A first look at the Ocean Noise Reference Station Network: The soundscape of Stellwagen Bank National Marine Sanctuary

Abstract

In order to compare long-term changes and trends in soundscapes around the United States, a multi-year network of identical autonomous passive acoustic recording systems, the Ocean Noise Reference Station (NRS) Network, has been established. In partnership with the National Oceanic and Atmospheric Administration (NOAA) Office of Oceanic and Atmospheric Research, NOAA Pacific Marine Environmental Laboratory, NOAA National Marine Fisheries Service, NOAA Office of National Marine Sanctuaries, and the National Park Service, hydrophone moorings were deployed in 12 discrete soundscapes in the Northeast Pacific and Northwest Atlantic oceans to record underwater ambient sound levels in the 10 to 2200 Hz frequency range. This initial analysis utilized the first year of available data from the NRS deployed in Stellwagen Bank National Marine Sanctuary (SBNMS), a busy area for both natural and anthropogenic activity. Preliminary results indicate that: (1) broadband (10-2200 Hz) ambient sound levels at SBNMS are stable year round in association with constant vessel activity in the nearby shipping lane to Boston, MA, (2) surface wind speed is positively correlated with broadband noise levels, (3) intensity of low-frequency baleen whale calling activity varies seasonally, but signals are acoustically detectable year-round. Future analyses will compare the soundscapes of all 12 NRS sites.