- website of the Acoustic Ecology Institute
newsCommunityResourcesSoundscapesAbout UsJoin Us
aeinews Home

Whales can dampen hearing: implications for ocean noise concerns

Animal Communication, Bioacoustics, Effects of Noise on Wildlife, Ocean, Science No Comments »

You may have noticed a recent flurry of press reports about research in Hawaii that begins to quantify a long-suspected quality of cetacean hearing: the ability to dampen hearing sensitivity so that loud sounds don’t cause damage.  Given the extremely loud volume of many whale calls, which are meant to be heard tens or hundreds of miles away, researchers have long speculated that animals may have ways of protecting their ears from calls made by themselves or nearby whales, perhaps using a muscle response to reduce their hearing sensitivity (not unlike a similar muscular dampening mechanism in humans).  Indeed, earlier studies by Paul Nachtigall’s team had found that some whales could do indeed reduce their auditory response to the sharp clicks they use for echolocation.  In the new study, Nachtigall trained a captive false killer whale named Kina to reduce her hearing sensitivity by repeatedly playing a soft trigger sound followed by a loud sound.  Eventually, she learned to prepare for the loud sound in advance by reducing her hearing sensitivity.  “It’s equivalent to plugging your ears…it’s like a volume control,” according to Nachtigall.

Well, that sounds like a pretty useful trick, given all the concern about human sounds in the sea.  And the media, led by the New York Times, jumped on board with headlines following on the Times‘ assertion that suggested whales  already “are coping with humans’ din” using this method. (Among the exciting headline variations: Whales Can Ignore Human Noise, Whales Learning to Block Out Harmful Human Noise, and UH Scientists: Whales Can Shut Their Ears.)

Oops, they did it again!  Grab some interesting new science and leap to apply a specific finding to a broad public policy question, often, as this time, giving us a false sense of security that the “experts” have solved the problem, so there’s no need to worry our little selves over it any more (as stressed in this NRDC commentary).  To be fair, the Times piece included a few cautionary comments from both scientists and environmental groups, but the headline rippled across the web as the story was picked up by others.

Two key things to keep in mind:  First, this whale was trained to implement her native ability, meant for use with her sounds or those of nearby compatriots, and to apply it to an outside sound made by humans.  This doesn’t mean that untrained whales will do the same.  

And second: If whales can dampen their hearing once a loud sound enters their soundscape, this could indeed help reduce the physiological impact of some loud human sounds, such as air guns or navy sonar. If indeed this ability translates to wild cetaceans, the best we could hope for is that it would minimize hearing damage caused by occasional and unexpected loud, close sounds that repeat.  There would be no protection from the first blast or two, but perhaps some protection from succeeding ones; or, if the sound source was gradually approaching or “ramping up,” as often done with sonar and air guns, animals may be able to “plug their ears” before sounds reach damaging levels, if for some reason they can’t move away.  Even then, the animals are very likely to experience rapidly elevated stress levels, as they would be less able to hear whatever fainter sounds they had been attending to before the intrusion. Yet research in the field suggests that most species of whales and dolphins prefer to keep some distance from such loud noise sources; this hearing-protection trick doesn’t seem to make them happy to hang around loud human sounds.  

Most crucially, these occasional loud sounds are but a small proportion of the human noises whales are trying to cope with. Noise from shipping, oil and gas production activities, offshore construction, and more distant moderate sounds of air guns all fill the ocean with sound, reducing whales’ communication range and listening area, and likely increasing stress levels because of these reductions.  This is the “din” of chronic moderate human noise in the sea, and Kina’s ability would not help her cope with any of it.  We’re a long way from being able to rest easy about our sonic impacts in the oceans.

To end this rant with a bit of credit where due, here’s what may be the more important take-away from the Times article:

Peter Madsen, a professor of marine biology at Aarhus University in Denmark, said he applauded the Hawaiian team for its “elegant study” and the promise of innovative ways of “getting at some of the noise problems.” But he cautioned against letting the discovery slow global efforts to reduce the oceanic roar, which would aid the beleaguered sea mammals more directly.

Offsore oil development expanding in remote Arctic seas

Effects of Noise on Wildlife, News, Seismic Surveys No Comments »

The Anchorage Daily News ran a  great, detailed piece on the expansion of offshore oil and gas development in the Beaufort and Chukchi Seas north and west of Alaska.  It’s well worth reading in full.  The nut of the story is that Shell Oil, which has conducted seismic surveys in the northerns seas for the past few years, is gearing up to drill their first new exploratory well in over a decade.  If they find the oil they expect to, further seismic exploration and drilling is likely to follow in these remote waters, home to many species of whales.  Bowhead whales are especially sensitive to noise, especially cow-calf pairs, and have been found to give seismic surveys a wide berth.

Oil companies have been doing extensive research into the seasonal distributions of whales (especially belugas and bowheads), and have agreed to suspend operations in late August to accommodate the Alaskan natives traditional bowhead hunting season.  Meanwhile, Chris Clark, the Bioacoustics Research Program director at Cornell says, “There are unanswered science questions.  It’s not clear what happens if a whale hears 1,000 of the explosions from air guns, or where it will go if an area is saturated with the sound. In addition, scientists are only beginning to study the effects of the sound on fish and other animals that make up the whole ecosystem.”

Go read the whole article!

Motorcycle noise in National Parks: take it slow

Effects of Noise on Wildlife, News, Vehicles, Wildlands No Comments »

I just came across a fascinating piece on Oregon Public Radio’s EarthFix site, in which author Ashley Ahearn, a rider herself, discussed motorcycle noise in National Parks with Karen Trevino of the NPS Natural Sounds and Night Skies Division.  

Trevino notes that most of the excessive noise on roads comes from bikes with aftermarket exhaust parts, while the vast majority of motorcycles pose no special noise problems.  Ahearn’s bike “sounds like a Singer sewing machine,” according to one of the enhance Harley owners that the author talked to outside a biker bar near Mount Rainier National Park.  That may be what Trevino and her NPS cohorts wish all bikes sounded like, but that’s not the case.  In the video below, the NPS charted the sound footprint of a single motorcycle traveling along the Going to the Sun Road in Glacier National Park; the Park Service has found that bikes can be heard up to 18 miles away in some situations.

