37
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      Beaked Whales Respond to Simulated and Actual Navy Sonar

      research-article

      Read this article at

      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Beaked whales have mass stranded during some naval sonar exercises, but the cause is unknown. They are difficult to sight but can reliably be detected by listening for echolocation clicks produced during deep foraging dives. Listening for these clicks, we documented Blainville's beaked whales, Mesoplodon densirostris, in a naval underwater range where sonars are in regular use near Andros Island, Bahamas. An array of bottom-mounted hydrophones can detect beaked whales when they click anywhere within the range. We used two complementary methods to investigate behavioral responses of beaked whales to sonar: an opportunistic approach that monitored whale responses to multi-day naval exercises involving tactical mid-frequency sonars, and an experimental approach using playbacks of simulated sonar and control sounds to whales tagged with a device that records sound, movement, and orientation. Here we show that in both exposure conditions beaked whales stopped echolocating during deep foraging dives and moved away. During actual sonar exercises, beaked whales were primarily detected near the periphery of the range, on average 16 km away from the sonar transmissions. Once the exercise stopped, beaked whales gradually filled in the center of the range over 2–3 days. A satellite tagged whale moved outside the range during an exercise, returning over 2–3 days post-exercise. The experimental approach used tags to measure acoustic exposure and behavioral reactions of beaked whales to one controlled exposure each of simulated military sonar, killer whale calls, and band-limited noise. The beaked whales reacted to these three sound playbacks at sound pressure levels below 142 dB re 1 µPa by stopping echolocation followed by unusually long and slow ascents from their foraging dives. The combined results indicate similar disruption of foraging behavior and avoidance by beaked whales in the two different contexts, at exposures well below those used by regulators to define disturbance.

          Related collections

          Most cited references43

          • Record: found
          • Abstract: found
          • Article: not found

          Birdsong and anthropogenic noise: implications and applications for conservation.

          The dramatic increase in human activities all over the world has caused, on an evolutionary time scale, a sudden rise in especially low-pitched noise levels. Ambient noise may be detrimental to birds through direct stress, masking of predator arrival or associated alarm calls, and by interference of acoustic signals in general. Two of the most important functions of avian acoustic signals are territory defence and mate attraction. Both of these functions are hampered when signal efficiency is reduced through rising noise levels, resulting in direct negative fitness consequences. Many bird species are less abundant near highways and studies are becoming available on reduced reproductive success in noisy territories. Urbanization typically leads to homogenization of bird communities over large geographical ranges. We review current evidence for whether and how anthropogenic noise plays a role in these patterns of decline in diversity and density. We also provide details of a case study on great tits (Parus major), a successful urban species. Great tits show features that other species may lack and make them unsuitable for city life. We hypothesize that behavioural plasticity in singing behaviour may allow species more time to adapt to human-altered environments and we address the potential for microevolutionary changes and urban speciation in European blackbirds (Turdus merula). We conclude by providing an overview of mitigating measures available to abate noise levels that are degrading bird breeding areas. Bird conservationists probably gain most by realizing that birds and humans often benefit from the same or only slightly modified measures.
            Bookmark
            • Record: found
            • Abstract: found
            • Article: not found

            Extreme diving of beaked whales.

            Sound-and-orientation recording tags (DTAGs) were used to study 10 beaked whales of two poorly known species, Ziphius cavirostris (Zc) and Mesoplodon densirostris (Md). Acoustic behaviour in the deep foraging dives performed by both species (Zc: 28 dives by seven individuals; Md: 16 dives by three individuals) shows that they hunt by echolocation in deep water between 222 and 1885 m, attempting to capture about 30 prey/dive. This food source is so deep that the average foraging dives were deeper (Zc: 1070 m; Md: 835 m) and longer (Zc: 58 min; Md: 47 min) than reported for any other air-breathing species. A series of shallower dives, containing no indications of foraging, followed most deep foraging dives. The average interval between deep foraging dives was 63 min for Zc and 92 min for Md. This long an interval may be required for beaked whales to recover from an oxygen debt accrued in the deep foraging dives, which last about twice the estimated aerobic dive limit. Recent reports of gas emboli in beaked whales stranded during naval sonar exercises have led to the hypothesis that their deep-diving may make them especially vulnerable to decompression. Using current models of breath-hold diving, we infer that their natural diving behaviour is inconsistent with known problems of acute nitrogen supersaturation and embolism. If the assumptions of these models are correct for beaked whales, then possible decompression problems are more likely to result from an abnormal behavioural response to sonar.
              Bookmark
              • Record: found
              • Abstract: not found
              • Article: not found

              A simple new algorithm to filter marine mammal Argos locations

                Bookmark

                Author and article information

                Contributors
                Role: Editor
                Journal
                PLoS One
                plos
                plosone
                PLoS ONE
                Public Library of Science (San Francisco, USA )
                1932-6203
                2011
                14 March 2011
                : 6
                : 3
                : e17009
                Affiliations
                [1 ]Biology Department, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, United States of America
                [2 ]North Atlantic Treaty Organisation Undersea Research Centre, La Spezia, Italy
                [3 ]Naval Undersea Warfare Center Division, Newport, Rhode Island, United States of America
                [4 ]Southall Environmental Associates, Aptos, California, United States of America
                [5 ]Long Marine Laboratory, University of California Santa Cruz, Santa Cruz, California, United States of America
                [6 ]Bahamas Marine Mammal Research Organisation, Marsh Harbour, Abaco, Bahamas
                [7 ]Protected Resources Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, La Jolla, California, United States of America
                [8 ]Bioacoustics Research Program, Cornell Lab of Ornithology, Cornell University, Ithaca, New York, United States of America
                [9 ]Space and Naval Warfare Systems Center Pacific, San Diego, California, United States of America
                [10 ]Sea Mammal Research Unit, Scottish Oceans Institute, University of St. Andrews, Fife, Scotland, United Kingdom
                National Institute of Water & Atmospheric Research, New Zealand
                Author notes

                Conceived and designed the experiments: PLT WMXZ DM BLS DEC JWD CWC IB. Performed the experiments: PLT WMXZ DM BLS DEC JWD CWC AD ND SJ EM RM JW IB. Analyzed the data: PLT WMXZ DM BLS DEC JWD CWC AD ND SJ EM RM JW IB. Contributed reagents/materials/analysis tools: PLT WMXZ DM BLS DEC JWD CWC AD ND SJ EM RM JW IB. Wrote the manuscript: PLT WMXZ DM BLS JWD IB.

                Article
                PONE-D-10-04977
                10.1371/journal.pone.0017009
                3056662
                21423729
                a63e5e9f-fa37-4b9e-ad3f-4199ac3becc5
                This is an open-access article distributed under the terms of the Creative Commons Public Domain declaration which stipulates that, once placed in the public domain, this work may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose.
                History
                : 28 September 2010
                : 17 January 2011
                Page count
                Pages: 15
                Categories
                Research Article
                Biology
                Ecology
                Marine Biology
                Marine Ecology
                Marine Monitoring
                Zoology
                Animal Behavior
                Mammalogy

                Uncategorized
                Uncategorized

                Comments

                Comment on this article