Long-distance movements of harbour seals (Phoca vitulina) from a seasonally ice-covered area, the St. Lawrence River estuary, Canada

2004 ◽  
Vol 82 (7) ◽  
pp. 1070-1081 ◽  
Author(s):  
Véronique Lesage ◽  
Mike O Hammill ◽  
Kit M Kovacs

Previous studies of harbour seal (Phoca vitulina L., 1758) movements indicate that this species is relatively sedentary throughout the year. However, few investigations have examined their movements and seasonal distribution patterns in ice-covered areas. This study used spatial analysis of ice data and movement data from harbour seals collected via satellite (n = 7) and VHF radiotelemetry (n = 15) to explore this species' spatial use patterns in a seasonally ice-covered region, the St. Lawrence River estuary, Canada. When solid ice formed within the bays of the estuary, four of the seven satellite-tagged animals (all adult males) left their summer haul-out areas, migrating 266 ± 202 km (range 65–520 km) to over-wintering sites. The seals exhibited preference for areas of light to intermediate ice conditions during the winter months; at least six of the seven seals occupied areas with lighter ice conditions than those that prevailed generally in the study area. Evidence of high abundance of potential prey for harbour seals in the estuary during winter suggests that reduced availability of adequate food resources is not the primary factor which influences the movement and distribution patterns of harbour seals. Movement patterns observed during the ice-free period concur with previously reported harbour seal behaviour; the seals remained near the coast (<6.1–11.0 km from shore) in shallow water areas (<50 m deep in 100% VHF and 90% SLTDRs (satellite-linked time-depth recorders)) and travelled only short distances (15–45 km) from capture sites. None of the VHF- or satellite-tagged seals crossed the 350 m deep Laurentian channel, which suggests that this deep body of water might represent a physical barrier to this coastal population.

2006 ◽  
Vol 33 (5) ◽  
pp. 361 ◽  
Author(s):  
Pierre-Yves Daoust ◽  
G. Mark Fowler ◽  
Wayne T. Stobo

Hot branding has been used for many years by researchers to identify seals from a long distance. In livestock, cold branding has been proposed as an alternative because it is thought to be less painful. The purpose of this study was to compare the healing process of hot and cold brands applied to harbour seal pups (Phoca vitulina). A total of 306 animals was branded with a unique set of four characters: three applied for 3–5 s with an iron heated to 500°C, and one applied for either 10 or 20 s with an iron frozen to –175°C. At three subsequent times over 10 weeks, 43, 41 and 51 animals, respectively, were recaptured, the macroscopic appearance of their brands recorded, and biopsies taken for microscopic examination. Cold brands had a faster healing rate than hot brands. However, they resulted in less destruction of hair follicles, and cold brands applied for 20 s caused more depigmentation. Regrowth of hair follicles could subsequently obscure brands, while depigmentation reduces the contrast between the brand and the surrounding fur. Cold brands applied for 20 s also caused more extensive deep vascular damage, which subsequently may have resulted in deeper wounds in some of these brands. Yet, macroscopically, other cold brands, or portions thereof, were almost invisible. On the basis of this short-term study, the technique of cold branding that we used in harbour seals does not appear to be as reliable as that of hot branding to provide permanent legible brands.


2003 ◽  
Vol 81 (2) ◽  
pp. 188-194 ◽  
Author(s):  
Y Dubé ◽  
M O Hammill ◽  
C Barrette

