scholarly journals Review on utilization and research on harbour seal (Phoca vitulina) in Iceland

2010 ◽  
Vol 8 ◽  
pp. 341 ◽  
Author(s):  
Erlingur Hauksson ◽  
Sólmundur T Einarsson

Harbour seals (Phoca vitulina) have been harvested in Iceland since the first settlers arrived in the 9th century. Pups were generally netted, clubbed and harpooned until 1875 when general use of guns for hunting began. Seal-hunting has been traditional amongst the farms legal rights. Seal hunting was an important supplement to other economic resources. Harbour seal skins, salted ordried, were exported and large dataset of catch statistics is available from trading logbooks since the late 19th century. In the early 20th century catch was about 6,000. In the ‘bounty’ period 1982 – 1989, maximum catches were of 4,000 animals with about 350 hunters participated; in 2006 catches were only about 100 animals with 18 hunters. After 1989 the population continued to decline even though catches decreased markedly. Unreported by-catch in fishing gear, hunt for local consumption and shooting of seals swimming in salmon rivers estuaries may have kept the total removal from the stock above sustainable levels. A considerable Icelandic knowledge base had been compiled about the biology of the harbour seal since the late 16th century, with the first written reference in 1588-1589. In the last decades, research on various aspects of its biology and monitoring have been intensified, with focus on abundance, distribution, diet and nematode infestation. The main results show that the Icelandic harbour seal population - has declined annually about 5% in the period 1980-2006, - was most abundant on the NW-coast, - feeds mainly on sand-eels and gadoids, - and was less infected with anisakid nematodes than grey seals. Seal watching, as a low-consumptive indirect utilization, may represent a new economical opportunity if properly regulated.

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. 147 ◽  
Author(s):  
Erlingur Hauksson ◽  
Sólmundur T Einarsson

The harbour seal (Phoca vitulina) is Iceland’s most abundant seal and has likely been exploited since the settlement of the country. Detailed information on skin exports is available as far back as 1912, and suggests that the catch, consisting mainly of pups, was far higher in the early 20th century than now. Assuming that skin exports were proportional to catches, these data were used to back-calculate the size of the Icelandic harbour seal population to the year 1912. The results indicate that the harbour seal population was considerably larger in the early 19th century than at present, about 60,000 (90% CI:40-100) animals. Aerial surveys conducted since 1980 indicate that the population has declined from 33,000 (90% CI:26,000-44,000) animals in 1980 to about 12,000 (90% CI:9,000-16,000) animals in 2006. The population time series suggests thatthe stock began to decline rapidly around 1960 and continued to decrease until 2003. In the period 1980 - 2003, the population declined even though reported catches were relatively low. Harvest rate had probably been about 10% before 1960. Between 1960 and 1980 the reported harvest rate increased to about 13%, but unknown numbers of adult seals were also taken as by-catch and shot in defence of salmon rivers. Since 2003, total removals have decreased and the population decline appears to have ceased. Entanglements in fishing gear and other incidental unreported hunting could increase again in the future. Therefore, the population must be monitored on a regular basis, and better information on by-catch and other unreported harvest is needed.


2010 ◽  
Vol 8 ◽  
pp. 227 ◽  
Author(s):  
Erlingur Hauksson

Harbour seal (Phoca vitulina) numbers along the coast of Iceland were monitored by aerial survey in the period 1980-2006. Trends in the abundance of the harbour seal population on the whole coast and in coastal regions of Iceland waters were estimated using ANCOVA on the survey counts, corrected for the influence of several covariates. Harbour seals were found in every coastal area, but were most abundant in Faxaflói, Breiðafjörður and on the northwest coast inthe beginning of this study. Harbour seal numbers declined significantly at a rate of rest = -0.04 (SE 0.005) yr-1 during this period. Decline was highest in Faxaflói and at the south coast (≅7%), while the east coast experienced a significant but lesser (≅1%) decline. Other coastal areas did not show significant trends. The northwest coast was the richest harbour seal area in Iceland in 2006. In Icelandic waters seals are commercially harvested, and unreported but probably high numbers of harbour seals are killed intentionally by shooting and accidentally in fishing geareach year. These factors likely contributed to the overall observed decline in seal numbers.


2010 ◽  
Vol 8 ◽  
pp. 161 ◽  
Author(s):  
Aqqalu Rosving-Asvid

The number of harbour seals (Phoca vitulina) in West Greenland declined rapidly after the 1950s and the seals have now abandoned their traditional haulout locations along the Greenland west coast. However, in recent years, a previously undetected group of about 60-100 harbour seals has been observed approximately 80 km upstream in a large river, and some traditional hauloutlocations are still in use near the south-eastern tip of Greenland. A small number of harbour seals is caught annually far from any of these locations, indicating that other groups might live unnoticed. Catch statistics provide the best evidence of the presence and locations of these remnant harbour seals. Therefore efforts were made to validate the recent catch statistics and to describe the catch history for the past 60 years. The catch statistics were also used to estimate plausibleranges of past and present numbers of harbour seals based on the assumption that hunting has caused the observed decline. The total number of harbour seals in Greenland according to these estimates was about 3,000 in 1950 and fewer than 1,000 in 2007. The number of harbour seals caught in the southernmost part of Greenland has, unlike in the rest of Greenland, increased significantly in some of the recent years. This change seems to be related to changes in the amount of drift ice. Drift ice reduces the frequency of contact between hunters and harbour seals in South Greenland and above normal quantities of drift ice from the mid 1960s to the mid 1980s probably allowed these seals to increase in numbers. Record low inflow of drift ice in some of the recent years, however, has resulted in record high catches, which likely have reduced the seals again. The remaining harbour seals in Greenland are few and without protection these sealsare potentially in danger of extinction.


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.


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.


2002 ◽  
Vol 80 (3) ◽  
pp. 442-449 ◽  
Author(s):  
Wayne T Stobo ◽  
L Paul Fanning ◽  
Brian Beck ◽  
G Mark Fowler

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.


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