I was pleased to be able to attend the 8th Wind and Wildlife Research Meeting, which took place in Denver from October 19-21.  Sponsored by the National Wind Coordinating Collaborative, this event brings together folks from agencies, the academic research community, some NGOs, and the wind industry.  The major focus is direct impacts on wildlife, including bat and bird strikes and habitat disruptions (see this recap of the meeting from NWCC, and view or download most presentations and posters here). This year, for the first time, noise had a place at the table, with an oral presentation by one of the lead researcher on the recent breakthrough National Park Service research into animal listening areas (see this AEInews post), and a poster by yours truly, embedded below.

In conversations with participants, there was a lot of interest in the emerging fact that even moderate noise levels can have a dramatic effect on animals nearby.  I stressed the point that while noise may rarely be a primary factor in animal impacts, the increased stress caused by dealing with elevated noise levels can often create synergistic effects that amplify the effects of other known impacts.

My detailed poster introduced what is known about individual variability to noise within animal populations, summarized some impacts of moderate noise on wildlife, explained noise levels around wind farms, and suggested several situations in which noise impacts on a more-sensitive subset of the local population could be a factor in wind farm impact planning (click image to view on SlideShare, or click full screen to view larger):

I’ve been way lax in posting about my trip to Cork, Ireland for the 2nd International Effects of Noise on Aquatic Life conference, which took place in mid-August.  It was such a treat to take part in this gathering of nearly 250 ocean scientists and regulators, leavened with a sprinkling of NGO folks.  It was a rare chance for me to actually talk face to face with people who read and circulate AEI’s reports and web content; among the surprises was that German regulators read me as regularly as do their American counterparts, and that the Navy’s marine mammal environmental compliance program is a hotbed of longhairs, in contrast to the toe-the-cultural-line conformity many of us have adopted over the years—bravo!

For now, I wanted to at least get my presentation up here and available to those interested.  The main theme is that there appears to be a spectrum of individual noise sensitivity, with about 20% being very sensitive to any new noise, 50% largely tolerant of most noise, and 30% in between, responding as the noise gets louder or more intrusive.  My initial idea was to share some of this research on humans, and to hear from humans living near windfarms, as a typically “out of the box” AEI approach to exploring questions about why we see such a wide range of responses from marine mammals to ocean noise.  But as I prepared the presentation, it began to appear to that there are some fairly compelling indications that this spectrum of noise sensitivity may in fact be a cross-species phenomenon, with many studies of animal disruptions seeming to peak at about half the population being affected.  Time will tell whether this is true, and if so, what the implications are.  I’m going to continue to explore this theme at a National Wind Coordinating Committee meeting on wind farms and wildlife in October.

Here I am giving the Cork presentation:

You can view the Powerpoint here, or click on the link and see it on the Slide Share site, where you can view it larger, or download it.

A research team that has been recording whale calls for the past nine years in the Gulf of Mexico has deployed six pop-up recorders in the same area, in hopes of hearing how the local whales are doing in the wake of the Deepwater Horizon disaster.

This blog post from Greenpeace summarizes the past and current research in areas 9 and 23 miles from the site of the accident.  The post notes the lack of recent whale sitings in the area (though one was seen at a site 63 miles away).  I’m not sure what a lack of whales at sites close to the explosion and spill would prove or imply: while the Gulf sperm whales are a resident population, they do range over a region, rather than a neighborhood, and it would be rather surprising if they had lingered near the site of both oil and massive amounts of ship traffic over the past few months.  Still, it’s great that there is a baseline of acoustic data for this area, and we’ll certainly look forward to results from this and future years’ studies there.

From August 15-20, 250 ocean noise researchers, agency staff, and NGOs gathered in Cork, Ireland for the 2nd International Effects of Noise on Aquatic Life conference.  I’ll be posting more on the confab later, but for today I wanted to note the quick jump made by two of the folks I was most glad to finally meet, each of whom headed directly out into the field upon their return home from Cork.  Their field blogs certainly remind me that their lives are VERY different than mine, where the post-conference field work involves garden beds burgeoning with beets, carrots, tomatoes, and basil, along with today’s excursion to town, where I write from a shaded cafe table looking up at the Sangre de Cristos in full autumn sun.

