16 Apr 2013:
U.S. Offshore Seismic Testing
Threatens Many Marine Species, Study Says
The proposed use of seismic air guns in the search for offshore oil and gas reserves along the U.S. East Coast could injure or kill nearly 140,000 marine animals
annually and disrupt the vital activities of other species,
Moira Brown/New England Aquarium
North Atlantic right whale
a new study says. The seismic testing, in which guns filled with compressed air are fired repeatedly over deep-sea target areas to provide energy companies an image of the deposits below, would threaten marine species of all sizes, from tiny fish eggs to large whales, according to an analysis by the conservation group Oceana
. The group said that the powerful air gun blasts, which it describes as “100,000 times more intense than a jet engine,” could disturb the breathing, feeding, and mating habits for dolphins and whales and cause injury or death to endangered species such as the North Atlantic right whale. The analysis comes as the U.S. Interior Department’s Bureau of Ocean Energy Management completes a study of the potential impacts of seismic activities from Delaware to Florida. Oil industry officials point to other research that shows seismic testing is unlikely to threaten marine mammals.
12 Apr 2013:
Many Marine Mammal Species
Have Rebounded Since U.S. Protections
Forty years after the passage of the Marine Mammal Protection Act (MMPA), no marine mammal species in U.S. waters has been extirpated and the populations of
many marine animals are more abundant
than in 1972,
a new study says. While many species, including the endangered right whale, remain at significant risk, the populations of other species — including gray seals in New England and sea lions and elephant seals on the Pacific coast — have “recovered to or near their carrying capacity,” scientists say. “At a very fundamental level, the MMPA has accomplished what its framers set out to do, to protect individual marine mammals from harm as a result of human activities,” said Andrew Read, a professor at Duke University and co-author of the study, published in the Annals of the New York Academy of Sciences
. Passed at a time when numerous species were on the edge of extinction, the MMPA imposed strict regulations against commercial killing and the incidental bycatch of marine mammals by the fishing industry.
11 Apr 2013:
Marine Council's ‘Eco-Labeling’
Process Is Too Lenient, Report Says
The process by which the Marine Stewardship Council (MSC) certifies seafood as sustainable is too lenient and discretionary
, allowing for “overly generous interpretations” from third-party certifiers and adjudicators, a new report says. Launched in 1997, the UK-based MSC administers a well known eco-labeling process to inform consumers which fisheries are sustainable and provide incentives for better fisheries management. But in an analysis of 19 formal complaints against the council, a group of researchers found that several of the fisheries that received the MSC’s “sustainable” label — accounting for 35 percent of labeled seafood — apparently do not meet the council’s standards. For example, they found that Canada’s longline fishery for swordfish resulted in an extraordinary amount of incidental bycatch of other species, with the annual catch of 20,000 swordfish also netting 100,000 sharks, 1,200 endangered loggerhead turtles, and 170 leatherback turtles, according to the report, published in the journal Biological Conservation
Interview: A Marine Biologist
Works to Create a ‘Wired Ocean’
Even as populations of sharks, bluefin tuna, and other large fish are being severely over-exploited, scientists still know surprisingly little about when and where the ocean’s biggest predators congregate to feed and spawn,
making it difficult to protect biological hotspots. Stanford University marine biologist Barbara Block is seeking to narrow that knowledge gap by deploying an armada of satellite tags on the backs of ocean creatures. Block envisions a wired ocean, a blue fount of data in which tags, smart buoys, and mobile robots reveal the secrets of marine life. In an interview with Yale Environment 360
, Block discusses the wealth of data gathered by the latest electronic tags and explains why it’s important to put the fruits of this research into the public’s hands “What we need is environmental interest and awareness that connects humans to the world,” says Block, "or else we're going to end up with the same problem we had on the continents, where the large mammals are gone."
