scholarly journals Trophic niche overlap between sympatric harbour seals ( Phoca vitulina ) and grey seals ( Halichoerus grypus ) at the southern limit of their European range (Eastern English Channel)

2021 ◽  
Author(s):  
Yann Planque ◽  
Jérôme Spitz ◽  
Matthieu Authier ◽  
Gaël Guillou ◽  
Cécile Vincent ◽  
...  
Keyword(s):  
Niche Overlap ◽  
Phoca Vitulina ◽  
Trophic Niche ◽  
Halichoerus Grypus ◽  
English Channel ◽  
Southern Limit ◽  
Harbour Seals

Fatal Interspecies Mating Attempts of a Grey Seal (Halichoerus grypus) with Harbour Seals (Phoca vitulina) on the German North Sea Coast

2020 ◽  
Vol 174 ◽  
pp. 166
Author(s):  
K. Hülskötter ◽  
S. Rohner ◽  
S. Groß ◽  
J. Lakemeyer ◽  
M. Fähndrich ◽  
...  
Keyword(s):  
North Sea ◽  
Phoca Vitulina ◽  
Halichoerus Grypus ◽  
Grey Seal ◽  
Harbour Seals ◽  
Sea Coast ◽  
North Sea Coast

scholarly journals Winter habitat use of harbour seals (Phoca vitulina) fitted with Fastloc™GPS/GSM tags in two tidal bays in France

2010 ◽  
Vol 8 ◽  
pp. 285 ◽  
Author(s):  
Cécile Vincent ◽  
Bernie J McConnell ◽  
Stéphanie Delayat ◽  
Jean-François Elder ◽  
Gérard Gautier ◽  
...  
Keyword(s):  
Habitat Use ◽  
Prey Availability ◽  
Phoca Vitulina ◽  
Coastal Areas ◽  
Foraging Strategies ◽  
Behavioural Plasticity ◽  
Winter Habitat ◽  
Southern Limit ◽  
Harbour Seals ◽  
Mussel Farms

Winter movements and habitat use of harbour seals (Phoca vitulina) were investigated in two tidal bays in France, at the southern limit of their species range in the Northeast Atlantic. We fitted 15 seals with Fastloc™GPS/GSMtags in the Baie du Mont-Saint-Michel (BMSM) and the Baie des Veys (BDV). Tags relayed 20.6±7.1 GPS locations per seal-day, 81% of all dives performed by the seals and 87% of haulouts, during an average tracking duration of 108±56 days. One seal travelled 380 km away from the BMSM but the other seals remained stationary, with 95% and 55% of at-sea locations ≤ 5 km from the haulout sites in BMSM and BDV respectively. Home range sizes were 137 and 161 km² in BMSM and BDV, and core areas’ sizes, 35 and 22 km² respectively. The seals remained very coastally in both sites with 93% and 71% of at-sea locations located in the intertidal zone of BMSM and BDV respectively. Accordingly, dives were shallow with 63% and 61% of dive maximum depths <4 m and 94% and 88% <10 m (in BMSM and BDV respectively). Preferred foraging areas were located in tidal channels in BMSM, sometimes in the vicinity of rocks or mussel farms. In BDV one seal made foraging trips 10-15 km offshore but all other seals repeatedly used coastal areas, often foraging around mussel farms, shipwrecks or intertidal rocks in tidal currents. We suggest that the importance of the tides combined with local features of the topography allow seals to predict prey availability, driving their foraging strategies towards a number of specific coastal areas. These results further illustrate the behavioural plasticity of the species according to habitat and environmental conditions. Fastloc™ GPS/GSM telemetry is particularly well adapted for the study of seals’ habitat use at a fine geographical and temporal scale, as long as they occasionally come close to shore within GSM coverage.

scholarly journals Observations on seals on the island of Surtsey in the period 1980-2012

2015 ◽  
Vol 13 ◽  
pp. 41-43
Author(s):  
Erlingur Hauksson
Keyword(s):  
Breeding Site ◽  
Phoca Vitulina ◽  
The Other ◽  
South Coast ◽  
Harbour Seal ◽  
Halichoerus Grypus ◽  
Grey Seal ◽  
The South ◽  
Breeding Sites ◽  
Harbour Seals

Grey seals (Halichoerus grypus Fabricius) and harbour seals (Phoca vitulina L.) have been surveyed on the coasts of Iceland since 1980. During the period 1980-2012, both seal species have declined markedly in numbers at the Icelandic coast. The grey seal has established a considerable breeding site on the northern spit of the Surtsey island. This is at present one of the biggest grey seal rookeries on the southern shores of Iceland, with estimated about 60 pups born there in the autumn of 2012. On the other hand, the harbour seal has not been numerous on Surtsey during breeding time in the summer. Breeding sites of harbour seals on the south coast of Iceland closest to Surtsey are in the estuaries of the glacial rivers Ölfusá, Þjórsá, Markarfljót and Kúðafljót. Harbour seals, however, haul-out in great numbers on the northern shores of Surtsey during the winter, presumably using the island as a resting place after foraging in the adjacent waters.