After leaving Cork, Sarah Dolman touched down only briefly in Edinburgh before heading off to the beautifully foreboding Outer Hebrides, the islands off the country’s northwest shore, where her team is based on the island of Harris and Lewis. The research task at hand is a simple population survey, though in the North Atlantic, it’s often not so simple!  The team is posting entertaining recaps of their days on the water (and sometimes limited to cliff-top surveys from shore) at the Whale and Dolphin Conservation Society field blog.  Lots of great pictures and tales!

Meanwhile, Brandon Southall is basking in relative comfort along the Southern California coast, where the main meteorological challenge has been morning fog.  He’s leading the most extensive Controlled Exposure Experiment (CEE) yet undertaken, and is posting daily on his SEAblog.  Alternatively known as a Behavioral Response Study, the study aims to place temporary acoustic tags on several species of whales, in order to track their responses to various sounds, which are projected in a controlled way into the water near the tagged whales. The tags record the actual received level of sounds, while also tracking the animals dive patterns and vocalizations.  While the project descriptions do not specify the sounds being played, earlier studies have used mid-freqency active sonar sounds, as well as the sounds of predators (orcas), and various artificial sounds; the experiment protocol starts sounds at 160dB, increasing gradually to 210dB re 1uPa, and limits sound exposure to 30 minutes, with long pre- and post-exposure periods that should clarify which behaviors are clearly in response to the sounds.  This 6-week project builds on earlier work done on a Naval range in the Bahamas, during Hawaiian Naval exercises, and last summer in the Mediterranean; while these earlier studies focused primarily on very hard to tag beaked and pilot whales, the current study is focusing largely on much more numerous and easier to approach larger whales.  Between August 22 and the August 30, they managed to deploy 29 tags and do 14 sound exposures with individuals of three species; by the conclusion of the project on October 1, SOCAL-10 will have a far more robust data set of behavioral responses to sound exposures than has ever been available before.

Attaching two tags to a blue whale (Photo courtesy J. Calambokidis, Cascadia Research)

For more on the SOCAL-10 study, see the SEAblog daily reports, plus:
This 18-page pdf summary of the project, including a good overview of the results of previous CEEs
Brandon’s Vimeo page, currently featuring 6 videos, including an hour-long introduction to the project  (again, including slides of data from previous CEEs)and a series of short videos from the field, including one of a tag being placed.

Using the same recording units that have provided a rich stream of new data on the effects of shipping noise on whale communication off Boston, Chris Clark of Cornell is spearheading a new project to study the acoustic ecology of the Gulf of Mexico.  According to a press release from Cornell:

“The team will anchor 22 marine autonomous recording units (MARUs) to the sea floor in an arc stretching from Texas to western Florida, along the edge of the continental shelf. These units will record underwater sounds for three months before they receive a signal to let go of their tethers and pop to the surface for retrieval. After analyzing the data, the team will deliver a report to NOAA and other agencies involved in the oil leak response. The MARUs will listen for endangered sperm whales and a small population of Bryde’s (BRU-des) whales. They will also pick up sounds of fish and ship traffic. Some devices will be placed in areas apparently unaffected by the oil to collect “control” site information; others will be close to the gushing well. The goal is to document the state of the sounds in the ecosystem over an extended period of time and compare them with known information of the oil spill.

Researchers deploy recording units (Photo: Danielle Cholewiak, BRP)

“This will be the first large-scale, long-term, acoustic monitoring survey in the Gulf of Mexico,” Clark said. “We can provide one more layer of understanding about this ecosystem, using sound to measure animal occurrences, distributions and communication, as well as background noise levels from shipping and weather, and perhaps visualize how these features are being influenced by the oil. The whales are like oversized canaries in the coal mine — they reflect the health of the environment they live in.”

An impressive array of 76 acoustic monitoring buoys is planned to be deployed in Scotland’s Moray Firth this summer, to listen in on local populations of dolphins, porpoises, whales, and seals.  Scientists from Aberdeen University will place the recording devices up to 70 miles offshore, expanding on work carried out last summer on a smaller scale.  Dr. Paul Thompson, one of the lead researchers, explains: “This will help us get a better understanding of the distribution of particular species. We will be looking at the impact primarily of oil and gas exploration, but also the development of wind farms. During construction phase of these developments, it can be quite noisy and affect marine mammals. It will allow us to get a better understanding of how they use different parts of the Moray Firth and to understand what parts are most important” to each species.  Read more at The Scotsman.