MotorcycleNoiseVid from EarthFix on Vimeo.

Trevino says that while the NPS is gathering data, there are no plans to impose restrictions on motorcycles in National Parks.  Rather, the NPS is partnering with motorcycle associations to ask riders to stay in smaller groups, not accelerate excessively and respect parks’ quiet hours.

Tension builds over expanded whale “takes” in new Navy sonar EIS

Effects of Noise on Wildlife, Ocean, Sonar No Comments »

The US Navy has released its initial Draft Environmental Impact Statements for the next 5-year round of permits it will seek from the National Marine Fisheries Service for its at-sea training activities, and the numbers of animals expected to be affected have skyrocketed.  This is in part thanks to the new EISs combining areas that were dealt with separately in the first round of permitting, which occurred after the NRDC challenged the lack of permits in court.  The new Hawaii-Southern California EIS not only combines these two previous separate areas, but also accounts for impact to animals in waters between Hawaii and California that were previously not considered.  In addition, the new EISs draw on more recent scientific evidence of lower impact thresholds for some species, including beaked whales, and on more advanced models that predict animal concentrations and movements.

While this expanded focus and better data is a valuable step forward, the numbers of animals expected to be injured or to have their behavior affected has increased so much that NRDC termed it “harm of staggering proportions.”  Clearly, attempts to foster more constructive dialogue between the Navy, NMFS, and NRDC during the EIS process has not led to a shared vision or lowered the heat all that much.  The Navy’s estimate of the number of animals whose behavior could be affected has jumped from 770,000 to 14 million, including 2 million cases of temporary hearing impairment, in addition to 2000 animals experiencing permanent hearing loss.  And, the Navy estimates that explosives training and testing could kill 1000 animals. 

But, Navy officials told CNN, these alarming numbers — a result of mathematical modeling — are worst-case scenarios.  “We believe … with our mitigation efforts and the Navy commitment that those injuries and mortalities will be none,” said John Van Name, U.S. Pacific Fleet senior environmental planner in Pearl Harbor, Hawaii. The report also indicated monitoring in 2009-2010 off Hawaii and Southern California showed 162,000 marine mammals with no evidence of distress or unusual behavior during Navy activities.  By comparison, the previous round of EISs estimated injury or death to about 100 animals in Hawaii and California during the five years from 2009-13; to date, two or three dolphins are known to have been killed by explosives testing.

Zak Smith of the NRDC responds that “I am not saying they are not well-intentioned. But I am not sure their choices make them the best environmental stewards they could be.”  In a blog post, Smith elaborates:

While the Navy’s understanding of how much harm it’s activities cause marine mammals has increased, it hasn’t taken any corresponding steps to minimize this staggering level of harm.  It’s mitigation protocol remains largely unchanged, with the Navy refusing to set aside areas of high marine mammal density where sonar should not be used.  This means sensitive breeding and foraging habitats and biologically unique areas within the training area can still be used for sonar and underwater explosives training. We know that safeguarding specific areas of sensitive habitat is the best way to lessen harm to whales and dolphins from sonar and other activities — don’t use the technology in the same areas where whale and dolphin numbers are high or during breeding seasons.  Faced with such incredible numbers and levels of harm, the Navy must do more to identify and set aside portions of its training areas (areas often the size of large states, like California) where it will not conduct training and testing.

For more on the EIS process, see the Navy’s information sites for the Hawaii-Southern California EIS and the Atlantic Fleet EIS.  Comments on both are being accepted through July 10.

Cook Inlet seismic survey permits challenged in court

Effects of Noise on Wildlife, Ocean, Seismic Surveys No Comments »

Permits issued by National Marine Fisheries Service to allow seismic surveys in Alaska’s Cook Inlet have been challenged in Federal Court.  Cook Inlet is home to a dwindling population of beluga whales (under 300), and the permits allow behavioral harassment of up to 30 belugas per year. In part, the challenge contends that this likely underestimates the impact, as, “NMFS based its analysis on an unrevised, outdated, 15-year-old assumption about take levels that some of the world’s leading bioacousticians recently urged NMFS to discard – and that ignores the only existing study of airguns and belugas, showing impacts at far greater distances than NMFS has predicted here.” Saying that the Marine Mammal Commission recommended against issuing the permits, the suit claims that NMFS erred in its finding of “no significant impact.”

BelugaIn addition to three environmental organizations, the Native Village of Chickaloon is party to the lawsuit, saying that NMFS did not fulfill necessary consultation with the tribe, and noting that while the tribe is barred from its traditional hunts due to declining beluga numbers, the permits allow oil and gas development to put whales at risk.

The suit claims that an Environmental Impact Statement should have been prepared, rather than a less comprehensive Environmental Assessment.  As covered in previous AEInews posts over the past four years, NMFS has declared parts of Cook Inlet to be essential habitat for the belugas, though the 180-mile long inlet continues to bear the brunt of substantial industrial activity, including the Port of Anchorage and ongoing oil and gas development.

Vermont wind farm challenged in court for intruding on nearby wilderness

Effects of Noise on Wildlife, Human impacts, Wildlands, Wind turbines No Comments »

Vermonters for a Clean Environment have filed a complaint in US District Court challenging the Forest Service’s planned permit for 15 new wind turbines in the Green Mountain National Forest.  The challenge includes several issues, but centers on the visual and sound impact of the new turbines on the nearby George D. Aiken Wilderness. Sound monitoring and modeling indicates that the boundary of the Wilderness is one of two areas in which the new turbines are likely to be audible above existing background sound levels (which includes sound from several older turbines near the new project site).

The recent court filing is not yet available on the group’s website, but an earlier appeal submitted to the Forest Service contains many of the same arguments.  A central point is expressed this way:

If the mechanical sound of the wind turbines can be heard within the George Aiken Wilderness, it is no longer a wilderness, plain and simple. See, e.g., 16 U.S.C. § 1131(c) (requiring that the area “retain[ ] its primeval character” and requiring that the “the imprint of man’s work [should be] substantially unnoticeable”).

