Construction Impacts on the Cook Inlet Beluga Whale at the Port of Anchorage Marine Terminal Redevelopment Project
Thesis presented to the faculty of Alaska Pacific University in partial fulfillment of the requirements for the Degree of Master of Science in Environmental Science
Cook Inlet beluga whales (Delphinapterus leucas) are geographically isolated and genetically distinct from other U.S. beluga stocks. They were recently listed as endangered under the U.S. Endangered Species Act. Many factors are identified as potential threats to the Cook Inlet beluga whale population, including coastal zone development and anthropogenic noise. The Port of Anchorage Marine Terminal Redevelopment Project, taking place in Knik Arm, Cook Inlet, involves several types of construction activities including dredging, gravel fill, and pile driving. In this study, I investigated the impacts of construction activity on beluga whales using visual and acoustic observations. First, I examined the behavior and distribution of Cook Inlet beluga whales pre- (2005-2007) and during (2008-2009) pile driving activity at the MTR Project by investigating differences in the sighting duration of beluga whales, behavioral states, group size, group composition, group formation, and beluga whale distribution within the study area. There were significant differences in sighting duration, behavior, group composition, and group formation between pre- and during pile driving periods. There was no significant correlation between monthly sighting rates and pile driving rates. Additionally, beluga whales were most frequently observed along the eastern shoreline of the study area during both periods; however, sightings increased along the western shoreline near Port MacKenzie during the pile driving activity. In the second part of the study, I focused on the effects of construction noise at the MTR Project on beluga whale vocal behavior by examining differences in the detected clicks rates during periods with and without construction activity. There was no significant difference in the detected click rate; however, the detected click rate was higher without construction activity. The results from this study indicate changes in beluga whale behavior in the presence of construction activity and possible avoidance of the area.