Subject:
New paper on how vessel noise cuts down communication space of Bryde’s whales (Rosalyn Putland)
Dear All,
We are pleased to announce that the following paper has been published which may be of interest to Marmamers:
Putland, R.L., Merchant, N.D., Farcas, A., Radford, C.A. (2017) Vessel noise cuts down communication space
for vocalizing fish and marine mammals. Global Change Biology. Advanced Online Publication 12 December 2017. 1365-2486
URL: http://dx.doi.org/10.1111/gcb.13996
Abstract
Anthropogenic noise across the world’s oceans threatens the ability of vocalizing marine species to communicate. Some species vocalize at key life stages or whilst foraging, and disruption
to the acoustic habitat at these times could lead to adverse consequences at the population level. To investigate the risk of these impacts, we investigated the effect of vessel noise on the communication space of the Bryde’s whale Balaenoptera edeni, an endangered
species which vocalizes at low frequencies, and bigeye Pempheris adspersa, a nocturnal fish species which uses contact calls to maintain group cohesion while foraging. By combining long-term acoustic monitoring data with AIS vessel-tracking data and acoustic
propagation modelling, the impact of vessel noise on their communication space was determined. Routine vessel passages cut down communication space by up to 61.5% for bigeyes and 87.4% for Bryde’s whales. This influence of vessel noise on communication space
exceeded natural variability for between 3.9 and 18.9% of the monitoring period. Additionally, during the closest point of approach of a large commercial vessel, < 10 km from the listening station, the communication space of both species was reduced by a maximum
of 99% compared to the ambient soundscape. These results suggest that vessel noise reduces communication space beyond the evolutionary context of these species and may have chronic effects on these populations. To combat this risk, we propose the application
or extension of ship speed restrictions in ecologically significant areas, since our results indicate a reduction in sound source levels for vessels transiting at lower speeds.
Please email me if you would like a PDF copy of the paper or if you have any questions regarding the work.
Best regards,
Rosalyn
Institute of Marine Science
University of Auckland