The complaint suggests that ridgelines in the Wilderness will have more visual impact than the Forest Service documented, and there was not a sufficient assessment of how far into the wilderness sounds may be audible. The permitting documents estimates that turbines will be 5-7dB louder than background sound at the Wilderness boundary, and will be less audible as you move deeper into the wilderness; these figures are long-term (day-long or night-long) average sound levels.

Bernie Krause’s Great Animal Orchestra

Arts, Bioacoustics, Effects of Noise on Wildlife, Wildlands No Comments »

Bernie bookBernie Krause’s new book, The Great Animal Orchestra, is a worthy culmination to his inquisitive career.  After working out a few writerly wrinkles on a couple of earlier books that touched on aspects of his fascination with the world of natural sound, this one offers up a wide-ranging tour of our sounding world, shared in a congenial voice.

This book has rightfully garnered widespread praise, including the coveted cover spot on the NY Times Book Review section, as well as write-ups in The Washington Post, The Ecologist, The San Francisco Chronicle, and Wired. Check each of these out for good, brief glimpses into the stories you’ll find between these covers. The Wired piece is particularly well done, with many sound samples; more sounds can be heard on the site of publisher Little Brown.

Several key themes provide the foundation of the book.  First and foremost is Krause’s segmentation of the soundscape into geophony (sounds of wind and water and other movement of natural objects), biophony (sounds of animals, both vocal and sounds of movement), and anthrophony (sounds of humans, especially mechanical and amplified sounds). Similar divisions are used by bioacousticians, as evidenced in a couple of talks at a recent Bureau of Ocean Energy Management workshop on sound and fish that I attended.  Likewise, Bernie is an eloquent spokesman for the widespread thought that early human music has its roots in a time when tribal peoples considered themselves but one voice in a local sounding landscape; this theme is emphasized in the subtitle to the book, “Finding the Origins of Music in the World’s Wild Places.”

Krause’s reflections on our urbanized relationship to sound are grounded in the soundscape tradition of R. Murray Schaffer, while his continuing efforts to understand the dynamics and relationships in natural soundscapes – using spectrograms to illustrate possible use of acoustic niches (differences in pitch, rhythm, or time of day) that allow a plethora of creatures to each be heard within a complex biophony – are contributions to the leading edges of scientific investigation of soundscape ecology.  Many reviewers note the rambling quality of the book as a small downside, but I found that it brought me as a reader into Bernie’s world, where pure wonder at the diversity of sounds crosses paths with speculative theories, sorrow at what’s disappearing, and a commitment to draw us into a deeper communion with the sounding world that surrounds us. A mindful engagement with sounds, or with the world as it is today, will inevitably bring us to such a mix of thoughts, feelings, and inquiries; this book one of the best invitations into the acoustic aspects of our times.

Tubular wind turbine foundation much quieter to install offshore

Effects of Noise on Wildlife, Ocean, Wind turbines No Comments »

As countries around the world gear up to expand offshore wind development, one of the major concerns of ocean biologists is the exceedingly loud noise of pile driving during construction. Studies suggest that some ocean species move at least 20km from turbine construction areas, and in areas with lots of planned construction (such as the North Sea), it’s possible that large swatches of shoreline could be impacted each summer for many years.

PREONmarine 2

A new mounting system from the French firm Vallourec uses a series of thin tubes to anchor three octagonal “feet”; these are inserted in to holes drilled only 20m into the seabed, rather than the 60m that piles are driven into the seabed, supporting the huge concrete foundations used in today’s standard construction technique.  Vallourec claims that construction noise is limited to about 75dB, as compared to pile-driving’s 200dB (though I suspect they’ve neglected to correct the 75dB for measurement in water; even the resulting 138dB would be a moderate noise by comparison to pile driving).  The initial press release and website does not give a ready sense of how the cost of the new “PREON Marine” system compares to traditional pile-driving and foundations.


Japan commits to floating offshore wind

Effects of Noise on Wildlife, News, Ocean, Ocean energy, Wind turbines No Comments »

In order to compensate for the abandonment of many nuclear plants, the Japanese government has set its sights on the abundant wind resources off its coast.  A 15MW pilot floating wind turbine project is under construction not far from Fukushima; if all goes well, the project could expand to as large as 1000MW.  Along with smaller pilot projects in Norway and Maine, the Japanese effort will be a key player in moving floating offshore wind forward.

Currently, capital expenditure is about $1.7 million a megawatt for an onshore wind project and $5.5 million a megawatt for offshore, according to Bloomberg New Energy Finance; floating offshore designs are still under development, raising initial costs even higher.  Over time, though, the cost is expected to come down enough to support widespread deep water floating wind farms; a feed-in tariff program promoting clean energy allows projects to receive higher-than-market rates as the sector develops.  Floating turbine designs are larger than onshore turbines, and can take advantage of stronger, steadier winds; foundation systems for floating turbines are much smaller than bottom-mounted near-shore foundations, minimizing impacts on the seabed and reducing the noise impact of construction.

US east coast seismic survey EIS draft released

Effects of Noise on Wildlife, News, Ocean, Seismic Surveys 1 Comment »

The US Bureau of Ocean Energy and Management (BOEM) has released the Draft Programmatic Environmental Impact Statement that is the first step toward oil and gas development off the east coast.  The PEIS assesses the impacts of geological and geophysical (G&G) activities, primarily seismic surveys and test wells.

OCS seismicI’ve yet to dig into the PEIS to examine its alternatives or proposed mitigation measures, but a quick look at maps illustrating applications already received from oil and gas exploration companies affirms that the entire east coast could become an active seismic survey zone (the map at left is one of nine applications; there is much overlap among them).

UPDATE, 3/30/12: While those maps look impressive, both the International Association of Geophysical Contractors and the American Petroleum Institute have issued statements that surveys are unlikely to take place until the path opens for actual leases to be issued; the decision was already made to not issue any Atlantic leases during the current 2012-2017 planning period.  The applications for surveys currently on file were submitted during a period in 2008 when a long-standing Presidential order excluding oil and gas development on the Atlantic coast was lifted. “Without an Atlantic coast lease sale in their five-year plan, theadministration’s wishful thinking on seismic research has no ultimate purpose,” said Erik Milito, upstream director at API. Chip Gill, IAGC President, stressed that “contrary to the statements [by US Interior Sec. Ken Salazar and BOEM Director Tommy P. Beaudreau], we do not expect seismic surveys to be conducted for years, and thus we don’t expect it to be available to help the federal government evaluate the resource base anytime soon.”