Read the interview
08 Mar 2013:
Largest U.S. Dam Removal
Releases Huge Amount of Sediment
Scientists tracking the aftermath of the largest dam removal in U.S. history say the dismantling of a dam in northwestern Washington state has unleashed about 34 million cubic yards of sediment and debris
that built up
A plume of sediment at the mouth of the Elwha River.
for more than a century. While about one-third of the 210-foot Glines Canyon Dam on the Elwha River still stands, vast amounts of sediment are already flowing downstream, allowing University of Washington (UW) scientists a rare opportunity to track the discharges and study their ecological impacts. Scientists say it is unclear where much of the sediment will end up — or what the environmental consequences will be. In an ongoing study, they will use sophisticated technology to track particles in the water and monitor their accumulation on the ocean floor. Scientists say the sediment — enough to fill 3 million truckloads — could create murkier water conditions, threatening the reproduction of salmon and blocking light for marine life.
08 Feb 2013:
Memory of Magnetic Landscape
Guides Salmon to Home Rivers, Study Shows
Although magnetism has been known to play a role in the remarkable homing ability of salmon, a new study clarifies just how the fish use magnetic fields
to travel thousands of miles to their natal rivers to spawn. Researchers at Oregon State University solved this mystery by studying 56 years of fishery data involving the millions of sockeye salmon that annually pour into British Columbia’s Fraser River. Vancouver Island sits in front of the Fraser, and the routes the salmon took around the island in different years offered clues to how the fish decipher shifting magnetic fields. When the magnetic field of the northern passageway around Vancouver Island was similar to that experienced by the fish when they left the river two years earlier, the returning salmon tended to chose the northern route;
the reverse was true when there was a more southerly magnectic field. Lead researcher Nathan Putnam said this showed that juvenile salmon imprint on the magnetic signature of their home rivers and then seek their way back using that signature. The research was published in Current Biology
05 Feb 2013:
Sea Urchins Offer a Clue
To New Way to Capture Carbon Dioxide
British researchers have discovered that sea urchins use nickel particles on their exoskeletons to effectively capture CO2 and turn it into a solid form, an intriguing finding that could offer an inexpensive way to capture and store carbon
from fossil fuel-fired power plants. Scientists from Newcastle University were studying how marine organisms absorb CO2 to make shells and skeletons when they discovered that sea urchin larvae have a high concentration of nickel on their exoskeletons, which helps them absorb CO2. When the researchers added nickel nanoparticles to CO2-saturated water, they discovered that the nickel completely removed CO2 and turned it into calcium carbonate
, a chalk-like mineral. Current efforts to capture and store carbon dioxide from power plants involve either pumping it underground or using an enzyme called carbonic anhydrase to convert it to calcium carbonate. But both methods are expensive, and the Newcastle researchers say that using nickel to capture and store CO2 bubbled through water could be a thousand times cheaper than employing carbonic anhydrase. “It seems too good to be true, but it works,” said Lidija Siller, a physicist at Newcastle. The research was published in Catalysis Science & Technology.
31 Jan 2013:
Massive UK Wind Turbines
Are a Sign of ‘Super-sizing’ of Wind Power
Two of the world’s largest wind turbines, with blades 60 meters (196 feet) long, have been installed off the Yorkshire coast, a sign of a growing trend toward producing colossal wind turbines to boost generating capacity.
The 6-megawatt turbines, manufactured by Siemens, are so large that they had to be installed using a specially built ship
, Siemens said. The pair of turbines is being erected on an experimental basis to gauge how they perform, but the operator of the offshore wind farm, the Denmark-based DONG energy group, has plans to install dozens more so that production will reach 210 megawatts at the site, located about five miles offshore. DONG says it intends to eventually install 300 of the massive turbines by 2017 at various offshore locations in the U.K., including some in deeper waters. Energy analysts say the 60-meter Siemens turbines reflect growing interest among wind energy companies to deploy ever-larger turbines, with plans in the works to manufacture turbines 100 meters long.
