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NATO sonar exercises, strandings in Crete

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

While recent years have seen an apparent reduction in the number of sonar-related strandings, one of the world’s hot spots for such tragedies saw a rash of strandings in recent days.  Two different stranding events occurred along the southern shore of Crete, the first involving 5-7 Cuvier’s beaked whales along a 16km stretch of coast, and the second occurring a few days later and 48km east, where three members of the same species came ashore.  In both cases, many of the animals were refloated and returned to sea (and unknown fates), while four whales died, including a fetus that was apparently close to term.

CRETE web

 

A NATO naval exercise, Operation Noble Dina, is ongoing in the area, involving US, Greek and Israeli forces. This part of the Mediterranean has been the site of several previous strandings, as noted by NRDC’s Michael Jasney:

For Greece, none of this is new. In 1996 and again in 1997, dozens of beaked whales of the same species turned up along the Peloponnesian coast; in 2011, they stranded on the island of Corfu as well as the east coast of Italy, across the Ionian Sea. In each case, navies were training with high-powered sonar in the area. Indeed, according to the Smithsonian Institution and International Whaling Commission, every multi-species beaked-whale mass stranding on record everywhere in the world has occurred with naval activities, usually sonar exercises, taking place in the vicinity.

One of the ongoing areas of contention between environmental advocates and the US Navy and federal regulators is whether sonar training (and naval live-fire and explosion exercises creating loud and potentially harmful noise) should be planned to avoid areas with known concentrations of marine mammals, especially those, such as beaked whales, known to be sensitive to noise.  As it turns out, the area of this stranding is one of a large number of areas recommended as Areas of Special Concern for beaked whales by that the Scientific Committee of ACCOBAMS (Agreement for the Conservation of Cetaceans of the Black and Mediterranean Seas, a consortium of governments in the region).  As reported by a long-time chair of the Scientific Committee, the recommendation fell on deaf ears when presented to the full ACCOBAMS meeting of the parties last year; military preparedness was the explicit reason for the rejection.

In the wake of the two stranding events, Operation Noble Dina continues, but has moved 100km south of Crete—outside the boundary of the proposed Area of Special Concern, and apparently still completing its military preparedness mission.

FAA adds insult to injury with new Grand Canyon flight permits

Human impacts, News, Wildlands Comments Off

Eighteen months after Senators John McCain (R-AZ) and Harry Reid (D-NV) joined forces to undermine the National Park Service’s Grand Canyon air tour management plan just before it was set to go into effect, the Federal Aviation Administration apparently feels that the discounted per-flight fee for quiet aircraft is not incentive enough to encourage the air tour industry to invest in new-generation planes. Rather, the FAA has decided that the best way to do so is to allow 1721 additional flights to the annual parade of planes piercing the skies over the Grand Canyon, so long as these new flights utilize “quiet” aircraft.

Grand Canyon view from air tour500

 

“The so-called quiet technology is not quiet,” said Sandy Bahr, director of the Sierra Club’s Grand Canyon Chapter. “It’s less noisy, but it’s not quiet.” Flagstaff resident Jim McCarthy, who did a master’s thesis at Arizona State University on noise pollution in the Grand Canyon, said air tour companies are “gaming the park.” Because the quiet technology is defined by noise per seat, aircraft can be noisier as long as they hold more people, he said. “It can be completely counterproductive.” (above image is the view from an air tour)

A park spokesperson notes that the additional flights only add about 3% to the flights already occurring; at peak times, planes take off every 90 seconds, heading for the two most popular air tour corridors.  As with snowmobiles in Yellowstone, the annual cap on allowed flights is far higher than the number of flights that have been occurring in recent years: the FAA authorized about 90,000 flights in 2012, the most recent year for which numbers were available, but only 55,185 commercial air tours were actually flown that year.

See earlier AEI coverage of this fiasco here

Oregon project aims for floating offshore turbine future

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After nearly five years of floating offshore wind farm planning off the coast of Maine, a project in Oregon may leapfrog those efforts.  An initial go-ahead from federal ocean regulators marks the starting line for a pilot project off Coos Bay, which will need to clear several more regulatory and financial hurdles before being built.  

Perhaps optimistically, Principle Power (the developer) is holding a target date of 2017 to have its initial five turbines operational.  These will be huge, 6MW, 600-foot turbines, similar in design to a model that’s already being tested in the water in Portugal.  The project is expected to cost $200 million, which would build around 100MW of capacity on land, as compared to the 30MW this pilot project will construct; Principle Power expects that steadier, stronger offshore winds will let these turbines operate at a higher capacity factor than onshore projects, partially making up that difference. Of course, experimental pilot projects are always far more expensive than later, full-scale build-outs; still, the financial feasibility of projects like this is a work in progress.

Virginia offshore wind developer agrees to avoid right whales for evaluation, but not for construction

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Last fall, Dominion Virginia Power won the first federal lease for developing wind power off the coast of Virginia.  As with all offshore energy and Naval activity on the east coast, one of the first environmental concerns to be raised was what measures would be taken to minimize impact on the critically endangered North Atlantic Right whale. While their population has been more or less steadily rising since 1990, with only about 400 individuals, they remain vulnerable to any negative impacts, from ship strikes to increased stress levels, which may reduce reproductive rates and success. (See NOAA’s most recent stock assessment report for details; it notes lower reproductive rates than other Right whale stocks, and concludes that the population will be negatively affected if it loses more than 0.9 whales per year to human impact.)

Turbine being boated offshoreWith all this in mind, Dominion Virginia Power’s first commitments to the Virginia Offshore Wind Development Authority fell far short of what many had hoped.  The company agreed to limit installation activity of test platforms (meteorological towers and preliminary test turbines) during the period when whales are most apt to be migrating past the Virginia coast, but made no such commitments about later, and much more extensive, pile-driving for hundreds of turbines in the eventual wind farm.

“We’re happy to talk” with environmental groups, said Mary C. Doswell, Dominion Resources Inc.’s senior vice president for alternative energy solutions, though she noted, “we can’t overlook the costs of compliance.”

The company said they’d minimize their first-phase activities from late November to late March.  The whales spend the summers in a large area off the coast of New England and the Canadian Maritimes, and concentrate at birthing grounds off the coast of northern Florida in winter. NOAA maintains a reduced speed zone along the mid-Atlantic coast, to protect migrating Right whales, from Nov.1 to April 30, close to two months longer than the company set aside as their cautionary season; even the speed restriction is seen by some as a potential obstacle to offshore wind data collection.

UPDATE: See also this article from last fall, which suggests that Dominion plans only to erect a 2-turbine test platform, with full-scae development of 200 or more turbines on hold until costs come down for offshore wind construction.  Some wind advocates suggest that Dominion, which has fought renewable energy initiatives in the state, secured the lease largely to prevent others from developing a large offshore capacity.

Vermont PSB asking for input on turbine noise standards

Human impacts, News, Wind turbines 1 Comment »

The state Public Service Board has initiated a public process for re-examining the noise standards used at wind and natural gas energy facilities in Vermont.  Geoff Commons, the PSB’s public advocate, notes that neighbor complaints from wind projects operating in compliance with a 45dB standard are part of the driver for this review.

VT SheffieldWEB“Even with these restrictions placed on several recently constructed facilities, the board has received complaints regarding sounds produced by the operation of some facilities. These complaints have raised questions about whether the limitations that the board has previously adopted are adequate,” the PSB stated in December.  ”As a result, the board has determined that it is appropriate to commence a general investigation into the issue of appropriate sound standards for facilities that are subject to the board’s jurisdiction.”

The PSB has established a website to track this process.  A pre-hearing conference was held on January 8, and based on discussions there, a scoping document outlining initial ideas about procedures and key questions for the process have were released on January 29, and can be downloaded here.  Public comments are being accepted through March 3, after which the final scope of the process will be determined, followed by a series of public workshops to address specific issues.  The outcome of this process will be a determination as to whether a new set of binding sound-related standards is needed; if so, that will occur during a separate formal process.