(and now back to our original post):
While very few animals are killed or injured by air gun sounds, behavior can be affected for tens of miles, and airgun sound can be heard (and so drown out some distant communication) for hundreds of miles.  I just returned from a BOEM workshop on the effects of ocean noise on fishes and invertebrates, where scientists shared research on reduced fish catch rates near surveys (the fish move away for a few days or weeks, then gradually return), and attempted to come up with a shared understanding of how to investigate whether ocean noise can affect fish communication, larval or egg development, or other aspects of ocean ecology (so far, there is little direct evidence of impacts, but some concern remains about masking of sounds fish use for many purposes, and the possible negative stress impacts of chronic noise exposure).

From looking at the maps of existing applications to do surveys (download pdf of rough maps of all 9 applications), it’s immediately apparent that BOEM could work to minimize duplicating of efforts by several companies.  It may be that there will be areas that are clearly inappropriate for oil and gas development (eg, key fishing grounds or other biologically important areas), or seasonal exclusions to reduce impacts on spawning or migration.

Of course, there’s also the bigger-picture climate change question of whether we really want to be continuing to pull more oil and gas from the ocean in the years after 2020 anyway; any new leases will be issued after 2017, with development following years later.  Meanwhile, BOEM is working hard to lay the groundwork for renewable energy development in offshore waters, targeting areas for wind, tidal, and wave energy systems.  For now, continuing to plan for oil and gas development is part of the Obama administration’s “all of the above” approach to meeting America’s future energy needs.

For more on the Draft PEIS, see BOEM’s PEIS website, which includes links to download the documents and submit comments, this press release from the Department of the Interior, and this blog post from NRDC (which stresses that quieter alternative technologies for oil and gas exploration are expected to be commercially available in 3-5 years).

Ocean noise assessment needs to look past dB, to context of exposure

Bioacoustics, Effects of Noise on Wildlife, Ocean, Science, Seismic Surveys, shipping, Sonar No Comments »

A paper recently published in Conservation Biology suggests that current ocean noise regulations are likely not providing sufficient protections against impacts on marine life.  The authors note that current regulations are based on preventing direct physical injury from very close exposure to sound, while considering behavioral impacts to decrease consistently with greater distance, or the “zones of influence” approach to noise impact assessment.  However, some key impacts, such as interruptions in feeding or temporary abandonment of important habitat, are not accounted for.

Rather than fully summarizing the paper here, I’ll turn you over once again to Caitlin Kight of Anthropysis, who has recently been providing excellent coverage of anthropogenic noise issues as part of her larger focus on human impacts in the natural world.  Please see her full post to get the whole story; here’s a teaser:

In a previous study on behavioral responses of marine animals to noise, one of the authors of the current paper found that the “zones-of-influence approach did not reliably predict animal responses.” Furthermore, we know from terrestrial studies that a variety of additional factors–an animal’s past experience and conditioning, current behavioral state, acoustic environment, and type of exposure, to name a few–all affect the extent to which it will be impacted by noise pollution.

…(Studies in terrestrial and ocean environments have shown that) noise can have more subtle, but equally important, effects on wildlife. For instance, abundance and diversity may shift as animals flee from, or learn to avoid, particularly noisy areas; individuals may alter their behaviors in counterproductive or even dangerous ways; and noise may make important acoustic signals difficult to hear, even in the absence of actual deafness. In short, the researchers write, the current marine noise concept “ignores a diverse suite of environmental, biological, and operation factors” that can impact both perception of, and response to, anthropogenic noise. Thus, they argue, it is necessary to overhaul the system and “[incorporate] context into behavioral-response assessment.”

Ellison, W.T., Southall, B.L., Clark, C.W., and Frankel, A.S. 2012. A new context-based approach to assess marine mammal behavioral responses to anthropogenic sounds. Conservation Biology, online advance publication.

Canadian sonar heard in US critical orca habitat

Effects of Noise on Wildlife, News, Ocean, Sonar No Comments »

HMCS OTTAWA 300x207A Canadian frigate used its mid-frequency active sonar this week during a training exercise in Haro Strait, north of San Juan Island and south of Vancouver Island.  The sonar emissions from the HMCS Ottowa (right) were picked up by whale researchers at Beam Institute, who raised concerns about sonar use in an area designated by the US as critical habitat for orcas. You can read a detailed report from Beam, including sonograms and MP3 files of the sounds heard, at their website. They note that “the peak power frequency is consistent with the 2-8 kHz frequency range specified for the SQS 510 sonar system, which is manufactured by General Dynamics Canada. Each ping had high intensity receive levels for ~0.5 second duration and pings were separated by about one minute.”

According to the Seattle Times:

The frigate was in Canadian waters at the time, said Lt. Diane Larose of the Canadian navy.  But the Ottawa’s sonar can travel 4,000 yards — more than two miles — and the sound was picked up by instruments in U.S. waters. Larose said the Canadians are well aware of sonar’s potential to hurt killer whales, which communicate by sound at similar frequencies. In 2008, the Canadian Navy adopted a policy requiring the use of radar, passive acoustic systems, underwater listening devices and night-vision goggles to make sure marine mammals aren’t present when sonar is deployed. “We take this very seriously,” Larose said. “It’s a very well-thought-out policy.”

Scott Veirs of Beam Research said that their monitoring network had tracked both transient orcas and endangered southern resident orcas in the area within 24 hours both before and after the incident. “This was a fairly high-risk event as far as we can tell…it’s concerning to me that the U.S. Navy has voluntarily refrained from unnecessary testing and training in the inland waters of Washington state, but the Canadian navy apparently still does,” he said. “The nightmare scenario is that you turn on sonar not knowing they are there and essentially deafen them either temporarily or permanently.”  Ed. note: Beyond this worst-case scenario, the use of this high-intensity sonar in waters close to designated critical habitat goes against the purposes of designating such protected zones; the US has banned all boat activity in some parts of the habitat, with the goal of assuring that the whales are not discouraged from using this region, one of their primary feeding grounds.

