A key research paper from National Park Service and Colorado State scientists has been published in Trends in Ecology and Evolution.  The paper, which got a lot of press when it was first made available online in the fall, introduces two key new metrics for measuring the effects of noise on animals.  The first, “alerting distance,” is the distance at which sounds can be heard: these may be sounds made by a species to alert others to danger, or sounds made by predators (which prey animals want to hear, so as to take cover).  The second, is “listening area,” the full area around an animal in which it can hear other animals’ calls, footsteps, and wingbeats.  A key insight offered by this approach is that even moderate increases in background noise (from nearby roads, airplanes, or wind farms) can drastically reduce an animal’s listening area.  The paper, which was free while in pre-press, is now available only to subscribers to the journal or other academic journal services; an article published in Park Science magazine and free to view online introduces much of the same material (be sure to click on the links to the figures, as they illustrate the concepts very well): see the article here, and check out the entire special soundscapes issue of Park Science here.

A very good article in the Aspen Times introduces the research, and includes many extremely insightful quotes from the researchers.  Go read the whole article! Three bits that are especially worth keeping mind are:

• “The male sage grouse, in its mating displays, produces high-frequency popping sounds and swishing sounds,” Fristrup said. “It also uses a low-pitch hooting sound, which carries the farthest from the display area as a long-distance advertisement. The danger is, it doesn’t take a lot of noise to substantially reduce the range at which females or other males could hear that low-frequency hoot. So the attraction radius of the display ground could contract substantially with the inability to hear a hoot.” The authors note that some species can reduce the effects of masking by shifting their vocalizations. This is especially true when members of a species are communicating with each other. However, when the sounds a species depends on emanate from another species (such as a mouse burrowing under the snow, which an owl needs to hear as it hunts), there is less room for compensation.
• Carnivores like lynx, who sit at the top of the food chain, can be particularly sensitive to habitat degradation of any type — including auditory — since each individual requires a huge hunting territory. “If one part of the range of a top-level predator is compromised, it may not take much to squeeze it out,” Fristrup said.
• Contrary to what one might expect, noise is not always more disruptive when it’s louder. Snowmobiles or cars, for example, might be less disruptive to elk or deer than a hiker or cross county skier would be. “There’s pretty good evidence that so-called quiet use can disturb wildlife. If it’s a noisy source, the animal perceives it a long way off and can track its progress. There are no surprises, and it can go on feeding or doing whatever else. A quiet sound, like a snowshoer’s footstep, is only perceptible when it is very close, potentially startling the animal,” Fristrup said.

To read AEI’s detailed lay summary of the research paper, published here in December, see this link.

This one slipped past me when it happened last June, but it’s well worth noting now.  Complicating assessments of the risks of bird deaths at wind farms is the fact that two-thirds of migrating bird species migrate mainly at night; Cornell’s Bioacoustics Research Program, which has already done groundbreaking work in elephant communication and underwater listening systems, has proposed that combining their autonomous recording devices with radar data could provide the missing information on exactly when and where concentrations of migrating birds may exist near proposed wind farms.

A compelling animation highlights the large-scale patterns: The color-coded radar map illustrates areas of precipitation over the coasts as well as vast movements of tens of millions of birds, bats and insects across the entire country. In the densest areas, the color-scales indicate movement of 2,000 birds per cubic kilometer. “You’re talking about a massive movement of birds overnight,” said post-doctoral fellow Andrew Farnsworth.

Radar imagery of night-migrating birds, bats, and insects

Although radar data can show the magnitude, location, timing, speed and direction of migration patterns and provide information on key stopover sites, they do not identify types of birds or accurate flight altitudes, Farnsworth said. But combining radar data with data from flight call recordings and tracking tags on birds could allow researchers to identify many species in key areas. Bioacoustics program director Chris Clark added that recorders are cost effective, can be automated for many months at remote sites, provide data on many species simultaneously, increase the probability of tracking secretive and endangered species, and could allow regulatory agencies to develop computer models to assess risks to birds from wind turbines. He acknowledged, however, that using such acoustic technology could produce a massive “data crunch”; a single microphone over a three-to-four-month period can record 120 to 140 gigabytes of data, so data from several hundred microphones would be too much to process without advanced software. Also, researchers would need to better recognize the wide variety of flight calls and learn to integrate data from radar with those from acoustics and tracking tags, he added. More research is needed, Clark stressed, to determine at what altitudes species tend to fly and whether birds sense turbine blades and avoid them.  Read full account of the presentation in the Cornell Chronicle, with link to the radar map animation.

