We are pleased to announce the publication of a short review that
summarizes our current ideas how sonar may interfere with diving in
cetaceans.
This article is an open access publication, which means that it is
freely accessible to any reader anywhere in the world. We encourage you
to share the article link with any colleagues who may be interested in
this work.
**
*
Title: * How man-made interference might cause gas bubble emboli in deep
diving whales*
*Authors: **Andreas Fahlman, Peter L Tyack, Patrick James Miller, and
Petter H Kvadsheim
**Journal: **Frontiers in Physiology**
URL:
**http://www.frontiersin.org/Journal/Abstract.aspx?f=65&name=physiology&ART_DOI=10.3389/fphys.2014.00013&utm_source=Email_to_authors_&utm_medium=Email&utm_content=T1_11.5e1_author&utm_campaign=Email_publication&journalName=Frontiers_in_Physiology&id=66907
****
*Abstract**: *
Recent cetacean mass strandings in close temporal and spatial
association with sonar activity has raised the concern that
anthropogenic sound may harm breath-hold diving marine mammals. Necropsy
results of the stranded whales have shown evidence of bubbles in the
tissues, similar to those in human divers suffering from decompression
sickness (DCS). It has been proposed that changes in behavior or
physiological responses during diving could increase tissue and blood
N_2 levels, thereby increasing DCS risk. Dive data recorded from sperm,
killer, long-finned pilot, Blainville's beaked and Cuvier's beaked
whales before and during exposure to low- (1-2 kHz) and mid- (2-7 kHz)
frequency active sonar were used to estimate the changes in blood and
tissue N_2 tension (P_N2 ). Our objectives were to determine if
differences in 1) dive behavior or 2) physiological responses to sonar
are plausible risk factors for bubble formation. The theoretical
estimates indicate that all species may experience high N_2 levels.
However, unexpectedly, deep diving generally result in higher end-dive
P_N2 as compared with shallow diving. In this focused review we focus on
three possible explanations: 1) We revisit an old hypothesis that CO_2 ,
because of its much higher diffusivity, forms bubble precursors that
continue to grow in N_2 supersaturated tissues. Such a mechanism would
be less dependent on the alveolar collapse depth but affected by
elevated levels of CO_2 following a burst of activity during sonar
exposure. 2)_During deep dives, a greater duration of time might be
spent at depths where gas exchange continues as compared with shallow
dives. The resulting elevated levels of N_2 in deep diving whales might
also make them more susceptible to anthropogenic disturbances. 3)
Extended duration of dives even at depths beyond where the alveoli
collapse could result in slow continuous accumulation of N_2 in the
adipose tissues that eventually becomes a liability.**
*Citation:* Fahlman A, Tyack PL, Miller PJO and Kvadsheim PH (2014) How
man-made interference might cause gas bubble emboli in deep diving
whales./Front. Physiol/.*5*:13. doi: 10.3389/fphys.2014.00013
--
Andreas Fahlman
Department of Life Sciences
Texas A&M- Corpus Christi
6300 Ocean Dr Unit 5892
Corpus Christi, TX 78412
Ph. +1-361-825-3489
Fax +1-361-825-2025
mail: andreas.fahl...@tamucc.edu
web: http://www.comparative-physiology.tamucc.edu/
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