3.0 Affected Environment - Knik Arm Bridge and Toll Authority

Knik Arm Crossing DraftFinal EIS
Affected Environment
In March 2005 NOAA Fisheries prepared the Draft Conservation Plan for the Cook Inlet
Beluga Whale. The document reviews and assesses the known and possible factors
influencing the Cook Inlet beluga whale and develops and presents a Conservation Strategy
to guide federal and other actions toward the goal of recovering this stock to a population of
no fewer that 780 whales. The document also maps beluga whale habitat within Cook Inlet,
including Knik Arm and the Study Area. The Study Area falls within Type 1 habitat termed
“High Value/High Sensitivity” and Type 2 habitat termed “High Value.” NOAA Fisheries
believes habitat considered “High Value/High Sensitivity” are areas most important and
sensitive areas for the Cook Inlet beluga whale. “High Value” habitat includes summer
feeding areas and winter habitat in water where whales typically occur in lesser densities or
in deeper waters, where they may be less prone to harassment and disturbance (NOAA
Fisheries 2005).
In August 2006, NOAA Fisheries released their review of a petition to list the Cook Inlet
beluga whale as an endangered species (NMFS 2006). NOAA Fisheries found that the
petition contained sufficient scientific or commercial information to warrant further action.
Within 1 year of receipt of the petition, and pending completion of a status review initiated in
April 2006, NOAA Fisheries will issue a finding whether or not to list Cook Inlet beluga as
an endangered species under the Endangered Species Act (16 U.S.C. 1531).
Long-term aerial surveys and satellite tracking conducted by NOAA Fisheries indicate
seasonal patterns of movement for beluga whales within Cook Inlet. Beluga whales are
mostly sighted in the inlet north of Kalgin Island. They tend to reside in Knik Arm in late
summer-autumn and in Turnagain Arm/Chickaloon Bay in autumn. During the winter, they
are often found in the middle of Cook Inlet, while in spring-early summer they occupy the
Susitna/Beluga River area (NOAA Fisheries 2005).
A year-long baseline study of beluga whale use of Knik Arm conducted for this EIS suggests
that beluga whale use of Knik Arm is correlated with seasons and tides (KABATA 2006t).
Seasonal use of Knik Arm is high during the fall (August–October), less frequent and
random during April–July and November–March. Beluga use of Knik Arm is infrequent
during other times of the year (mid-December–March). During the fall, beluga whales transit
between Eklutna, Eagle Bay, and Sixmile Creek. They tend to move to the head of Knik Arm
on the flood tide and out as far as Sixmile Creek on the ebb tide. They occasionally leave
Knik Arm during the fall. At other times of the year, there were more infrequent whale
sightings and a less noticeable pattern of tidal movements.
Although observed throughout the year, beluga whale sightings were generally lower in the
Study Area compared with other parts of Knik Arm. Belugas were seen most often in the
Study Area during fall and spring and at low tide. They were observed less often during the
winter and summer and high tides. Many of the Study Area sightings were associated with
the whales transiting in and out of Knik Arm. Whales were observed diving more often and
resting less often while in the Study Area. See KABATA (2006t) for information collected
during the beluga study on behavioral activities, sighting rates, and group composition.
3-212 12/18/07