The Spring 2010 issue of Currents, the quarterly magazine published by N45, the Navy’s environmental readiness division, features a long article on recent research by Ted Cranford of San Diego State University, which is revealing new details about the anatomy of beaked whales.  Cranford has developed an innovative technique to use x-ray CAT scanners designed to scan rocket motors, and with the data garnered there, is working with an expert in Finite Element Modeling (FEM) to model the ways that sound moves through and around the jaws of beaked whales before reaching their ears.

The results are not all that surprising, in a big-picture way: indications are that the whales’ auditory system filters sounds so that frequencies used in communication and echolocation are accentuated, with other frequencies dampened.  The frequencies used by mid-frequency active sonar, which are near the low end of beaked whales’ auditory range, are filtered by the sound transmission path, so that they impinge on the ear at levels 6dB or more lower than they arrived at the whale’s jaw.

The article doesn’t specify the sound levels used in the tests, to help us compare these results to what animals experience at sea. However, the captions and text repeatedly frame the results to mean that mid-frequency sonar is “largely filtered out before reaching the ear.”  The implication that a 6dB, or even greater, dampening largely removes the signal seems quite misleading; rather, only near the very faintest received levels that would be heard will the dampening render them inaudible.  It’s unsurprising that these frequencies are not of inherent interest to the whales, and it’s reassuring that their anatomy may help protect them from direct physiological damage by such sounds.  But clear behavioral responses to mid-frequency active sonar signals tell us that they clearly hear them, and respond more dramatically than most others to these sounds.  Perhaps these test results could also suggest that beaked whales are especially sensitive to sound in general, or to these sounds at the low end of their audible frequency range; for example, harbor porpoises are well-known to react to quieter sounds than many other species, and recent research has shown that they experience temporary hearing loss (TTS) at lower levels as well.  We may be simply learning that when beaked whales are exposed to, say, 160dB sonar signals, their bodies reduce the sound levels to 150dB by the time it reaches their ear–but they still react, even to this reduced sound.

While the new research is fascinating in its own right (and will be even more compelling if ongoing current research validates the modeling being used), it seems that the Navy needs to be careful in how they present the implications.  To imply that beaked whales are “largely filtering out” sonar sounds is no more helpful in fostering informed public and scientific dialogue than the perception that mid-frequency sonar is a “death-ray” for whales.

Currents is well worth following.  Each issue has a column by the Director or Assistant Director of N45, and about twice a year they run extensive features on various ocean noise topics:
Currents main web site
Spring 2010 feature on Ted Cranford’s research
Winter 2010 feature on Dave Moretti and the Navy’s Marine Mammal Monitoring program, including various tagging programs (Dave raised the “death ray” perception in his interview)
Winter 2009 feature on the Navy’s Marine Mammal Science program

Natural England, a recently-established “statutory consultee” charged with advising the UK government on projects that may affect wildlife or the English countryside experience, has published a document that outlines its approach to providing guidance on wind farm siting.  The guidance considers both established parks and other unprotected wild lands and geo-diversity sites, as well as areas of deep peat, and areas of hightened bird sensitivity.  It also mentions previously-mapped areas of the greatest tranquility, though it is not clear just how much weight each of these various designations will carry as it balances the many factors that go into its recommendations.

Read more about the guidance on this post at New Energy Focus, or read Natural England’s press release here.  You can download the guidance document from this web page.

Paul Spong and Helena Symonds are legends in the field of whale research; since the early 1970’s they’ve dedicated themselves to studying orcas from their independent lab on an island between Vancouver Island and the mainland.  Over those many years, they’ve accumulated 20,000 hours of tapes, which are now being digitized and cleaned up (to remove hiss and other noise and make the orca calls more prominent) by George Tzanetakis of the University of Victoria.  A recent article in the Toronto Globe and Mail focuses on Tzanetakis’ work, which is being posted online for researchers and curious listeners as the Orchive.  The entire collection isn’t online yet, but there’s plenty!

