Abstract
Eleven boat-based surveys were conducted from 21 April through the 26 June, 2013 at the Deepwater Offshore Wind Test Site near the island of Monhegan, Maine. This is the proposed offshore location of the University of Maine’s two full-scale 6MW SemiSubmersible Turbine Platform test units. Previous surveys were conducted in the fall of 2011 (Kennedy & Holberton 2012) and late summer of 2012 (Kennedy 2012b) at Monhegan with primary objectives to record observations of seabirds and other wildlife at the test site during the pre-deployment stage of the project. This year, an additional set of surveys were conducted during the pre-deployment stage to fulfill the same objectives. Observations included species, number, behavior, flight height and direction, as well as weather and sea conditions. A total of 608 birds were recorded (5.53 birds/km2), consisting of 21 identifiable species. The most abundant species were Herring gulls (HERG; Larus argentatus) at 2.84/km2 followed by Northern gannets (Morus bassanus) at 0.6/km2. Species of Conservation Concern (SCC) included five Razorbills (Alca torda), five Atlantic puffin (Fratercula arctica), one Great shearwater (Puffinus gravis, GRSH), six “Unidentified” terns, and 11 “Unidentified” alcids. Other recorded wildlife included two species of seal, Harbor porpoise (Phocoena phocoena), and a school of baitfish. The most common bird behaviors included direct flight (32% were HERG), sitting (60% were HERG), milling (55% were HERG), and scavenging (94% were HERG). Of the flying birds, the vast majority flew at one meter, consisting of 44% Order Charadriiformes and 39% Order Anseriformes. With the proposed height of the test turbine’s rotor-sweep zone being 35-164m high, none of the birds during this season’s survey were observed in this zone. Potential sources of impact may include direct collision with the platform or tower by the large gulls due to attraction to the structure for loafing habitat or increased foraging opportunities due to additional fish habitat from the floating platform. Sea ducks, loons, and alcids are known to avoid turbine structures, therefore habitat displacement and disturbance associated with the presence of the two turbines may occur. However, the small spatial scale of the proposed turbines may realistically reduce the effect of that reaction, and therefore is a minor concern.