Abstract
To assess the distribution and abundance of marine mammals and sea turtles in the Massachusetts Wind Energy Study Area (MA WESA), aerial survey and passive acoustic methods were used. We chose to use a multi-pronged approach for this assessment, including aerial surveys with new vertical photographic capabilities to enhance data collection on sea turtles and dolphins. In addition, because weather can ground aerial surveys for extended periods, continuously recording underwater acoustic-recording devices were deployed for most of the year to detect large whale presence throughout the survey area. Although not all large whales vocalize, many do, and the underwater recording effort provided an additional independent data stream on large whales. The NEAq and PCCS conducted aerial surveys over the MA WESA and surrounding waters for whales and sea turtles from 9 October 2011 to 17 September 2012 twice a month, weather permitting. The Cornell University Bioacoustics Team placed Marine Autonomous Recording Units (MARUs) at 6 locations within the MA WESA on 9 November 2011, which recorded any anthropogenic and biological sounds (including large whale sounds) passively and continuously (with a single day swap-over break) through 3 October 2012.
The aerial surveys recorded right, humpback, fin, minke, sei, and sperm whales during the year. The bulk of these large whale sightings occurred in the period from March through June, with scattered sightings at other times of year. The surveys also recorded leatherback, loggerhead, and Kemp‘s ridley sea turtles. Most sightings of sea turtles occurred in the late summer, primarily August and September. A wide diversity of delphinids and one phocoenid were observed, including bottlenose, white-sided, common, and Risso‘s dolphins, pilot whales, and harbor porpoise.
The acoustic study detected at least 7 large whale species, including right, fin, minke, humpback, blue, sei, and sperm whales. The presence of these species varied over time, but vocalizations were generally detected more often during the winter and spring months. These data indicate that all of the large whale species known to occur within the temperate waters of the western North Atlantic Ocean can be detected from subsurface hydrophones deployed within the MA WESA, indicating that this area is frequently used and may be ecologically important for these species.
This report is divided into three sections: 1) Executive Summary, 2) Aerial Surveys for Marine Mammals and Sea Turtles, and 3) Passive Acoustic Monitoring for Marine Mammals. Appendices are attached.
Data are available upon request via email to offshorewind@masscec.com.