A study just published is a tentative first step toward knowing where beaked whales may be foraging, and so perhaps avoiding exposing them to mid-frequency active sonar without having to see or hear them first.

The study, briefly described in this press release, found that beaked whales were more numerous in an area of their known habitat where salinity and temperature conditions increased the abundance of their prey.  Yup, that’s right:: they found that beaked whales congregate in areas where there are more fish they like to eat!!  Ain’t science great?

Seriously, though, such studies are important to ocean planners, as they provide the necessary causal data that can later (once the results are replicated elsewhere) be used to craft operational measures meant to protect beaked whales from harm.  These whales, which surface for only a few minutes at a time between 90-minute foraging dives, are notoriously hard to see, and not much easier to listen for, making it difficult to be sure whether they are nearby before a Navy ship begins sonar exercises.  The Navy has been reluctant to set aside potential habitat as “no-go” zones for their training, since even in possible habitat, there is no way to really know that animals are present.  Studies such as this one are small steps along the way toward getting solid enough data to know, more specifically, where whales may be more likely to congregate. Previous studies on harbor porpoises and bottlenose dolphins have shown how modeling habitat can be a powerful tool to inform spatially adaptive management of ocean predators.

The US National Renewable Energy Laboratory is about to begin a new study of the turbulent wakes that appear downwind from wind turbines.  Such turbulence can decrease the efficiency of turbines as well as creating physical stresses on the machinery; many researchers also suspect that inconsistent wind speeds across the rotor diameter contributes to increased noise.  It’s certainly easy to imagine that turbines inside the wakes pictured at the left (from an offshore wind farm in Denmark, where moisture reveals the normally invisible patterns) might be under stresses that would increase noise output.

For more on the NREL study, see this feature in Science Daily.

A new study finds that there is plenty of already disturbed land in the US to meet the 20% by 2030 goal for wind energy production.  Noting that habitat fragmentation is a key issue that can slow wind development, the researchers took a state-by-state approach that looked at both disturbed landscapes and wind resources, to see whether there is enough disturbed land (farmland, oil and gas fields, roads) on which to build out our wind future.

The answer: clearly yes. In fact, there’s enough disturbed land to build more than ten times the number of turbines needed.  While some states, including Maine, California, Pennsylvania, and Michigan, don’t have enough undisturbed land to meet their goals, many others have far more potential capacity than needed (see chart). “A disturbance-focused development strategy would avert the conversion of ~2.3 million hectares of undisturbed lands relative to the unconstrained scenario in which development is based solely on maximizing wind potential….Agriculture and oil and gas make up the vast majority of the disturbed lands identified in our analysis, such that removal of other disturbed lands would not qualitatively change our results. However, we believe that ridges surrounding abandoned surface mines and areas adjacent to existing roads also constitute disturbed areas where wind energy development should be considered.”

The researchers also note that “Placing turbines on disturbed lands may also benefit the expansion of transmission lines and associated infrastructure that will be critical to facilitate wind development. Because disturbed lands are already in areas of high road and transmission line density, they may ease the development of new or expanded transmission capacity. “

While their analysis focused on ground-based conservation needs, and so it is likely that some areas of bird and bat migration would need to be excluded from their disturbed-land analysis, there is enough extra potential capacity to easily move in this direction. What’s needed, they authors suggest, is policies that make it cheaper to build in disturbed land and more expensive to build on pristine land, which “could improve public value for both wind energy and biodiversity conservation.”

Read full paper online here.

Conservation Magazine’s Journal Watch has a nice summary of an important new overview of acoustic monitoring (more at the link):

Computer and electronics revolutions have produced sound-recording gear that is “transforming the way we study individuals and populations of animals, and are leading to significant advances in our understandings of the complex interactions between animals and their habitats,” a multinational team of researchers writes in the Journal of Applied Ecology.

Using arrays that can include dozens of microphones, for instance, researchers have been able to closely track tiny birds through nearly impenetrable tropical undergrowth and map out their territories. And specialized sound-analysis software can even help researchers figure out the species, age, and sex of noisy animals. Acoustic arrays have also enabled scientists to figure out when birds, such as sage grouse and blackbirds, are calling in a particular direction, or when they are sending broader signals.

“The wide-scale application of acoustic recording and processing technology has the potential to transform the fields of ecology, behaviour and conservation biology,” the team writes. But it will take a little innovation – and some sharing — to make the most of the new tools, they add. One “pressing challenge” is developing better signal-processing algorithms; another is developing common technologies that researchers can share – as opposed to the “customized” systems now in use.

