Aug 25 2008
LAY SUMMARY OF THE FOLLOWING RESEARCH REPORT:
Jochens, A., D. Biggs, K. Benoit-Bird, D. Engelhaupt, J. Gordon, C. Hu, N. Jaquet, M. Johnson, R. Leben, B. Mate, P. Miller, J. Ortega-Ortiz, A. Thode, P. Tyack, and B. Würsig. 2008. Sperm whale seismic study in the Gulf of Mexico: Synthesis report. U.S. Dept. of the Interior, Minerals Management Service, Gulf of Mexico OCS Region, New Orleans, LA. OCS Study MMS 2008-006. 341 pp. [DOWNLOAD REPORT]
For four summers, from 2002-2005, a diverse team of researchers studied the sperm whale populations of the northern Gulf of Mexico; this final report presents the results of three distinct lines of research: to learn more about the population sizes, social patterns, and group and individual behavior of this population of sperm whales, to characterize habitat use in this area, and to examine possible changes in behavior in response to the noise of seismic survey airguns. By all accounts, the study was very successful on the first two counts, dramatically increasing our understanding of the overall populations and habitat use, especially in the key areas of the Gulf where the oil and gas industry is moving into deeper waters. It is the third topic, effects of noise, that especially interest us here at AEI, and on this count, the results were not as clear-cut. Over the course of two field seasons in which researchers attached acoustic D-tags to sperm whales, only a total of eight whales were tagged and subsequently exposed via controlled exposure to air guns towed by ships participating in the study. Read the rest of this entry »
Aug 22 2008
The Minerals Management Service has released the final report of the Sperm Whale Seismic Study, which lasted five years and used acoustic D-tags that track the movements of whales while also recording received sound levels. Unfortunately, few of the 98 whales that were successfully tagged during the study came any closer than 5km to the seismic survey air guns being used as the test sound source, so the final conclusions only address long-range impacts. According to Doug Biggs of Texas A&M, one of the lead scientists, “The bottom line is that airgun noise from seismic surveys that are thousands of yards distant does not drive away sperm whales living in the Gulf.” Biggs also noted that some individual whales feeding at depth reduced the rate at which they made echolocation clicks while in search of prey when the air guns came closer; not enough instances of this occurred during the study to make definitive conclusions about how large an impact this might cause. The study provided a wealth of new information about the Gulf of Mexico sperm whale population, which appears to be genetically distinct from open-ocean sperm whale stockes, smaller in size and with distict vocalization patterns. Sources: PhysOrg.com, 8/21/08 [READ ARTICLE] ScienceDaily/Texas A&M, 8/21/08 [READ ARTICLE]
Aug 21 2008
Been wondering what’s up with the great “Sonar Kills Whales”/”Everything’s Fine, Just Go Away” rhetorical battle between NRDC and the Navy? As you might suspect, the reality is not nearly so neatly defined as either of them might suggest….and if you’re up for digging into it more deeply, the Acoustic Ecology Institute has just posted an AEI FactCheck that explores three key questions:
- Dead Whales: How Common?
- Behavioral Reactions: Millions of Whales Affected, or Negligible Impact
- Additional Mitigation: Common Sense Precautions or Undermining Sailor Safety?
There’s a fair dose of decoding science and regulatory details in this document, as well as acknowledgment of the underlying unspoken ethical questions that lead to radically different perspectives on the same data.
Check it out at
AEI is a resource/information center for sound-related environmental issues, run by editor/writer Jim Cummings (yup, that’s me…). We’ve some how managed to become friends with top scientists and agency staff, major environmental groups, and even a few folks in the Navy and oil and gas industry. More at http://AEInews.org
Aug 13 2008
A federal district court has approved a settlement between the Navy and a NRDC-led coalition of environmental groups that will limit training missions using Low-Frequency Active Sonar to several specific regions in the Paciific Ocean. Negotiations were ordered by the court after NRDC challenged the legality of permits the Navy received which would have allowed nearly worldwide use of the powerful submarine-detection system. Ed note: in practice, the Navy’s two LFAS-equipped ships have remained in the western Pacific, where they can monitor Chinese and North Korean subs. The new agreement allows the Navy to use LFAS in more areas than were allowed under a similar agreement several years ago, including waters near the Philippines and Japan (with seasonal restrictions), as well as areas north and south of Hawaii, while explicitly banning its use in some biologically important areas, including marine sanctuaries near Hawaii. Read the rest of this entry »
Aug 05 2008
As a new UK Navy report suggests that beaked whales made “potentially very significant” behavioral changes in response to mid-frequency active sonar signals, a team of scientists has just completed a pilot study that involved monitoring the detailed behavior of whales during a major Naval exercise. The UK military report details observations of whale activity during Operation Anglo-Saxon 06, a submarine war-games exercise in 2006. Produced for the UK’s Defence Science and Technology Laboratory, the study used an array of hydrophones to listen for whale sounds during the war games. Across the course of the exercise, the number of whale recordings dropped from over 200 to less than 50. “Beaked whale species appear to cease vocalizing and foraging for food in the area around active sonar transmissions,” said the report. Read the rest of this entry »