Noise Levels and Sources in the Stellwagen Bank National Marine Sanctuary and the St. Lawrence River Estuary

Authors:

Peter M. Scheifele and Michael Darre
National Undersea Research Center, North Atlantic and Great Lakes, and Animal Sciences Department, University of Connecticut

Although ambient (background) noise in the ocean is a topic that has been widely studied since pre-World War II, the effects of noise on marine organisms has only been a focus of concern for the last 25 years. The main point of concern has been the potential of noise to affect the health and behavior of marine mammals. The Stellwagen Bank National Marine Sanctuary (SBNMS) is a site where the degradation of habitat due to increasing noise levels is a concern because it is a feeding ground and summer haven for numerous species of marine mammals. Ambient noise in the ocean is defined as "the part of the total noise background observed with an omnidirectional hydrophone." It is an inherent characteristic of the medium having no specific point source. Ambient noise is comprised of a number of components that contribute to the "noise level" in varying degrees depending on where the noise is being measured.

This report describes the current understanding of ambient noise and existing levels in the Stellwagen Bank National Marine Sanctuary.

Key Words: ambient noise, Stellwagen Bank, sanctuary, background noise, Stellwagen Bank National Marine Sanctuary

Citation: Scheifele, Peter M. and Michael Darre. 2005. Noise levels and sources in the Stellwagen Bank National Marine Sanctuary and the St. Lawrence River Estuary. Marine Conservation Series MSD-05-1. U. S. Department of Commerce, National Oceanic and Atmospheric Administration, Marine Sanctuaries Division, Silver Spring, MD. 26pp.