Those of us  who know the pleasures of cueing up Newport Jazz or good ol’ Grateful Dead shows from online taper archives like Archive.org and Bill Graham’s Wolfgang’s Vault will be familiar with the scope of this project: right now I’m nearly half-way through a 45-minute “set” from 9/1/05 known on the Orchive as Tape 449A.  As with jam band and jazz taper archives, the quality is decent though not crystal clear, creating a great background stream of pleasurable audio, ebbing and flowing from quiet and calm to more active, interspersed with moments of truly exciting interplay and melodic joy.  The audio is presented with a basic spectrogram, and even field notes (the scientific version of Dick Latvala’s show notes):

A sweet set from 9/1/05

Visit the Orchive!

The Acoustic Ecology Institute has published Ocean Noise 2009, the fourth in its annual series of reports reviewing new research and regulatory developments in ocean noise. AEI’s annual recaps are widely anticipated and circulated among ocean noise scientists and regulators, as well as within NGO and journalist communities.

The report can be viewed or downloaded as a 45-page PDF, or viewed in the SlideShare plug-in, below.

This year’s report includes coverage of two ongoing issues, seismic surveys and Naval active sonars, with particular focus on the Navy’s continuing roll-out of Environmental Impact Statements for its offshore training ranges and the targeting of Columbia University’s seismic research vessel by environmental activists.

This year’s report introduces a new feature that will be of special interest to journalists: AEI Resource Collections on two topics that will be central to ocean acoustics policy and research in the coming years.

More details below the fold Read the rest of this entry »

A radical new approach to offshore wind turbines is being developed by UK researchers could solve one of the major challenges of offshore wind development.  The Novel Offshore Vertical Axis (NOVA) Demonstrator puts the moving parts at the bottom of the unit, greatly simplifying maintenance. (How they will deal with corrosive factors will be interesting to see!)  The units are 100m tall, and are planned to generate 5-10MW; however, they are some years away, with the initial test model planned for deployment in 2015.

Aerogenerator NOVA concept

For more on this new design, see this article in the Guardian and the NOVA website.

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.

The latest podcast from Touch Music, a British label that’s been the source of many of the best soundscape releases over the past decade, is a wonderful 45-minute radio documentary style piece from Chris Watson, who recently spent time in Antarctica.  The Disquiet blog has a nice introductory post and embedded audio, so go there to listen to Chris share his experiences in words and sounds.  His narrative descriptions of landscape and his travels (including flying into the south pole), and of course his stellar recordings of penguins, seals, and creaking ice, are well worth spending an hour with!

While pondering Antarctica, I want to also mention a recent CD release that will appeal to the science-minded among you: Andrea Polli, an educator and sound artist with a special interest in sonification of scientific data, especially as related to climate change, spent much of her time in Antarctica following working scientists around as they pursued their many fascinations.  Her CD, Sonic Antarctica was released last year on the fantastic German Gruenrekorder label; the CD is a uniquely satisfying immersion into the sounds and science of the southern continent.   Andrea’s site 90 Degrees South is also a great place to go to read and hear posts on her time there, and to view a short film she created, Ground Truth, which focuses on why  people go to remote, uncomfortable and often hazardous locations, to do what is known as ‘ground truthing.’

It seems that hooking a grant-ride on the Antarctic Express has become quite the rite of passage for many sound artists in recent years.  Doug Quin was among the first, going down in 1996 and again in 1999 to be there at the turn of the millennium. More recently,  Craig Vear, from the UK, created the most elaborate artistic response to the place with his DVD, CD, and book Antarctica: Musical Images from the Frozen Continent, which features compelling imagery, historic films, and a half-hour audio-video piece combining field recordings and spoken remembrances from Antarctic scientists.

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.

The new Navy Undersea Warfare Training Range (USWTR), being planned for off the coast of northern Florida, has hit a roadblock that’s been fairly visible since the location was announced last July: environmental groups are challenging the permitting process that allows construction to commence before the Navy completes its environmental assessment of future operations there.  The USWTR will encompass 500 square miles, beginning 50 miles offshore, while a key winter birthing and nursing ground for North Atlantic right whales extends out to 20 miles offshore.

