Aerial Survey of Belugas in Cook Inlet Alaska August 2012
Aerial survey of the beluga population in northern Cook Inlet, Alaska, August 7-9, 2012, to obtain high-resolution video of beluga groups in order to determine age structure and number of calves
NOAA Fisheries conducted an aerial survey of the beluga population in northern Cook Inlet, Alaska, 7-9 August 2012. The goal of the survey was to obtain high-resolution video of beluga groups in order to determine age structure (white relative to gray individuals and dark gray calves) and number of calves. The survey (15.4 hours total) covered the coastal areas down to Kenai River and north of West Forelands. Following protocol used by NOAA Fisheries since 1993, the August 2012 beluga survey was flown in a high-wing, twin-engine aircraft (AeroCommander 690A N222ME) at an altitude of 244 m (800 ft) and a speed of 185 km/hr (100 kt). The survey track paralleled the coast (1.4 km offshore) and daily surveys occurred during the falling tide when possible.
Beluga groups were found in the Susitna delta (from the Beluga River to the Little Susitna River) and in Knik Arm every day, while only one beluga group was found in Turnagain arm on one of the three survey days. On 7 August, we videoed and/or counted 3 beluga groups: one large group spread out from the mouth of the Theodore river to outside the Ivan River (median count = 219), a group in the Northeast channel of the Susitna River (median count =76), and a group in Eagle Bay, exiting Eagle River (median count =27), for a total median count of 322. On 8 August, belugas were seen in Turnagain Arm, moving from Bird Point to Rainbow Creek and continuing toward Indian Creek along the Seward Highway (median count = 33). Two groups were seen at the Susitna River, one group spread across the river mouth, and the second group slightly north (median counts =176 and 55, respectively). A fourth group was found in Eagle Bay moving north along the cliffs on the incoming tide (median count = 11), making 275 the total median count for 8 August. We observed five groups on 9 August. A single whale was seen near the mouth of Chickaloon River. A large group was found spanning the mouths of the Theodore and Susitna rivers (median count =268) and a medium-sized group in the Little Susitna River (median count =18). Two groups of whales were found in Knik Arm, a small group of 2 whales at the dock at Point MacKenzie and a group of whales in Goose Bay (median count = 12), making 301 the total median count on 9 August.
The range of median estimates (275-322) of belugas seen in August 2012 (a quick index of relative abundance not corrected for missed whales) was within or above medians observed over the last 7 years (2005 (236-277), 2006 (126-143), 2007 (141-181), 2008 (109-194), 2009 (196- 212), 2010 (128-266) and 2011 (204)).