Marine Conservation News: A Brief Consideration of the Kulluk Stranding: Biodiversity of Sitkadilak Island

Sitkadilak Island’s seabirds and marine mammals

Right now, as I sit here writing this blog the drilling rig Kulluk is sitting in its temporary anchorage in Kiliuda Bay which is located just north of the grounding location (Figure 1a & b) on the eastern side of Kodiak Island. News sources have reported there is no evidence of oil leakage from the rig. Initial mentions of possible risks to wildlife were scant with a brief mention of Steller sea lion habitat. This region is in fact one of high biodiversity. Diversity and abundance of coastal and nearshore species may be at their highest during summer months, but there are species that use this area during the winter months as well.

Figure 1 (a&b). Location of Kulluk stranding. Source: Arctic ERMA [1].

Seabirds

According to a US Fish and Wildlife Service wildlife biologist, the department’s ship-based surveys, which include the south east coast of Sitkalidak Island, indicate that there are at least sixteen species of seabirds that occur in highest abundance in the in the protected waters of Sitkalidak Straits (on the west side of Sitkalidak Island) and adjacent bays. These species occur in lower abundance on the exposed side of Sitklidak Island where the rig is currently stranded. This area is an important foraging area for seabirds year round so any event that might cause a decline in the abundance or quality of forage fish may have a negative impact on seabird populations.

Marine mammals

In addition to prime seabird habitat, the nearshore area is critical habitat for both the federally endangered Steller sea lion (Eumetopias jubatus) and the federally threatened sea otter (Enhydra lutris) (Figure 2). According to the Endangered Species Act (ESA) critical habitat is by definition specific areas that contain physical or biological features essential to conservation of the species. There is a known Stellar sea lion haul-out location at near Cape Barnabas which is located at the north east end of Sitkalidak Island [2].

Figure 2. Location of Kulluk stranding on Sitkalidak Island in relationship to Steller sea lion and sea otter critical habitat. Source: Arctic ERMA [3].

Below is a brief list of mammal and seabird species that might be found within the vicinity of the Kodiak archipelago:

Seabirds (Only those that may occur during the winter are listed):

Sea ducks

Harlequin duck
Barrow’s goldeneye
Red-breasted merganser
Common merganser
Black surf scoter
White-winged surf scoter
Long-tailed duck

Loons

Pacific Loons
Red-throated loon
Yellow-billed loons (infrequent)

Grebes

Horned grebe

Red-necked grebe

Alcids

Marbled murrelets (fairly common in the winter and breed on Kodiak Island)

Pigeon guillemot
Common murre

Terrestrial Mammal

Kodiak brown bear (This subspecies only occurs on the islands of the Kodiak Archipelago. The population was estimated to be 3,526 in 2005 [4]. The Kodiak brown bear is included in this list because it utilizes coastal resources during the spring and summer.)

Marine Mammals (all marine mammals are listed without regard to seasonality of occurrence):

Sea Otter
Steller sea lion
Dall’s porpoise
Harbor seal
Fin whale
Gray whale (Migrating whales most commonly observed during the spring and fall.)
Humpback whale
Minke whale
Orca (Most common during the spring and summer.)

A take home message
The Alaskan coastal wilderness is just that—wilderness. For the most part the Alaskan coast is pristine. When we hear reports about industrial accidents in this region it may be in the best interest of the responsible parties to minimize the perceived potential damage to natural ecosystems. These places may be subjected to harsh abiotic conditions that may at first seem inhospitable, but they are inhabited by a diverse suite of plants and animals that by default depend on us to ensure that their habitats remain pristine. Whether it is the image of an adorable sea otter breaking open a sea urchin for lunch, or the monetary benefits of maintaining Alaskan ecosystems for the purposes of sustaining fisheries, think about these images next time you hear about an accident that may at the face of it appear to have little impact on the surrounding habitats.