UPDATE, 10/2013: Court sides with Navy, USWTR plans continue forward

While the Navy released its final EIS in July (see AEI summary), including its proposed operational and mitigation measures to protect whales, it became clear soon after that the Navy was only applying for permits from NOAA related to construction activities; the Navy said it would apply for permits to allow actual Navy training activities in 2012 or 2013, in advance of planned opening of the range in 2014. (Update, 2015: the USWTR website now estimates that operations will commence in 2019; no operations permits filed yet.) The EIS indicates that the range will be heavily used:  up to 480 anti-submarine mid-frequency active sonar exercises per year, including 100 ship-based events (2/week on average, lasting 3-4 hours each).

From the start, NRDC and other environmental groups questioned the Navy’s legal standing to commit to $100 million in construction costs before receiving National Marine Fisheries Service (NMFS) permits that would approve their plans for operations, including safety measures to protect marine life.  The new lawsuit alleges Read the rest of this entry »

NOAA Administrator Jane Lubchenco has announced a series of sweeping new initiatives designed to push the Navy forward in its efforts to understand and mitigate the impacts of mid-frequency active sonar on marine mammals.  In response to a request from the Council for Environmental Quality (CEQ), which asked NOAA to conduct a comprehensive review of this controversial issue, Lubchenco outlined several important new initiatives which mark a more active role for NOAA in moving both the science and policy efforts forward.  Previously, NOAA had worked closely with the Navy on its Environmental Impact Statements, but had largely rubber-stamped the resultant Navy mitigation plans, which consistently rejected any alternatives that set biologically important portions of US coastal zones off-limits to sonar training.

The new NOAA initiatives include four key elements, three of which dovetail closely with long-time concerns and requests from environmental organizations for NOAA to more actively protect areas of biological significance from both Navy and oil and gas noise, and three of which will help fill key data gaps identified by research scientists over the past decade.

• First, NOAA will work with other civilian agencies (e.g., MMS) to reinitiate comprehensive aerial cetacean and sea turtle surveys, in order to establish more fine-scale population estimates, especially in Navy training ranges.  Currently, many Navy EISs rely on coarse, regional population estimates, leading to unrealistic estimations of population density being spread evenly across large areas.
• Second, NOAA’s National Marine Fisheries Service will host a workshop aimed at developing a plan to create a comprehensive “ocean noise budget.”  This is a long-time desire of both researchers and environmentalists, and would identify areas in the ocean where human noise is relatively sparse, as well as areas in which new human activity would not add substantially to already high noise levels.
• Third, another NMFS workshop will be organized to identify marine mammal “hot spots” of particular biological significance.  All three of these initiatives tie together nicely to bring acoustics into the Obama administration’s stated aim of moving toward more coherent Marine Spatial Planning, a sort of ocean zoning approach that would help guide human activities toward areas where they will have less impact on animals.  In a clear indication that NOAA may take a more proactive role in pushing the Navy to leave some areas out of its training zones, the letter stresses that “Protecting important marine mammal habitat is generally recognized to be the most effective mitigation measure currently available.”
• Finally, NOAA has already begun taking an active role in ongoing meetings between the Navy and the National Resources Defense Council; these meetings were part of a legal settlement and are designed to resolve outstanding differences about Navy active sonar operational and mitigation measures.  Lubchenco notes that “NOAA’s participation will enhance these discussions and help resolve differing views….I also expect the Navy to be open to new ideas and approaches to mitigation that are supported by the best available science.”

Indeed, including “spatio-temporal restrictions” (areas or times when activity is prohibited) in active sonar permitting has been a major sticking point between the Navy and NRDC and other environmentalists, and is something the Navy has consistently and explicitly rejected in the first round of sonar EISs, which have been finalized over the past year for most of the key Navy ranges (California, Hawaii, East Coast and just this week, the Gulf of Mexico), none of which included any limits on where and when the Navy could do sonar training. “The Navy’s Southern California range is over 120,000 nautical miles in size — about the size of California itself,” NRDC’s Michael Jasny points out. “The Bush administration did not put a square mile of this vast area off limits to sonar.”

All in all, this is a remarkable and very productive first step for this administration as it enters the long-contentious waters of active sonar regulation, ocean noise in general.  You can download Lubchenco’s detailed letter at the NOAA website.