To hurdle these obstacles, the authors suggest scientists “set up a website or wiki to serve as a repository for collective experiences and knowledge” – or expand an existing resource, such as the Bioacoustics listserv. Overall, however, they believe “the future for bioacoustic monitoring in the terrestrial environment is bright.”

Blumstein, D., Mennill, D., Clemins, P., Girod, L., Yao, K., Patricelli, G., Deppe, J., Krakauer, A., Clark, C., Cortopassi, K., Hanser, S., McCowan, B., Ali, A., & Kirschel, A. (2011). Acoustic monitoring in terrestrial environments using microphone arrays: applications, technological considerations and prospectus. Journal of Applied Ecology DOI: 10.1111/j.1365-2664.2011.01993.x

Related: See these two recent posts about related work being done by a team of researchers touting a new subdiscipline, soundscape ecology.

It’s “wind week” at the Maine state legislature, where the Utilities and Energy Committee is hearing two days of testimony on a slate of 14 bills that have been introduced to regulate wind energy development.  One bill would mandate property value guarantees, and another would impose setbacks of a mile and a quarter from homes.  Maine’s been a hot spot for community noise issues, with a ridgeline wind farm in Mars Hill spurring noise and health complaints from most of the residents within a half mile or so, and a three-turbine farm in Vinalhaven triggering noise issues for around half of the similarly nearby neighbors.

Legislators heard starkly differing views from supporters of the wind industry and community groups that have been pushing for more protection for landowners who don’t want to hear turbines from their homes.  Predictably enough, the rhetoric was at times extreme, with one opponent positing that development up til now has been “a well-planned legislative fraud perpetrated on the citizens of Maine.”  On the other side of the coin, a local realtor said, “I have seen no negative impacts whatsoever on real estate values in Mars Hill,” but didn’t specify whether any of the homes within a half mile or so that have been severely impacted have been on the market.  (Ed. note: while most evidence agrees that prices of homes a mile or more from wind farms are not dramatically affected, there is less clarity or consensus about the few homes within a half mile or mile; in rare cases, homes in this range have been abandoned by owners.  It’s clear that easy reassurances about impacts in the community at large, ie within several miles or within sight of turbines, often don’t reflect the experiences of those living closest.)

The Portland Press Herald and  Bangor Daily News have more coverage of the hearings, including this exchange:

Several people living near wind power facilities questioned whether a few hundred temporary construction jobs is a worthwhile trade-off when the turbines force some homeowners who support the local economy year-round to move away.

“I’m listening to employee after employee come up and say, ‘I’m more important than somebody’s home,’” said Carrie Bennett, who lives near a three-turbine facility near Freedom. “Do you want to buy my house? Do you want to live in my house? Of course not.”

Researchers have determined that Americans between 25 and 64 years old hear better than their grandparents did at the same age.  Comparing research done in 1959-1962 with similar studies in 1999-2004, it appears that upper-frequency hearing is notably better than it used to be; middle-frequency hearing is roughly the same.

Researchers suspect that a combination of better treatment of childhood ear infections, fewer smokers and better health care in general, and a reduction in manufacturing jobs (as well as better hearing protection in today’s workplaces) have led to the improvement.

The reduction in upper-frequency hearing loss is especially important in speech recognition.

Women from three generations converse (NIDCD)

For more, see this NIDCD press release and this post on About.com that includes several related links.

Two recent features on NPR looked at (and listened to) new academic research that is being framed as “soundscape ecology.”  Very similar to our work with acoustic ecology, the new discipline aims to be seen as a subset of the established field of landscape ecology, with a focus (naturally!) on the ways soundscapes can inform us about the health of habitats.

The first piece, from last month, was a 5 minute segment on Weekend Edition, with Bryan Pijanowski of Purdue and Jesse Barber of Boise State (who has also worked extensively with National Park Service researchers).  It can be heard (and read) here.

The second piece is close to a half-hour long, and is a conversation with Pijanowski and Bernie Krause of Wild Sanctuary.  It can be seen and heard here.

A ten-year study in the western Pacific has documented the ways that new humpback whale songs move through several distinct populations over the course of a breeding season. “Our findings reveal cultural change on a vast scale,” said Ellen Garland, a graduate student at The University of Queensland. Multiple songs moved like “cultural ripples from one population to another, causing all males to change their song to a new version.” This is the first time that such broad-scale and population-wide cultural exchange has been documented in any species other than humans, she added. (Ed. note: researchers have also suggested that cultural patterns are passed among sperm whale populations)

Once a new song emerges, all the males seem to rapidly change their tune. Those songs generally rise to the “top of the chart” in the course of one breeding season and typically take over by the end of it. “We think this male quest for song novelty is in the hope of being that little bit different and perhaps more attractive to the opposite sex,” she said. “This is then countered by the urge to sing the same tune, by the need to conform.”