From my first reading of the preliminary scoping document, it appears that the focus may be strongly oriented toward health effects, and the standard effort to determine “state of the art” scientific information; the initial list of questions doesn’t appear to consider quality of life impacts.  However, the final scope may change, based on comments during this scoping phase.

Legal challenges mount to new round of Navy training permits

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In December, the Navy’s current five-year plan for training and testing activities around Hawaii and off the southern California coast were approved by NOAA regulators, covering the years 2014-2018.  The approval authorized incidental takes of marine mammals, including both widespread behavioral changes and close-range injuries and some deaths, as a result of sound exposure from sonar and explosives, as well as ship strikes.

ShoupImmediately after NOAA’s approval, environmental organizations filed suit in federal court in Hawaii, and this week, other organizations filed suit in a San Francisco federal court (the Navy pushed back in a brief statement).  It’s unclear from early press coverage how much overlap there is between the two; the Hawaii suit, led by Earthjustice, initially named just NOAA, but has been amended to also name the Navy as a defendant.  The San Francisco suit, led by the NRDC, targets NOAA, charging that federal regulators did not use “best available science” and that their finding of “negligible impact” violates the Marine Mammal Protection Act.

At issue in both suits is the shockingly large numbers of animals that are permitted to be affected, amounting to nearly 10 million behavioral responses, the potential for 2000 permanent injuries (including hearing impairment), and 155 deaths over the course of five years.  ”This is an unprecedented level of harm,” Zak Smith, an attorney with the Natural Resources Defense Council, said. “In order to authorize these impacts on marine mammals, the service had to turn its back on the best available science.”

It’s important to note that while sonar has been the focus of most public concern, explosions during testing and training are predicted to cause most of the injuries and deaths.  The Navy and NMFS consider the estimates to be extremely cautious (ie far higher than actual likely impacts) for a number of reasons; see the bullet list in this earlier AEI post for more on why.

NRDC, Earthjustice, and the other plaintiffs continue to stress that the Navy can and should limit its activities in areas and times of particular biological importance to marine species; the lack of such “spatio-temporal restrictions” has been a bone of contention for many years, and this time, as in past rounds of permitting, the Navy and NMFS determined that such restrictions would yield little biological benefit.  A largely similar lawsuit filed in 2012, challenging NOAA permits for Navy training in the Pacific Northwest, ended up in a split decision, with the “best available science” ruling going against NOAA, but the large takes challenge (including the lack of exclusion zones, as well as faulty negligible impact ruling) falling short, with the court approving of NOAA’s analysis and actions.

UPDATE, 2/10/14: See this article from NRDC, outlining their reasons for this lawsuit and how it fits in with their 20-year history of focusing on ocean noise issues.

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23 Texas wind farm hosts sue over noise, nuisance

Human impacts, Wind turbines 14 Comments »

In what may be an unprecedented move, 23 Texans who host wind turbines on their property have filed suit against two different wind farm developers, claiming that companies “carelessly and negligently failed to adequately disclose the true nature and effects that the wind turbines would have on the community, including the plaintiffs’ homes.”

The plaintiffs host hundreds of turbines on projects developed by Duke Energy and E.ON, and as a Duke spokesman noted, they did consent to the placement of the turbines.  However, the lawsuit stresses that the companies told residents the turbines “would not be noisy, would not adversely impact neighboring houses and there would not be any potential health risk.”  

This court challenge stands apart from most previous nuisance suits, nearly all of which been filed by non-participating neighbors of wind farms (ie, local residents who are not hosting turbines themselves).  Most annoyance surveys suggest that wind farm hosts are less likely to be bothered by turbine noise than non-participating neighbors, and many wind projects make an effort to spread the financial benefits to include some non-host neighbors, because of suggestions that broader project participation will increase community acceptance.  In this case, however, the plaintiffs are receiving lease payments and tax benefits that will exceed $50 million over the life of the projects.

Among the plaintiffs are Willacy County Commissioner Noe Loya, who is said to “no longer enjoy sitting outside because of the loud noise,” with turbine noise inside and outside his home “disturbing the peace and making it difficult to enjoy living there.”  Another plaintiff, a local Justice of the Peace, “has difficulty sleeping, cannot have his windows open (and) cannot enjoy the sound of nature, due to loud noise from wind turbines.”  The lawsuit also claims that some residents have abandoned their homes. In addition to noise issues, the suit includes visual impact, property value, and health effects claims.

E.ON spokesman Elon Hasson, says the company is reviewing the suit. “We develop all of our wind farms in a safe, state-of-the-art and responsible manner. . . We believe these claims will be shown to have no validity.” 
UPDATE, 1/31/14: Spokesmen from both companies issued statements noting that one claim of the suit—that the companies had no plans to remove the turbines at the end of their useful life—is false, and stressed their ongoing monitoring and maintenance of the machines.  They more generally dismissed the other accusations, as well. 

The suit was filed in State District Court in November.  In December, the companies requested that it be moved to federal court, where U.S. District Judge Hilda Tagle has called for a response from the companies by February 6.  

Ed. note: Some wind development leases I’ve seen explicitly preclude hosts from filing nuisance suits. There is limited information online about this case, and it’s unclear whether the plaintiffs’ contracts include such restrictions; if they do, then the legal case may be open-and-shut, or it may be that the crux of the legal challenge is the veracity and completeness of information provided to hosts prior to signing contracts. (It may be worth noting that lease agreements don’t usually include “gag clauses” against speaking publicly about noise or other post-construction experiences; confidentiality clauses usually cover only financial terms and development plans.)

New research listening in on whales as they hunt

Bioacoustics, Effects of Noise on Wildlife, Human impacts, Ocean, Science, Seismic Surveys, shipping Comments Off

Two new research projects are taking important next steps in understanding the importance of sound, and clear listening, to whales.  In recent years, ocean bioacousticians have introduced the concept of “communication space” or “effective listening area” to scientific parlance. This began as a conceptual framework for thinking about how human sounds (especially shipping noise) may reduce the area across which whales can hear and be heard; researchers are now digging into more of the details of how this may actually impact animals in their daily lives.  After several recent studies that focused on whales hearing each other (and so framing their results in terms of “communication space”), two new studies are gathering initial data that may inform considerations of the ways whales listen for the presence of prey.  While whales can, and do, change some of their communication signals or patterns in order to be better heard by other whales in noisy conditions, there’s no such compensation that can help a whale hear their prey through a wash of noise.

Both of the new studies are taking advantage of acoustic tags to allow scientists to listen in on whales as they are foraging.  These tags are about the size of a large cell phone, and are attached to the animals with suction cups; they remain attached for up to 16 hours, then float to the surface for retrieval.  While attached, they record all sounds the whales hear and make, as well as logging swimming speed and dive orientation.

Orca attack seal near shoreWEBOne study is further along, having just published its first results, which confirm that orcas can hunt in near-total darkness, apparently relying only on zeroing in on their prey (in this case, seals) by listening for their mating calls.  These orcas do not use echolocation while hunting (other orcas, hunting salmon, do echolocate); they hunt in stealth mode, then dispatch their victims with a swat of their tail flukes.  This initial evidence is not totally conclusive; followup studies will confirm that orcas do, indeed, seek out seal sounds.  And, this sort of study is but the first step toward quantifying the extent to which ocean noise may limit the range over which orcas can hear seals while hunting.

The second study will begin next year, and will be putting the acoustic tags on large whales, to see whether they’re using acoustic cues to help locate aggregations of fish.  According to Dr. Rochelle Constantine:

“Acoustics within the marine space are really important for many organisms, yet we don’t know a lot about how it drives organisms’ interaction with their environment. We’re interested in looking at how the larger animals use the acoustic environment, particularly for food, and testing the hypothesis that food patches have specific sound signatures.”