Ongoing research in Stellwagen Bank National Marine Sanctuary is providing ever more compelling visualizations of shipping noise and the much quieter calls of whales in the area. Scientists from Woods Hole Oceanographic Institute, NMFS, and Cornell have deployed networks of sound recorders, which allow them to track individual whales and ships and see how their sounds interact.  The Sanctuary, which contains the shipping lanes into Boston harbor, is one of the more urbanized ocean environments to be closely studied thus far.  Here, we see four panels; the top left is wind noise, bottom left is right whales, and the right hand ones show that two ships completely drown out the whales as they pass through the area. “Every day, five to six large ships move into and out of Boston, and their acoustic footprint can last for hours.” says Cornell’s Chris Clark. “As a result, the Right whales trying to make a living off Boston are losing about 80 percent of their opportunities to keep in contact every day, day after day, month after month, year after year.”

From Sciencemag.com; click to read source article

“Right whales are long-lived animals. When they were kids and teenagers, their world was normal,” Clark says. “Acoustic habitat loss is a stressor and there are multiple stressors on a species.” His team has found that the whales often no longer bother answering calls from their peers. In this world of constant noise, they wouldn’t be heard anyway. “Their social network is constantly ripped apart,” says Clark. “In one area, noise levels are now 105 decibel where they should be 75.” Other researchers from the Right Whale Consortium found that the animals show dramatic loss in vital body fat: In some individuals, the blubber layer is thinner than normal, hinting at the possibility that they no longer find enough food due to the noise.

At conferences over the past year, project scientists have shared compelling animated sequences showing similar patterns; so far, only still images are available online. UPDATE! A recent article on this work in the journal Science (from which the Clark quotes above were drawn) has a link to a good video (note: the video has minimal interpretation. I find the upper left graph most compelling: it shows the whale call (in blue), loud near the whale and fainter as the cone spreads out; the red disc is the noise from the ship, gradually getting louder than the whale calls, until it drowns out the whale everywhere except very nearby). For more on this important research, see this recent article which contains two stills from a different animation, this section of the Stellwagen website on the passive acoustic monitoring program,  this movie which visualizes the movements and sounds of two nearby and some more distant humpback whales, and hear this local radio piece on the Stellwagen research.

The most recent issue of the Marine Ecosystem and Management newsletter (download here) has several features that offer a good sense of current efforts to adopt Marine Spatial Planning (MSP) and its related management principle, Ecosystem Based Management (ESB).  The lead article centers on reports from Massachusetts, Norway, and Germany, each oriented toward the relationship between MSP and ESB.  Shorter pieces include interrviews on related topics and direct readers to recent management plans, proposals, and reports by the US Federal Government, the State of Massachusetts, and Papahanaumokuakea Marine National Monument in Hawaii.  For more on MEAM programs and publications, see the MEAM website.

The final EIS in the Navy’s multi-year effort to get its training activities into legal compliance with NEPA requirements is heading for the finish line.  Adding to the drama, however, is the fact that the Navy is pushing to introduce active sonar training into the Gulf of Alaska—while previous EISs at other training ranges proposed continuing sonar training at or near levels that have been taking place for years, the Alaskan proposal would bring sonar training for the first time into Alaskan waters rich with marine mammal habitat.  While the Alaskan range where sonar training would take place is relatively small compared to many of the other ranges on the east and west coasts of the continental US, it is within dozens of miles of key whale habitat, and locals have expressed much concern at public hearings.  For more detail, see these links to Alaskan newspaper coverage.

Meanwhile, as the Navy completes the EIS, it has also applied for the Incidental Harassment Authorization from the National Marine Fisheries Service, which announced in early February its intention to issue a Letter of Authorization to permit Navy activities as planned from December 2010 to December 2015.  The Navy estimates that its covered activities will take individuals of 20 species of marine mammals (15 cetaceans and 5 pinnipeds) through Level B behavioral harassment. “Further, the Navy requests authorization to take 3 individual beaked whales (of any of the following species: Baird’s beaked whale, Cuvier’s beaked whale, Stejneger’s beaked whale) annually by serious injury or mortality.” See the Navy’s IHA application here, and NMFS notice of intent to issue the LOA here.

