[MARMAM] Comments sought for impact on mm by proposed geophysical survey in SE Asia
pcrassidens at rogers.com
Sat Jan 10 21:12:04 PST 2009
Comments sought for impact on mm by proposed geophysical survey in SE Asia
Many if you may not have time to read the details of a proposal to NMFS (US) to ‘take’ marine mammals in SE Asia during a geophysical survey by Lamont-Doherty Earth Observatory (Columbia University). Pasted below is a summary of the proposed survey but the US Federal Register notice is also attached for anyone desiring more details. You can also find the notice and additional documents related to this activity at the following NMFS web-pages:
Federal Register notice: http://www.nmfs.noaa.gov/pr/pdfs/fr/fr73-78294.pdf
Local and international marine mammal scientists, conservationists, eco-tour operators and other interested parties were recently made aware of this notice in the US Federal Register and are very concerned about the impacts of this geophysical survey on marine mammals in SE Asia where several highly endangered and sensitive cetaceans are found. The region already suffers from many threats at levels that are unknown in many developed countries, including the US. Furthermore, the understanding of marine mammal biology in this region is greatly inadequate.
Once such a survey is permitted in one region where marine mammals are poorly understood (and with no evidence demonstrating it is safe to these animals), it is likely to be allowed in other regions that are similarly deficient of information about marine mammals. Marine mammal biologists have worked hard to avoid research that is destructive and even mildly intrusive to their subjects. These efforts could be wasted if other fields of research are allowed to harm these animals without the same level of care about the impacts of their activities and adequate consultation with marine mammal experts in the region. The impacts of seismic surveys do not seem to be limited to marine mammals. Other marine life including sea turtles and fish are also likely to be affected if adequate precautions are not taken.
I would encourage anyone with concerns about or expertise in the potential impacts of the proposed geophysical survey in SE Asian waters on local marine mammals to send their comments and concerns to:
Michael Payne, Chief, Permits, Conservation and Education Division, Office of Protected Resources, National Marine Fisheries Service, 1315 East-West Highway, Silver Spring, MD, 20910–3225. The mailbox address for providing email comments is:
PR1.0648 XL89 at noaa.gov
michael.payne at noaa.gov.
Comments sent via email including all attachments, must not exceed a 10–megabyte file size.
Note: The deadline for comments is 21 January (an extension for the commenting period has been requested but it is unknown yet if the request will be granted).
John Y. Wang, Ph.D.
FormosaCetus Research and Conservation Group
Trent University (Adjunct Professor)
George Mason University (Affiliate Professor)
Incidental Takes of Marine Mammals During Specified Activities; Marine Geophysical Survey in Southeast Asia, March–July 2009
US NMFS received an application from the Lamont-Doherty Earth Observatory, L-DEO (a part of Columbia University), for an Incidental Harassment Authorization (IHA) to take marine mammals, by harassment, incidental to conducting a geophysical seismic survey in SE Asia between 21 March and 14 July 2009 to better understand mountain building processes but information gained from the surveys will allegedly also increase understanding of the nature of earthquakes.
The 71.5m long R/V Marcus G. Langseth will be towing a large 36-airgun array (6,600 in3; the nominal source level is 265 dB re 1μPam, peak-to-peak) through 15,902km of track lines in waters that are bounded by 17o30’ and 26oN and 113o30’ and 126oE covering all waters of and surrounding Taiwan (from 25 to 6,585m of water depth). From March 21 to April 19, the Langseth will be operating airguns in the South China Sea. From April 20 to June 7, the Langseth will be operating in the Luzon Strait and Philippine Sea and from June 21 to July 14, the Langseth will be surveying the waters immediately around Taiwan. It will be operating in the EEZs of China, Taiwan, Japan and the Philippines as well as adjacent high seas. The nearest approach to land masses will be within 1km of Taiwan’s coastline, within 10km of China’s coastline, within 16km from the Ryuku Islands and 32km from Luzon (but will be within 8km of some of the Babuyan and Batanes
According to NMFS, to avoid permanent physiological damage, cetaceans should not be exposed to received pulsed underwater noise levels of 180 dB re 1μPam (rms) or more. This would be ‘Level A Harassment’ whereas received levels above 160 but lower than 180 dB re 1μPam (rms) would be considered ‘Level B Harassment’. The predictions of where 180 dB re 1μPam (rms) will be received vary between 710m and 3,694m from the source (36-airgun array) depending on the depth at which the array will be towed and the depth of water (the deeper tow depth and over shallower water, the farther the distance will be). For the 160 dB re 1μPam (rms) level, the distances varied from 4,670 to 8,000m from source.