Surveys to estimate the daily growth rate of harbour seal (Phoca vitulina) pups from birth to weaning and to determine the distribution of births were carried out from early May to late August 1998, 1999, and 2000 at two haulout areas in the St. Lawrence River estuary, Canada. Pups gained mass at a rate of 0.544 kg/day (standard error (SE) = 0.141, range 0.118–0.875 kg/day, N = 110). Births began between 12 and 17 May. The median dates of birth were 28 May (95% confidence interval (CI), 27–30 May) in 1998, 25 May (95% CI, 24–28 May) in 1999, and 26 May (95% CI, 24–27 May) in 2000. Births followed a normal distribution in 2000, but late pupping led to an extended tail in both 1998 and 1999. Pupping occurred at the same time in the St. Lawrence River estuary as at Sable Island, a colony located 600 km to the south, but occurred earlier than predicted by the relationship of Temte et al. (1991). The estimated median dates of weaning were 1 July (95% CI, 20 June to 12 July) in 1998, 30 June (95% CI, 19 June to 11 July) in 1999, and 26 June (95% CI, 20 June to 2 July) in 2000. Pooling years resulted in an average lactation duration of 34 days (SE = 1.8).


The Auk ◽  
2002 ◽  
Vol 119 (3) ◽  
pp. 676-684 ◽  
Author(s):  
Michel Robert ◽  
Réjean Benoit ◽  
Jean-Pierre L. Savard

Abstract Little is known of the eastern North American population of Barrow's Goldeneyes (Bucephala islandica), which was recently listed as “of special concern” in Canada. In 1998 and 1999, we marked 18 adult males wintering along the St. Lawrence River, Québec, with satellite transmitters to document their breeding, molting, and wintering distribution and phenology, and to describe timing and routes of their spring, molt, and fall migrations. Thirteen males moved inland from the St. Lawrence River to breed; the spring migration averaged 5.9 days, and birds arrived on breeding areas on average 9 May. All breeding areas were inland, on the north shore of the St. Lawrence River estuary and gulf. Breeding areas averaged 64.8 km from the St. Lawrence corridor. Males stayed on their respective breeding area a mean of 34.5 days, and left on average 11 June. Twelve males were tracked to their molting areas, one of which stayed on its wintering area until 5 June and flew directly to its molting area. Their molt migration averaged 18.6 days, and the mean arrival date on molting areas was 30 June. All molting areas were located north and averaged 986 km from breeding areas. Four males molted in Hudson Bay, four in Ungava Bay, two in northern Labrador, one on Baffin Island, and one inland, near the Québec–Labrador border. The mean length of stay on the molting areas was 105.3 days, and the mean date of departure from molting areas was 4 October. All goldeneyes for which the radio still functioned during fall migration returned to winter in the St. Lawrence River estuary, on average 6 November. Our results refute the idea that the main breeding area of the eastern North American population of Barrow's Goldeneyes is located in northern Québec and Labrador and rather indicate that it is in the boreal forest just north of the St. Lawrence River estuary and gulf. They also indicate that Barrow's Goldeneye males undertake a genuine molt migration, and highlight the importance of molting areas because birds stayed there approximately four months each year.


2005 ◽  
Vol 85 (4) ◽  
pp. 1015-1016 ◽  
Author(s):  
Laurent J.J. Seuront ◽  
Perrine Prinzivalli

The abundance of the harbour seal (Phoca vitulina) was recorded on a tidal bar in the Dover Strait off Calais, over a six-year period between 1999 and 2004. Despite clear seasonal and interannual variability in the number of individuals hauled out on the bar, underwater activities devoted to the installation of industrial wastewater pipes conducted during seven weeks 1 km away from the bar led to a dramatic decline in the number of seals hauling out. A full 19 months after the end of the operations the harbour seal population had not recovered their initial abundance. The results of this study have critical consequences on the conservation of P. vitulina in areas impacted by anthropogenic activities.


