We are pleased to announce the publication of the following paper in
Endangered Species Research. This paper is part of a Theme Section on
"21st Century paradigms for measuring and managing the effects of
anthropogenic ocean noise."
Tennessen JB, Parks SE (2016) Acoustic propagation modeling indicates
vocal compensation in noise improves communication range for North
Atlantic right whales. Endang Species Res 30: 225-237. doi:10.3354/esr00738
Abstract:
Sound from transoceanic shipping is a major component of ocean noise
budgets. Baleen whale communication may be particularly vulnerable to
shipping noise impacts due to overlap in the frequencies of signals and
noise. Baleen whales rely upon acoustic signals to mediate a variety of
social interactions when separated beyond visual range. We investigated
the potential for noise to interfere with critical reunion events
between mother-calf pairs of Endangered North Atlantic right whales Eubalaena glacialis,
and whether vocal compensation can improve or maintain communication
space between the sender and receiver. This information is necessary to
inform future conservation efforts. We used acoustic propagation
modeling to predict the transmission loss of the primary tonal
communication signal used during mother-calf communication, the
‘upcall’, to (1) estimate over what ranges a receiving whale can detect a
signal in anthropogenic noise, and (2) determine the effects of vocal
compensation on detection range. Our results indicate that both
point-source noise from nearby container ships and increased background
noise from distant shipping may significantly limit communication space.
Additionally, we show how amplitude and frequency compensation can
increase the likelihood of detecting communication signals in masking
noise under present conditions. We discuss these impacts of ship noise
on communication, as well as the evidence that documented noise
compensation behaviors of right whales can improve communication range
in the presence of low-frequency ship noise.