Communicating amidst the noise: modeling the aggregate influence of ambient and vessel noise on baleen whale communication space in a national marine sanctuary

Authored by Michael Thompson, Danielle Cholewiak, Christopher W Clark, Dimitri Ponirakis, Adam Frankel, Leila T Hatch, Denise Risch, Joy E Stanistreet, Elizabeth Vu, Parijs Sofie M Van

Date Published: 2018

DOI: 10.3354/esr00875

Sponsors: No sponsors listed

Platforms: No platforms listed

Model Documentation: Other Narrative

Model Code URLs: Model code not found

Abstract

Anthropogenic noise negatively impacts many species One of the more insidious effects of elevated noise levels is the reduction in area ovei which animals are able to acoustically communicate, often termed communication masking. This study utilizes modeling approaches to evaluate relative levels of masking for 4 baleen whale species from the combination of current ambient noise conditions and noise from discrete vessels operating in the Stellwagen Bank National Marine Sanctuary. Acoustic data were collected using bottom-mounted autonomous recorders. One day was analyzed for each of 5 different species-specific sound types, corresponding to peaks in occurrence of fin and humpback whale songs, humpback whale social sounds, minke whale pulse trains and North Atlantic right whale gunshots. Source levels for animals and 3 categories of vessels were calculated empirically, sound propagation was modeled using Bellhop ray tracing. An agent-based modeling framework was used to calculate changes in communication space (CS) in comparison to reference conditions (10 dB lower than current ambient noise) In these singleday snapshots, current ambient noise and noise from vessels for which automatic identification system (AIS) data were available contribute most heavily to loss of CS, followed by whale-watching and fishing vessels Right whale gunshots experience the least amount of masking, while fin, humpback and minke whale signals experience masking levels of 80\% or more. While these results incorporate several simplifying assumptions, this study further develops the framework by which to comparatively quantify masking, providing information on the relative degree of masking experienced between species and allowing for important insights on the relative contributions of different anthropogenic sound sources

Tags

Behavioral-responses Anthropogenic noise Communication space Baleen whales Communication masking Anthropogenic noise Atlantic right whales Megaptera-novaeangliae Humpback whales Balaenoptera-acutorostrata Acoustic communication Calling behavior Active space Ship noise