30 Jan 2013:
Satellite Analysis Shows
Gulf Oil Spills Typically Underestimated
An analysis of satellite images has revealed that small oil spills that have become common in the Gulf of Mexico are often much larger than reported
, U.S. scientists say. Using technology that calculates the size of oil slicks based on differences in the texture of water surface, as captured in publicly available satellite photos, a team of oceanographers at Florida State University (FSU) estimated that known human-caused spills in the Gulf were typically about 13 times larger than reported to the U.S. Coast Guard’s National Response Center. The spills are typically the result of minor drilling mishaps or fuel discharges from ships. “There is very consistent underreporting of the magnitude of [oil] releases,” Ian MacDonald, a FSU scientist and team leader, told Nature
. While these relatively minor oil spills may not cause significant environmental damage, the cumulative damage is not known since officials are unaware of the true extent of the spills, said John Amos, president of SkyTruth, a nonprofit organization that participated in the study.
15 Jan 2013:
Key Offshore Transmission Line
To Be Built For U.S. East Coast Wind Power
A group of prominent U.S. investors, including Google, is expected to announce today that it is moving forward with construction on the first leg of an ambitious $5 billion undersea transmission line
that will connect
Atlantic Wind Connection
New Jersey Energy Link
future offshore wind farms along the mid-Atlantic coast, a project they say will avert the regulatory hurdles required in connecting each individual wind farm to land-based electricity lines. The first segment of the project, which will occur in three phases, includes construction of a 189-mile transmission cable along the New Jersey coast. Coordinators of the project, known as the Atlantic Wind Connection, say the cable would deliver more than 3,400 megawatts of electric capacity
from future offshore wind projects to three locations in New Jersey. Construction is expected to begin in 2016, according to the sponsors. The project intends to eventually link offshore wind farms with electricity grids from Virginia to New York.
14 Jan 2013:
Tidal Energy Can Meet 20%
Of UK Electricity Needs, Study Says
UK officials are underestimating the vast energy potential of marine tides
, a renewable and reliable energy source that could meet 20 percent of the nation’s
Kawasaki Heavy Industries
electricity needs, according to a new report. Writing in the journal Philosophical Transactions of the Royal Society A
, researchers explain that while the process of exploiting tidal energy remains expensive, it has the potential to be a more reliable energy source than wind or wave energy and to be more easily managed on electricity grids. While the technology is in the early stages, the researchers say they are optimistic that the two principle means of exploiting tidal energy — construction of barrages across tidal estuaries that generate power from the ebb and flow of the water, and adding underwater turbines in fast-flowing currents — can be implemented in the near future. “From tidal barrages you can reasonably expect you can get 15 percent of UK electricity needs,” Nicholas Yates, a researcher at the National Oceanography Centre and co-author of the report, told BBC News
Interview: What’s Damaging U.S.
Salt Marshes and Why It Matters
For centuries, salt marshes along the U.S. coast have been disappearing, with some experts estimating that 70 percent have been lost to development, rising seas,
and other threats. One factor scientists always thought marshes could withstand was nutrient enrichment, such as the flow of nitrogen and phosphorus from fertilizers and septic systems. But a nine-year study led by Marine Biological Laboratory scientist Linda Deegan shows that an over abundance of nutrients may be contributing to the demise of these salt marshes. In a Yale Environment 360
interview, Deegan describes the study's implications and the vital services that would be lost if marshes disappear, from nourishing marine species to providing a barrier for coastal communities during storms such as Hurricane Sandy. Read the interview
21 Dec 2012:
Changing Oceans May Be Adding
To U.S. Fisheries Decline, Scientists Say
As U.S. fishing regulators weigh stricter catch quotas to allow time for critical species to recover in the waters of New England, scientists say that changing ocean conditions may be a factor in historic fish declines, not just decades of overfishing. Warmer ocean temperatures and changing ecosystems are contributing to declining populations of cod and flounder
in the northeastern U.S., government officials say. In the Gulf of Maine this year, water temperatures were the highest ever recorded, according to the Northeastern Regional Association of Coastal and Ocean Observing Systems. National Oceanic and Atmospheric Administration (NOAA) scientists say that about half of 36 fish stocks — including cod and flounder — have been shifting northward into deeper, cooler waters for four decades. And while some regulators say the only chance of restoring populations is for tougher quotas on bottom-dwelling “groundfish” species, the New England Fishery Management Council this week delayed a vote on such cuts
after fishermen said the reductions would devastate their industry.
