  
Fish Stocks ◽  
Cystophora Cristata ◽  
Pseudoterranova Decipiens ◽  
Large Numbers ◽  
Harbour Seals ◽  
Contracaecum Osculatum

Stomachs of 270 phocids from five species (bearded, Erignathus barbatus; hooded, Cystophora cristata; grey, Halichoerus grypus; harbour, Phoca vitulina; and ringed, P. hispida), collected off Newfoundland and Labrador during 1985–1993 were examined, and the numbers and percentages of larval and adult ascaridoid nematodes determined. Samples of adult nematodes were also identified using previously described allozymes. Bearded seals were infected mainly with Contracaecum osculatum A, C. osculatum B, and Pseudoterranova decipiens C, whereas hooded seals harboured mostly Phocascaris spp. Grey seals harboured large numbers of C. osculatum B, and small numbers of adult Anisakis simplex; harbour and grey seals were the only phocids heavily infected with P. decipiens B. Ringed seal stomachs contained fewer nematodes than other seal species and were mainly infected with C. osculatum B and Phocascaris spp. In several seal species positive, but no negative, associations in abundance were observed between nematodes. Sex ratios of adult nematodes among individual seals were heterogeneous, but changes in sex ratio suggest a bias towards female nematodes among larvae infecting fish and a selective loss of adult females during maturation. Overall, the results suggest that grey and harbour seals are the main source of larval sealworm (P. decipiens B) occurring in fish stocks off Newfoundland and Labrador, although small numbers of adult P. decipiens B also occurred in hooded seals.

The Newfoundland Seal-Fishery and its Possible Influence on the Greenlanders

Polar Record ◽  
1938 ◽  
Vol 2 (16) ◽  
pp. 99-103 ◽  
Author(s):  
John Colman
Keyword(s):  
Phoca Vitulina ◽  
Point Of View ◽  
Standard Of Living ◽  
Bearded Seal ◽  
The West ◽  
Cystophora Cristata ◽  
Phoca Groenlandica ◽  
South West ◽  
The People ◽  
Drift Wood

The culture of most tribes of Eskimo is based largely on the hunting of seals, but the species of seal differ from region to region. The West Greenlanders are dependent on two species, the Harp or Greenland seal, Phoca groenlandica, and the Hood or Bladder-nose, Cystophora cristata, the former being the more abundant. The East Greenlanders make more use of the small fjord seals, Phoca vitulina, which supply the greater part of their food, while the importance to them of the two larger species and of the Bearded seal, Erignathus barbatus lies in the suitability of their skins for covering kayaks and other special purposes. The East Greenlanders, centred on Angmagssalik and Scoresby Sound, are the least touched by European contacts, and can still almost satisfy their needs, except for pipes, tobacco and knives, with drift wood, seals and other animals. The West Greenlanders have been in contact with Europeans for a much longer time, and have modified their primitive culture to some extent. Their kayaks are often made of canvas, and in the south-west they have taken up fishing and sheep farming on a considerable scale, but seal hunting from kayaks is still their most important job in life. The Danes are trying with remarkable success to improve the standard of living of the Greenlanders, while at the same time keeping them as independent as possible of foreign sources of supply. If, for any reason, the number of seals should fall too low to supply the needs of the people, the whole policy of the Danish Administration might have to be altered, and this would almost certainly not be an improvement from the point of view of the Greenlanders.

Redescription of Filaroides (Parafilaroides) gymnurus (Railliet, 1899) (Nematoda: Metastrongyloidea), with comments on other species in pinnipeds

1997 ◽  
Vol 75 (3) ◽  
pp. 359-370 ◽  
Author(s):  
Jean-François Gosselin ◽  
Lena N. Measures
Keyword(s):  
Phoca Vitulina ◽  
Valid Species ◽  
Halichoerus Grypus ◽  
Museum Specimens ◽  
Phoca Hispida ◽  
Ringed Seals ◽  
Phoca Groenlandica ◽  
Harbour Seals ◽  
Species Inquirenda

