YIP Expansion: Ocean basin impact of ambient noise on marine mammal detectability, distribution, and acoustic communication
Abstract
PROJECT ABSTRACT Low frequency sound has increased in the NE Pacific Ocean over the past 60 years (Ross, 1993, 2005; Andrew et al., 2002; McDonald et al., 2006; Chapman and Price, 2011) and in the Indian Ocean over the past decade (Miksis-Olds et al., 2013). More recently, observations in the NE Pacific show a level or slightly decreasing trend in low frequency noise (Andrew et al., 2011). Results from recent YIP Award supported research also reported decreases in the ambient sound levels over the past decade in the Equatorial Pacific and South Atlantic Oceans. The long-term increases have been mainly attributed to increases in shipping activity, but the dominant source mechanisms or combination of source mechanisms driving the present trends remain unclear. The proposed work will be an extension of previously funded research under a recent YIP Award focused on quantifying short term variability and long term changes of ocean basin sound levels for application to marine mammal detection and communication. Results from the YIP effort revealed that ocean sound levels have increased in the Indian Ocean, but have not uniformly increased across the globe over the past decade. Additionally, combining observed sound levels with propagation modeling demonstrated that regional soundscape dynamics can change the size of detection areas for passive acoustic monitoring purposes and communication between vocalizing animals by over an order of magnitude. The proposed work will extend the trend analyses of decadal ocean sound levels to an analysis of trends and shifts in characteristics of specific source mechanisms contributing to the soundscape over time. The primary sources of interest are baleen whales, as it is critical to identify any shift in vocalization characteristics over time to ensure optimal performance of automatic detectors used in passive acoustic monitoring, mitigation, and density estimation applications. Secondary sources of interest are seismic airgun signals, shipping, and geophysical contributions from wind and ice because contributions from these sources have the potential to mask biological signals targeted in monitoring and mitigation efforts and to impact animal behavior.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Aug 12, 2016
- Source ID
- N000141512581
Entities
People
- Jennifer Miksis-Olds
Organizations
- Office of Naval Research
- Pennsylvania State University
- United States Navy