Lunging Brydes Wha 300WEBShe said the sound of “bait balls” of prey, such as schools of fish, could be greatly heightened when a feeding frenzy involving larger fish and seabirds broke out.  Dr Constantine said whales had been observed swimming rapidly from over a kilometre away toward prey aggregations, “so we’re very interested to find out if there are specific acoustic cues they home in on”.

This study plans to play recorded sounds of fish aggregations and other prey sounds while the tags on the whales.  (I suppose if they happen to get lucky and have an actual feeding event occur while tags are attached, that will be a bonus, but the playback will serve as a reliable testing condition.)  This team is also interested in using acoustic tags on large fish and sharks, to explore the ways they may rely on listening, as well.

New paper details the acoustic quality of critical whale habitats

Bioacoustics, Effects of Noise on Wildlife, Human impacts, Ocean, shipping Comments Off

AEI lay summary of:
R. Williams, C.W. Clark, D. Ponirakis, and E. Ashe.  Acoustic quality of critical habitats for three threatened whale populations.  Animal Conservation (2013).

Innovative research along the coast of British Columbia has quantified the degree to which shipping noise is reducing the distance at which whale vocalizations can be heard.  This is one of the first studies to use recordings of actual ocean noise levels to examine how the “communication space” of whales is affected by shipping noise in an area where whale conservation is a priority.  Among its troubling findings is that endangered orcas are facing the highest levels of noise in areas that are legally designated as critical habitat, with communication space reduced to 25% or less even in average noise conditions; over the entire study region, the area over which orcas can hear each other can be reduced by 62% during average noisy conditions, and 97% during the noisiest times.  Humpback whales face nearly as large reductions in some key areas (though not formally designated critical habitat; and, notably, are showing signs of a tenuous recovery in some of the areas studied), while fin whales, who have louder calls than the other species, are only mildly affected by shipping noise.

WilliamsCROP(noise levels and communication space in median noise conditions)

Communication space (alternatively termed “effective listening area”) is a relatively recent introduction into scientific parlance; it’s a measure of the area within which a particular species can hear and be heard by others of its kind; both marine and terrestrial bioacousticians have begun using this framework to better understand the ways animals may be affected by increased background noise introduced by human activities, including shipping, roads, and airplane overflights.  Previously, small increases in background noise were commonly considered to cause only negligible impacts, since there is rarely a clear or consistent behavioral reaction.  However, many animals rely on hearing things at the edges of audibility (calls of their kin, the approach of predators, the presence of prey), and a significant reduction in an animal’s communication space can cause a need to use more energy hunting, or to be in a heightened state of alertness (and stress) to avoid predation.

 

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Ocean noise may disrupt larval development

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AEI lay summary of:
Natasha Aguilar de Soto, Natali Delorme, John Atkins, Sunkita Howard, James Williams, Mark Johnson.  Anthropogenic noise causes body malformations and delays development in marine larvae.  Nature Scientific Reports, 3:2831.  DOI: 10.1038/srep02831 Download PDF

Just months after shipping noise was shown to cause dramatic behavioral changes in crabs, this new paper provides the first evidence that low-frequency seismic airgun sounds may trigger developmental delays and malformation in the larvae of shellfish.  Over the past decade or so, as researchers have looked more closely at behavioral disruptions caused by human noise sources, including temporary displacement of some fish stocks away from seismic surveys, there has been some concern that acute noise exposure from high-intensity sound sources such as airguns could also affect larval development.  If this were shown to be so, then regulators may need to consider protecting some vulnerable areas from intense noise exposure during seasons of key larval development.

This study exposed scallop larvae to recorded sounds of airgus, and compared larval development beginning after 24 hours of sound exposure and continuing until 90 hours.  This encompassed several stages of larval development, with 470-800 larvae examined at each sampling time.  

AirgunsLarvae350For the first day and a half, larvae exposed to airgun noise showed significant developmental delays.  At close to two days, the noise-exposed group appeared to be nearly as likely to be fully developed as the control group (upper right chart).  But, after passing the 48-hour mark, as the larvae moved into the next stage of development, those in noise lagged again; at 66 hours, all of the control larvae had completed the D-veligar development, while a large proportion of those exposed to noise did not complete this transition.  In addition, a significant proportion of the noise-exposed larvae began exhibiting physical abnormalities (localized bulges in the soft body of the larvae, but not in the shell).  By the end of the study, at 90 hours, an average of 46% of noise-exposed larvae showed malformations, ranging from 27%-91% in the four flasks being independently analyzed. (Ed. Note: I’ve reproduced five of the seven charts here, omitting samplings at 54hrs and 90hrs for the sake of better readability.)

The authors note that “the abnormalities observed here are comparable to those caused by chemical pollutants or water acidification, which have a clear impact on larval survival.”  They suggest several possible mechanisms for the abnormal bulges observed, and conclude that “although the exact mechanism is far from evident, physiological stress is likely the mediator for the developmental delays and growth abnormalities reported here.”  Further, the authors note that while behavioral responses vary widely both among and within species, stress response mechanisms are more generally similar across taxa, “suggesting that other invertebrates with similar growth patterns may be similarly affected.”

Of course, the nature of sound exposures in the ocean will be markedly different than those in this laboratory experiment, in which larvae were repeatedly exposed to a steady stream of 160dBrms impulses, once every three seconds for 24-90 hours.  In particular, the authors suggest that particle motion, rather than sound pressure, is the likely trigger for the effects, and acknowledge that several factors make it difficult to accurately predict the impact zone around an airgun in which particle motion would approach the 4-6mm/s RMS experienced by the sound-exposed larvae here.  In addition, the long periods of continuous exposure used in this testing procedure, while necessary in order to determine if there were indeed clear dose-response effects, may not be widely replicated in the wild.  Accordingly, the authors recommend that future research aim to establish the thresholds of exposure levels and durations that cause the effects seen here.

However, the authors stress that “given the strong disruption of larval development reported here, weaker but still significant effects can be expected at lower exposure levels and shorter exposure durations, especially if some ontogenetic stages such as the D-veliger prove to be particularly sensitive.”

Aussie wind farms moving forward with 2km setbacks

Human impacts, News, Wind turbines 1 Comment »

Despite much gnashing of teeth among wind developers and some wind advocates, it appears that the Australian wind industry is adjusting to larger setback requirements.  In the past two months, two large wind farms have cleared key approval hurdles in New South Wales, with both incorporating the 2km setback requirement from non-participating homes that is included in draft NSW wind planning guidelines.

The 33-turbine Bodangora Wind Project received approval from the NSW Planning Assessment Commission in late August, which noted that while “noise emissions from the turbines will be audible from some surrounding dwellings,” sound models suggest that sound at non-participating neighbors will be 30dBA or less (and 52dBC or less), noting that “the 2km buffer provided in this instance is highly precautionary.”

CollectorMeanwhile, the 63-turbine Collector Wind Farm has been received a recommendation for approval by the NSW Department of Planning this week, and now awaits final approval from the Planning Assessment Commission.  Despite the recommendation, Tony Hodgson of Friends of Collector said strong opposition remained in the community, which would be enthusiastically voiced at a community meeting with the PAC at the end of October. “We spent a lot of time and a lot of energy putting in our submission, and nobody from the department ever talked to us,” Mr Hodgson said. “We feel very, very hard done by. We think it’s an outrage, and the whole thing’s been a complete waste of our time.”  The Collector project includes one home just inside the 2km buffer, and a couple more just outside it, as seen on the most recent site map (above; yellow line is 2km; red turbine sites have been removed). The project’s Sound Assessment found that the three closest non-participating homes would remain just under the 35dBA noise limit (10-minute average), as well being well below the 60dBC limit.

