The Davis Strait - DCE - Nationalt Center for Miljø og Energi

surround the eyes and line the oral cavity, respiratory surfaces, the anal and
urogenital orifices. In addition, oil can poison seals through ingestion or inhalation.
Finally, oil spills can have a disruptive effect by interfering with
normal behavior patterns. Effects of oil on seals have the greatest impacts on
the pups (St. Aubin 1990 and references therein). Pups are sessile during the
weaning period and can therefore not move away from oil spills. They are
protected against the cold by a thick coat of woolly hair (lanugo hair) and oil
will have a strong negative effect on the insulating properties of this fur. The
mother seals recognise their pups by smell and a changed odour caused by
oil might therefore affect the mother’s ability to recognise its pup. Although
the sensory abilities of seals should allow them to detect oil spills through
sight and smell, seals have been observed swimming in the midst of oil
slicks, suggesting that they may not be aware of the danger posed by oil (St
Aubin 1990).
Hooded seal, Cystophora cristata
Distribution and numbers: Hooded seals are migratory seals (Fig. 4.8.3). The
vast majority of the seals from the West Atlantic population whelp in areas
near Newfoundland, but part of the population whelp in the Davis Strait.
The positions of this whelping patch as well as the number of seals that use
this area for whelping change significantly from year to year. The location of
the Davis Strait whelping patch also changes during the whelping season as
the seals give birth on non-consolidated drifting pack ice. Published locations
of whelping hooded seal in the Davis Strait (Sergeant 1974, 1976, 1977,
ICES/NAFO 1997 , Kapel 1998) show that some years the hooded seal
whelps within the assessment area and some years just outside the area.
The hooded seals give birth in late March-early April and the lactation period
is only 4 days (Perry & Stenson 1992). The female mate shortly after the
lactation period and the adult seals disperse in early April. The pups will
stay a few weeks around their birth place before they also swim away. Most
hooded seals from the West Atlantic (both the seals that have been whelping
near Newfoundland and in Davis Strait) swim to Southeast Greenland during
May-June and moult on the drift ice off east Greenland in June-July. In
August-September they swim back to Davis Strait and Baffin Bay where
many of them forage throughout the winter regularly diving below 500 m
(down to 1500 m (Andersen 2009)). They prey mainly on large fish and
squids before they return to the whelping areas in spring.
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