The human-induced sources of underwater noise and their potential impacts on marine animals are topics of substantial interest and concern among scientists and the public. Although these concerns have mainly focused on injury and/or behavioral disturbance of whales exposed to short-duration sounds, such as sonars, possible impacts to marine animals exposed to continuous sources, such as commercial shipping, have recently begun to garner more attention. For more information click Background.
Preliminary assessments of background underwater noise levels within the Stellwagen Bank National Marine Sanctuary (SBNMS) were conducted in the summers of 1996 through 1999. In addition, preliminary passive acoustic surveys for sound-producing fish were conducted in the sanctuary in 2001 and continued through collaboration with fishermen between 2002 and 2005. For more information on this research click Ambient Noise, Soniferous Fish.
Following a pilot project in 2004, in 2006, a year-long passive acoustic monitoring project was conducted to characterize the sanctuary’s low frequency “noise budget”. Integration of acoustic data with ship tracking data provided initial estimates of noise contributions from large commercial vessels within the frequencies used by vocally-active marine animals in the sanctuary. For more information on this research click Noise Budgets.
Building on these results, a three-year research project was initiated in 2007 to better understand the acoustic environment experienced by, as well as created by, vocally-active animals in the sanctuary. By combining information on the distributions and behaviors of vocalizing marine animals and the distributions, operational conditions and acoustic signatures of vessels and other human and natural sources of underwater sound, researchers are examining the potential for impacts to sanctuary species, including possible changes in communication capabilities due to background noise levels. For more information on this research click Noise Mapping.