More, including whale song audio, here.

Related story: Acoustic recorders reveal new humpback breeding areas in central Pacific.

Traffic noise is the second biggest environmental problem affecting our health in Europe, after air pollution, according to a report published in late March by the World Health Organisation (WHO). According to the WHO study, 1.8% of heart attacks in high income European countries are attributed to traffic noise level higher than 60dB.

“This new health evidence highlights the urgent need to reduce transport noise”, says James Grugeon, Chief Executive of Environmental Protection UK. “EPUK are working to reduce noise from road traffic. Our Campaign for Better Tyres, launched this week, encourages transport operators and drivers to choose tyres that are quieter.” The European Commission is expected to release a proposal in June for more stringent vehicle noise standards, and from November 2012 new regulations for stricter tyre noise levels and tyre labeling for noise come into force.

European citizens are well aware of the health impacts of traffic noise. According to a recent Eurobarometer (6), almost half of all Europeans believe that noise affects their health “to a large extent” and another one-third said that it affected their health “to some extent.”

Source: Environmental Protection UK

Download WHO report here

Two years after proposing changes in whale-watching rules  in Puget Sound to protect endangered orca populations, NOAA has finalized its new standards.  Boats will need to stay twice as far from the whales (200 yards), and a half-mile wide “no-go” zone has been established along the entire west coast of San Juan Island, an important feeding zone.

For detailed coverage of the new plans, see these earlier AEInews posts.

UPDATE, 4/15: Canadian regulations lag those on the US side of the border; a recent study found that an average of about 20 boats surround orcas in summer months in one popular whale-watching area.  See this recent article that summarizes a set of proposed regulations developed by the University of Victoria (BC) Environmental Law Clinic, including 500 meter approach limits, 30 minute time limits, and weekly “days of rest” with no whale watching boats in the water.

New research indicates that squid and their relatives are injured by exposure to low frequency noise similar to the “acoustic smog” created by widespread shipping and localized seismic surveys.  This is the first study to show physiological damage caused by noise in animals who do not have ears or hearing organs. The study exposed squid, cuttlefish, and octopuses to two hours of low frequency sound in a variety of frequencies from 40 to 400Hz; the fish were in a tank, and could not move away from the noise.  According to a report in New Scientist, the researchers “were astonished by extensive damage to the statocyst, a bulbous organ in the head of cephalopods that senses gravity and motion, enabling them to balance in the water and direct where and how fast they swim. Without this organ, cephalopods are practically powerless to move, are unable to hunt, and will become easy prey themselves.”  In 2001 and 2003, giant squid were found beached in an area where seismic surveys were taking place; though the injuries observed then could not be tied to acoustic trauma, the new research suggests that such damage can be caused by sound exposure.

The New Scientist article continues:

Post-mortems showed that the linings of statocysts from cephalopods not exposed to sound retained the fine hairs that sway as the animals move through water, and are essential to the animals’ balance and orientation. Statocysts from the exposed animals, by contrast, had lost huge patches of hair, leaving holes in the membranes of the organ’s cells. The insides of the cells had pushed their way through the holes, and mitochondria – the power plants of cells – had suffered extensive damage. By killing and examining the animals at intervals up to four days after the single sound exposure, the team showed that the damage got worse with time, long after the sound had been turned off.

The sounds used in the study were of moderate intensity: SPLs of 157dB re 1uPa, with peaks at 175dB, roughly equivalent to the sound of a large ship at 100 yards or a seismic survey at 500-1000 yards. (By comparison, injury is not presumed to take place in marine mammals unless sound is 180-210db). Similar studies in fish, using caged animals, have sometimes found similar hair damage to hearing organs, but only at much higher sound levles, and, in many cases even high levels of sound did not cause such injury.

Michel André, lead researcher, notes in a statement that “If the relatively low intensity, short exposure used in our study can cause such severe acoustic trauma, then the impact of continuous, high intensity noise pollution in the oceans could be considerable…This is the first study indicating a severe impact on invertebrates, an extended group of marine species that are not known to rely on sound for living. It left us with several questions: Is noise pollution capable of impacting the entire web of ocean life? What other effects is noise having on marine life, beyond damage to auditory reception systems? And just how widespread and invasive is sound pollution in the marine environment?”

UPDATE, 4/15: While this study has been widely praised as an important step in understanding possible noise impacts on a new family of ocean creatures, there are some caveats being put forward as well.  Michael Stocker of Ocean Conservation Research notes in a letter to his network that it is as yet unclear whether the impacts are more related to “particle motion” or “pressure gradient” aspects of acoustical energy, so “it could be that the closeness of the lab signals may have different impacts than equally loud exposures generated from further distances.”  T. Aran Mooney, who agrees it’s a “good first step,” suggests that more information is needed about how the noise exposure was measured.  And of course, these results will need to be replicated and expanded upon, as always.

