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

majority of the biomass. From a biodiversity perspective the high prevalence
of species found at only one site and of species represented only by a single
specimen also suggests that mortality induced from disturbance from oil
spills or exploration can potentially cause a significant reduction in the total
species richness for a long period of time.
11.2.4 Oil spill impacts on ice habitats
There is very little knowledge available on oil spill impact on the sea-ice ecosystem
(Camus & S. 2007, Skjoldal et al. 2007). Oil may accumulate under
the ice and stay until break-up and melt; weathering processes are inhibited
which means that the toxicity may persist much longer than in open waters.
See also section 11.1.3 above.
At least in laboratory experiments with sea-ice amphipods sublethal effects
of exposure to WSF have been demonstrated on sea-ice fauna (Camus &
Olsen 2008, Olsen et al. 2008). Polar cod have also been exposed to PAHs
and crude oil, both in the field and laboratory, and several sublethal effects
were demonstrated. Moreover polar cod seems to be a suitable indicator
species in relation to monitoring pollution effects caused by oil (Nahrgang et
al. 2009, Christiansen et al. 2010, Jonsson et al. 2010, Nahrgang et al. 2010a,
Nahrgang et al. 2010b, Nahrgang et al. 2010c, Nahrgang et al. 2010d).
The sympagic ecosystem is however very resilient as it necessarily has to reestablish
each season when new ice is formed, at least in areas dominated by
first-year ice.
It is apparent that polar cod could be particularly sensitive, due to the fact
that their eggs stay for a long period just below the ice, where also oil would
accumulate (Skjoldal et al. 2007).
11.2.5 Oil spill impacts in coastal habitats
One of the lessons learned from the Exxon Valdez oil spill was that the nearshore
areas were the most impacted habitats (NOAA 2010). Many of the animal
populations from this habitat are assessed to have recovered (birds,
fish), but certain populations are still in recovery (several bird species, clams,
mussels) and a few were recently assessed as ‘not recovered’ (pigeon guillemot
– a close relative to the black guillemot in Greenland, and also Pacific
herring) (NOAA 2010).
In coastal areas where oil can be trapped in shallow bays and inlets, oil concentrations
can build up in the water column to levels that are lethal to adult
fish and invertebrates (e.g., McCay 2003).
An oil spill from an activity in the assessment area which reaches the coast
has the potential to reduce stocks of capelin and lumpsucker, because these
fish spawn here and the sensitive eggs and larvae may be exposed to high
oil concentrations. Arctic char may be forced to stay in oil contaminated
shallow waters when they assemble before they move up into their native
river to spawn and winter. Other fish species that can be affected in coastal
waters include Atlantic halibut (Hippoglossus hippoglossus), capelin, lumpsucker
and local populations of Atlantic cod.
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