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)

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Download a Word doc version of this commentary

A report issued by the American Wind Energy Association (AWEA) and the Canadian Wind Energy Association (CanWEA) purports to assess all currently available research on the health effects associated with exposure to wind farm noise, and concludes that there are no such problems.  The report, funded by North America’s two key wind industry trade organizations, centers on the symptoms of the reported “wind turbine syndrome,” and while it offers a robust critique of the idea that low frequency noise from wind farms can cause direct health impacts, it’s hard to take its message of wind’s “clean bill of health” at face value, thanks to many topics that are ignored or underplayed.  The report minimizes the levels of annoyance and impacts on quality of life reported in other studies, and completely omits any assessment of the most widely reported health-related impact of living near wind farms, sleep disruption. (For more complete assessments of health-related issues related to wind farms and noise, see recent reports from the Minnesota Department of Health report and World Health Organization.)

The authors of the new AWEA/CanWEA report acknowledge that some people may be annoyed by the sounds of wind turbines, but stress that annoyance is not an “adverse health effect.”  They also seem intent on assuring that any mention of annoyance rates is kept to 10% or below, which necessitates some creative re-interpretation of one of their key sources, a recent paper by Eja Pederson that compiled results from three surveys near wind farms in Scandinavia, summarized in October by AEI. In particular, they combine results from two studies in rural areas and one in a suburban area, which Pederson explicitly presented separately, because they illustrate that annoyance rates are far higher in rural areas (since the suburban study had more participants, the overall average is dominated by the suburban results).  In AEI’s view (as regular readers will know), the bottom line in all annoyance studies is that while many (or even most) people who are within earshot of wind turbines are not strongly affected by the noise, a substantial minority (ranging from 5-40% depending on how close they live) are negatively impacted, sometimes to the point of abandoning their homes; our challenge is to decide how many people we feel OK disrupting, and regulating wind farm siting to match that choice.

The report also repeatedly states that “the sound emitted by wind turbines is not unique,” while it elsewhere briefly acknowledges the often fluctuating nature of turbine noise (amplitude modulation) and its role

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 mining industry is looking more actively at the vast opportunities available if they can tap into the three quarters of the earth’s surface that is under the oceans.  A new generation of undersea technology, developed in part by the oil and gas industry, is opening this door that was previously mostly a dream.  Undersea crawlers, remotely operated vehicles with robotic arms, and subsea processing units are all key to the new mineral rush that may be starting.  The Woods Hole Oceanographic Institute magazine Oceanus ran a good piece on the history and current plans in this realm; much of the focus has been on undersea vents, where biologists are concerned about impacts on rare species (extinct or dormant vents may have the minerals with far less active communities of life).  Meanwhile, the International Maritime Minerals Society has released a new draft of its Code for Environmental Management of Marine Mining, and is accepting comments through April 15, 2010 (email to Verlaan AT hawaii DOT edu).  The draft code has some fairly progressive provisions, including leaving corridors to facilitate biological re-establishment after mining, and leaving nearby similar areas untouched to serve as research/environmental controls; the code makes no mention of assessment of the noise footprint of mining, which is bound to be locally significant.

(this item first appeared in AEI’s lay summaries of new research)

Wade, Whitehead, Weilgart. Conflict of interest in research on anthropogenic noise and marine mammals: Does funding bias conclusions? Marine Policy 34 (2010) 320-327.

In the United States, the US Navy funds about 70% of the research into the effects of ocean noise on wildlife (and half, worldwide). For many years, conservation groups have questioned whether this preponderance of funding is skewing research results, whether by constraining the types of questions being studied, or by leading researchers to downplay negative impacts of noise in order to continue receiving funding. The authors of this new study report a significant correlation between Navy funding and results reporting “no effect” of noise, based on their analysis of  several wide-ranging reviews of ocean noise science, and of the primary research papers cited in these reviews.  While the data behind their conclusion is clearly explained, the results don’t look nearly as clear-cut to me; I question the comparability of the five reviews used, and while the trends in primary papers is more obvious, it’s hard to ignore the fact that the majority of military-funded papers still found that noise had effects.  Indeed, as the authors make clear, it’s the conservation-funded reviews and primary research that is most clearly one-sided in its results (though there are good reasons for this, also fleshed out by the authors and in AEI’s commentary below).  In AEI’s view, studies like this – and indeed, reviews such as those considered here – are diligent exercises in quantifying an issue that has become, for all practical purposes, an exercise in divergent world views and beliefs talking at and past each other.