Interestingly, a commenter on the Beam Reach website notes that the Canadian Navy’s safety zone for their mid-frequency active sonar is 4000 yards, or over two miles.  Whether they can effectively detect whales at that distance, especially at night, is highly questionable. The Seattle Times clip above mistakenly presumes that the sounds travel only that far. In fact, this is just where they tend to drop below the sound levels considered likely to seriously disrupt behavior; mid-frequency active sonar can be heard for tens of miles, and in the complex underwater landscape of where this event took place, is likely to create dramatic peaks and drops in sound levels as the noise bounces from islands and the seabed, making it difficult for animals to know how to reduce their exposures.

Serendipitous study: whales relaxed in shipping lull after 9/11

Effects of Noise on Wildlife, Ocean, shipping No Comments »

Ship and whaleA fascinating new study provides the first direct evidence that shipping noise may increase stress levels in whales.  During the days after the World Trade Center attacks, global shipping was halted; a team of researchers studying right whales in the Bay of Fundy decided to go ahead and continue collecting fecal samples, and were struck by how peaceful it was: Rosalind Rolland recalls that day and those following were like a primal ocean scene, “There was nobody out there except for us and the whales.”

In 2009, Rolland realized that another researcher, Susan Parks, had recordings of noise levels for the days before and after 9/11, and so they joined forces to see whether the samples taken from whales on those days showed any changes in stress levels (fecal matter contains stress hormones that can be measured).  As it turns out, the days after 9/11 mark the only time during Rolland’s five-year study that stress hormone levels were markedly lower than the overall average, and corresponded to a dramatic reduction in noise, especially low-frequency noise.

““This is what many of us had been looking for,” said Christopher Clark, director of the bioacoustics research program at the Cornell Lab of Ornithology, who was not a paper co-author. “Here is the first solid piece of evidence that says there’s a link between noise level and stress.” Clark noted stress has long been tied to longevity, reproduction, disease and other key health indicators in whales. Researchers have long speculated that noise could be a stressor for ocean creatures, but there is no practical way to test a correlation, since ocean noise is nearly omnipresent in most areas.

The fact that this is an opportunistic study does mean that it’s unlikely to be considered solid proof, or to influence ocean noise policy.   As Dr. Rolland noted, “These are after all 50 tonne animals so they don’t make terribly easy things to study…Past studies have shown they alter their vocalisation pattern in a noisy environment just like we would in a cocktail party, but this is the first time the stress has been documented physiologically.”

Dr. Ian Boyd of the University of St. Andrews in Scotland, home to many top ocean noise researchers expressed uncertainty that such a short time period and small sample “shows what is claimed.”  Boyd is one of a group of researchers advocating for a Quiet Ocean Experiment, in which large portions of ocean would be quieted for brief periods, allowing for more comprehensive studies of animal behavior and physiology before, during, and after the experimental periods.  To implement this idea, global shipping routes would need to be shifted for the duration of the experiment.

NRDC re-opens legal battle with Navy, NOAA over sonar

Effects of Noise on Wildlife, News, Ocean, Sonar No Comments »

Three years after the NRDC and U.S. Navy reached an agreement that was meant to create avenues for dialogue and collaboration, a new lawsuit filed this week suggests that the hopes both sides held have not been realized. The main sticking point remains the same now as it was then: environmental advocates insist that some biologically rich areas should be entirely off limits to any sonar training activity, while the Navy holds that short-term exercises pose no great risk to wildlife. The final Environmental Impact Statements submitted by the Navy, and the permits issued by the NOAA Fisheries Service (which collaborates closely with the Navy in developing guidelines), allow the Navy full access to extensive training ranges that stretch along most of the coastlines of United States. The suit filed this week challenges NOAA permits issued in 2010 for one of the Navy’s dozen or training ranges, off the coast of Washington, Oregon, and northern California. It differs from an earlier high-profile legal challenge, which reached the Supreme Court, in that the previous suit challenged the Navy’s sonar operational guidelines, whereas this one challenges NOAA’s permits.

Navy ranges WEB

The Navy is already beginning work on Environmental Impact Statements that will accompany new permit request for all of its ranges, each of which must receive fresh authorization from NOAA every five years. The Navy has recently completed its first-ever EIS’s for training ranges around the world (a process spurred largely by earlier legal challenges); these 5-year permits were issued for some ranges in 2009, and are due for renewal in 2014 and beyond.  The operating conditions proposed by the Navy and approved by NOAA for the first-round EISs and permits are generally similar to the way the Navy had been doing things for many years. Marine mammal monitoring is maintained on sonar vessels, with sonar intensity reduced when whales are seen nearby, and operations stopped when whales approach very close to boats. The litigants point out that visual monitoring misses 25-95% of whales, and is particularly ineffective in high seas. “We learn more every day about where whales and other mammals are most likely to be found,” said Heather Trim, director of policy for People for Puget Sound, “We want NMFS to put that knowledge to use to ensure that the Navy’s training avoids those areas when marine mammals are most likely there.”

By and large, ocean noise regulations concern themselves only with noise that may be loud enough to cause injury, which occurs only at very close range (under a half mile). More moderate noise, which may cause behavioral changes up to 50 miles away, is assessed in the EIS, but these behavioral changes are generally considered to be of negligible impact to the animals. Recent NOAA permits routinely allow for tens or hundreds of thousands of animals to respond in some way to the sounds of naval maneuvers, with sonars mounted on ships, on floating buoys, and dangled from helicopters being the primary noise source triggering behavioral responses (any behavioral response is considered a “take” in permitting language).

The Navy says that in the Northwest Training Range Complex sonar training exercises typically

Read the rest of this entry »

UK researchers examine effects of noise on fish, crustaceans

Effects of Noise on Wildlife, Ocean, Ocean energy, Science 2 Comments »

A research project in England is preparing to do some of the first field studies designed to see how human-made sound may affect non-cetaceans.  While many field studies have tracked the responses of whales and dolphins in both opportunistic and controlled settings, and some lab studies have noted how fish or other sea creatures react to noise when introduced into tanks, a team from the University of Hull is preparing to project human sounds from a research vessel and see how fish and crustaceans (crabs and lobsters) respond.