The species Filaroides (Parafilaroides) gymnurus (Railliet, 1899) Anderson, 1978 is redescribed, based on examination of mature fifth-stage specimens from wild infected ringed seals (Phoca hispida), harp seals (Phoca groenlandica), harbour seals (Phoca vitulina), and grey seals (Halichoerus grypus) collected in eastern and arctic Canadian waters. Mature specimens of Filaroides (Parafilaroides) hispidus Kennedy, 1986 from ringed seals and grey seals were also examined. Comparison of these worms with museum specimens and the literature led to a review of species in the subgenus Parafilaroides (Dougherty, 1946) Anderson, 1978. Filaroides (Parafilaroides) gymnurus (Railliet, 1899) Anderson, 1978, F. (P.) decorus (Dougherty and Herman, 1947) Anderson, 1978, F. (P.) hydrurgae (Mawson, 1953) Kennedy, 1986, and F. (P.) hispidus Kennedy, 1986 are recognized as valid species. Filaroides (Parafilaroides) arcticus (Delyamure and Alekseev, 1966) Kennedy, 1986 and F. (P.) krascheninnikovi (Yurakhno and Skrjabin, 1971) Kennedy, 1986 are synonymized with F. (P.) gymnurus (Railliet, 1899) Anderson, 1978. Filaroides (Parafilaroides) caspicus (Kurochkin and Zablotsky, 1958) Kennedy, 1986 is considered a species inquirenda.

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 A Short Investigation into the Habits, Abundance, and Species of Seals on the North Cornwall Coast

1934 ◽  
Vol 19 (2) ◽  
pp. 189-501 ◽  
Author(s):  
G. A. Steven
Keyword(s):  
Relative Abundance ◽  
Direct Evidence ◽  
Phoca Vitulina ◽  
Halichoerus Grypus ◽  
Grey Seal ◽  
The North ◽  
Single Night ◽  
Considerable Size

1. In the course of three trips to the herring grounds in the vicinity of St. Ives five seals were sighted. Seven others were also seen at various other times and places in the course of five days spent in that locality.2. During a single night at sea in Port Isaac Bay eight seals were sighted.3. It was obvious from the movements of certain of the seals observed on the fishing grounds that they were attracted to the herring nets.4. Direct evidence that the seals actually remove fish from the nets was not obtained.5. Damage done to drift nets by seals is negligible.6. Grey Seals (Halichœrus grypus) are present in considerable numbers, and are probably the commonest seals in Cornish waters.7. Brown Seals (Phoca vitulina) appear to be few—they may even be rare—around Cornwall.8. There is at least one seal colony of considerable size in certain caves near Boscastle. This appears to consist of Grey Seals. Probably other such colonies exist on the Cornish coast.9. Clupeoid remains have been found in two out of the three Grey Seal stomachs which have been examined.10. Further and more exact knowledge of the habits and relative abundance of Grey and Brown Seals around the Cornish coast is desirable.

Repetition enhances hearing detection thresholds in a harbour seal (Phoca vitulina)

1993 ◽  
Vol 71 (5) ◽  
pp. 926-932 ◽  
Author(s):  
S. D. Turnbull ◽  
J. M. Terhune
Keyword(s):  
White Noise ◽  
Background Noise ◽  
Phoca Vitulina ◽  
Harbour Seal ◽  
Detection Thresholds ◽  
Noise Masking ◽  
Phoca Groenlandica ◽  
Hearing Thresholds ◽  
Lower Detection ◽  
Pinniped Species

Pure-tone hearing thresholds of a harbour seal (Phoca vitulina) were measured in air and underwater using behavioural psychophysical techniques. A 50-ms sinusoidal pulse was presented in both white-noise masked and unmasked situations at pulse repetition rates of 1, 2, 4, and 10/s. Test frequencies were 0.5, 1.0, 2.0, 4.0, and 8.0 kHz in air and 2.0, 4.0, 8.0, and 16.0 kHz underwater. Relative to 1 pulse/s, mean threshold shifts were −1, −3, and −5 dB at 2, 4, and 10 pulses/s, respectively. The threshold shifts from 1 to 10 pulses/s were significant (F = 12.457, df = 2,36, p < 0.001) and there was no difference in the threshold shifts between the masked and unmasked situations (F = 2.585; df = 1,50; p > 0.10). Broadband masking caused by meteorological or industrial sources will closely resemble the white-noise situation. At high calling rates, the numerous overlapping calls of some species (e.g., harp seal, Phoca groenlandica) present virtually continous "background noise" which also resembles the broadband white-noise masking situation. An implication of lower detection thresholds is that if a seal regularly repeats short vocalizations, the communication range of that call could be increased significantly (80% at 10 pulses/s). This could have important implications during the breeding season should storms or shipping noises occur or when some pinniped species become increasingly vocal and the background noise of conspecifics increases.

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