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

waters longer. The coastal fishery was banned for four months after the
Braer incident off the Shetland Islands in 1993, and for nine months after the
Exxon Valdez incident in Alaska in 1989 (Rice et al. 1996). However, some
mussel and lobster fishing grounds were closed for more than 18 and 20
months, respectively, after the Braer incident. During the Deepwater Horizon
spill in September 2010, 230,000 km 2 were closed for both commercial
and recreational fishing and in September 2010 approx. 83,000 km 2 were still
closed (Graham et al. 2011). Some fisheries remained closed one year after
the spill (Law & Moffat 2011, NOAA 2011a).
The offshore fisheries for Greenland halibut within the assessment area constitute
a significant proportion of the overall Greenland/Canada fishery in
Davis Strait. In 2010, half the Davis Strait landings were caught in the assessment
area (14,000 tons, Jørgensen 2010). The main offshore fishing
grounds are located west of Nuuk (Fig. 5.1.3). Closing the fishery in this area
could therefore have socio-economic impacts. There is a risk that closure
zones could extend further west and also cover Canadian fishing grounds.
This is because Greenland halibut moves considerable distances over a very
short time, and contaminated (tainted) fish may move out of the assessment
area and be caught far from a spill site.
11.2.7 Oil spill impacts on seabirds
It is well documented that birds are extremely vulnerable to oil spills in the
marine environment (Schreiber & Burger 2002). Birds which rest and/or dive
from the sea surface, such as auks, seaducks, cormorants and divers
(loons), are more exposed to floating oil than birds which spend more time
flying and on land. But all seabirds face the risk of coming into contact with
spilled oil on the surface. This particular vulnerability is attributable to their
plumage. Oil soaks easily into the plumage and destroys its insulation and
buoyancy properties. Therefore, oiled seabirds readily die from hypothermia,
starvation or drowning. Birds may also ingest oil by cleaning their
plumage and by feeding on oil-contaminated food. Oil irritates the digestive
organs, damages the liver, kidney and salt gland function, and causes anaemia.
Sublethal and long-term effects may result. However, the main cause of
seabird losses following an oil spill is direct oiling of the plumage.
Many seabirds aggregate in small and limited areas for certain periods of
their life cycles. Even small oil spills in such areas may cause very high mortalities
among the birds present. The high concentrations of seabirds found
on coasts, e.g. breeding colonies, wintering areas or in offshore waters at
important feeding areas, are particularly vulnerable.
Oiled birds which have drifted ashore are often the focus of media attention
when oil spills occur and demonstrate the high individual sensitivity to oil
spills. However, of greater concern must be the case where whole populations
suffer from oiling. To assess this issue, extensive studies of the natural
dynamics of affected populations and the surrounding ecosystem are necessary.
The seabird species most vulnerable to oil spills are those with low reproductive
capacity and a corresponding high average lifespan (low population
turnover). Such a life strategy is found among auks, fulmars and many seaducks.
Thick-billed murres (an auk), for example, do not breed before they
reach 4–5 years of age and the females only lay a single egg per year. This
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