Aug 25
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
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
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
http://www.AcousticEcology.org/srSonarFactCheck.html
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 05
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 »
Jun 22
Kvadsheim, Benders, Miller, Doksaeter, Knudsen, Tyack, Nordlund, Lam, Samarra, Kleivane, Godo. Herring (slid), killer whales (spekknogger) and sonar - the 3S-2006 cruise report with preliminary results. Norwegian Defence Research Establishment (FFI). 30 April 2007
This paper reports preliminary results from an ambitious multi-national Controlled Exposure Experiment using acoustic D-tags, which allow researchers to record received sound levels while charting dive patterns. Six orcas were tagged, with 17 hours of data collected, with one animal exposed to LFAS signals, two to mid-frequency active sonar signals, and one used as a control, fewer samples than hoped. The whale exposed to LFAS signal did not change its behavior, nor did its companions. However, the group exposed to mid-frequency sonar signals ceased feeding and moved rapidly away; in addition, they exhibited an unusual dive pattern, Read the rest of this entry »
Jun 22
Peter L. Tyack. Implications for marine mammals of large-scale changes in the marine acoustic environment. Journal of Mammalogy, 89(3): 549-558, 2008. [DOWNLOAD PAPER(pdf)]
In this wide-ranging literature review, Peter Tyack of Woods Hole Oceanographic Institute sketches the history of research into the effects of noise on marine life, with some references as well to effects noted on terrestrial creatures. He begins by noting that while acute disturbance of individuals attracts the most attention, the likely more profound effects of chronic disturbance on population vitality (success in foraging and mating) are much harder to discern. Several examples are presented of studies that documented both temporary and long-term abandonment of key habitat when loud noise was present Read the rest of this entry »
Jun 16
The Biological Viability of the Most Endangered Marine Mammals and the Cost-effectiveness of Protection Programs. A Report to Congress from teh Marine Mammal Commission. February 2008. [DOWNLOAD REPORT (pdf)]
This 400+ page report is the culmination of a multi-year initiative by the MMC. It includes about 60 pages of summation, followed by several lenghty appendixes, the most substantial being a 160-page species-by-species assessment of endangered, threatened, and depleted marine mammals, focusing on historic and current populations, and the status of protection programs for each, and a 30-page report on the population viability of each species; two other sections address Right whale recovery efforts, as this species is a major focus in the western Atlantic. Among the goals of the report is to make recommendations as to how best to prioritize population recovery efforts, within the context of limited funding. The report notes, for example, that some species have received relatively high levels of attention via directed funding (e.g., western Sterallar sea lions), while others have not received enough funding to prevent or even fully understand their ongoing declines (e.g., Cook Inlet beluga whales). Its key recommendation is that a coherent national strategy be developed, centered on a dynamic and adaptable approach that includes both a separate funding stream for research and management for marine mammal population recovery, and a strategy to prioritize recovery attention basedon objective criteria including risk of extinction, expected conservation benefits, competing conservation needs, based on a structured and transparent risk/benefit analysis. One striking element to the MMC report is the consistant attention paid to noise as a key factor in species stress, decline, and recovery.
Jun 14
Caroline Weir. Overt Responses of Humpback Whales (Megaptera novaeangliae), Sperm Whales (Physeter macrocephalus), and Atlantic Spotted Dolphins (Stellena frontalis) to Seismic Exploration off Angola. Aquatic Mammals 2008, 34 (1), 71-83.