NOTE: Apologies for my boring post title.  I thought it was pretty decent – clear, explanatory – until this one showed up in by Google News ocean noise feed, covering the same story: “Ocean Noise Pollution Blowing Holes in Squids’ Heads.” I bow before the page-click-attracting Master over at Discovery News…

Two new studies on seismic survey impacts have been released by the Joint Industry Program (JIP) Sound and Marine Life research program, funded by oil and gas companies.

The first looked at the effectiveness of “soft start” ramp up of seismic survey airguns at night and at times of poor visibility.  This has become standard procedure, but there have been some concerns that if marine mammals were very close to the ship, even the low sound levels at the start of the ramp up could be loud enough to cause hearing damage.  Based on two different modeling approaches, the study found “no instances…in which the threshold levels for hearing injury for cetaceans were reached during the initial stages of the soft-start sequence. This suggests that the animals are not at significantly greater risk of harm when a soft start is initiated in low visibility conditions.”  Link to pdf of report at the website of the International Association of OIl and Gas Producers.

The second study aimed to address “the rarely-charted relationship between oil Exploration and Production (E&P) activities and trends in cetacean stocks.”  The study cites case studies involving populations of sperm whales in the Gulf of Mexico, humpback whales, blue whales and fin whales off the coast of California, northern bottlenose whales off Nova Scotia and harbour porpoises and minke whales off the east coast of the UK. The study, published in Aquatic Mammals,  provided new insights into the worldwide distribution of E&P activity in relation to marine mammal populations and has also revealed striking data gaps in our understanding of cetacean population numbers and trends. While the report’s review of seven stocks “found signs of an increase in numbers in one population (Californian humpback whales),” for the remaining six, “population trends could not be assessed due to the high variability in the abundance estimates.”  Link to pdf of this report.

In essence, there is not enough data to really tell us whether ongoing oil and gas activity has reduced stocks over the long term.  As usual in the many cases where ocean noise and population studies come up against this paucity of solid data, the researchers recommend that someone should fund of future studies ‘that provide more comprehensive data on cetacean stocks.”

JIP research page
Main JIP website

OGP publications page
OGP main page

In what must be one of the slowest EIS processes on record, the National Park Service and the Federal Aviation Administration is moving…methodically…to develop a new air tour management plan (ATMP) for Hawaii Volcanoes National Park.  After being upgraded from an EA to an EIS in 2005, the joint planning process began work on the EIS in 2007.  Four years later, rather than releasing a Draft EIS, the project planners have released a first draft of the proposed alternatives, and are asking for comment on these.  After incorporating comments, the DEIS will follow.  Sometime.

All ribbing aside, the fact is that this is actually one of the faster moving ATMP’s coming out of the seemingly uncomfortable partnership between the FAA and the NPS, which were  jointly charged in 2000 with developing ATMPs for all parks with existing or proposed flight tours.  The Park Service has taken a lead among federal agencies in addressing impacts on natural soundscapes of parks, while the FAA’s focus is more on air safety than resource protection.

“Hawai‘i Volcanoes is known for spectacular volcanic landscapes, significance of Native Hawaiian culture, Hawaiian species found nowhere else in the world, and for vast expanses of designated wilderness that stretch from summit to sea,” stated Cindy Orlando, Park Superintendent. “Whether it’s the crackling of new lava, song of a honeycreeper, or a magical Hawaiian chant floating across Halemaumau Crater or just silence—the soundscapes of Hawaii Volcanoes are unusual and valued as part of the park experience. We also protect some of the quietest places in the park service —secluded locations that are quieter than even humans can hear. Natural quiet is becoming an increasingly important attribute of the national parks.”

You can download a newsletter that shares the draft alternatives, and submit comments, from this page; see the full project planning website here; and check out a short video and news report on the process here.

Conservation Magazine highlights a fascinating new study:

A loud motor boat can be annoying. If you are a hermit crab, however, the sound could be deadly. Last year, researchers discovered that playing boat noise distracted the crabs, preventing them from paying attention to potential predators. It’s just one example of how human-created sounds can interfere with “biologically important decisions about food selection, mate selection, and predator detection,” a new review of animal “attention” finds.

The paper reviewed a wide range of research studying attention in many animals, and found that human noise can have either pros or cons for conservation; in some instances, we could use noise to disrupt animals causing habitat disruptions.  Overall, “we need studies that aim to better understand the population consequences of distraction on wildlife populations,” the authors conclude.