Workshop Suggests Ways for MPAs to Provide Acoustic Refuge
Bioacoustics, Ocean, Science Add commentsAgardy, Aguilar, Canadas, Engel, Frantzis, Hatch, Hoyt, Kashner, LaBrecque, Martin, Notarbartolo di Sciara, Pavan, Servidio, Smith, Want, Weilgart, Wintle, Wright. 2007. A global Scientific Workshop on Spatio-Temporal Management of Noise. Report of the Scientific Workshop. 44 pages. [DOWNLOAD(pdf)]
AEI Lay Summary
In June 2007, a workshop was held in the Canary Islands to consider the potentials for extending the management principles used in Marine Protected Areas to provide some protection from anthropogenic noise. Fundamental to the purpose and effectiveness of MPAs are “spatio-temporal restrictions” (STRs) of specific human activities: for example, excluding fishing, from a specific area (spatial restriction), or sometimes at times of special biological importance, such as spawning (temporal restriction). Few of today’s MPAs are large enough to provide protection from “elevated levels of ensonification:” buffers of tens of kilometers would be necessary for protection from mid-frequency sound, and a hundred or more kilometers from low-frequency sound. Of today’s 350 MPAs that include some cetacean habitat, 64 are large enough to provide some mid-frequency protection, 20 are large enough to provide at least some low-frequency protection (e.g. shipping), and only the 6 largest are probably sufficient to protect from shipping noise. (of course, shipping is not generally excluded from MPAs: this is merely a hint at the scale of noise STRs that would be useful.) The Workshop report includes several key sections:
- Descriptions of some existing attempts to provide STRs focused on noise: In 2003, Brazil established a large buffer zone around a small existing MPA, to exclude the sounds of seismic survey airguns from entering the MPA (the buffer was withdrawn by a court due to jurisdictional issues; attempts are underway to re-establish it). In the Canary Islands, a 50 nautical mile buffer zone has been established around the islands, in which active sonar is not allowed (there have been some subsequent strandings that raise questions whether this is large enough a buffer).
- Recommendations for MPA managers, centered on a framework for making management decisions regarding possible noise-related STRs.
- Recommendation that noise-producers provide more information, and longer lead times prior to operations near MPAs, to allow for analysis of effects of proposed noise. A far-reaching element of this is a call for use of “detectability curves” to reflect how easy it is to find various species of whales, and to insure that more effort is made to find hard-to-detect whales, rather than assuming that they are not present if none are found using standard observational techniques.
- Recommended measures that could reduce the noise impacts of the primary noise producing activities.
- Suggested MPAs or proposed MPAs where noise-oriented STRs could be introduced, as case studies for future MPA managment protocols. These include the PELAGOS Sancturay in the northwestern Mediterranean, off France, Italy, and Monaco, the Alborian Sea/Strait of Gibraltar, the Bay of Bengal, and East Asian waters off Japan, China, and the Philippines.