This post includes more analysis and interpretation by AEI than we generally include in our science summaries; it’s a long read, but the issues that triggered this study are important ones. Though the clear-cut results reported here are difficult to take at face value, it is well worth considering the underlying forces that drive tensions between environmental groups and Navy/industry actions in the seas.  While primary research and even literature reviews funded by the military don’t appear overly biased toward finding no effect (since in both cases, they include far more results showing effects than not), it remains that in practical terms, the EIS’s generated by the Navy and the mitigation measures imposed by regulators on both military and oil and gas activities are largely grounded in the belief – and regulatory determination – that any effects of these activities are “negligible,” to use the formal term. Thus the focus of the conservation community on funding research and publishing overviews that emphasize credible studies outlining observed negative effects is understandable.

Of special note is that the authors did not find any strong trend toward bias of results reported by independent, academic researchers receiving Navy funding for research studies – these studies showed a similar proportion of effect and no effect results as studies funded by neither the military nor conservation groups (though when comparing military-funded studies with all the others, including consevation-funded, a non-statisticially significant trend of 1.64 times more “no effect” findings was observed).  This should diffuse widespread concerns that cash-strapped academic researchers are “cooking the books” or avoiding publishing negative findings in order to retain Navy funding (though it is perhaps unsurprising to note that few if any key Navy-funded scientists are among the researchers who are willing to speak out publicly to push for stronger regulations on ocean noise). The authors conclude that “much of the bias in military-funded research was in work carried out at military institutions, rather than in studies funded by the military but carried out at universities and other institutions.”  Thus, research coming directly out of military offices is likely to remain less reliable as representing “the whole picture,” as may research entirely funded by conservation groups. Still, by integrating and considering the full range of studies reported in all of these reviews, the public can get a pretty decent picture of current state of our understanding of the effects of ocean noise.

Of note, though, is that the proportion of “no effect” to “effect” findings is slightly lower in military-funded studies. In addition, military-funded studies are three times as likely to report BOTH effects and lack of effects in a single paper; this could indicate either a more careful assessment of the margins where effects are just noticeable, or a tendency to split the difference in order to either underplay the effects or accentuate the non-effects to assuage funders.

While ocean noise issues came to public awareness after a series of stranding deaths and lawsuits, the fact is that deaths and injuries caused by noise are very rare.  Even the leading environmental activists have shifted their focus, and today nearly all of the controversy over military and oil and gas noise boils down to differing interpretations of how important moderate behavioral changes are, and whether they should be avoided or not. And science is nearly incapable of shedding any definitive light on how important behavioral changes are, thus leaving the two sides largely reliant on their divergent faith: the Navy and oil industry’s faith that the behavioral changes are transient and negligible, and environmentalists’ faith that chronic behavioral disruption by human noise is bound to have negative consequences. Meanwhile, ethical questions about humanity’s relationship to the natural world are outside the bounds of discussion on one side, and central to the whole discussion on the other.  This is not as black and white a picture as either side may paint, but it’s where we are.

For AEI’s full summary and discussion of this important new study, dive in below the fold…..

Read the rest of this entry »

(this item first appeared in AEI’s lay summaries of new research)

Tougaard, Henriksen, Miller. Underwater noise from three types of offshore wind turbines: Estimation of impact zones for harbor porpoises and harbor seals. J. Acoust. Soc. Am. 125 (6), June 2009. 3766-3773.

Underwater noise was recorded from three different types of wind turbines in Denmark and Sweden. The authors note that virtually all airborne noise from the turbine blades is reflected off the surface of the water, while vibrations from the machinery are transmitted through the tower and into the foundation, from where it radiates out into the water column and seabed. In general, turbine noise was only measurable above ambient noise at frequencies below 500Hz, with total SPLs of 109-127db re 1uPa rms, measured at 14-20m from the turbines’ foundations. By comparing measured sound levels with audiograms of harbor seals and harbor porpoises, the researchers determined that the sounds were only slightly audible for the porpoises at ranges of 20-70m, whereas harbor seals may hear the sounds at ranges of 100m to several kilometers. As a bottom line, researchers suggest that behavioral changes are very unlikely in harbor porpoises except at very close ranges, while seals may have some behavioral reaction out to a few hundred meters. For both species, masking is predicted here to be low to non-existent (due to differences between vocalization frequency patterns and the predominantly low-frequency turbine noise), and the sound is not loud enough to cause physical injury, no matter how close the animals are.