The researchers plan to film animals while playing the sounds of ships, concrete pile driving, or operating wind turbines; the results will provide data for far more accurate environmental impact assessments of offshore construction and renewable energy projects.

For more, see this recent article from OffshoreWind.

Ocean listening stations go online; US Navy aims to filter out its activities

Effects of Noise on Wildlife, News, Ocean, Science, Sonar No Comments »

A growing network of ocean observatories are adding hydrophones to their arrays of instruments, opening ears into the undersea world.  The data has been shared widely among scientists for the past few years, and a website, Listening to the Deep Ocean Environment, is now compiling the real-time acoustic streams from 15 of the observatories, allowing anyone to listen in; another 11 observatories will be added in the coming months.  This excites scientists and citizens alike. (Though truth to tell, most of the audio streams aren’t all that interesting to listen to most of the time!)

The US Navy isn’t quite so pleased, however. According to a recent BBC article, US Navy oceanographers have arranged to filter data from one of the largest ocean observatories, NEPTUNE, off the coast of British Columbia.  Citing concerns that the recordings will disclose areas of Navy operations, real-time recordings are cleansed of Navy ship (and presumably sonar) sounds, then returned to NEPTUNE operators for uploading to the web. 

Cornell University’s Chris Clark doubts that the Navy’s approach will catch on at other observatories around the world.  According to a piece on The World, from PRI and the BBC, (sounds above from there; roll over tiny screens to ID the sounds), Clark says the US Navy doesn’t own the ocean acoustic environment and has to accept that what was once military technology is now in the hands of civilians.  “The cat’s out of the bag, the horses are out of the barn, whatever the metaphor is, it’s happening,” he says.  The piece notes that this is similar to what happened with satellite imagery. For decades, it too was sensitive military data, but now anyone can go on Google Earth and look down from space.

Fish survey sounds reduce humpback songs 120 miles away?

Bioacoustics, Effects of Noise on Wildlife, Ocean, Science No Comments »

AEI lay summary of the following paper:
Risch D, Corkeron PJ, Ellison WT, Van Parijs SM (2012) Changes in Humpback Whale Song Occurrence in Response to an Acoustic Source 200 km Away. PLoS ONE 7(1): e29741. doi:10.1371/journal.pone.0029741
Read or download online (free)

An ongoing research project that monitors whale calls and shipping noise in Stellwagen Bank east of Boston Harbor has reported an unexpected reduction in humpback whale songs during an 11-day period in which their recorders picked up low frequency sounds from a fish-monitoring system 120 miles away.  If this data does indeed represent whales ceasing singing or moving away in response to the distant sonar, this would be the first clear-cut indication that discrete human noise events may affect marine mammal behavior outside the immediate area.  The authors note that these results could suggest that impact assessments need to consider effects at longer ranges, and that effects may occur at received sound levels much lower than those generally considered worthy of concern.  This study simply reports the reduction in singing; any longer-term effect that may have on the animals is unknown (these are not mating calls).

The reduction in songs occurred at a time of year (early fall) when humpback songs are beginning to increase in this area; on years when the fish sonar was not in operation, the numbers of songs steadily increased over the 33-day study period.  But in 2006, when the fish sonar was heard at Stellwagen Bank for 11 days (8 of which included sonar sounds for over 7 hours), the number of minutes per day when humpbacks were singing dropped, some days to zero.  The average (mean) number of hours of whale song dropped from about 75 in the previous 11 days to about 15 minutes during the time the fish sonar was heard, before increasing to close to 3 hours per day once the sonar transmissions ceased.

The figure below shows the data from each of three years.  For each year, there are 33 days of data, with the middle 11 days being the period (Sept. 26-Oct 6) in which the sonar sound occurred in 2006.  The open circles are the mean minutes/day for each 11-day period, with the rectangular boxes representing the upper and lower quartiles of data for each period; black dots represent one or two days in each period in which the calling rates for that day were unusually far outside the range for other days in that period.

Risch 2012 dataWEB

Ed. note: Interpreting the results of vocalization studies is complicated by the fact that there is much variability in vocalizing rates, and response/sensitivity to human noise, from one animal to another; and similarly, in numbers of whales in the area from year to year.  (This acoustic data counts singing minutes, but not animal numbers, which must be monitored visually.)

Read the rest of this entry »

Belugas continue to struggle in face of Cook Inlet development

Effects of Noise on Wildlife, News, Ocean, Science No Comments »

NOAA Fisheries has released its latest annual estimate of the beluga population in Alaska’s Cook Inlet, and the numbers are sobering.  Their 2011 estimate, 286 animals, is the second-lowest found in the 18 years of surveys, and is 20% lower than last year’s count.  However, NOAA officials stress that year-to-year counts are approximate, with differences in observing conditions and beluga distributions accounting for an error range of plus or minus as many as a hundred animals; long-range trends are more reliable indicators.  Officials say they did not see a large enough number of dead whales this year to suggest that there was indeed a 20% decline.

“Only three dead belugas were reported this year, which indicates that large numbers of mortalities did not occur in 2011,” said Alaska Fisheries Science Center Director Doug DeMaster (over the past ten years, an average of 10 whales a year have been found dead). “While NOAA remains concerned that this population is not showing signs of recovery, at this time we do not believe this estimate represents a marked decrease in the population.”  Indeed, twice before, the counts showed even larger declines, with later years suggesting that actual numbers were not so dire; the previous low count, 278, occurred one year after a count of 366, and two years later, counts were back up to 375. However, since then, counts have been at least 10% lower than that high.  This is especially worrisome, in that this genetically-distinct population of belugas has been listed as endangered, and NOAA designated much of Cook Inlet as critical habitat. (Many other beluga populations remain in other areas, including the western and northern coasts of Alaska, and northern and northeast Canada).

On the longer term, NOAA notes that there appears to be a continuing gradual decline in Cook Inlet beluga numbers, estimated at about 1% per year.  This population of belugas experienced a population crash in the 1980’s (from 1300 down to around 300) which is widely blamed on over-harvesting by native subsistence hunters, but has not recovered since the hunting was limited.  Pollution, limited salmon runs, and noise are all considered likely factors in the population’s struggle to survive.

