Characteristics of the soundscape before and after the construction of the Block Island Wind Farm

The Block Island Wind Farm (BIWF) south of Rhode Island is the first offshore windfarm in the United States. As part of the Ocean Special Area Management Plan, acoustic data were collected before the construction in the fall of 2009. Noise budgets were estimated based on this data and showed the dominant sources of sound in a 1/3-octave band centered at 500 Hz were shipping and wind. Data were again collected during and after construction of the wind farm and will be presented and compared to pre-construction levels. In 2009, Passive Aquatic Listener (PALs) were deployed. After construction was complete, data from a tetrahedral hydrophone array (~50 m from one of the wind turbines) were analyzed to study the soundscape from December 20, 2016 to January 14, 2017. The acoustic environment near the BIWF after construction showed contributions from shipping, wind, and marine life. Noise from the wind turbine was measured near 70 Hz at approximately 100 dB re 1 mPa at a range of 50 m. Significant marine mammal vocalizations were recorded including from humpback and fin whales. (Work supported by the Bureau of Ocean Energy Management.)