The NSW Draft Planning Guidelines, which were released in December 2011 and have yet to be finalized, included a requirement that projects receive permission from all homeowners within 2km.  NSW’s southern neighbor Victoria has been operating under a 2km setback requirement for two years now; over 20 wind projects are in the planning stages, with one in the midst of the approval process.  NSW’s other neighbors, South Australia and Queensland, are also charting cautionary paths, though without absolute 2km limits on the table so far (both have 35dBA noise limits, which generally requires setbacks of 1.5km or more).  As in Australia, the US state of Oregon appears to have a robust wind development environment, despite the widespread use of a 36dBA noise limit, which similarly pushes turbines significantly further away from neighboring homes than is typical in much of the US and Canada.

Sandia workshop highlights new understanding of turbulence in wind farms

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A long, detailed article in Windpower Engineering provides a fascinating look at current efforts to understand the complex wind flows in and around wind farms.  Recent research at NREL, Sandia National Laboratory, and Texas Tech is highlighted in the article, which also includes several compelling graphic representations of the patterns of turbine wakes inside wind farms.  For the first time, researchers are now able to measure wind speed and direction in three dimensions in working wind farms, using multiple dopplar radar units; this data has led to new and far more detailed computer models that can be used to investigate how small changes in turbine operations may reduce stresses on downwind turbines.

Read the whole thing at the link above; here are a few teasers:

“It’s almost as if we added a dye into the wind that changes color with speed,” says Moriarty, commenting on the video he presented. “The images show high winds in red or hot colors, and slower winds speeds in blue, and how well downstream turbines are working.

What has been known for a while, he says, is that under certain atmospheric conditions, turbines are getting beat up by what’s called a mildly stable atmosphere. “Even though this has been known for a while, we don’t know exactly what is happening in the flow that influences damage events” says Moriarty.

Although tuning a wind plant is difficult, Moriarty’s simulations suggest adjustments. “We have run several simulations, for example, that de-rate (reduce the power) the first row to let more energy through. That works under some conditions. And then there’s wake steering, moving a wake. Changing the yaw on one or more turbines allows controlling where the wake flows, ideally away from downstream turbines. Depending on yaw angle, results show a 4.5% increase in energy capture.”

UPDATE, 10/17/13: Here’s more on turbulence research, this time in India, where the Tamil Nadu province has some insane turbine densities (check out the image at the link; note the 2km bar at the bottom right).

First ruling in new sonar challenges fails to limit huge take numbers

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The first ruling is in from the latest round of legal challenges to Naval training permits, and it’s a split decision.  You’ll need to click through to read the full post to get all the details, but here’s a preview of the conclusion you’ll find at the end:

It appears that the places that the court found NMFS falling short are in the details of how they prepare and analyze information, while the end results of the Navy activities and NMFS analysis and permits were upheld as valid. The court did not accept the plaintiff’s core concerns about the huge numbers of animals authorized to be affected (as litigated on the questions of protected habitats, mitigation measures, and cumulative impacts), deferring to the NMFS analysis that deemed even these large numbers to be acceptable, largely because most impacts are minor and temporary. The rulings that went against NMFS each appear to require simply more data analysis, which will then be fed into the same decision-making process that has been upheld as valid. 

In 2012, Earthjustice, NRDC, and others challenged both the 2010 Northwest Training Range Complex permits authorizing five years of mid-frequency active sonar and explosions at sea, and permits authorizing global deployment of low-frequency active sonar through August 2017. While earlier challenges targeted the Navy’s environmental analysisor originally, the lack thereof—and ran aground when the Supreme Court ruled the Navy has broad discretion to weigh environmental safety against national security interests, this new round of lawsuits is directed at the National Marine Fisheries Service’s regulations and permits for the activities. 

In both cases, the primary focus of the challenges, at least as described in press releases, was insufficient protection of biologically important areas.  For several years, NRDC and others have stressed that Navy training ranges, which stretch along nearly the entire east and west coasts of the US, contain enough area for diverse training while setting aside some seasonal or year-round exclusion zones where training is avoided due to concentrations of marine animals.  Navy estimates of the numbers of animals likely to hear sonar or explosions, leading to either behavioral changes or injury, are alarmingly high, and the plaintiffs suggest that these numbers could be reduced significantly by setting some areas off limits, at least at key times. Unlike in previous challenges directed at the Navy itself, the plaintiffs did not seek any sort of injunction to halt the training exercises; rather, they asked that the court require the NMFS to revisit and revise their previous rules or authorizations in light of any deficiencies the court determined to be present.

As the NWTRC case moved into the argument phase, several specific challenges to NMFS procedures, analysis, and conclusions were raised and addressed. In a ruling issued by US Magistrate Judge Nandor Vadas in late September, the plaintiffs came away with at least a temporary win on several points, while the NMFS prevailed on several other fronts, including on the fundamental arguments about habitat protection and long-term impacts.  As in previous rounds of this legal battle, it appears that the end result will be Navy training continuing pretty much as it was before any of the legal challenges began—though with detailed analysis of potential impacts continuing to be pushed into new realms by the legal challenges.

The court ruled that the NMFS had improperly failed to include some relevant studies from 2010 and 2011 when issuing a 2012 Letter of Authorization and Incidental Take Statement, two years after the initial Five-Year Regulations were issued, and so did not rely on the “best available evidence” and likely underestimated the number of animals affected by Navy activity in its 2012 permitting documents.  In addition, the court ruled that the NMFS should analyze impacts not just over the five years of each planning cycle, but for a longer (unspecified) time period, because Navy training is considered to be a permanent, long-term activity.  Over the next month, NMFS will file a brief describing what they see as an appropriate scope and duration of any order to change their previous documents, and the plaintiffs will file a reply; presumably, the Court will rule shortly thereafter on specific remedies.

However, the NMFS prevailed on several substantial issues, including the primary one and two important related challenges.  On the central question of setting aside exclusion zones to better protect essential habitats, the court ruled that the NMFS had given such exclusions due consideration, and lawfully concluded that such exclusions would not be likely to reduce take numbers significantly.  Likewise, the court ruled that NMFS determination of no significant impact did not rely on insufficient mitigation measures (primarily visual observers) in making its assessment of likely harm; rather, NMFS determined that even before mitigation measures were implemented, the numbers of animals affected and the degree of impact did not pose long-term risks to local populations.  

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Powerful mapping sonar likely triggered Madagascar mass stranding

Effects of Noise on Wildlife, Ocean, Sonar 1 Comment »

AEI lay summary of:
Southall, B.L., Rowles, T., Gulland, F., Baird, R. W., and Jepson, P.D. 2013. Final report of the Independent Scientific Review Panel investigating potential contributing factors to a 2008 mass stranding of melon-headed whales (Peponocephala electra) in Antsohihy, Madagascar.
Download full report or executive summary.
See IWC website for report and all supporting materials 

Madagascar whalesWEBFor the first time, a mass stranding appears to have been triggered by a relatively high-frequency mapping sonar; most previous strandings (though rare) have been associated with mid-frequency military sonars.  An international, independent scientific review panel (ISRP) of five well-known marine mammal researchers has concluded that a 2008 stranding event on the northwest coast of Madagascar was likely precipitated by an avoidance response to a multi-beam echo-sounder system (MBES) being used to map the seafloor.

Over a hundred melon-headed whales, deep-water foragers who normally live far offshore, became trapped in a shallow estuary one day after the MBES was active 65km off the coast; locals and international marine conservation organizations collaborated for three weeks to save floundering whales, with at least 75 confirmed dead.  The ISRP investigated all known possible causes for such events, and concluded that the most likely trigger was that the whales were moving away from the sonar, and became trapped in the unfamiliar surroundings of the narrow La Loza Bay estuary.  There, they found it hard to orient and navigate in the shallow, murky water; lack of food sources, stress/fatigue, and an accumulation of small injuries led to eventual death for most.

Madagascar mapWEBAcoustic modeling suggests that the whales would have been able to hear the MBES signals for at least 30km from the survey vessel, to near the island seen on the map to the right, 25km offshore, at which point they apparently continued moving toward shore until straying into the stranding zone.  Why the animals continued moving inshore after the sonar was no longer audible is unclear.  This is a species that normally lives only in deep waters; once the whales moved past the cliff near the survey area and into shallow shelf waters, they may have been quite confused, and further behavioral anomalies (including ending up in the estuary) may be unrelated to the survey sounds.

