Unit |
Area |
Reason for Designation |
Changes from Proposal |
Central Yukon-Kuskokwim Delta |
988.6 mi2; lands inundated by tidal waters between Askinuk
Mtns. & Nelson Island. |
Breeding area; presence of lead shot in environment poses continuing threat. |
16% reduction - eliminated unsuitable habitat. |
South Yukon-Kuskowkim Delta |
89.7 mi2; lands inundated by tidal waters between Nelson Island
and Chefornak. |
Breeding area; presence of lead shot in environment poses continuing threat. |
65% reduction - eliminated unsuitable habitat and areas that do not appear
to make significant contribution to recovery. |
Norton Sound |
4087.3 mi2; Norton Sound east of 1620 47', excluding
specified waters within Norton Bay; marine waters 5-25m deep. |
Molting area; high, consistent use during flightless molting; the only
molting area known to be used by breeding females from YK Delta; high gastropod
biomass; shipping activities may pose threat. |
40% reduction - removed areas that water depth and sparse sightings of
eiders suggest areas are not essential for molting. |
Ledyard Bay |
5,390.0 mi2; waters of Ledyard Bay within about 74 km (40 nm)
of shore, excluding waters less than 1.85 km (1 nm) from shore; marine waters
5-25m deep. |
Molting area; principle molting area for breeding females from North Slope;
shipping activities may pose threat. |
43% reduction - local observations that eiders don't use < 1 nm from
shore; excluded waters don't contain features essential to conservation;
few or no eiders sighted in excluded portions. |
Waters South of St. Lawrence Island |
28,436.3 mi2; U.S. waters south of St. Lawrence Island between
the latitudes 610 N and 630 30' N, and between the
longitudes 1690 W and 1740 30' W; marine waters <
75m deep. |
Wintering area; most or all spectacled eiders use some portion of this
unit each winter for substantial portion of annual cycle. Flux in Bering
Sea ecosystem is cause for concern. |
No change in boundary from proposal, but modified primary constituent
elements to exclude waters > 75m deep. |
Unit |
Area |
Reason for designation |
Change from proposal |
Yukon-Kuskokwim Delta |
989 mi2 +337 miles shoreline; lands inundated by tidal waters
between Askinuk Mtns. & Nelson Island. |
Breeding area; recovery plan likely to include re-establishment of YK
Delta breeding population; listing based on near-disappearance from YK Delta;
increasing abundance on YK Delta will reduce AK-breeding population vulnerability
to extirpation. presence of lead shot in environment poses continuing threat. |
18% reduction - eliminated unsuitable habitat. |
Kuskokwim Shoals |
1,472 miles2 + 115 miles shoreline: northern Kuskokwim Bay
from the mouth of the Kolavinarak River to near Kwigillingok village, approx.
11-24 miles offshore.
|
Molting and spring staging area; high concentrations (>5000 Steller's
eiders in most years & >10000 in >1year) and known use by Alaska-breeding
Steller's eiders. Environmental perturbations may pose threat to population. |
Subset of proposed Kuskokwim Bay unit - eliminated southern portion of
proposed unit and reduced northern portion of proposed unit to more accurately
reflect areas used by Steller's eiders. |
Seal Islands |
24 miles2 + 65 miles shoreline; includes waters within Seal
Islands Lagoon and marine waters 1/4 mile offshore of islands and adjacent
mainland. |
Molting and spring staging area; high concentrations (>5000 Steller's
eiders in most years & >10000 in >1year) and known use by Alaska-breeding
Steller's eiders. Environmental perturbations may pose threat to population. |
Unchanged from proposed rule. |
Nelson Lagoon complex |
205 miles2 + 149 miles shoreline; includes Nelson Lagoon and
1/4 mile offshore, and portions of Port Moller and Herendeen Bay. |
Molting and spring staging area; high concentrations (>5000 Steller's
eiders in most years & >10000 in >1year) and known use by Alaska-breeding
Steller's eiders. Environmental perturbations may pose threat to population. |
Eliminated portions of Herendeen Bay & Port Moller where Steller's
eiders not detected in significant numbers. |
Izembek Lagoon |
140 miles2 + 186 miles of shoreline; Includes waters of Izembek
Lagoon, Moffett Lagoon, Applegate Cove, Norma Bay, and water 1/4 mile offshore
of Kudiakof Islands and adjacent mainland. |
Molting and spring staging area; high concentrations (>5000 Steller's
eiders in most years & >10000 in >1year) and known use by Alaska-breeding
Steller's eiders. |
Unchanged from proposed rule. |
Units removed |
Reason for removal |
North Slope - land |
Entire proposed unit likely not necessary for recovery as specified in
recovery plan, though some portion is essential. Available information insufficient
to delineate which areas are essential to species. Benefits of exclusion
outweigh benefits of designation. Inaccurate representation of critical
habitat would negate informational & educational benefits associated
with designation. Premature and inaccurate designation would undermine cooperative
efforts with local residents to identify and implement recovery efforts. |
North Slope - marine |
Available information does not support critical habitat designation. Few
sightings, short duration of individual use; unable to determine the type
of eider use so cannot identify physical/biological features important to
the species. |
Yukon-Kuskokwim Delta Marine Units |
Insufficient information about type of use so cannot identify physical
and biological features necessary for conservation of species. Limited telemetry
information suggests individual use is of short duration each year. |
North Yukon-Kuskokwim Delta |
Habitat apparently unsuitable for eider nesting; contribution to species
recovery is low; area not needed to meet recovery goals. |