There are many species of concern in this region including: the western gray whale, N. Pacific right whale, blue whale, humpback whale, sperm whale, beaked whales, the ETS population of Sousa chinensis and others. The first two species have not been observed in the waters around Taiwan. However, at least the gray whale is suspected of passing through some of these waters during migration to and from their summer wintering grounds in Russian waters and a yet unknown wintering ground(s) in the South China Sea. A small population of humpback whales winter in the waters of the Babuyan Islands in the northern Philippines and they pass through Taiwanese waters during their migrations. Both Taiwan and the Philippines appear to have fairly high numbers of beaked whales (including the very rare Longman’s and ginkgo-toothed beaked whales) as evidenced by strandings and some recent sighting records (much of this information is unpublished). The ETS
Sousa chinensis population was recently listed as Critically Endangered in the 2008 IUCN Red List of Threatened Species, numbers less than 100 individuals (possibly fewer than 70 individuals based on recent preliminary photo-ID mark-recapture analysis), has been shown to be distinct from adjacent provisional populations in Chinese waters and is found in a very restricted and more or less linear distribution along the coastal waters of western Taiwan (spanning a distance of <200km and from the shoreline to at least 3km from shore, with a proposed 5km offshore boundary for major habitat designation having recently been approved by the newly established Eastern Taiwan Strait Sousa Technical Advisory Working Group).
The proposed geophysical surveys will pass through waters in which these species are found. One of our greatest concerns is that the Langseth will also operate the airguns in and adjacent to the known distribution of the ETS Sousa with the predicted received levels exceeding 180 dB re 1μPam (rms), which will likely result in permanent damage to the auditory system even if the proposed mitigation measures are implemented fully – i.e., staying outside of 2km from the shoreline, the predicted received levels will far exceed 180 dB re 1μPam (rms) in all waters where the ETS Sousa reside. Furthermore, throughout the ETS Sousa distribution, there is no sizable area where animals can find shelter acoustically from any loud energy source. Finally, the proposed seismic surveys are during a period when calving appears to peak for this population. Given the small population size of the ETS Sousa, even a minimal ‘take’ will result in a heavy impact
on the survival of this critically endangered population.
The survey track lines to within 1 km from shore of Taiwan will also bring the Langseth over or very close to the continental shelf edge along more or less the entire east and large parts of the north and south coasts of Taiwan (there is a very narrow continental shelf along these coasts). The shelf edge is a structure that concentrates marine mammals in eastern Taiwan, where one of the fastest growing cetacean-based eco-tourism industries in the world has developed since the late 1990s. Off SW Taiwan, the waters in and around a deep trough/canyon that leads to an important upwelling area have also been reported to support many cetaceans but cetacean research is limited here. Off NE Taiwan, another important upwelling area, resulting from a steep change in the ocean floor bathymetry is an important fishing ground and where cetaceans appear to congregate in large numbers (as evidenced by past captures before legal protection). Many beaked whale
strandings have been reported from Taiwan, including those from several recent unusual stranding events involving multiple species that are generally considered rare. Taiwan meets the criteria as a “key area” for beaked whales (as defined by MacLeod and Mitchell, 2006). The proposed survey in the spring is also the season when most calving occurs so females that are accompanied by their highly vulnerable neonates also become vulnerable to threats as well. Taiwan and its adjacent waters have a high diversity of marine mammals with known records of about 35 species from Taiwanese waters alone.
Finally, all cetaceans are fully protected legally in at least some of these countries/regions/political entities/economies/etc. and some have been given the highest and strictest level of legal protection.
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