During ten months of seismic surveys off the Angola coast, 2769 hours of marine mammal observations were made from a survey vessel, seeking to determine whether marine mammals avoided the airgun noise. This study did not examine subtler responses, such as dive patterns or call rates, but simply tracked sighting rates and distances. The total number of marine mammal sightings was rather small, given the long timeframe (66 humpbacks, 124 sperm whales, 17 dolphins); the author does not offer any hints as to whether populations are simply low in that area, or whether observations were limited for any other reason (weather, single observer, high seas, etc.). Airguns were active roughly half the time, providing a balanced set of data to look at. The mean distance at which all species were seen was greater when airguns were active than when they were silent, though only the dolphins showed a statistically significant difference. The closest approach of humpbacks averaged 3000m with guns off and 2700m with guns on, with sperm whale results virtually identical; dolphins, by contrast, came much closer during guns-off, 209m, than when guns were on, 1080m. Read the rest of this entry »
May 16
Humpback whales are the inspiration for a new approach to blade design being used in fans and tested for wind turbines. The bumps along the edge of the whales’ long fins had long been considered an anatomical anomaly, but a biology professor in Pennsylvania has shown that they channel water across the surface of the fin in ways that create more maneuverability and power. Dr. Frank Fish has formed WhalePower to develop new industrial designs based on this discovery; the results are a sharp break from previous attempts to make fan and turbine blade edges as smooth as possible. Read the rest of this entry »
Apr 28
Agardy, 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. Read the rest of this entry »
Apr 11
Stellwagen Sanctuary Noise Monitoring to be Model for “Sound Budget” Research Worldwide - The hydrophone array deployed in Stellwagen Bank is far more than a ship-strike warning system; it is the first large field test of what many bioacousticians have been long calling for: a global network of monitoring systems that will dramatically increase our understanding of the distribution of human noise in the world’s oceans, and the ways local animals respond. NOAA researcher Sofie Van Parijs says the Sanctuary is a perfect place to build a case study that can provide a benchmark Read the rest of this entry »
Feb 28
Digital downloads of favorite Pulse of the Planet programs - Pulse of the Planet, the long-running 2-minute public radio feature, is now offering large collections of mp3 versions of shows, grouped in popular themes. The first three sets (23-49 shoes each, priced at $5-9) focus on hurricanes and tornadoes, whales, and global warming. [WEBPAGE]
Jan 25
Toothed Whale Hearing Senstivities Can Be Turned Up and Down
Supin, Nachtigall, Breese. Hearing sensitivity during target presence and absene while a whale echolocates. J. Acoust. Soc. Am. 123 (1), January 2008, 534-541
This very interesting paper, digging deeper into a topic that had emerged in previous studies of toothed whale hearing, reveals that a pilot whale could apparently “turn up” its hearing sensitivity, so that it could listen for fainter (more distant) sounds when echolocation clicks did not reveal nearby echoes. The research used a captive whale, outfitted with suction-mounted EEG electrodes to measure evoked potentials as it echolocated; half the time, a target fish was nearby, and half the time there was no nearby fish. When no fish was present, hearing sensitivity was 20dB higher (ie it could hear sounds 20dB more faint).
Dec 20
Quiet Autonomous Gliders Promise “New Era” in Acoustic Monitoring - A major step forward in acoustic monitoring has passed its first test. “We are entering a new era of underwater sensing,” says Jim Theriault of Defence Research and Development Canada, in Dartmouth, Nova Scotia, who ran the first trial of small torpedo-shaped “gliders” as a platform for acoustic monitoring. Unlike other systems, which require a boat nearby to monitor either the tagging of whales or other autonomous vehicles, the gliders can use a satellite phone connection to return data to distant research bases. Also, the new system has enough data capability to detect not only low-frequency baleen whale calls, but also the high-frequency calls of sperm and beaked whales, Read the rest of this entry »
Dec 16
Initial Cruise Report From First Controlled Exposure Studies of Beaked WhalesIan Boyd, Diane Claridge, Christopher Clark, Brandon Southall, Peter Tyack. Behavioral Response Study-2007, Cruise Report, Phase 1 A summary of the project, and the preliminary cruise report are available: [WEBSITE]During August and September, 2007, the first controlled exposure experiments aimed at learning more about the ways that beaked and pilot whales respond to exposure to mid-frequency active sonar took place in the Bahamas. Read the rest of this entry »
Dec 13
Extended Near-surface Dives May Be Cause of Beaked Whale BendsWalter, M.X. Simmer, Peter L. Tyack. Repetitive shallow dives pose decompression risk in deep-diving beaked whales. Marine Mammal Science, Volume 23 Issue 4 Page 888-925, October 2007. ScienceNow summary of paper: [WEBSITE]It is apparent that beaked whales are especially sensitive to mid-frequency sonar, but the reasons have remained elusive. This study explores a new idea about how the whales’ dive patterns may be disrupted enough to cause decompression sickness (DCS, ie “the bends”). Some have suspected that exposure to sonar may cause the whales to surface more quickly than usual, but since the whales’ lungs are collapsed in dives deeper than 70m (thus preventing nitrogen from entering the bloodstream and infiltrating into tissues where it could cause damage), it is not readily apparent how faster surfacing would cause DCS. Instead, this study looks at the “recovery” period observed in beaked whales, during which they make a series of near-surface dives before embarking on a new deep foraging dive. The researchers modeled the possible physiological effects of having this recovery period extended longer than usual. The team incorporated known physiological data into a model that charts how the bubble size might increase in the circulatory system, brain, muscles, and fat tissues when a whale dives repeatedly to between 30 and 80 meters for as long as 3 hours. The team’s model predicts that if the whales’ lungs do not collapse during a long series of shallow dives, the increased pressure can cause nitrogen bubbles to diffuse into tissues, increasing the risk of bubble formation on ascent. Such behavior may result if the whales perceive sonar transmissions as a predator: Read the rest of this entry »