The latest in AEI’s ongoing series of comprehensive special reports on key topics is finally done!

This one is modeled on AEI’s acclaimed annual reviews of science and policy developments in ocean noise, but focuses for the first time on wind farm noise issues.  The 30-page report covers new research, public concerns, and industry trends over the past year.

Read the report in the embedded pdf reader below, or download a pdf copy.  Click on to below the fold for a table of contents and the report’s brief Introduction.

Read the rest of this entry »

This came out in December, but I forgot to post about it then.  The National Park Service’s science magazine has published an entire issue devoted to the NPS’s soundscape studies and programs.

A couple strolls through Cathedral Grove on a quiet morning in winter when visitation is typically low. Signage at the entrance to this area reminds visitors that they are in a quiet zone. (NPS Photo/Lou Sian)

Articles include:

• Measuring and monitoring soundscapes in the national parks
• Integrating soundscapes into NPS planning
• Conserving the wild life therein–Protecting park fauna from anthropogenic noise
• Soundscapes monitoring and an overflight advisory group: Informing real-time management decisions at Denali
• Soundscape management at Grand Canyon National Park
• Generator noise along the US-Mexico border
• A program of research to support management of visitor-caused noise at Muir Woods National Monument

And, as they say, much, much more!  See the issue online here; from there, you can read every article in full. Note that the html views break each article into several separate pages, but you can also view in a “printer-ready” format that loads the entire article into a FlashPaper format, or you can view or download the full articles as pdfs.

I’ve just finished reading what must be the most exciting research paper I’ve seen this year, barely nudging out a similar paper addressing terrestrial noise impacts. A small group of researchers, with Chris Clark of Cornell as the lead author, took a giant step forward in addressing the impacts of ocean noise on the communication ranges of whales.  They came up with a clear and strikingly rigorous set of new metrics that will allow researchers and ocean planners to have a much more practical picture of how numerous noise sources combine to create cumulative impacts on acoustic habitat.  The new approach centers on the “Communication Space” of individual animals, as well as groups, and provides an intuitively obvious way to both imagine and assess the effects of ocean noise – measuring the area in which an animal can hear or be heard by others of its species.

My formal “lay summary” of this paper is reprinted in full below the fold, and I encourage anyone with a deep interest in ocean noise to read through that five-paragraph overview, or to download the paper yourself.  The key takeaway for those of you with a more casual interest in these issues is that in the test case that they used to illustrate their new approach, the researchers found that shipping noise has dramatically different impacts on different species, even though all three species they studied are low-frequency communicators.  In the area off Boston Harbor that they investigated, the critically endangered right whale is by far the most affected by shipping noise: on a day when two ships passed through the area (the average is often six), right whale Communication Space was reduced by an average of 84% over the course of the day, with several hours in which they could hear and be heard in an area less then 10% of that which would be expected without shipping nearby. Since right whales call back and forth to find each other as they form groups for feeding, this is truly worrying (though the key question of how a reduced communication range actually affects animals remains unanswered).  Fin whales and humpbacks were far less dramatically affected, with their Communication Spaces reduced by just 33% and 11% respectively.

These first examples focus on the effects of low-frequency shipping noise on low-frequency communication by large whales, but this approach can easily be used to address mid- or high-frequency noise sources (sonars, airguns) and higher frequency animal sounds such as those used for echolocation, opening a vast and exceedingly useful new doorway for biologists and ocean managers, as well as the general public, to appreciate the impacts of human sounds in the sea.   (click through for complete lay summary)

Read the rest of this entry »

An ongoing research project from the National Park Service Natural Sounds Program is about to publish a groundbreaking paper that outlines the many ways that even moderate increases in human background noise can create major impacts on animals.  The study proposes a new metric for use in bioacoustics research, the “effective listening area.”  This is the area over which animals can communicate with each other, or hear other animals’ calls or movements; as might be expected, animals focus especially on listening for sounds at the very edges of audibility, so that even a small increase in background noise (from a road, wind farm, or regular passing of airplanes) can drown out sounds that need to be heard.  The authors note analyses of transportation noise impacts often assert that a 3dB increase in noise – a barely perceptual change – has “negligible” effects, whereas in fact this increased noise reduces the listening area of animals by 30%. A 10dB increase in background noise (likely within a few hundred meters of a road or wind farm, or as a private plane passes nearby) reduces listening area by 90%.