A detailed statistical analysis of 5000 homes sold within ten miles of wind farms has failed to find any clear relationship between sales price and proximity to, or views of, industrial wind farms.  However, close reading of the results raises some questions about trends within a mile of turbines, and the authors recommend more detailed study of the closest homes as a top priority for future research.  Co-author Ryan Wiser affirmed that “It is possible that individual homes have been impacted, and frankly, I think it would be a bit silly to suggest otherwise. Human development impacts property values.”

As I look closely at the result, it seems likely that the apparent trend toward some property value effect largely mirrors surveys of residents near wind farms.  The “problem” in interpreting this data and the surveys is that there is NOT a universal increase in annoyance or sleeplessness or dropping property values as you move closer to turbines; rather, there is an increasing MINORITY of neighbors who are negatively impacted.  Several earlier posts address this factor: from 10% of neighbors at around a mile or so, increasing to 25% or so at a half mile, and perhaps 40% at a quarter mile, survey results reflect the well-known individual variability in susceptibility to noise.  It seems clear that the “small and infrequent” numbers of homes negatively affected in the study addressed here, are mostly concentrated near turbines, and may represent a similar percentage of landowners as report sleep disturbance and other noise impacts.  If so, the 5% average price hit is apt to represent a much larger valuation drop in a quarter or so of the homes that are within a mile.

The study, funded by the US Department of Energy at the Lawrence Berkeley National Lab, took into account size and other features of the homes, and looked particularly for any trends in prices resulting from views of wind turbines, having turbines in the vicinity (1-5 miles), and nuisance factors like shadow flicker and noise.  This third focus is the one of most interest to AEI, and we took a close look Read the rest of this entry »

As the Obama administration moves toward completion of its ocean policy and planning blueprint, it’s becoming clear that the new kid on the block has grown into a dynamic young adult, ready to change the shape of ocean planning forever.  Marine Spatial Planning (MSP) is taking a central role in the ocean task force’s work, and a recent symposium on MSP put together by NOAA’s Office of National Marine Sanctuaries offers a great introduction to the power of this approach. At its root is a simple idea, one we’re very familiar with after decades of zoning on land: let’s identify which areas offer the best opportunities for fulfilling each of our goals and needs in the sea, then use this information to focus each activity in areas where it will have the least cumulative impact on other priorities.  Where are the regions most important for each species’ reproduction and feeding?  Which areas have the best possibilities for wind energy?  Where is shipping concentrated?  How about recreational diving and near-shore boating?  Navy training, underwater cables, key fishing grounds, and all other ocean uses are mapped into layers, from which we can make informed choices about where to focus each activity.

The link above will take you to a page from which you can see the full agenda and topics considered at the symposium; I found the following three presentations to be especially useful in getting a sense of this new field:

Steven Murawski, Ecosystem Goal Team Leader for NOAA, offered a good overview of the science and planning elements that are being developed.  Of special note is the inter-relation between MSP and new “Integrated Ecosystem Assessments,” which can provide much of the data needed to make good choices about how to use each area in MSP.

Charlie Wahl of NOAA’s Marine Protected Areas Center introduced work developing a regional Ocean Uses Atlas for the west coast.  Drawing on both scientific data and workshops at which key stakeholders (fishermen, kayakers, etc.) identify areas most important to them, the Ocean Uses Atlas culminate in maps showing, for example, how many other uses co-exist in areas where offshore wind farms may be built.  The maps show that in some places, up to 17 other uses are trying to co-exist, while there are other places where only one or two other uses target the same area. When combined with wind resources data, wind farms can be targeted for the “holes” in the conflicting uses maps.

Finally, Sally Yozell, Director of Marine Conservation for The Nature Conservancy, presents a national picture, with some extra focus on the east coast. The TNC has taken the initiative of compiling a slew of existing data on biologically rich areas, wind, wave, and tidal energy, and other ocean uses to create first drafts of maps similar to those that the MPA center has developed for the west coast.  (TNC is also actively working on a similar approach to alternative energy siting on land, especially with wind in the midwest.)