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

From Sciencemag.com; click to read source article

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

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

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

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

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

The 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.

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.  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.

This good news is courtesy of Brandon Southall’s SEAblog:

DNV, a Norwegian-based company that develops classification-specific standards for the construction of vessels, has released the first industry standard for reducing underwater noise for commercial vessels.  While not targetted at the largest cargo ships and tankers necessarily, this is a notable development within the commercial shipping industry regarding noise impacts on marine life.  A press release from DNV, which notes the ongoing effort within the International Maritime Organization’s Marine Environment Protection Committee on this issue, may be found at: http://www.dnv.com/news_events/news/2009/dnvsilentnotationmakessomenoise.asp

I’d just add that the company’s press release notes that DNV “will offer sound radiation evaluation services and recommendations on hull, propulsion and engine design to reduce noise.”

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

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

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

Read the rest of this entry »

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.

NOAA has released its proposed critical habitat for the endangered Cooks Inlet beluga population: it includes the entire upper part of the inlet (which includes Anchorage and Wasilla), and a coastal stretch of the lower part of the inlet as well.  This isolated population of belugas experienced a population crash in the 1980’s which is widely blamed on over-harvesting by native subsistence hunters, but has not recovered since the hunting was limited.  Pollution, limited salmon runs, and noise are all considered likely factors in the population’s struggle to survive.  Over the past few years, it has become apparent from field research studies and monitoring around seismic surveys that belugas are among the more sensitive cetacean species to sound; they tend to avoid noise sources at greater distances than most other whales, often tens of kilometers.

According to the Anchorage Daily News, NOAA officials said the proposed rule and the prior listing of belugas could trigger some changes to major development projects over the next decade — seismic drilling for offshore oil and gas, and a dock for the Chuitna coal strip-mine proposed on the west side of Cook Inlet, for example, the agency said.  NOAA said it doesn’t anticipate the stepped-up scrutiny will result in rejection of energy projects in the Inlet. The rule would require other federal agencies to consult with the federal fisheries service before approving projects in the proposed critical habitat areas. Ongoing construction at the Port of Anchorage, planned to continue for several more years, includes monitoring for belugas that may be close enough to be seriously disturbed, though the Port Director said they will be submitting comments on the proposed designation.

UPDATE: Public comments on the critical habitat designation have been extended to March 2010. A NOAA biologist assured locals attending a public meeting that the new designation would not add “onerous” oversight.

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.)

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

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

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

Thanks to Brandon Southall’s blog on his new SEA-inc website, which is fast becoming one of the best places to stay abreast of key ocean acoustics research, I heard today the details of what’s planned at the upcoming Minerals Management Service three-day workshop on Acoustic Mitigation and Monitoring Systems for Marine Mammals.  The workshop website now has the agenda online, and will include links to conference documents.  I was surprised and delighted to see that my most recent annual ocean noise report is first on the list of Background Documents to be read by attendees! This report, Ocean Noise 2008: Science, Policy, Legal Developments, can be downloaded from the conference site; it is also available, along with its brethren from 2006 and 2007, at AEI’s page on DocStock.com.  Several of my conference Powerpoint presentations are also now available for viewing and download as well, at AEI’s SlideShare page.

The three-day workshop takes place in Boston later this month, and is bringing together most of the key players in the field, including Southall, Cornell’s Chris Clark, Oregon State’s Dave Mellinger, Aaron Thode of Scripps, Leila Hatch of Stellwagen Bank, passive device designers Peter Stein and Gordon Hastie, and several key oil and gas industry players, including Bill Streever (check out his great new book on the north, entitled Cold), David Hedgeland, and Bernard Padovani.

The promise of deep offshore wind energy is moving forward rapidly in the wake of the world’s first floating wind turbine, deployed off Norway  in September by StatoilHydro. The Gulf of Maine is in line to see similar turbines in coming years, thanks to a focused effort by the National Renewable Energy Lab and regional energy planners.  In Massachusetts, plans are progressing for a test deployment of a floating turbine not far from the embattled near-shore Cape Wind site, while in Maine, a public comment period is underway prior to selecting test sites for floating offshore turbines.  This Powerpoint presentation (here in pdf format) from a NREL researcher provides a good overview of the current plans in Maine.  These deep offshore designs promise to avoid the troublesome noise impacts that have become common with onshore wind farms within a half mile or mile of homes, as well as both visual and noise concerns with near-shore wind farms.

Three Deep Offshore Turbine Designs

According to EENews (subscription required), energy planners in Maine made the choice to push the new deepwater technology, rather than facing the political hurdles of near-shore wind: ”We made the decision at the outset to solve engineering questions and not legal ones,” Habib Dagher said, alluding to legal and political problems faced by Cape Wind. The first deepwater turbines are slated to hit the water by April 2011 in a yet-to-be-determined location in the Gulf of Maine and at a site in the Isle of Shoals. The initial project sites will be 3 nautical miles offshore for ease of access, but commercial models would be 20 miles or more from shore, Dagher said.

EENews, cont’d: The DOE recently awarded the University of Maine $8 million to develop three deepwater offshore floating wind turbines. With $5 million coming from the Energy and Water Appropriations bill and additional state and private funds, the project is expected to have a budget of about $20 million. More than 30 research and industry partners will be tackling the deepwater initiative.  The key to the success of the models — ranging in power from 10 to 100 kilowatts — is engineering that keeps the turbines buoyant and lets waves sway them without rocking them from their moorings.  One model will be similar to StatoilHydro’s, and the company will be pitching in to assist with the work. “It’s like taking Windows 2.0 and giving it a major upgrade,” explained Habib Dagher, director of the Advanced Structures and Composites Center at the University of Maine, who will be heading up all three projects. Dagher plans to use lighter composite materials than the original Norwegian steel-based model and to make the structure larger.

UPDATE: 12/15   The State of Maine has chosen three sites off its coast, where scale models of several different floating turbine designs will be tested beginning in 2011.  And, here’s a link to a quick overview of future-looking developments in offshore wind discussed at the recent European Offshore Wind conference in Stockholm.

(this item appeared recently on AEI’s lay summary of new research page)
Reeder, Chiu. Ocean acidification and its impact on ocean noise level: An analysis using empirical and physical models of acoustic transmission loss. Presented at ASA October 2009 meeting.

Udovydchenkov, Duda. Ocean noise level change in response to ocean acidification. Presented at ASA October 2009.

These two papers take a closer look at the widely-noted ocean noise implications of increasing ocean acidification (a combination of factors related to global warming is triggering a steady increase in the ocean’s pH, which decreases sound absorption). When the acidification results were first released there was much speculation that shipping noise would propagate farther, resulting in cumulative ambient noise increases throughout the oceans. These two papers, presented at this fall’s Acoustical Society of America meeting, both come to the same conclusion: low frequency noise will not be significantly increased due to ocean acidification; rather, the primary changes will occur at mid-frequencies. This calms concerns about shipping noise, but may (over time) lead to slightly larger areas being impacted by mid-frequency active sonar, some acoustic harassment devices used by fish farms, noise from recreational boating, and other mid-frequency noise.

Rather than simply looking at the effects of sound absorption Read the rest of this entry »