Abundance and maturity of three species of parasitic anisakine nematodes (Pseudoterranova decipiens, Contracaecum osculatum, Anisakis simplex) occurring in Sable Island harbour seals (Phoca vitulina)

2002 ◽  
Vol 80 (3) ◽  
pp. 442-449 ◽  
Author(s):  
Wayne T Stobo ◽  
L Paul Fanning ◽  
Brian Beck ◽  
G Mark Fowler
Keyword(s):  
Prey Species ◽  
Phoca Vitulina ◽  
Final Host ◽  
Anisakis Simplex ◽  
Halichoerus Grypus ◽  
Commercial Fish ◽  
Pseudoterranova Decipiens ◽  
Harbour Seals ◽  
Seal Population ◽  
Contracaecum Osculatum

Three species of anisakine nematodes (Pseudoterranova decipiens, Contracaecum osculatum, Anisakis simplex) co-occur in the stomachs of Sable Island harbour seals (Phoca vitulina). The sealworm, P. decipiens, was the commonest nematode in these seals. Anisakis simplex was found in much smaller numbers, none mature, indicating that the harbour seal is not a true final host to this parasite. Contracaecum osculatum was rare but half were mature. Pseudoterranova decipiens increased in abundance with size of the seal. An inverse relationship was observed between P. decipiens abundance and the age of seals of similar size, probably owing to changes in diet. Numbers of P. decipiens may have declined over the summer, coincident with an increase in the proportion of mature worms in the stomach. From similarities between the worm infections of grey seals (Halichoerus grypus) and harbour seals, we infer that A. simplex abundance may also exhibit a decline in abundance. Contracaecum osculatum was only encountered during the latter half of the year, suggesting an association with prey species of corresponding periodicity in their distribution. We estimate that the abundance of sealworm in harbour seals is about 2.5% of that carried by the grey seal population. This could imply that harbour seals represent an insignificant vector of the sealworm infecting commercial fish species in the Northwest Atlantic, provided density-dependent relationships exist between worm abundances in different host species.

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.

scholarly journals Campylobacter pinnipediorum subsp. caledonicus and C. pinnipediorum subsp. pinnipediorum recovered from abscesses in pinnipeds

2020 ◽  
Vol 142 ◽  
pp. 41-46
Author(s):  
G Foster ◽  
JL Baily ◽  
F Howie ◽  
AC Brownlow ◽  
JA Wagenaar ◽  
...  
Keyword(s):  
Bacterial Isolate ◽  
Novel Species ◽  
Phoca Vitulina ◽  
Halichoerus Grypus ◽  
The Novel ◽  
California Sea Lions ◽  
Sea Lions ◽  
Harbour Seals ◽  
Phocid Seals ◽  
Bite Wounds

Campylobacter pinnipediorum was described recently for isolates recovered from pinnipeds. The novel species was further split into 2 subspecies based on host and geography, with C. pinnipediorum subsp. pinnipediorum recovered from otariid seals in California (USA) and C. pinnipediorum subsp. caledonicus recovered from phocid seals in Scotland. We report details of the infections of 7 pinnipeds from which C. pinnipediorum was isolated: C. pinnipediorum subsp. caledonicus was isolated from 2 harbour seals Phoca vitulina and a single grey seal Halichoerus grypus, and C. pinnipediorum subsp. pinnipediorum was isolated from California sea lions Zalophus californianus. Six of the isolates were recovered from samples collected at post-mortem investigation. In 2 of the Scottish seals and in 3 of the California seals, C. pinnipediorum was the sole bacterial isolate recovered from abscesses present and suggests they may have resulted from conspecific or intraspecific bite wounds.

Levels and enantiomeric ratios of α-hch, oxychlordane, and pcb 149 in blubber of harbour seals (Phoca vitulina) and grey seals (Halichoerus grypus) from iceland and further species

Chemosphere ◽  
1998 ◽  
Vol 37 (9-12) ◽  
pp. 2501-2512 ◽  
Author(s):  
Ulrike Klobes ◽  
Walter Vetted ◽  
Bernd Luckas ◽  
Karl Skímisson ◽  
Jochen Plötz
Keyword(s):  
Phoca Vitulina ◽  
Halichoerus Grypus ◽  
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.

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