2010 ◽  
Vol 8 ◽  
pp. 37 ◽  
Author(s):  
Sergey V Zyryanov ◽  
Sergey A Egorov

Harbour seals are observed along the Murmansk coast of Russia, but they are not very abundant there. The estimated abundance for this area was about 500 individuals in 1998. The number of seals observed during winter months is less than during summer. During summer, the main habitats are the Pechenga inlet, the Motovsky and Kola Bays of the Western Murman coast and the Ivanovskaya Bay in the Eastern Murman coast. The Ivanovskaya Bay was thought to be the easternmost breeding colony of the subspecies Phoca vitulina vitulina. However, recent sightings may indicate the establishment of a breeding site further to the east, which then becomes the easternmost known habitat for this subspecies. A substantial, recent decrease in abundance has been observed in the Ivanovskaya Bay. The population numbered about 120 seals in the early 1990s, but only about 20 seals were seen in 2007 and 2008. It is presumed that the reasons for this reduction include hunting, fishery by-catch, disturbance and depletion of the food supply in this semi-enclosed inlet. A gender-specific daily activity pattern was observed in the IvanovskayaBay. The highest number of single animals (primarily adult males) hauled out during mid day, while hauled out females with pups showed two peaks per day associated with low tides.


2010 ◽  
Vol 8 ◽  
pp. 7 ◽  
Author(s):  
Arne Bjørge ◽  
Geneviève Desportes ◽  
Gordon T Waring ◽  
Aqqalu Rosing-Asvid

Introduction to Volume 8: Harbour seals in the North Atlantic and the Baltic 


2015 ◽  
Vol 13 ◽  
pp. 41-43
Author(s):  
Erlingur Hauksson

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.


1981 ◽  
Vol 59 (7) ◽  
pp. 1457-1459 ◽  
Author(s):  
J. R. Geraci ◽  
J. F. Fortin ◽  
D. J. St. Aubin ◽  
B. D. Hicks

Heartworms, Dipetalonema spirocauda, are common in harbour seals, Phoca vitulina, that strand along the New England coast. Lice, Echinophthirius horridus, taken from a stranded harbour seal infected with seal heartworm carried three developmental stages of D. spirocauda. This is the first report of an intermediate host of the seal heartworm.


2004 ◽  
Vol 82 (7) ◽  
pp. 1147-1156 ◽  
Author(s):  
J L Hicks ◽  
R J O'Hara Hines ◽  
J F Schreer ◽  
M O Hammill

Harbour seal (Phoca vitulina L., 1758) pups are aquatically active from birth and have been shown to develop increased cardiac control throughout the nursing period. In an attempt to quantify and compare these developmental changes, data previously collected on pups in the St. Lawrence River estuary, Quebec, Canada, were analyzed. Time–depth recorders and heart-rate recorders were employed on eight pups to obtain depth and heart-rate measurements simultaneously. Analyses involved partitioning the data into intervals of surface–dive–surface. These intervals were then allocated into nine consecutive segments: presurface, predive surface, descent, prebottom, bottom, postbottom, ascent, postdive surface, and postsurface. Mean heart rate for each segment was then correlated with the mean depth per segment and overall dive duration. With increasing dive depth, a decrease in heart-rate variability with age was observed. There was no apparent relationship between mean heart rate during the dive and overall dive duration. The proportion of time spent in the lower heart-rate mode was observed to increase with age during most phases of a dive. Relative changes in mean heart rate between consecutive dive segments indicated an initial decrease in mean heart rate prior to submersion and an increasing trend before surfacing. These findings indicate that harbour seal pups develop increased cardiac control prior to weaning and that anticipatory cardiac responses to diving and surfacing (bradycardia and tachycardia, respectively) may be evident.


2010 ◽  
Vol 8 ◽  
pp. 143 ◽  
Author(s):  
Bjarni Mikkelsen

The harbour seal was exterminated as a breeding species in the Faroe Islands in the mid-19th Century. Historical sources document that the harbour seal used to be a common inhabitant of the sheltered fjords where breeding occurred. It was reported to be more common than the grey seal, the other pinniped specie resident around the Faroes. But the number of harbour seals seemingly decreased as human settlements and other anthropogenic activities increased. Seal hunting was apparently already introduced by the Norse that arrived on the islands in the 7th century, a hunt that finally lead to the extermination of the harbour seal. For the last 40 years the harbour seal has only been positively identified twice in the Faroe Islands, in 2001 and 2005.


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