UPDATE, 10/10/13: This WaPo article includes some skeptical responses, centering on the uncertainties about other factors (before and/or after the MBES sound exposure) that may have contributed to the stranding, and concerns that the strong language of this report could lead to an over-reaction among regulators.  A spokesman for Exxon-Mobil, which helped fund the study and the initial stranding responses, said, “our contract vessel happened to be there in that time frame, but there are so many uncertainties in the area that we’re not sure it’s us.” Still, the company has changed its practices to avoid use of MBES near sharp cliff faces, since the panel speculated that echoes off the cliff may have confused the whales, sending them further inshore.

The ISRP report concludes that “this clearly appears to be an atypical event,” yet also stresses that the MBES system may pose previously unrecognized risks:

It is important to note that these systems, while regularly used throughout the world in hydrographic surveys, are fundamentally different than most other high-frequency mapping or navigational systems (ed. note: or fish-finding sonars). They have relatively lower source frequencies (12 kHz is within the range of likely best hearing sensitivity for all marine mammals), very high output power, and complex configuration of many overlapping beams comprising a wide swath. Intermittent, repeated sounds of this nature could present a salient and potential aversive stimulus.

Click on through for more details on the stranding, the ISRP report, and maps.

Read the rest of this entry »

Ontario towns flock to declare themselves “unwilling hosts” for wind farms

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In the wake of several years of heated wind farm resistance in Ontario, premier Kathleen Wynne said several months ago that the province would aim to site new projects in “willing communities.”  In response, 71 southern Ontario communities have formally passed resolutions declaring their towns “unwilling” (red on map; interactive version here) and another 33 have expressed some measure of concern about local siting (yellow); together, this represents a bit over half of the 197 municipalities in the southern part of Ontario where wind development has been concentrated.   A coalition of these towns formed at an August meeting of the Association of Municipalities Ontario. It remains to be seen whether provincial officials will alter siting decision based on these declarations; provisions of an altered wind strategy appear to focus on “consultations” with localities (rather than requiring local approval of projects) and incentives to encourage local support for wind development.

UPDATE, 12/2/13: The Dufferin County Council has voted to declare the county an unwilling host, become the first county to do so; several town within the county are among the over 90 Ontario towns that have made similar declarations.

Unwilling 500

In a statement issued this week, the coalition of “unwilling” towns said: “Municipalities are seeing the impact of existing turbines on their communities or their neighbours and do not want the same things to happen in their municipality.  The government’s proposals for community benefit programs and community sponsorship do not address the core problems being created when wind turbines are located too close to people.”  Added Wainfleet mayor April Jeffs, “Municipalities are looking for solutions to the real problems, not public relations gimmicks.” 

“The government has indicated that an announcement regarding the guidelines for new large-scale FIT projects is planned for the end of October or in early November,” said Kevin Marriott, mayor of Enniskillen. “Municipalities are looking for real planning authority for wind turbines to be returned to local governments.  Municipalities are better placed than Queen’s Park civil servants to identify local issues that need to be addressed in reviewing wind turbine projects. They also have processes in place to review and approve other complex or controversial building projects within their jurisdiction.”

Earlier, Marriott had noted that while the Premier has spoken about wanting to locate projects in willing host communities, no concrete plans have been proposed to give municipalities substantial input in the siting process, and wind turbine projects have continued to get provincial approval without consideration of municipal concerns. 

UPDATE, 10/10/13: This week, a wind project received provincial approval in Kincardine, one of the towns that has declared itself an unwilling host.  One local council member noted with dismay that the province had embarked on an expensive change of siting for two gas-fired electric plants because the initial communities had not welcomed them, while similar concerns about wind farms are ignored.

Indeed, Wynne made her commitment to continued wind development clear even as she attempted to outline a more responsive relationship with communities, stressing that the province needs to find a way to ensure green energy projects are “going to willing communities.” In a draft of the new FIT structure released in September, there was no mention of communities being able to opt-out, though there are provisions for “local consultations.”  

Her Energy Minister, Bob Chiarelli, has been overseeing the revamping of the FIT, including a new requirement that companies consult with local authorities before going to the province for approval.  ”They will have a much stronger voice in all of the significant energy projects,” said Chiarelli “Communities spoke, mayors spoke, and we listened.”  Since localities do not seem likely to get veto power, the formal “unwilling hosts” designations appear to be more of a public statement than marking the establishment of wind-free zones.  The revamped FIT program will include incentives including new funding for municipalities who want to do energy planning; Chiarelli said, “We believe that process will result in a much higher level of buy-in and participation by municipalities.”

Well, maybe not, if the summer and fall rush to declare themselves “unwilling hosts” is any indication; it appears that the Ontario wind wars will be continuing. 

The Wilderness Speaks. Are You Listening? (New NPS video)

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The National Park Service is gearing up for next year’s 50th Anniversary of the Wilderness Act.  As part of their celebration, the NPS has just released this wonderful short video highlighting Olympic National Park and its compelling and varied soundscapes.  Fittingly, this production is built around Gordon Hempton’s sound archive; the park is his backyard, and he’s spent countless hours over the past few decades reveling in its sounds.

This is part of a video series, America’s Wilderness, that’s available on YouTube—subscribe to their channel!  And to get a deeper taste of Gordon’s Olympic recordings check him out on iTunes: autumn with elk, cobblestone beach, driftwood log wave resonances, creek from beach to forest.

IMO shipping noise guidelines complete, awaiting approval

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After a couple of years with no progress to report, the International Maritime Organization (IMO) appears to be nearing completion of “Voluntary Guidelines for the Reduction of Underwater Noise from Commercial Shipping.”  This process began in 2008 with a burst of activity and focus from the US and European IMO representatives, but appeared to languish in recent years (see this earlier AEInews report, with links to key documents).

Ship and Barge2

The effort falls under the purview of the IMO’s Marine Environmental Protection Committee (MEPC), which assigned development of the standards to its sub-committee on Ship Design and Environment (DE).  The DE formed a “drafting group” led by the US, and this group has nearly completed its work, with just one paragraph in the preamble still to be solidified.  At its March 2013 meeting, the DE subcommittee approved the draft guidelines; their next step along the long and winding bureaucratic road will be their submission to the full MEPC at its next meeting, in April 2014.

The draft guidelines are currently not publicly available, but the DE meeting summary notes:

The non-mandatory Guidelines are intended to provide general advice about reduction of underwater noise to designers, shipbuilders and ship operators and consider common technologies and measures that may be relevant for most sectors of the commercial shipping industry. Designers, shipbuilders, and ship operators are encouraged to also consider technologies and operational measures not included in these Guidelines, which may be more appropriate for specific applications.

The guidelines give recommendations on predicting underwater noise levels, such as using underwater noise computational models; standards and references that may be used, including ISO/PAS 17208-1 “Acoustics – Quantities and procedures for description and measurement of underwater sound from ships – Part 1: General requirements for measurements in deep water” (see this ISO press release on these new standards); design considerations; onboard machinery selection and location; additional technologies for existing ships; and operational and maintenance considerations.

Here’s hoping that the MEPC is able to take up the Guidelines at their 2014 meeting as planned, completing this modest first step of encouraging the shipping industry to incorporate noise emissions into the design of new vessels.  The ISO/PAS standards will provide clear guidance for measuring the noise footprint of ships, though the IMO is not ready to suggest or mandate any particular maximum noise levels at this time. See this AEInews post on NOAA’s recent ocean noise mapping project; shipping noise is the predominant human contributor to overall ocean noise levels.