In addition to introducing this important new metric, the paper provides a good overview of previous research that has addressed the impacts of moderate noise on various animals, including bats, antelope, squirrels, and birds.  The paper will be published next year, though an “in press” version is available for download.  A recent BBC article also covered this important new work.  A full detailed lay summary of this paper, as previously published on AEI’s science research page, appears below the fold: Read the rest of this entry »

The newly-formed Fiji Islands Voyager Society was christened at the start of the South Pacific Pageant this week, with the dawn launch of the canoe Uto Ni Yalo (Heart of Souls).   In June of next year,  a flotilla of canoes will sail from Fiji to Hawaii to advocate the protection of our ocean environment and rekindle traditional voyaging, sailing and navigational skills.

Warriors launch canoe from beach (click for Fiji Times article)

Representing the Pacific Voyaging movement, Rawiri Patekere from New Zealand, said people of the Pacific had been the innocent victims of ocean noise pollution for years. “And the time has come for the Pacific to unite, stand firm while they voice their concerns,” Mr Patekere said. “The sea has been crying for years and it is time to answer that call for help.”  Recalling the words of his grandfather, he said, “when you paddle your canoe, paddle quietly.”   Director Letila Mitchell says the Wasawasa Dawn Festival celebrates Pacific Culture, and that “the Ocean Noise project will raise awareness to help stop the increase in noise pollution being brought about through shipping.”   Read more at these three Fiji news outlets.

Just a quick note to say that I did the first major update to AEI’s Special Report on wind farm noise today.  I added several key new pieces that will be familiar to regular readers of this blog.  The report aims for AEI’s typical sweet spot of providing a comprehensive yet concise overview of all the key issues, presented in a balanced way, with links to source material and advocates on all sides of the issue. The report can be viewed online here, or downloaded as a 33-page pdf here.

This one just popped up, though it’s from last spring: a seemingly quite comprehensive survey of people living within a half-mile of one of the major wind farms in Wisconsin that has triggered noise concerns.  The results reinforce the emerging picture: many people are being affected, but negative impacts are not inevitable or universal.

The survey was returned by over 200 families, just under half those who live within a half-mile  or so of at least one turbine in the Blue Sky Green Field wind project, which covers 10,600 acres of farmland.  It would have been interesting to see some of these numbers broken out to see responses from those with several turbines in within a half mile, but for now, this is what we learn:

• Overall, 50% were bothered by noise; an equal number were not
• Of those within 3000 feet, 56%  (90) were bothered by noise, while 44% (72) were not; beyond 3000 feet, 3 of 10 families reported noise issues; among those who did not specify a distance, 15 were troubled, and 19 were not.
• Of 23 respondents who had leased land for turbines, 9 (39%) noted that noise was a problem for them, and 6 (26%) said they would not so, if they knew then what they know now.
• 30% reported negative effects on pets, farm animals, or wildlife; 70% saw no such effects
• 25% said their sleep was interrupted at least once a week; 75% had no sleep issues
• 33% reported various stress-related health issues, while two-thirds did not.
• 62% said the setbacks should be a half mile or more; 22% supported the current 1000 foot setback.

Once again, we are left with the murky social question: what proportion of the population is it OK to bother?  Should we move turbines further away (thus sacrificing some sites) in order to reduce impacts on the scale we see here? Or, with a healthy majority of people reporting no negative health impacts, is it fine to proceed as we have been?  I suspect that the answer to these questions is equally clear to some on each side of the issue, while many others likely struggle to find a balance that makes sense.

See this recent AEInews post summarizing three recent scientific papers on annoyance and health impacts from wind turbine noise, which lead to similarly murky conclusions.