06 Dec 2012:
Google Images Document
Devastation of 2011 Tsunami in Japan
As part of an ongoing project to digitally archive the aftermath of the 2011 tsunami in northeastern Japan, Google has published several new panoramic images
that provide a sobering glimpse of the widespread
devastation in communities across the region. The images, taken with the company’s Street View technology in four cities in the Tōhoku region, allows users to take a virtual tour of seriously damaged buildings before they are demolished. One panoramic view of a public housing project illustrates the height of the tsunami wave, which ruined everything up to the fourth floor of the building. Another image, of the condemned Ukedo Elementary School, shows the collapsed auditorium floor beneath the banner of a graduation ceremony that was never held. The images were added to Google’s “Memories for the Future
” website, which is chronicling the affected areas from before and after the tsunami.
30 Nov 2012:
Accelerated Ice Sheet Melt
At Both Poles Documented in Study
The ice sheets of Greenland and Antarctica are losing three to five times as much ice annually
as they did two decades ago, a rate of ice loss equivalent to sea level rise of 0.04 inches per year, according to a new study supported by NASA and the European Space Agency
. In an analysis of data from 10 different satellite missions, the international team of 47 experts calculated that the rate of melt in Greenland is five times greater than during the mid-1990s. While the new findings on total ice loss fall within the range produced by the Intergovernmental Panel on Climate Change in 2007, the new study provides a more definitive assessment that Antarctica’s ice sheets, like Greenland’s, are shrinking. Combined, these ice sheets have added .44 inches (11.1 millimeters) to sea levels worldwide since 1992, accounting for about 20 percent of total sea-level rise during that period. “This will give the wider climate science community greater confidence in ice losses and lead to improved predictions of future sea-level rise,” said Andrew Shepherd, a scientist at the University of Leeds and co-leader of the study, which is published in the journal Science
26 Nov 2012:
Snails in Southern Ocean
Showing Effects of Ocean Acidification
The shells of some sea snails in the Southern Ocean are already dissolving as a result of ocean acidification
, according to a new study. In an analysis of free-swimming pteperods collected from Antarctic waters in 2008, scientists found that the outer layers of the animals’ shells showed signs of unusual corrosion, potential evidence that ocean acidification caused by excess carbon dioxide in the atmosphere may already be disturbing vulnerable marine species. Laboratory tests have shown that acidic water threatens many invertebrate marine species, such as clams and corals, since it hinders their ability to grow shells and exoskeletons. The most vulnerable species are those, like pteropods, that build their shells from aragonite, a form of calcium carbonate that is sensitive to increased acidity, according to the study, published in Nature Geoscience
16 Nov 2012:
Majority of Marine Species
Still Remain Unknown to Scientists
While more new marine species were identified over the last 10 years than during any previous decade, as many as two-thirds of the plant and animal species living in the oceans may still be unknown to scientists, a new study says. Writing in the journal Current Biology
, a team of international scientists estimates that there are
The marbled swimming crab
likely 700,000 to 1 million species in the oceans, of which only 226,000 species have so far been identified
. Another 65,000 are sitting in scientific collections awaiting identification, according to the study. The study, which was produced by 270 experts from 32 countries, represents the most comprehensive inventory of marine life, and notes that the majority of unknown species are composed of crustaceans, mollusks, worms, and sponges. “For the first time, we can provide a very detailed overview of species richness, partitioned among all the marine groups,” said Ward Appeltans, a biologist at UNESCO's International Oceanographic Commission and one of the study’s authors. The complete inventory can be viewed online at www.marinespecies.org
13 Nov 2012:
Gains in Antarctic Sea Ice Cover
Triggered by Wind Shifts, Study Says
Scientists say they have the first direct evidence that changes in Antarctic sea ice drift caused by changing winds have produced an increase in Antarctic sea ice
cover over the last two decades even as historic declines have been observed in the Arctic. Using more than 5 million measurements of daily sea ice movement collected over 19 years, researchers from NASA and the British Antarctic Survey detected long-term changes in sea ice drift
, a phenomenon that has caused overall increases in sea ice cover. While sea ice around Antarctica is constantly being blown away from the continent by northerly winds, the rate of ice movement in some areas has doubled since 1992, causing total sea ice, which reflects heat from the sun, to expand out from Antarctica, according to their findings, which were published in Nature Geoscience
. “The Antarctic sea ice cover interacts with the global climate system very differently than that of the Arctic, and these results highlight the sensitivity of the Antarctic ice coverage to changes in the strength of the winds around the continent,” said Ron Kwok of NASA’s Jet Propulsion Laboratory.