NPS to study how soundscape quality affects park visitors

Effects of Noise on Wildlife, Human impacts, News, Science, Wildlands Comments Off

Equipment GRSA squareWEBFor over a decade, the National Park Service has been on the forefront of public lands agencies in addressing the role of sound and noise on both wildlife and park visitors.  NPS’s Natural Sounds and Night Skies Division has catalyzed baseline acoustic monitoring in seventeen parks, and carried out groundbreaking research on the effects of noise on wildlife.

Now, NPS is planning a national survey on how the quality of park soundscapes affects visitation at national parks, and the economies of gateway communities.  An August 9 Federal Register notice is seeking public comment on the value such a study, with the hope of doing a small-scale pilot survey in 2014, in preparation for the full study in 2015.  The last time NPS sought comments on a similar proposal, they received no public comments and did not proceed.  Now’s the time to chime in, as comments close on September 9.  (Go here, and be sure to note the topics they want input on, and send your comments to both email addresses listed.)

“In addition to parsing out the extent to which visitors value being able to hear the sounds of nature, the study will provide other useful information such as how acoustic conditions affect the likelihood of repeat visitation to national parks,” the agency said in a summary of the survey.  

At a daylong public outreach workshop on Noise in Communities and Natural Areas earlier this month (which I was fortunate to attend), Kurt Fristrup and Frank Turina outlined some of the ongoing soundscape work in parks. Turina described a pilot project at Rocky Mountain National park that uses flashing signs to notify motorcyclists of the noise levels of their bikes (much like instantaneous speed-tracking signs), with the goal of encouraging riders to moderate their noise while enjoying park roads.  Fristrup shared some fascinating research revealing that hikers on the Hermit Trail at the Grand Canyon nearly universally reported lower levels of overall satisfaction with their visitor experience after overflight helicopters start flying each morning. Hikers were asked to rate their experience on a 7-point scale, from Very Pleasant to Very Unpleasant.  Prior to the start of flights, Very Pleasant (7) received was the most chosen rating, with no one choosing the lower Unpleasant to Very Unpleasant ratings of 3, 2, or 1.  After flights began, the graph of responses shifted distinctly toward the less pleasant ratings: the number of people rating their experience at 7 dropped dramatically and the lower ratings, all the way down to 1, joined the mix.

Indiana wind developer sues over 1500ft setback, says zoning chair shouldn’t consider experience with existing wind farm

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Over the past several months, I’ve been watching with interest an apparently growing concern in farm country about wind farm setbacks.  Several counties in Indiana and Illinois have been moving toward somewhat larger setback requirements after living with a first round of large-scale wind development.

This week, juwi Wind filed a suit challenging recent decisions by the Tipton County Board of Zoning Appeals, which in March approved a conditional use permit for the proposed Prairie Breeze Wind Farm, while requiring a 1500ft setback from non-participating property lines.  The county zoning ordinance requires just 1000ft from non-participating homes, and in July, juwi requested that the permit conditions be changed to 1400ft from non-participating homes and 750ft from non-participating property lines.  juwi claims that their request for this change was summarily rejected by the BZA without the required public hearing at which they could make their case.  (Ed. note: It appears that the conditional use permit has no provisions for easements from landowners willing to live with turbines closer to their homes; the vast majority of turbine locations planned by juwi are closer than 1500ft from neighboring property lines.)

Wildcat 1 SmallIn addition, juwi is making provocative claims that BZA chair Jerry Acres is no longer capable of making an unbiased decision, thanks to comments he’s made suggesting regrets about his support of the Wildcat Wind Farm (left), which began operating early this year and has generated complaints from at least 20 homeowners.  At the March hearing at which the Prairie Breeze conditional use permit was approved, Acres said, “On the E.ON vote (approving the Wildcat Wind Farm), I looked more at the financial gains than probably the long-term losses. I probably didn’t do my homework on E.ON and that’s what I’m saying.”  Acres also said at that meeting that he’s had some personal experience with siting issues, after visiting a friend who lives near Wildcat.  This apparently straightforward response from a public official who is charged with understanding the consequences of his decisions is attacked by juwi; the complaint alleges that “these comments from the Board’s President, Acres, demonstrate that he was not unbiased and objective, and that he improperly injected his personal feelings into the matter, for whatever reason.”

Neighboring Howard County has settled on an increase from 1050ft to 1500ft from non-participating homes, along with a decrease in the noise limit from 55dB to 50dB, as Wildcat Wind Farm moves into Phase 2 and 3. Two other counties have enacted formal or informal bans on wind development; Marshall County formally banned wind farms, and Clinton County passed a non-binding motion to stay windfarm free. “I tell you, it’s not about money, it’s about people with me,” County Commission President Skip Evans said. “It’s about quality of life. It’s about all the citizens of Clinton County, not just those who stand to profit.”  

Meanwhile, Delaware County has paused for two years, waiting to see how recent wind farm developments in the region work out before settling on a development plan.  Tom Green, chair of the city-county plan commission, said in his proposal to pause, “I have noted many changes in policies around the country regarding this issue, some of those changes are a complete reversal of existing policy. Let us not make the same mistakes or reactions in providing guidance for our community.” 

Film features the stories of Fairhaven wind farm neighbors

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Fairhaven Film ScreenshotA new film from Fairhaven, MA, features the compelling real-life experiences of several local residents who live close enough to the wind turbines to hear them on a regular basis.  The film, entitled Too Close, has a calm and caring tone, and is free of side-issues that can at times clutter the wind turbine siting debate (e.g., economic or carbon-reduction arguments), and focuses nearly solely on audible noise, with only a brief mention of infrasound.  Also, refreshingly, quality of life (including sleep disruption and intrusion in backyard solitude) is given as much or more attention as more acute health effects, and the film is free of the more alarming/alarmist claims that are featured in some other concerned citizen documents.

The 44-minute film can be viewed here.

There are just a couple of things I would add for context, which may be useful as you consider these stories from a range of “regular” people dealing with this new noise in their local soundscape.  First, though it’s mentioned in passing a couple of times, some of the issues, especially shadow flicker, but also noise for some more distant residents, are more problematic at particular times of year. For the closest residents, it can be daily or near-daily, while at other places, the problems may at times recede from the intensities described here.  When interviewees speak of things that happen “sometimes” or “some days”, it’s not always clear how commonly (how many days a month, hours a day, or months of the year) these experiences occur.

Also, as in every town with noise issues, these hardest-hit residents are a minority of nearby residents.  Surprisingly, few solid surveys exist to help us get a better sense of the proportion more severely affected, but some numbers from Fairhaven offer a sense of it.  There are just over 700 homes within 3000 feet, and residents of at least 56 of these have filed formal complaints; that would represent about 8% of homes, a small proportion, but a significant breadth of impact.  In this video, all or nearly all of the residents live significantly closer (950-2100ft); it’s quite likely that most of the complaints come from this closer zone, and that somewhere between 10-20% of closer homes have complained.  Also, we need to bear in mind that not everyone is comfortable publicly complaining; doubtlessly, more than 56 homes are experiencing issues similar to those discussed here.

A valid question can be raised about how high a proportion of negative impact is acceptable around any new infrastructure or industrial development.  Some will surely argue it’s reasonable to expect to impact 5-10% (or even 20%) of nearby residents, while providing social benefits for many more.  Yet, in a small town, when over 50 families are having their lives disrupted, it can cause a serious rupture in the local social environment; this “tearing the community apart” effect has been stressed in many other locales where noise became an issue.  As reasonable as it may be to suggest that “you can’t please everyone,” it’s also entirely valid for towns to consider the effects on their sense of local community if dozens of homeowners were to become aggrieved at a proposed new development.

All in all, this film provides a credible and compassionate look at the personal side of an issue that is often swept up into polarizing hyperbole and self-serving rhetoric from both sides.  

Crabs affected by shipping noise, too

Effects of Noise on Wildlife, Science, shipping 1 Comment »

CrabWEBAdd crabs, and perhaps by extension other crustaceans, to the list of animals negatively affected by shipping noise in the world’s oceans.  