A northern bottlenose whale that wandered deep into Loch Eli recently is one of ten that have either stranded or seen in lochs in recent years.  Researchers wonder whether noises at sea may be “herding” normally deep-water whales into the narrow lochs, where they become disoriented and perhaps also trapped by other noises.  In the recent case, whale was only persuaded to leave when a nearby fish farm had turned off its seal-scaring device. Volunteers from the Marine Life Rescue Unit then used underwater loudspeakers to play sounds of their own – including a recording of a hunting killer whale — to push the 10-metre whale back out to sea. In recent days, one such whale died after being helped toward sea, and one survived.

A northern bottlenose whale stranded in Scotland (click for London Times article)

The seal-scaring “acoustic harassment device” is “an awful siren sound — very, very loud,” said Dr Patrick Miller of the Sea Mammal Research Unit in St Andrews. “There’s quite a bit of research that says they have more effect on cetaceans than seals. It may very well be that the seal-scarer had a big effect on keeping the animal inside the loch.”

“The whales are migrating at this time of year, so we normally do see more of them, but to have so many washing up is a little strange. There’s an enormous amount of man-made noise out at sea off the northwest of Scotland, and we can’t rule out that this is what causing them to come ashore,” said Mark Simmonds, Director of Science for the Whale and Dolphin Conservation Society.

“Although we think of these as open ocean animals, for so many to come in there may be something we’re missing,” said Dr. Millar. “Maybe they’re looking for food. We just know so little about the animals it’s difficult to make strong conclusions.”

In what may be a legal breakthrough for soundscape protections, a Federal Judge has issued a preliminary injunction forbidding drilling on a National Wildlife Refuge adjacent to the Great Sand Dunes National Park in Colorado while a challenge from environmentalists moves forward; the groundbreaking bit is that he apparently has followed the National Park Service’s lead in considering the natural soundscape as a resource deserving of protection.  Thanks to the National Parks Traveller blog for the heads-up – head over there and read all about it!

A study commissioned by the Royal Society for the Protection of Birds (RSPB) found that many species of birds avoid nesting in areas within 500 meters of wind turbines.  The RSPB, like its US conterpart the Audubon Society, has been largely supportive of wind energy.  The new study was the most detailed yet of bird distribution around wind farms: twelve major upland wind farms were surveyed six times during the breeding season for a dozen common species including waders and gamebirds (golden plover, lapwing, curlew, snipe, red grouse), raptors (buzzard, hen harrier, kestrel), and songbirds (skylark, meadow pipit, stonechat and wheatear).  Of the 12 species studied, 5 seemed undisturbed, while populations of 7 were 15-53% lower when within 500m of a wind turbine.  The displacement effects continued out to a distance of about 800m (roughly a half mile).  The affected species were buzzard, hen harrier, golden plover, snipe, curlew, wheatear and meadow pipit.

Image from The Telegraph; click to read article

It is crucial to note that this study was looking at nesting patterns, and does not suggest that birds are being killed by the turbines, but rather that they avoid nesting near them, presumably because of increased noise, which could disrupt communication between birds or reduce the amount of prey and make it more difficult to hunt (whether for insects or rodents).

UPDATE: I recently came across a paper from last year that found no obvious avoidance of wind farms by most wintering species of UK farmland birds.  This paper looked not at nesting patterns during breeding season, like the paper above, but rather at wintering birds’ presence (they walked randomized paths, and counted birds seen; most were seen when flushed from the grain).  Looking at numbers seen in 5 sets of distances (from 0-150, to 600-750m), wintering farmland birds (seed-eaters, corvids, gamebirds and Eurasian skylarks) showed no increase with increasing distance. A further investigation of 0-75m and 75-150m also showed no trend.  Only pheasants showed a tendency to be found in the segments further from turbines.

Ongoing research by NOAA’s Northwest Fisheries Science Center continues to look more deeply into the effects of boat noise on Puget Sound orcas.  The research team, led by Marla Holt, had previously found that orca calls increase in volume in step with background boat noise: for each decibel of added background noise, their calls also got a decibel louder.  In their latest round of research, the team is trying to determine whether the background noise is diminishing their foraging success due to masking (drowning out) some of the critical group communication, and whether calling louder makes the animals use more energy.

