The Bluff Colonies IBA is located on the north shore of Norton Sound, approximately 50 km east of Nome, between Safety and Golovin bays. Sheer cliffs extend for 3 km along the coast of Norton Sound. The terrain inland from the cliffs is gently sloping dwarf shrub tundra. The seabird colony at Bluff has been studied more continuously than any other in Alaska. Studies were started in 1975, and monitoring has been conducted in most years since then.
[The information herein constitutes a revised nomination. The original nomination, by Olga Romanenko (Audubon Alaska) and G. Vernon Byrd (AMNWR), was accepted as a state-level IBA in 2003.]
The Bluff colonies are by far the largest congregation of cliff-nesting seabirds on the mainland coast of Western Alaska, outside of Bristol Bay (600 km to the south). The site includes 5 closely located colonies with common feeding areas at sea. The Bluff colony is the largest, with around 125,000 nesting seabirds. The Square Rock colony is the next in size, while the other three are considerably smaller. Common Murres make up the majority of the population, and this site hosts more than 1% of the continental population. Black-legged Kittiwakes are also present in significant numbers, and Pelagic Cormorants nest at Bluff.
There have been no whole-colony counts since 1988. However, several lines of evidence, outlined below in excerpts from personal communication by Dr. Ed Murphy, UAF, provide confidence in the whole-colony estimates for murres and kittiwakes at this site:
Common Murre: The highest boat-based count of all colonies since the mid-1970s was 43,275 in 1979. The last boat-based count of all colonies was in 1988. Although Dean Kildaw and Jay Schauer?s counts on five different days in that year averaged only 21,856, much more extensive land-based counts of two large cliff faces (1979-2007) suggest that numbers have remained stable or increased very slightly since 1979. The best model suggests a 1% annual increase. It's difficult to extrapolate from boat-based counts to actual numbers of adult murres at the colony because counts of this type are biased low and off-duty mates of active breeding pairs are generally away from the colony. Assuming considerable undercounting, my best guess is that numbers have not changed overall at the colony from 1979 to 2007 and an upper estimate for murres would be 100,000 individuals.
These numbers do not include Square Rock and the adjacent mainland cliffs, however, a few miles east of the east end of the Bluff colony. I have photographed murres on the top of Square Rock in most summers, but there have not been any counts there since the late 1970's. I estimate the number or murres on Square Rock and the nearby mainland cliffs at 10,000 individuals.
Thick-billed Murres: Small numbers of Thick-billed Murres are scattered among the Common Murres throughout the colony.
Black-legged Kittiwakes: The last boat-based counts of all colonies were also in 1988, when one count equaled 12,095 individuals. Since boat-based counts are biased low, however, 30,000 individuals would be a reasonable estimate for that year. On the 2 large cliff faces regularly count from above, numbers increased from 1979 through the early 1990's and have since decreased. Numbers recently are similar to, or slightly lower than, numbers in 1979. Black-legged Kittiwake numbers probably peaked at about 30,000 and are now estimated at 25,000 individuals.
General references for older species data lacking species-specific citations:
Biderman, J.O., W.H. Drury, J.B. French Jr., and S. Hinckley. 1978. Ecological studies in the northern Bering Sea: birds of coastal habitats on the south shore of Seward Peninsula, Alaska. Environmental Assessment of the Outer Continental Shelf, Annual Reports of Principal investigators 2:510-613. NOAA Environmental Assessment Laboratory, Boulder, CO.
Dragoo, D.E., G.V. Byrd, and D.B. Irons. 2000. Breeding status and population trends of seabirds in Alaska in 1999. USFWS, Alaska Maritime National Wildlife Refuge, report AMNWR 2000/02. Homer, AK.
Murphy, E.C. 1991. Bluff. Pp. 70-99 in V.M. Mendenhall, ed. Monitoring of populations and productivity of seabirds at St. George Island, Cape Peirce, and Bluff, Alaska, 1989. U.S. Minerals Management Service, OCS Study MMS 90-0049. Anchorage, AK.
Murphy, E.C., A.M. Springer, and D.G. Roseneau. Population status of Common Guillemots at an Alaskan colony: results and simulations. Ibis 128:348-363.
The current and known threats to birds in the Bering Sea, including the Bluff Colonies, include:
*Invasive species: Shipwrecks of commercial cargo ships and other ships regularly occur in the Bering Sea, and can result in the accidental introduction of non-native species. Invasive species can also be brought to islands or coasts by visiting ships (e.g. fishing, ecotourism, military, or research vessels).
*Shipping: Shipwrecks regularly occur in the Bering Sea, and can result in spills of fuel oil, petrochemical cargo, or other damaging cargo, and can also result in the introduction of non-native species, such as rats.
*Climate Change: Climate change has been shown to alter food webs and is likely to change species populations and distributions; though it is important to note that this is not strictly a threat in the sense of population reduction, since some species may increase while others decline.
Specific current and known threats to birds at the Bluff Colonies include:
Intensive placer mining for gold was carried out on various lands near Nome during the past century, including immediately west of the Bluff cliffs. During the 1990s a seagoing dredge operated offshore of Nome for a few years. There is no mining currently, but it could be resumed at any time.
A small amount of vessel traffic serves villages farther up Norton Sound.
Potential threats to birds across the Bering Sea, including Bluff Colonies, include:
*Fishing alteration of food webs or damaging benthic habitat
*Light pollution (applies to nocturnal species)
Approximately 92% of the Bluff Colonies IBA is federally owned, and is managed by the US Fish & Wildlife Service as part of the Alaska Maritime National Wildlife Refuge.
Around 7% of the IBA, which includes the largest concentration of cliff-nesting birds, is owned by the White Mountain Native Corporation. The Bering Straits Native Corporation owns less than 1% of the IBA.
Note that of the federally owned portion, 9% of acreage is "selected": State of Alaska 9%, and Bering Straits Native Corporation 5% of Refuge acreage overlapping the State's selection.
The Bluff Colonies IBA mainly includes sea cliffs, with some sloping dwarf shrub tundra.
Note that categorization and percentages of habitat types presented here are estimates, and are not based on field data, remote sensing data, or other rigorous analysis of habitat types.
It is important to note that this proposed IBA currently includes only terrestrial habitat. The marine birds that dominate this site, however, are also critically dependent on marine habitat. We aim to include a science-based delineation of essential marine habitat associated with this site in the future.
Land use is mainly nature conservation and research. Seabird populations have been monitored annually since the mid-1970s.
There is some subsistence gathering and hunting. Target species include seabirds, both adults and eggs. There is also subsistence hunting of caribou, but no sport hunting in the immediate area.