06 Nov 2012:
World’s Rarest Whale Species
Identified After New Zealand Beaching
Scientists have confirmed that two whales that washed onto the New Zealand coast two years ago were spade-toothed beaked whales, an enigmatic species so rare that no human is known to have ever seen one alive
. Writing in the journal Current Biology
, New Zealand and U.S. researchers provide the first full description of the species, which previously was known only from three skull fragments recovered over a 140-year span, the most recent of which was found 26 years ago. When conservation workers initially found the adult whale and her 11-foot male calf on a New Zealand beach in December 2010, they thought they were Gray’s beaked whales, a far more common species. But DNA tests of tissue samples collected from the animals revealed that they were actually spade-toothed beaked whales
), a species whose males have blade-like tusk teeth, and researchers later exhumed the whales to conduct additional tests.
05 Nov 2012:
China and Russia Block
Proposal to Protect Antarctic Waters
International talks to protect large areas of the Southern Ocean surrounding Antarctica collapsed last week
after several nations, including China, blocked the proposal over concerns about fishing access, according to reports. Representatives from 25 member states — including China, Russia, the U.S., the European Union — gathered in Australia to negotiate plans that would have protected approximately 4 million square kilometers in the Southern Ocean, including provisions that would have banned industrial fishing operations. Some regions would have also been set aside for scientific research into the effects of climate change on polar ecosystems. According to The Australian newspaper
, China and Russia were among the nations that rejected the plans. Alex Rogers, a conservation biologist at the University of Oxford, told Nature
that the stalled talks reflect a wider “global dichotomy” about how to manage marine resources, with some states looking to impose greater conservation and management policies and others targeting increased exploitation. “Time really is running out on these issues,” he said. “If we don’t get protection in place now, exploitation of these systems will increase.”
02 Nov 2012:
Sea-Level Rise Projections
Ignored Critical Feedbacks, Researcher Says
A U.S. researcher says projected sea-level rise over the next century has been underestimated because current models fail to consider several critical feedbacks
that might accelerate rising seas in the coming decades. While the 2007 report of the Intergovernmental Panel on Climate Change predicted that global sea levels could rise 0.2 to 0.5 meters by 2100, current projections suggest that seas could rise a meter or more. One of the factors ignored by earlier models, says University of Colorado geologist Bill Hay, is the influx of warm, briny ocean water into the Arctic that occurs when melting fresh water is released, a phenomenon he says acts as a sort of “heat pump” in the Arctic, adding more ice-free waters, which then absorb more solar energy. According to Hay, who will present his findings at the annual meeting of The Geological Society of America, another factor that was ignored is the potential melting of large ice sheets in Greenland and western Antarctica. A third feedback, he said, is the vast amounts of groundwater being removed to address humankind’s surging water needs, much of which ultimately ends up in the oceans.
01 Nov 2012:
Timelapse of Hurricane Sandy
Shows Birth and Death of Historic Storm
As the storm that was Hurricane Sandy weakened over Pennsylvania, NASA released a timelapse animation of the lifespan of the massive storm
, tracking its path from
the Caribbean, where it developed, to its violent landfall on the mid-Atlantic coast of the U.S. The collection of images, taken by the NASA GOES-13 satellite from Oct. 23 to Oct. 31, illustrates the storm gaining intensity as it traveled north, at times reaching nearly 1,000 miles in width. When the storm reached the mid-Atlantic on Oct. 29, it became wedged between a cold front over the Appalachian Mountains and a high-pressure air mass over maritime Canada, preventing it from moving north or east and instead driving it ashore. At that point Sandy became a Nor’easter, triggering historic storm surges in coastal areas of New York and New Jersey and blizzard conditions in the mountain regions. Meteorologists say the swath of high winds produced by Sandy while it was a hurricane covered nearly 2 million square miles
In New York, The Rising Threat Of
Flooding Was Predicted for Years
While climate experts hesitate to say Hurricane Sandy was caused by climate change, scientists for years have predicted that such devastating events would become increasingly common as sea levels rise and ocean
Rising Currents: A 2010 exhibit showed visions of New York adapting to climate change.
