BACTERIAL MICROBIOTA IN HARBOR SEALS (PHOCA VITULINA) FROM THE NORTH SEA OF SCHLESWIG-HOLSTEIN, GERMANY, AROUND THE TIME OF MORBILLIVIRUS AND INFLUENZA EPIDEMICS

AbstractThe Seal Rehabilitation and Research Centre (SRRC) in Pieterburen, The Netherlands, rehabilitates seals from the waters of the Wadden Sea, North Sea and Southwest Delta area. Incidental observations of albinism and melanism in common and grey seals are known from countries surrounding the North Sea. However, observations on colour aberrations have not been systematically recorded. To obtain the frequency of occurrence of these colour aberrations, we analysed data of all seals admitted to our centre over the past 38 years. In the period 1971-2008, 3000 common seals (Phoca vitulina) were rehabilitated, as well as 1200 grey seals (Halichoerus grypus). A total of five albinistic common seals and four melanistic grey seals were identified. This results in an estimated incidence of albinism in common seals of approximately 1/600, and of melanism in grey seals of approximately 1/300. The seals displayed normal behaviour, although in the albinistic animals, a photophobic reaction was observed in daylight.

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The importance of the North Sea for winter dispersal of harbour seals Phoca vitulina from the Wadden Sea

Biological Conservation ◽

10.1016/s0006-3207(96)00092-4 ◽

1997 ◽

Vol 81 (1-2) ◽

pp. 97-102 ◽

Cited By ~ 7

Author(s):

Mardik F. Leopold ◽

Bert van der Werf ◽

Edith H. Ries ◽

Peter J.H. Reijnders

Keyword(s):

North Sea ◽

Wadden Sea ◽

Phoca Vitulina ◽

The North ◽

Harbour Seals ◽

The North Sea

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Seals in Orkney

Proceedings of the Royal Society of Edinburgh Section B Biological Sciences ◽

10.1017/s0269727000004188 ◽

1985 ◽

Vol 87 (1-2) ◽

pp. 95-104 ◽

Cited By ~ 1

Author(s):

Bernie McConnell

Keyword(s):

North Sea ◽

Total Population ◽

Phoca Vitulina ◽

Management Policy ◽

Halichoerus Grypus ◽

Grey Seal ◽

Total Population Size ◽

The North ◽

The North Sea ◽

Domestic Use

SynopsisGrey seals (Halichoerus grypus) and common seals (Phoca vitulina) both occur in Orcadian waters. In previous centuries they formed an important resource for both domestic use and export.Annual grey seal pup production has more than doubled since 1964. Productivity on individual islands is influenced by human activity. Total population size is estimated to have risen from around 10,000 in 1964 to around 20,000 in 1982 despite a management policy of culling originally intended to stop population growth. Grey seals tagged in Orkney have been recovered around most parts of the North Sea, Norway, the Faeroes and south to Ireland.Considerably less is known about the biology of common seals in Orkney. A boat survey in 1979 counted 2653 adults and 420 pups.

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Relationships between in vitro lymphoproliferative responses and levels of contaminants in blood of free-ranging adult harbour seals (Phoca vitulina) from the North Sea

Aquatic Toxicology ◽

10.1016/j.aquatox.2013.08.014 ◽

2013 ◽

Vol 142-143 ◽

pp. 210-220 ◽

Cited By ~ 11

Author(s):

Aurélie Dupont ◽

Ursula Siebert ◽

Adrian Covaci ◽

Liesbeth Weijs ◽

Gauthier Eppe ◽

...

Keyword(s):

North Sea ◽

Phoca Vitulina ◽

The North ◽

Harbour Seals ◽

The North Sea ◽

Free Ranging

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Identification and real-time PCR quantification of Phocine distemper virus from two colonies of Scottish grey seals in 2002

Journal of General Virology ◽

10.1099/vir.0.80962-0 ◽

2005 ◽

Vol 86 (9) ◽

pp. 2563-2567 ◽

Cited By ~ 19

Author(s):

John A. Hammond ◽

Patrick P. Pomeroy ◽

Ailsa J. Hall ◽

Valerie J. Smith

Keyword(s):

North Sea ◽

Active Role ◽

Phoca Vitulina ◽

Primary Site ◽

Halichoerus Grypus ◽

Grey Seal ◽

Acute Effects ◽

The North ◽

Phocine Distemper Virus ◽

The North Sea

The North Sea European harbour seal (Phoca vitulina) population has endured two phocine distemper virus (PDV) epidemics in 1988 and 2002. The grey seal (Halichoerus grypus) is a sympatric seal species that shows little or no mortality from PDV. Two Scottish grey seal breeding colonies were sampled for evidence of PDV infection approximately 2 months after the peak of the 2002 epidemic. In both colonies, a proportion of mothers (13/109) and pups (6/84) tested positive for PDV in their leukocytes. All infected animals were asymptomatic and completed the breeding season successfully. These results illustrate that grey seals come into contact with infectious seals and can become infected themselves without experiencing acute effects. In some seals the virus is able to replicate from the primary site of infection. This study provides evidence that grey seals may have an active role in the spread of PDV during an epidemic.

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Predicting recurrent PDV epizootics in European harbour seals (Phoca vitulina)

NAMMCO Scientific Publications ◽

10.7557/3.2690 ◽

2010 ◽

Vol 8 ◽

pp. 275 ◽

Cited By ~ 1

Author(s):

Tero Härkönen ◽

Karin C Harding

Keyword(s):

North Sea ◽

Herd Immunity ◽

Phoca Vitulina ◽

High Rate ◽

The North ◽

Rate Of Spread ◽

Phocine Distemper Virus ◽

Harbour Seals ◽

The North Sea ◽

Sea Area

Phocine Distemper Virus (PDV) caused mass mortality in European harbour seals (Phoca vitulina) in 1988 and in 2002. Both epizootics likely originated from refugia in Arctic seals, where data indicate PDV hops among populations and species. The metapopulation structure of host populations is suggested to be the reason why PDV is preserved among Arctic seals, since the high rate of spread of PDV would require much larger panmictic populations to maintain an infection. The pattern of sudden outbreaks of PDVis also seen in grey seals (Halichoerus grypus), the only to date identified species that could act as a vector between Arctic and North Sea seal populations. Harbour seal populations along mainland Europe were below critical herd immunity levels by 3-5 years after the events, and thus vulnerable for new outbreaks, but historical data and the 14 years between the 2 epizootics suggest that harbour seals in the North Sea area are only rarely exposed to the infective agent. The risk for new outbreaks of the seal plague in North Sea harbour seals is likely linked to the dynamics of the disease in Arctic seal species as well asvector species.

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