Image courtesy National Geographic

A 20% population decline among the Southern Resident orcas during the late 1990’s has been attributed to a combination of fewer salmon, toxins, and vessel noise. According to a recent article on National Geographic.com, Holt, who will present the team’s preliminary findings in October at the Biennial Conference on the Biology of Marine Mammal in Quebec, said that their research indicates killer whale communication is particularly important during hunting. What’s more, previous studies in birds had suggested that the animals consume more oxygen to raise their voices above ambient noise, making their metabolic rates spike and burning up stored energy, Holt said, adding that it’s possible the same phenomenon could be occurring with killer whales, although it’s too early to know for sure.

NOAA’s recovery efforts for the orcas include new regulations that will keep whale-watching vessels 200 yards from orcas, as well as efforts to reduce toxin pollution and to restore salmon runs.  Longtime orca researcher Ken Balcomb feels it all comes down to the decline in salmon: “If you deny them the food, [there’s] basically no point in worrying about other factors,” Balcomb said. He calls the whale-watching limits “feel-good thing,” adding that “my observations over 35 years [are] that [whales] don’t really get disturbed by anything, much less vessels.”  Holt acknowledges the limits of the new regs, saying that “a lot of people would argue, Why focus on these vessel regulations? But it’s one thing we can do immediately.”  It appears to AEI that the question is not really whether the boat noise disturbs the orcas, but whether it may drown out parts of their foraging communication, making it more difficult for them to find and eat the few salmon that do remain available to them.  And, given their tenuous situation, if they are forced to use more energy to call during hunting, their overall health is likely to be at least somewhat affected.  Moreso, each time that a particular foraging attempt is aborted due to a noise intrusion, a larger bit of the daily energy budget has gone to waste.  Time will tell whether the new boat limits actually lower the received sound levels for foraging whales; if so, it’s a step in the right direction.

A feature article in the fall issue of The Nature Conservancy’s magazine takes a close look at the rapid expansion of the wind industry in America’s prairie heartland.  The rolling hills of Kansas are a prime wind energy corridor, and TNC is concerned that the remnants of tallgrass prairie habitats could be irrevocably harmed if new wind farm development is not done carefully.  Rob Manes, TNC’s Director of Conservation for Kansas, sits on the Fish and Wildlife Service advisory committee that is developing wind farm siting guidelines, where he has proposed that key habitat be identified in advance, so that wind companies can plan around it.  Such landscape-scale analysis is already being done by some wind companies, and Manes urged the committee to recommend that the practice become standard procedure.  Manes imagines an ever-expanding regional database that would not only would provide maps of important environmental data, such as critical habitat for endangered species, but also would designate wind-friendly areas where turbines and wildlife are less likely to be in conflict.  (This idea is closely related to Marine Spatial Planning, as addressed in this recent AEInews post.)

From the TNC article: Manes is certain that a national set of detailed maps overlapping wind and wildlife resources is crucial to “doing wind power right.” That is because the Conservancy and its partners have already implemented a system of maps in Kansas. And local developers have responded enthusiastically. Horizon Wind Energy even worked with the Conservancy and the Ranchland Trust of Kansas to set aside protected lands to offset the footprint of one of its wind-farm developments.  “Our contacts in the wind industry said, Show us where we can develop our projects — so we did,” Manes says. The map shows the state’s native prairies, prairie chicken habitat, wildlife refuges and nature preserves, as well as where the best wind resources are. Now, when a wind developer wants to build in Kansas, the company knows which sites are likely to raise the ire of conservationists — and which areas aren’t.

The Conservancy has created similar maps in a handful of other states, including Colorado, Montana and Oklahoma. And in mid-2009, the Conservancy was awarded a contract to create a wind and wildlife resource map for the entire country. The map initiative is funded by the American Wind and Wildlife Institute, a coalition of wind-industry and conservation organizations with the aim of reducing conflicts between wind development and wildlife.

UPDATE: In the UK, the Royal Society for the Preservation of Birds, along with Scottish Natural Heritage, has initiated a similar project, centered on the production of a Bird Sensitivity Map for use in planning wind farms in Scotland. See this link for more information on the program, and click here to download the BSPB Bird Sensitivity Map Report.  Scottish Heritage previously released “Strategic Locational Guidance” for onshore wind farms.

