When the noise goes on: received sound energy predicts sperm whale responses to both intermittent and continuous navy sonar [RESEARCH ARTICLE]

Saana Isojunno, Paul J. Wensveen, Frans-Peter A. Lam, Petter H. Kvadsheim, Alexander M. von Benda-Beckmann, Lucia M. Martin Lopez, Lars Kleivane, Eilidh M. Siegal, and Patrick J. O. Miller

Anthropogenic noise sources range from intermittent to continuous, with seismic and navy sonar technology moving towards near-continuous transmissions. Continuous active sonar (CAS) may be used at a lower amplitude than traditional pulsed active sonar (PAS), but potentially with greater cumulative sound energy. We conducted at-sea experiments to contrast the effects of navy PAS versus CAS on sperm whale behaviour using animal-attached sound- and movement-recording tags (n=16 individuals) in Norway. Changes in foraging effort and proxies for foraging success and cost during sonar and control exposures were assessed while accounting for baseline variation [individual effects, time of day, bathymetry and blackfish (pilot/killer whale) presence] in generalized additive mixed models (GAMMs). We found no reduction in time spent foraging during exposures to medium-level PAS (MPAS) transmitted at the same peak amplitude as CAS. In contrast, we found similar reductions in foraging during CAS (d.f.=1, F=8.0, P=0.005) and higher amplitude PAS (d.f.=1, F=20.8, P<0.001) when received at similar energy levels integrated over signal duration. These results provide clear support for sound energy over amplitude as the response driver. We discuss the importance of exposure context and the need to measure cumulative sound energy to account for intermittent versus more continuous sources in noise impact assessments.

Source link

Related posts

Erratum for Sehrawat et al., "Cancer-Associated Eukaryotic Translation Initiation Factor 1A Mutants Impair Rps3 and Rps10 Binding and Enhance Scanning of Cell Cycle Genes" [Errata]


Targeting Cellular Senescence as an Intervention in Aging


An Interview with Reason at Undoing Aging 2019


This website uses cookies to improve your experience. We'll assume you're ok with this, but you can opt-out if you wish. Accept Read More

Privacy & Cookies Policy


COVID-19 (Coronavirus) is a new illness that is having a major effect on all businesses globally LIVE COVID-19 STATISTICS FOR World