temperatures become warmer. For more than a decade, reports have warned that climate change will likely trigger more intense hurricanes and more frequent and severe flooding in low-lying areas
, such as occurred in New York and New Jersey. And with sea levels projected to rise by as much as six inches per decade by mid-century and as much as several feet by 2100,
experts say New York City’s flood zone will continue to expand
. In Sandy's wake, New York officials are starting to discuss projects that might withstand such surges
, including building a levee system or barriers.
25 Oct 2012:
Rapid Thinning of Glaciers
Seen After Collapse of Antarctic Ice Shelf
NASA has released satellite photos that vividly depict the precipitous thinning and retreat of two Antarctic glaciers
following the disintegration of the Larsen B Ice Shelf. That ice shelf — which floated on top of the
Weddell Sea and once was the size of Connecticut — collapsed in 2002 after several years of warm summer temperatures. The Larsen B had acted as a buttress slowing the flow of numerous glaciers into the sea. The NASA satellite images, taken in 2002 and in 2012, demonsrate how swiftly the Green and Hektoria glaciers behind the ice shelf surged into the ocean. The 2002 photo shows the glaciers covering much of nearby mountain ridges and the termini, or end points, of the glaciers are not visible. The 2012 photo shows that the thinning glaciers now cover considerably less of surrounding mountain ridges and the termini of both glaciers are visible. The 2012 image also shows the numerous crevasses that have formed as the glaciers have thinned.
24 Oct 2012:
Plastic Waste Increasing
On Remote Arctic Seabed, Cameras Reveal
Deep-sea cameras deployed to monitor biodiversity on the Arctic seabed have documented a significant rise in the amount of plastic waste and other litter
on the remote sea floors of the Far North, according to a new study. While looking at many thousands of seabed photos taken in 2011 between Greenland and the Norwegian island of Spitzbergen, deep-sea expert Melanie Bergmann of the Alfred Wegener Institute for Polar and Marine Research was struck by the number showing plastic waste. In a detailed analysis of the photographs — which are taken every 30 seconds by a deep-sea observatory reaching depths of 2,500 meters — Bergmann and her colleagues found that while plastic waste was seen in only one percent of photographs taken in 2002, that number had jumped to 2 percent in 2011. Two percent may not seem like a high occurrence, Bergmann said, but the quantities observed in this remote Arctic region were greater than recorded in a deep-sea canyon near Lisbon, Portugal. According to the study, published in the journal Marine Pollution Bulletin
, about 70 percent of the plastic litter had come in contact with deep-sea organisms.
22 Oct 2012:
Shifting Arctic Wind Patterns
May Cause Increased Melt, Study Says
U.S. scientists say unusual air pressure patterns over the Arctic during the month of June in recent years have altered wind patterns in the region, funneling warmer air into the Arctic and contributing to record low Arctic
Air pressure over the Arctic, 2007-2012.
summer sea ice extent from 2007 to 2012. Writing in the journal Geophysical Research Letters
, a team of researchers illustrated how the formation of two unusual high pressure areas over the North American Arctic and Greenland disrupted the normal westerly flow of winds, creating “blocking highs” that led to an unusually strong flow of warm southerly air. That sent more warm air into the central Arctic and Greenland
, which may have been a factor in unusually dramatic summer thaws beginning in 2007. While it is unclear why these unusual patterns of high pressure have occurred in each of the last six Junes, NOAA researcher James Overland believes it may be related to declining snow cover in the Canadian Arctic in recent years. “We don’t know that part of the story yet,” he said.