After a bit of a lull, I’ve spent much of the past couple days catching up on the folder full of research published in recent months, and summarizing key papers on the main Acoustic Ecology site.  Among the studies worthy of attention are:

• The first direct test of harbor porpoise sensitivity to seismic survey airguns confirms many observations from the field that this species is especially sensitive to noise; both temporary hearing loss and avoidance of sound occur at relatively low noise levels
• Orcas and dolphins seen to reduce foraging in the presence of boat noise
• Wind turbines don’t seem to replace most small wintering farm birds, but oil development noise can reduce forest bird abundance
• Right whales summer habitat is loud most of the time, suggesting a pressing need to identify their breeding grounds and assure they can hear each other there
• Two great overviews of fish hearing

See these and more at the AEI lay summaries of new research page.

The revised draft of wind energy wildlife impact guidelines released by a US Fish and Wildlife Service Federal Advisory Committee was released in March, and like the first version, contains not a single occurrence of the words “noise” or “acoustic.” The Committee is directed to “recommend effective measures to avoid or minimize impacts to wildlife and their habitats related to land-based wind energy facilities.” How they can provide provide this guidance without considering acoustic impacts is simply unimaginable.  Modern wind turbines are hundreds of feet tall, and create significant sound; even the minimal setbacks for human residences are 1000 feet, with many cases of bothersome noise (especially at night) at a half mile or more.  Wildlife impacts of wind farms are sure to include increased ambient background noise over a fairly large area (half mile to a mile in diameter), which can make it more difficult for predators such as owls and coyotes to find their small prey, and likewise force prey animals to be more vigilant against attack, which has clear energy costs for the animals.  In addition, low-frequency noise radiated into the ground could affect burrowing animals.  Especially in “islands” of woods along ridgelines surrounded by farm land, this acoustic degradation could displace animals from key habitat; even in larger woodlands, steep terrain along ridgelines often contains a different mix of trees and thus habitat that is locally important.  As AEI noted in comments submitted to committee members in February, “In at least some situations/locations, acoustic impacts could be a primary or substantial contributing factor in displacement from habitat, as well as triggering stress that may have synergistic relationships with other impacts.”  Such considerations are basic requirements for effective analysis of impacts on wildlife.  The Committee briefly considered noise impacts, but concluded that no data (specifically involving turbine noise) was available with which to assess the possible effects.  As with ocean noise, though, this lack of specific data does not preclude assessing possible or likely impacts, using studies of other noise sources or even other species than those present at a given project area; NOAA and the Navy routinely take this approach to assessing the impacts of various ocean noise sources.  There is plenty of research on the noise impacts of oil and gas installations, road noise, and aircraft noise on many families of wildlife (birds, rodents, large mammals, etc.).  The National Park Service Natural Sounds office and bioacoustics researchers at universities across the country are good sources of information that this Federal Advisory Committee surely needs to consult before moving forward with guidelines for assessing the impacts of wind farms on wildlife.  These guidelines will shape wildlife impact analyses for years to come, and need to be done right.  

For more on the FWS wind advisory committee, see:
http://www.windaction.org/articles/21154
Industrial Wind Action Group letter to Sec. of Interior Salazar, May 2009

http://www.fws.gov/habitatconservation/windpower/wind_turbine_advisory_committee.html
Advisory Committee website 

The early 2009 issue of Conservation magazine, the popular press publication of the Society for Conservation Biology, has a great overview piece on the effects of noise on animals. It focuses on changes in animal behavior and song that have been observed over the course of the past decade, drawing on studies from several different researchers. Much will be familiar to AEI regulars, but it remains highly recommended for sharing with others and for the concise overview it provides.

See the article at http://www.conservationmagazine.org/articles/v8n2/not-so-silent-spring/

A three-year research project in Scotland has been announced, which will study the impacts of tidal energy turbines on sea life. From Wave and Tidal Energy News:

The groundbreaking study will be conducted through a PhD studentship at the Scottish Association for Marine Science (SAMS UHI). It will look specifically at the background noise levels in areas being considered for tidal renewables development, as well as the noise made by tidal turbines. It will also explore the extent to which marine animals, particularly protected species, can detect and, potentially, avoid colliding with such devices.