Cook Inlet is a large waterway, leading from the southern Alaska coast inland to Anchorage and Wasilla; a major port expansion is underway, as well as oil and gas exploration and development.  For more on the backstory here, see these previous AEInews post from 2008-2011.


New tech may reduce harmful noise of sonar, airguns

Effects of Noise on Wildlife, Ocean, Sonar No Comments »

Several new R&D projects are underway by providers of ocean technology, each of which either aims to reduce the harmful behavioral impacts on marine creatures, or may limit harmful impacts as a byproduct of their innovations.

My good friend Michael Stocker already wrote up a solid blog post  that summarizes three such projects, with links to source material and more information. Head on over to his Ocean Conservation Research blog to hear more about sonar signals modeled on sperm whale clicks (likely to be far less distressing for whales and dolphins that today’s grating signals), continuous low frequency sonar (which could reduce the source level), and airguns with less stray noise outside of the frequencies used to probe the seabottom.

Mass whale stranding during Italian Navy exercises: sonar heard?

Effects of Noise on Wildlife, Ocean, Sonar 3 Comments »

Over the past week, a mass stranding of Cuvier’s beaked whales has taken place along the shoreline of Corfu (a Greek island) and southern Italy. The first whales came ashore on November 30, halfway through an Italian Navy exercise taking place in waters on both sides of Italy, including the 130-mile wide Ionian Sea, which separates the two stranding sites. At least one of the Italian ships is known to be equipped with mid-frequency active sonar.

While it’s become common media sport to mention sonar in conjunction with any whale strandings, to the point that once I read the coverage, I rarely see any real evidence, this case is different.  Most strikingly, rescuers in two separate locations during the initial strandings report hearing a “whistling” noise at 10-15 second intervals; it’s quite likely that this sound was what drove the animals ashore. While rare, this is not the first time that humans above the water have heard underwater sound transmissions during stranding events.


On November 30, three or four Cuvier’s beaked whales stranded on Corfu, while two (a female and calf) came ashore across the Ionian Sea in italy. Some were helped back to sea by bystanders, and some died; two of the Corfu whales were collected and necropsies were done, with one being fresh enough for detailed observations.  On December 6 and 7, a total of four more Cuvier’s washed ashore in the same area of Corfu; these were all dead, and decomposed to the point that researchers believe they died at about the same time as the initial strandings took place. According to Alexandros Frantzis, a longtime beaked whale researcher, “It is reasonable to think that there are more animals in the pelagic waters of the Ionian Sea, which may never reach the coasts. The local and apparently small Ionian population unit has suffered three stranding events coinciding in time and space with use of military sonar in the past (plus one in east Sicily earlier this year). There should be little doubt (if any) that the cumulative damage at the population level is high.”

Marine mammal scientists in the region share Frantzis’ alarm about the vulnerability of this population of beaked whales. Both Guiseppe Notarbartolo di Sciara and Natacha Aguilar de Soto have sent urgent letters to officials at ACCOBAMS, a multinational binding agreement between most European and several North African and Middle Eastern countries aimed at coordinating cetacean conservation efforts in the Mediterranean and Black Seas. They ask ACCOBAMS to take the lead in investigating the circumstances of this stranding event, and stress the need to avoid further such incidents in this highly vulnerable population. di Sciara, a former chair of the ACCOBAMS Scientific Committee, notes agreements already made, and asks what steps have been taken to assure compliance and follow-through. In her letter, Aguilar de Soto notes that in the Canary Islands, after several such strandings, active sonar use was banned within 50 miles of the islands, and no further strandings have taken place; she note that similar policies may be necessary “in known important areas of distribution of beaked whales in the Mediterranean, to guarantee the sustainability of the populations.”

You can read the letters of Drs. di Sciara and Aguilar de Soto after the break.

Read the rest of this entry »

UK wind farm challenge ended by financial settlement, the latest of many

Effects of Noise on Wildlife, Wind turbines 2 Comments »

Jane and Julian Davis’ long-running dispute with a wind farm located 1km (just over a half mile) from their  home in Deeping St. Nicholas has come to an end.  On the day before their case, seeking either a permanent shut-down of the wind farm or 2.5 million pounds in damages, was due to hear the final witnesses at London’s High Court, a settlement was announced between the Davis’ and the wind farm developer. The details of the settlement are confidential, and likely less than the Davis’ were seeking, but we can likely presume that it is enough for them to buy another piece of rural property; they moved out of their home less than a year after the wind farm began operation in 2006. Update, 12/6/11: a local newspaper talks to the couple.

The settlement comes as somewhat of a surprise, considering the vehemence with which their claims of being forced from their home were challenged in the first round of testimony at the High Court this summer. However, a spokesman for Renewable UK, the wind energy trade association, welcomed the news of a settlement, saying that the organization always encourages its members to work closely with local residents when planning projects to ensure that any local issues are resolved without ending up in court.

To which I might say, they were a bit behind the curve this time! Yet certainly the industry would prefer to not risk negative court judgments in a high profile case such as this, which was the first such challenge to a wind farm on basis of a “nuisance” rather than as violating specific wind farm operational guidelines. This settlement is but the latest of quite a few situations in which wind developers felt it made more sense to buy property or otherwise settle disputes financially than fight nearby neighbors who had moved out of their homes or were prominent local voices about the noise impacts of siting choices. (That spree of links reflects buyouts in Ontario, Washington, Oregon, and Australia.) While the prospect of purchasing property is often said to introduce untenable uncertainty into project financing, the actual cost of purchasing a few nearby properties is dwarfed by the cost of the turbines themselves (over a million dollars each). Most of these settlements have been concessions by developers after problems arose, though in at least one Australian case, the buyouts were presented as a “sell your house or live with it” option prior to construction, which neighbors felt was an untenable and unfair choice.

There is clearly movement here, in that developers are recognizing that impacts are more dramatic on some neighbors than on others, and than had been expected.  Yet we also clearly have a way to go before we can say that dialogue on these variable impacts has become routine or an influence on setback distances proposed by developers.  So far, we’ve yet to see any developers take the proactive approach of agreeing to keep turbines well away from unwilling neighbors, and to work with willing neighbors or willing sellers to come up with a viable site plan. That time is not far away, though, I suspect; the industry will surely benefit from reducing the contention that results when site plans lead to significant audible noise impacts on unwilling neighbors.

