Monitoring Ship Noise To Assess Their Impact
This study establishes a baseline record of natural and human-produced underwater noise at two sites in northeastern Scotland for use in future research looking at the impact of noise on hunting, communication, navigation, stress levels, reproduction, and survival of native marine mammals. The authors used recording devices in conjunction with cameras to record noise levels and frequencies, and monitor the sources of human-produced noise. They conclude that underwater noise is primarily the result of shipping traffic and industrial activity, and offer observations about possible limitations in recently-mandated government monitoring, with suggestions for improving the efficacy and relevance of the monitoring.
[Abstract excerpted from original source.]
“The potential impacts of underwater noise on marine mammals are widely recognised, but uncertainty over variability in baseline noise levels often constrains efforts to manage these impacts. This paper characterises natural and anthropogenic contributors to underwater noise at two sites in the Moray Firth Special Area of Conservation, an important marine mammal habitat that may be exposed to increased shipping activity from proposed offshore energy developments. We aimed to establish a pre-development baseline, and to develop ship noise monitoring methods using Automatic Identification System (AIS) and time-lapse video to record trends in noise levels and shipping activity. Our results detail the noise levels currently experienced by a locally protected bottlenose dolphin population, explore the relationship between broadband sound exposure levels and the indicators proposed in response to the EU Marine Strategy Framework Directive, and provide a ship noise assessment toolkit which can be applied in other coastal marine environments.”