Marine ecologist Dr Ben Wilson, who will be supervising the project, said: “This is an exciting opportunity to contribute to both sustainable marine energy extraction and conservation. Scotland is rapidly becoming a magnet for the companies developing devices to capture energy from tidal currents. These machines however will have to share the sea with vulnerable and protected species like whales, seals and fish. Understanding how these animals will perceive and behave around underwater turbines is a mystery but sound will undoubtedly be the most important sense for them, particularly at night and in murky water. Knowing what the natural sound-scape is like in prospective tidal energy sites and the noise output of different devices will help us identify those devices that marine animals will most easily move around without harm. With this understanding we will be better able to promote those machines that have the most gentle ecological footprints.”

Miller, Solangi, Kuczaj II. Immediate reponse of Atlantic bottlenose dolphins to high-speed personal watercraft in the Mississippi Sound. Journal of the Marine Biological Association of the United Kingdom (2008), 88:1139-1143 [ABSTRACT, CONTACT AUTHOR]

This study, using opportunistic observations in the Mississippi Sound (a 90-mile intercoastal waterway, between the coast and a series of barrier islands; depths up to 20 feet), evaluated the responses of bottlenose dolphins to the appearance of personal watercraft (jetskis). In just under half the incidents, a dolphin group’s behaviour changing within one minute of the presence of a high-speed personal watercraft. The most notable changes were that groups that were feeding shifted dramatically to “traveling”mode. Interestingly, groups of dolphins that were already in “traveling” mode often paused and began “milling.” In addition, mean dive duration increased dramatically, from 12-16 seconds to 42-82 seconds. Researchers note that “The results demonstrated an immediate, short-term change in dolphin behaviour, suggesting that an increase in the frequency of high-speed personal watercraft in this area could produce long-term detrimental effects.” The authors suggest more research into the differences in reactions to high-speed and lower-speed jetskis and the effects of increasing distance of jetski approach; in addition, they note that long term studies of growth and reproduction in places with different densities of personal watercraft would help clarify any population-level impacts that may accumulate over time.

An interesting sidelight to this research highlights the difficulty inherent in almost all field research of cetaceans: the study took place over two years, four days per month, and resulted in 329 encounters with dolphin groups, among which there 137 instances in which a watercraft passed by. However, only 17 of these 137 were suitable for the study purposes (ie, they were high speed personal watercraft, and 10 minutes of video of the dolphins was captured before the watercraft passed). Two years of diligent study resulted in just 17 useable encounters! And, truthfully, n=17 is pretty impressive compared to most cetacean field studes….

A week after the UK’s worst dolphin stranding since 1981, reports from locals and the UK Navy are conflicting. Two weeks of live-fire exercises were wrapping up in the area over last weekend, with the Navy first claiming to have concluded those exercises Sunday afternoon, then saying that in fact the last live-fire took place far offshore on Friday, with a mid-frequency submarine-hunting sonar used on Thursday. However, local Falmouth Coast Guard personnel report heavy Naval activity through Sunday afternoon in Falmouth Bay. And, Nick Tomlinson, a local fisherman working 12 miles offshore, experienced a most dramatic blasts than he has felt in the 35 years he has been working the waters off the Cornish coast. “I’m used to the big military guns going off but this was something different – bang, bang, bang, very close, very loud. The vibrations went through the boat and up through my backbone. The whole boat was shuddering.”
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Reports of unusual stranding events around the world this week are each triggering questions about possible sonar connections, despite little clear evidence thus far. In Madagascar, over fifty melon-headed whales stranded and died after becoming trapped in a bay; in the UK, 26 common dolphins (mostly juviniles) died along the shores of an estuary river a pod of fifteen strayed into, likely feasting on fish feeding at an algae bloom, with up to seventy more following in the hours that followed, perhaps responding to their distress calls; other dolphins were found dead on two other nearby shorelines within 15km, including another estuary. In Japan, three Cuvier’s beaked whales have been found dead on beaches in the past three weeks, the latest of 81 whale fatalities (9 of them Cuvier’s) since March. Read the rest of this entry »

 A surge in lease sales along Alaska’s west and north coasts has spurred predictable resistance from locals and environmental groups. While the effect of any possible oil spills in harsh waters is certainly a major focus of concerns being voiced, the impacts of the first phase of oil and gas exploration have moved to the forefront of discussions. The oil industry is gearing up to explore a record number of offshore lease areas in the next few years, and this summer, up to five seismic survey vessels are scheduled to be off the Alaskan coast, firing airguns 2-4 times per minute and listening for the echoes Read the rest of this entry »