Onshore wind farm raises ocean noise concerns in Chile

Effects of Noise on Wildlife, News, Ocean, shipping, Wind turbines No Comments »

For the first time, an onshore wind farm has triggered calls for caution from marine mammal protection organizations.  The 2500-acre, 56-turbine wind farm will be built along a steep shoreline that funnels nutrient-rich waters from Antarctica to the surface, spawning a dense aggregation of phytoplankton and krill. Along the coast of Isla Grande de Chiloé, blue whales and right whales gather from January to April to feast on this abundance; blues come as close as 400m to shore, and rights have been seen only 5m offshore.

Environmentalists, including local organizations like Santiago’s Centro de Conservación Cetacea, and international voices such as the Whale and Dolphin Conservation Society have raised dual concerns, regarding construction of a new port to bring construction materials to the site, vastly increasing ocean noise from ship engines in this relatively acoustically pristine area, and possible disturbance or even displacement of animals due to noise from pile driving during construction and airborne wind turbine noise during operations. Even the International Whaling Commission’s scientific committee has called for “the urgent development of an environmental impact assessment in this region and to reconsider locating the wind farm towers further away from coastline.”

The importance of the feeding ground to southern hemisphere blue whales, combined with having 40% of the turbines right along the shore, raise the question of whether the ongoing blade noise will keep whales at a distance; there is some evidence that airplane overflights cause whales to move away, and the sound levels of the turbines will be similar to a small plane. Whether whales might be able to move a small distance away and still find enough krill is the big question. Chile’s environmental authorities approved the project in August after requiring a simple environmental declaration, rather than a detailed impact study; the Chilean Supreme Court is hearing a lawsuit from opposing groups, and will make a decision in the next few months.

National Geographic News has a good, detailed article on these questions.

Moderate noise changes bird communities

Bioacoustics, Effects of Noise on Wildlife, Science, Wind turbines No Comments »

Research summary of Francis, C.D., Ortega, C.P., Cruz, A. 2011. Noise pollution filters bird communities based on vocal frequency. PLoS ONE 6(11):e27052.

An ongoing research project in New Mexico continues to shed more detailed light on the question of how moderate human noise affects nearby wildlife.  In a study design that effectively separates out the impact of the noise from other habitat disruption effects, Clint Francis and his colleagues are finding that some species are displaced, while others seem to thrive in areas with coalbed methane compressor stations creating noise around the clock.  The most recent paper to be published by Francis et al finds that species that sing at lower frequencies are most likely to avoid the noisy areas, while those who vocalize at higher frequencies are more apt to be unaffected or even thrive.

While this research studies an area with oil and gas development noise, it’s likely that similar effects would occur in and near wind farms, which also produce predominantly low-frequency noise. And, as the authors note to conclude their paper: “At the community-level, we must still determine whether noise is an agent of ecological filtering for other taxa that rely on acoustic communication.”

Rather than doing the full AEI lay-summary of the most recent paper, I want to point you to the great summary already written by Caitlin Kight, biologist who studies the effects of anthropogenic disturbances on animals; it was recently featured on her Anthrophysis blog.

Assessing the noise impact of a wave energy installation

Effects of Noise on Wildlife, Ocean, Ocean energy, Science No Comments »

Ireland Wave EnergyWEB

IBM is collaborating with The Sustainable Energy Authority Ireland to measure the noise output from a wave energy installation of the west coast of Ireland, which is one of the world’s most promising areas for wave power development.  The acoustic data will be collected in real-time, and will will produce one of the largest continuous collections of underwater acoustic data ever captured. This data will be made available to marine researchers and regulatory agencies to further advance knowledge of natural and man-made underwater sound, and help develop standards and reporting, benefitting marine environmental agencies as well as industries including renewable energy, shipping, and offshore oil and gas.

“Underwater noise is a global environmental issue that has to be addressed if we are to take advantage of the huge potential of ocean energy,” said European Union Commissioner for Research, Innovation and Science Máire Geoghegan-Quinn.  “This project is a great example of collaboration among global companies, industry experts and government agencies, and will help us make real progress toward practical and sustainable ocean energy systems.  I’m delighted to see Ireland playing a lead role in this area, which has great importance for meeting the EU’s energy challenges.”

Wind turbine manufacturers aim to reduce noise

Effects of Noise on Wildlife, Human impacts, News, Wind turbines No Comments »

Two recent articles in trade magazines caught me up on efforts taking place within the wind power industry to reduce the noise levels of wind turbines. While it’s great to know it’s on everyone’s mind, it also appears that so far, noise reductions are modest.

In the July 2011 issue of North American Windpower (back issues not available for online reading, sorry to say), one of the feature articles was “Turbine Manufacturers Focus on Reducing Noise Emissions.”  It included discussions with reps from most of the major turbine manufacturers, and was full of fascinating hints of ongoing research.  As the article noted:

As the so-called “low-hanging fruit” of land with good wind and transmission access gets used up and wind turbines move closer to residential areas, noise concerns are expected to become more prevalent, according to wind turbine manufacturers.

“It’s on the top of the minds for all manufacturers,” said Paul Thompson, commercial director of Mitsubishi’s wind turbine group, “we’re all doing things to reduce the amount of noise that’s generated.”  GE’s Henrik Stiesdel stressed that wind turbines do “have a noise impact.  The main remedy is to ensure that they are not sited to close to dwellings. If that’s not possible because you are in a densely populated area, then we have remedies where we control the power output when conditions are such that noise might be exceeding limits.” The article describes this system:

GE’s sound power management (SPM) works by optimizing control setting based on real-time wind conditions, according to Sean Fitzgerald. The SPM option can be configured for day and night modes, at angular intervals depending on the mode switching and based on wind turbine placement. “These applications enable the customer to specify the appropriate, desired sound emission characteristics by customizing the sound power curve to the precise requirements over the entire wind speed range,” Fitzgerald tells NAW.

Gamesa’s Miguel Angel Gonzalez-Posada notes that there’s a trend of having to keep noise as low as possible near populated areas, especially at night.

Read the rest of this entry »