Solar Geoengineering Projects
Could Be More Effective on Regional Scale
A new modeling study by several geoengineering experts suggests that injecting aerosols into the atmosphere to block more of the sun’s energy and reduce temperatures could be most effective when done on a region-by-region basis
. The study, published in the journal Nature Climate Change
, said that injecting aerosols over the Arctic Ocean in summer, for example, might be an effective way to not only slow the rapid loss of Arctic sea ice but possibly even restore it to pre-industrial levels. The researchers — led by David Keith of Harvard University, Ken Caldeira of the Carnegie Institution for Science, and Douglas McMartin of the California Institute of Technology — cautioned that their models were rough and that bringing about changes in regional climate patterns can have global effects
. But they said the study shows the need for more detailed research into how solar geoengineering techniques could be used to slow or reverse the effects of climate change on rapidly warming areas. “Our research goes a step beyond the one-size-fits-all approach to explore how careful tailoring of solar geoengineering can reduce possible inequalities and risks,” said Keith.
19 Oct 2012:
Increased Ocean Acidification
May Alter The Acoustics of Seawater
Increased ocean acidification over the next century could alter the acoustic properties of seawater
, giving the planet’s oceans the same hi-fi sound they had during the age of the dinosaurs. In an analysis of ocean acidity over 300 million years, U.S. researchers David G. Browning and Peter M. Scheifele calculated that increased ocean acidity as a result of global warming will have a negative effect on the absorption of low-frequency sounds. By 2100, they predict, sounds near the oceans surface, such as whale songs or sounds created by ships, will travel perhaps twice as far as they do today. The scientists based their calculations on historic levels of boron in seafloor sediments and an analysis of its sound-absorption traits and impacts on low-frequency transmission. “[This knowledge] impacts the design and performance prediction of sonar systems,” said Browning, who will present the findings at the annual meeting of the Acoustical Society of America
. “It affects estimation of low frequency ambient noise levels in the ocean. And it's something we have to consider to improve our understanding of the sound environment of marine mammals and the effects of human activity on that environment."
18 Oct 2012:
Increased Nutrient Levels
May Drive Collapse of Salt Marsh, Study Says
Increasing levels of nutrients seeping from septic systems and lawn fertilizers may be driving the steady decline of salt marshes
that has occurred along the U.S. East coast in recent decades, a new study has found.
David S. Johnson/MBL
While scientists had long believed that salt marshes have an unlimited capacity for removing nutrients such as nitrogen and phosphorus, a long-term experiment by researchers at the Marine Biological Laboratory (MBL) at Woods Hole, Mass. found that nutrient enrichment can drive salt-marsh loss. Over nine years, the researchers added amounts of nitrogen and phosphorus to tidal waters flushing through salt marsh in an undeveloped coastal area consistent with the nutrient levels present in developed areas such as Cape Cod, Mass. and Long Island, N.Y. Within a few years, they observed wide cracks in the grassy banks of tidal creeks; eventually, the researchers say, the banks would collapse altogether into the creek. “The long-term effect is conversion of a vegetated marsh into a mudflat, which is a much less productive ecosystem,” said Linda Deegan, an MBL scientist and an author of the study published in Nature
16 Oct 2012:
Online Atlas Illustrates
Critical Areas for World’s Seabirds
A new online atlas provides the first global inventory of ocean sites critical to the world’s seabirds, a free digital resource that its creators hope will help guide protective policies and the creation of conservation areas globally. The site (www.birdlife.org/datazone/marine
was created by the group BirdLife International, identifies 3,000 important sites that are critical to seabirds, from penguins to sandpipers, including breeding grounds, foraging areas, and migration routes. These so-called “important bird areas” (IBAs) comprise about 6.2 percent of the world’s oceans, according to BirdLife International. While seabirds are particularly vulnerable to threats
because of the great distances they travel across international waters, many conservation groups have cited a lack of data as a reason for inaction in protecting these areas, Ben Lascelles of BirdLife International told Reuters