A new study has found that ship noise markedly changes some important crab behaviors:

Working with the same common shore crabs that children delight in catching on crablines in UK harbours, the team found ecologically-critical effects of ship noise-playback on behaviour.

Matt Wale from the University of Bristol said: “Crabs feeding on mussels were often distracted when ship noise was playing compared to quiet harbour recordings. Furthermore, crabs took longer to retreat to shelter after simulated attacks in noisy treatments, and if turned upside-down they flipped back far quicker in noisy conditions rather than turning slowly to avoid attracting attention of potential predators.”

Dr Steve Simpson from Biosciences at the University of Exeter said: “We have already found that ship noise raises the metabolic rate and energetic needs of crabs. If coupled with reduced foraging and worsened responses to predators, this cocktail of impacts may negatively affect growth, fitness, survival and, ultimately, harvested populations and whole ecosystems.”

Cetaceans (whales and dolphins), fish, and larvae of reef creatures have previously been found to respond to shipping noise in ways that can increase energy expenditures and stress levels; this is the first clear indication that crustaceans are also negatively affected.

Australian report on LF, infrasound at Macarthur windfarm

Human impacts, Wind turbines 2 Comments »

AEI lay summary of:
Resonate Acoustics.  Macarthur Wind Farm Infrasound & Low Frequency Noise: Operational Monitoring Results. 18 July 2013.  Author: Tom Evans.  Client: AGL Energy Limited.  Download report here.

A new report from Australia is being touted as the latest definitive proof that infrasound around wind farms is no louder than infrasound from wind and human activity in areas with no wind farms. While providing a relatively robust new set of data, the study design leaves some important questions raised by wind farm neighbors and other acousticians unanswered.

This may be the most comprehensive infrasound/low-frequency study released yet: it includes several days of measurements made prior to construction of the wind farm, along with at least ten days of measurements made when the wind farm was partly operational, and ten more days once the wind farm was fully operational.  Sound was measured down to 0.8Hz, lower than some similar studies.  Most importantly, sound was recorded inside the homes, which were1.8km (1.1mi) and 2.7km (2.7mi) from the nearest turbines, on opposite sides of the wind farm; at both homes, there were many more turbines at slightly greater distances than the closest ones.

At the more distant home, daytime infrasound levels prior to construction were commonly 60-70dBG, with a few peaks of 80-90dBG (grey circles below); these measurements capture the natural ambient infrasound levels caused by the wind itself, along with contributions from machinery and vehicles in the area (the threshold for human perception is about 95dBG for pure tones, perhaps lower for pulsing sounds).  The peaks were much lower at night than during the day, only reaching 70dB at the highest wind speeds.  With the wind farm operating (yellow diamonds below), the range of results was generally similar.  Note that the operational data is not all turbine noise; some periods will have peak sound levels caused by the same local ambient sounds captured in the pre-operational monitoring period.

Macarthur wind farm dataWEB

(dBG weighting accentuates 10-30Hz, the threshold between audible low-frequency sound and infrasound, and includes 2Hz-70Hz)

At the closer home, a limited pre-operational monitoring period only captured wind from a couple of directions, so the report’s operational results only consider periods with these two wind directions, as well.  (An appendix includes the full dataset of the operational period, which closely resembles that of the more distant home shown above, though peak sounds remain below 80dBG). In the limited dataset, pre-operational levels were significantly lower, clustered between 40-60dBG.  After construction, the bulk of measurements were in the same range, though there was a clear increase in periods with measurements of 60-70db, with a few peaks up to 75dB.  The authors of the report suggest that some of these higher measurements appear to be due to a transient non-turbine source (one chunk of them all occurred in one short period during which wind speed and direction did not change), and much of the rest may reflect higher daytime wind-related sound, rather than turbine sound, since the limited pre-operational period did not capture much data at high wind speeds.  They also note that, regardless of the source, even these peaks were within the range recorded at the more distant site pre-operation, so they reflect sound “no greater than levels that occurred naturally in the local environment (prior to the) operation of the wind farm.”

A separate section of the report addresses audible low-frequency noise, using the dBA-lf metric (dBA weighting, applied only to sound from 10-160Hz), and also reported as linear (unweighted) results at each frequency band (down to 10Hz when compared to regulatory criteria, and to 0.8Hz in a series of charts of median levels in each frequency band).  Again, results showed compliance with regulatory thresholds, except for a few 10-minute periods (roughly 2% of the periods); the authors of the report consider it likely that most of these are extraneous sounds, or would be in compliance if found to be steady, rather than variable, sounds.

(Ed. note: It must be mentioned that the authors of the report are exceptionally diligent in suggesting plausible alternatives to turbine noise for each of the occasions where operational sounds appear to be higher than pre-operational; on-site human monitoring would allow at least some of these ambiguous time periods to be more definitively characterized.)

This report offers some good, solid new data, collected over a relatively long period of time (10 days or so, rather than a single day) with a decent range of wind directions and with raw data collected down to below 1Hz.  While affirming that infrasound remains well below the 95dBG human perceptual threshold and 85dBG regulatory threshold, and also generally below the frequency-band limits widely applied to low frequency noise (10-160Hz), a few limitations in the research design leave several key questions unexplored:

First, the houses used in the study were relatively far away from the wind farm.  While there are some noise complaints at the distances studied (especially in Australia and New Zealand), the vast majority of neighbor complaints occur when turbines are closer, from a quarter to half mile especially, and out to three-quarters of a mile (a bit over 1km) with some regularity.  This study takes the important step of recording inside sound levels, but with many complaints coming at half or quarter the distance of even the closer home here (and a tenth the distance of the further home), we are left without a clear idea of infrasound or low-frequency noise levels at such locations. This may be especially relevant to the low-frequency findings, since even at the greater distances, inside low frequency sound was much closer to regulatory limits than were infrasound levels.

Second, the primary data is presented as 10-minute average sound levels.  In an attempt to consider whether they were missing important shorter-term variation, the researchers also looked at 1-minute averages, and for part of the data, 10-second averages.  They found that the 10-second averages closely tracked the 10-minute averages, with a similar amount of variation.  However, several acousticians have suggest that the negative effects reported by some neighbors are caused by much shorter pulses of low-frequency or infrasound: investigations have centered on the roughly once-per-second blade-pass frequency, and on even more rapid fluctuations that can only be captured when filtering sound at at time frames of 10 milliseconds, matching the sensitivity of human hearing.  It’s very likely that the 1-second peaks would show higher peak levels than the 10-second averages and 10-minute averages; one such analysis found 1-second peaks of 5-8dB higher than 10-second averages, with variations of up to 30dBG or more around the average when measured at 10ms, leading to peaks 10-17dB higher than the ten-second average.  While regulatory criteria rely on longer averaging times, human responses to much shorter-term peaks, and/or to short and long-term variability, may well underlie many  of the more vehement complaints that occur even when turbines are meeting regulatory noise limits.  Investigating this possibility more widely would help settle what is becoming a central question in community responses to wind farms.

Finally, even ten days of monitoring may well not capture conditions that are particularly troublesome for neighbors.  No indication is offered as to whether the monitoring was scheduled with any consideration for “worst-case” noise conditions, especially times of high atmospheric turbulence, or seasons when complaints have been highest (operational monitoring took place in southern hemisphere summer and autumn).  The report notes just one two-day period when the resident at one of the homes noted that the noise seemed particularly bothersome (results those nights were generally clustered within the typical scatter of data, though on the high side of the range).

While it may appear to some that these final points are nit-picking attempts to find any small reason to ignore the overall findings of this study, I offer them not so much as critique, but rather as a nudge to researchers, to dig deep enough to more definitively address some of the particular qualities of wind turbine noise that are being hypothesized as contributors to community responses to turbines.  In particular, averaging times for noise analysis must be well below one second (eg 125ms, or one-eighth of a second) in order to capture the amplitude modulation that gives many turbines their distinctive pulsing or throbbing sound quality.  

This study does a good job at assessing the wind farm’s infrasound and low-frequency sounds against the regulatory criteria; however, with community complaints being common even around projects in compliance, there’s a need for research that can help clarify whether wind turbine sound does—or does not—have unusual qualities or variability patterns that existing regulatory standards are not designed to address.

SOCAL begins 2013 behavioral response study

Effects of Noise on Wildlife, Ocean, Science Comments Off

The 2013 field season of the 5-year Southern California Behavioral Response study is underway now.  This research applies suction-cup tags to whales, which track the whales’ movements (dive patterns, speed, direction, etc.) while also recording the sounds the whales are hearing, including sounds of mid-frequency active sonar played underwater by the researchers under carefully controlled conditions.  Earlier years’ results have begun to quantify the level of sound that can spur behavioral reactions in several species of whales, including the beaked whales that have appeared to be more sensitive to sonar sound, resulting in several stranding incidents over the past fifteen years.  Most recently, two new papers reported that both blue whales and Cuvier’s beaked whales seem to avoid sonar sounds, and at times stop feeding, at sound levels below most current regulatory thresholds.

SOCAL researchers will be posting updates from the field here.

Behavioral Response Study – Tagging Beaked Whales from Brandon Southall on Vimeo.

Blue, beaked whales stop foraging when exposed to sonar?

Effects of Noise on Wildlife, Ocean, Science, Sonar Comments Off

AEI lay summary of:
Goldbogen JA, Southall BL, DeRuiter SL, Calambokidis J, Friedlaender AS, Hazen EL, Falcone EA, Schorr GS, Douglas A, Moretti DJ, Kyburg C, McKenna MF, Tyack PL. 2013 Blue whales respond to simulated mid-frequency military sonar. Proc R Soc B 280: 20130657. http://dx.doi.org/10.1098/rspb.2013.0657 (download here)
and
DeRuiter SL, Southall BL, Calambokidis J, Zimmer WMX, Sadykova D, Falcone EA, Friedlaender AS, Joseph JE, Moretti D, Schorr GS, Thomas L, Tyack PL. 2013 First direct measurements of behavioural responses by Cuvier’s beaked whales to mid-frequency active sonar. Biol Lett 9: 20130223. http://dx.doi.org/10.1098/rsbl.2013.0223 (download here

Results from studies off Southern California have quantified for the first time the reactions of Blue whales and Cuvier’s beaked whales to simulations of naval mid-frequency active sonar.  In both cases, scientists found that whales tended to move away from sonar signals, and appeared to suspend feeding activity for an hour or more at times.   

The Cuvier’s beaked whale results marked the first time this species had successfully been monitored during a controlled exposure to sound while wearing a temporary suction-cup “D-TAG” that allows researchers to track animal dive and movement patterns while also recording the sound level of the sonar signal that the animal is hearing. As with similar experiments done on other species of beaked whale, the two whales tagged in this study changed their normal dive patterns, paused or stopped echolocating for food, and waited longer at the surface after the sonar sound ended before they began diving normally again.  The pause in foraging lasted for 6 hours in one whale, and at least 90 minutes for the other.  

The whales’ behavior was changed at sound levels (89-127dB) that are far below the levels typically considered problematic by regulators (typically 160-180dB; though some Navy EIS’s use 120dB for beaked whales, because of their previously observed noise sensitivity).
CORRECTION, 1/31/14: The current round of Navy EISs and NOAA permits consider exposures down to 120dB in their analysis of behavioral “takes” for all species.

Researchers concluded that “The observed responses included vigorous swimming and extended time without echolocation-based foraging, imposing a net energetic cost that (if repeated) could reduce individual fitness.”  While they did not see rapid ascents from dives that would support an early theory that some beaked whales may suffer tissue damage similar to what human divers experience as “the bends,” they suggest that the disruption of normal dive and surface-resting patterns could affect the animals’ dive metabolism in ways we don’t yet understand.  Also of interest in this study was an unexpected period during which a tagged animal was exposed to sound from a distant (over 100km) naval exercise; in that case, the animal showed no response, though received levels were similar (78-106dB); researchers suggest that the animals could tell that these signals were much more distant than the test signals, which were under 10km away.

The Blue whale results were a bit more ambiguous, as there was significant individual variation among the 12 whales that were tagged and exposed to sonar-like sounds. Some whales were foraging at the surface, some were deep-diving feeding, and some were diving but not feeding.  Whales at the surface showed little response, while diving animals reacted more strongly, including some instances of clear avoidance (i.e., swimming away, or “horizontal displacement” in the research parlance).  

While the Blue whale results were not as uniform as the Cuvier’s results, this is the first time that blue whales have been studied to see how they respond to mid-frequency sonar, and the researchers consider even the modest effects to be significant, especially since blue whale populations are not rebounding similarly to other large whales.  As the  researchers conclude: “our results suggest that frequent exposures to mid-frequency anthropogenic sounds may pose significant risks to the recovery rates of endangered blue whale populations, which unlike other baleen whale populations (i.e. humpback, grey and fin whales), have not shown signs of recovery off the western coast of North America in the last 20 years.” 

Using a complex set of measurements of 54 behavioral metrics (including such factors as orientation angle to the sound, change in pitch or angle of descent or ascent, and the number of lunges per dive), and applying a statistical formula that resulted in the average “response” ratings on the left axis of the charts below, researchers found statistically significant changes three key areas.  The chart below shows the clear, yet subtle, changes in dive patterns (a), body orientation (b), and horizontal displacement (c), especially among the deep-feeding animals:

CEE blue whales500

Researchers note that the whale that showed the largest reaction stopped feeding as soon as hearing the sonar signal and swam away from the sound; it did not begin feeding again for an hour, during which time it would have eaten over a ton of krill, which is about the minimum amount a whale needs per day (i.e., it’s a metabolically significant loss).  

The responses noted occurred at average peak received levels of 130-160dB, again, notably lower than most regulatory thresholds for behavioral responses, which range from 160-180dB. CORRECTION, 1/31/14: The current round of Navy EISs and NOAA permits consider exposures down to 120dB in their analysis of behavioral “takes” for all species; in fact, the bulk of behavioral responses for “low frequency cetaceans,” such as blue whales, is expected at exposures similar to those here. There was a large range of response ratings for both dive patterns and body orientation (the chart above shows the average among all individuals); the avoidance responses showed a more modest range of variability, except for the one extreme response noted above.  Overall, the results confirm previously-observed importance of behavioral context: “Since some of the most pronounced responses occurred near the onset of exposure but other, higher level exposures provoked no response, the data suggest that the use of received level alone in predicting responses may be problematic and that a more complex dose – response function that considers behavioural contexts will be more appropriate. Management decisions regarding baleen whales and military sonar should consider the likely contexts of exposure and the foraging ecology of animals in predicting responses and planning operations in order to minimize adverse effects.”

 

Global industry council forms new ocean noise working group

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The World Ocean Council, an “international, cross-sectoral alliance for private sector leadership and collaboration in Corporate Ocean Responsibility,” has launched a new initiative to address ocean noise issues.  Planned to complement the ongoing efforts of the oil and gas industry’s Sound and Marine Life program and the International Maritime Organization’s ocean noise policy work addressing shipping noise, the WOO’s Marine Sound Working Group will be especially helpful in raising awareness of ocean noise issues among ocean industries—including ocean mining and port construction—that have been less involved in the issue over the past decade or so of intensive study.  

In an interview after the initial meeting of the Marine Sound Working Group, co-chair Brandon Southall noted efforts to find alternatives or noise-masking techniques for some noisy activities in which the noise is a by-product, rather than a necessary component of the work; he also stressed ongoing efforts to better understand the widespread effects of chronic moderate noise, in contrast to researchers’ earlier focus on localized, acute effects of specific loud noise sources.  See the full 6-minute interview with Brandon here.