The long-standing controversy over the effect of sonar signals on whales has festered over the years primarily due to that fact that the whale's supposed adverse reaction to the electronics sounds was theorized, implied, but never definitively proven. All evidence was anecdotal. Friedlaender" height="167" width="250">By studying whales fitted with electronic tags, researchers have been able to ascertain that beaked whales alter their behavior in response to naval sonar. Friedlaender, U.S. Navy |
Researchers from the Woods Hole Oceanographic Institution (WHOI) have become the first to conclude definitively that naval sonar affects whale behavior and movement. This follows years of anecdotal evidence linking naval exercises with mass strandings of several species of cetaceans. The research team developed experiments to slowly increase the level of sonar directed at a tagged whale, to stop exposure as soon as the whale started responding, to measure that exposure and to define the response.
"These experiments were very difficult to develop, and it was a major breakthrough simply to be able to develop a study that could safely study these responses," said Peter Tyack of WHOI, the lead author of the study, which was published in the online open-access journal PLoS One. "All three times that tagged beaked whales were exposed experimentally to playback of sounds when they were foraging at depth, they stopped foraging prematurely and made unusually long and slow ascents to the surface, moving away from the sound."
The team then monitored reactions of beaked whales during actual sonar exercises on a naval testing range where an array of underwater microphones, or hydrophones, covered the seafloor, allowing whale sounds to be monitored over 600 square miles (1,554 square kilometers). "During actual sonar exercises, beaked whales were primarily detected near the periphery of the range, on average 10 miles (16 kilometers) away from the sonar transmissions. Once the exercise stopped, beaked whales gradually filled in the center of the range over 2 to 3 days," they write. In a press release, Tyack said that the research shows beaked whales are particularly sensitive to sound, and that they altered their behavior when exposed to sound levels below those previously believed. But, he added, "The observations on the naval range suggest that while sonar can disrupt the behavior of the whales, appropriate monitoring and management can reduce the risk of stranding."
Source: Tyack, P., et al. 2011. Beaked whales respond to simulated and actual navy sonar. PLoS One 6(2011): e17009; doi:10.1371/journal.pone.0017009.
Surfbird News reports on all things related to coastal surfbirds and the environments that support them. The site recently reported on the findings of an international consortium of scientists on the impact on CO2 sequestration with the loss of coastal ecosystems like mangroves and marshlands. The destruction of coastal carbon ecosystems, such as mangroves, seagrasses and tidal marshes, is leading to rapid and long-lasting emissions of CO2 into the ocean and atmosphere, according to 32 of the world’s leading marine scientists.
That key conclusion highlights a series of warnings and recommendations developed by the new International Working Group on Coastal “Blue” Carbon, which convened its first meeting in Paris last month. The Working Group was created as an initial step in advancing the scientific, management and policy goals of the Blue Carbon Initiative, whose founding members include Conservation International (CI), the International Union for Conservation of Nature (IUCN), and the Intergovernmental Oceanographic Commission (IOC) of UNESCO.
Much of the carbon emitted when mangroves, seagrasses or tidal marshes are destroyed is estimated to be thousands of years old because the CO2 stored in these ecosystems is found not only in the plants, but in layer upon layer of soil underneath. Total carbon deposits per square kilometer in these coastal systems may be up to five times the carbon stored in tropical forests, due to their ability to absorb, or sequester, carbon at rates up to 50 times those of the same area of tropical forest. The management of coastal ecosystems can supplement efforts to reduce emissions from tropical forest degradation.
Dr. Emily Pidgeon, Marine Climate Change Director at Conservation International, and a leading blue carbon conservation scientist emphasized, “We have known for some time the importance of coastal ecosystems for fisheries and for coastal protection from storms and tsunamis. We are now learning that, if destroyed or degraded, these coastal ecosystems become major emitters of CO2 for years after the plants are removed. In the simplest terms, it’s like a long slow bleed that is difficult to clot. So we need to urgently halt the loss of these high carbon ecosystems, to slow the progression of climate change.”
“The capacity of coastal wetlands to reduce climate change by capturing and storing carbon dioxide is considerable, but has been overlooked” says Jerker Tamelander, Oceans and Climate Change Manager for IUCN. “If valued and managed properly, coastal ecosystems can help many countries meet their mitigation targets, while supporting adaptation in vulnerable coastal areas.”
Read the entire article in Surfbird News.
WASHINGTON -- The flowering trees that symbolize friendship between the United States and Japan are blooming for the 99th time in Washington in the wake of one of the world's worst natural disasters.
If you love nature — or live entertainment— this is the time to escape to the Coachella Valley.
With corals reefs being assaulted, it would seem, from all directions with global warming, pollution, and damage from urban development or tourism pressure all taking its toll; would it not be a valuable tool to have the means to gauge a reef's susceptibility to various environmental pressures, to be able to determine whether one reef has a better chance of survival over another?
The unfortunate reality to all of this is that, while it would seem to be advantagous to be able to clearly identify regions that deserve protection based on those that would appear to have a more promising future, the flipside would imply that some regions would be sacrificed, basically written off because limited management resources would only be able to focus on those coral reefs with the best chance of survival in today's conditions.
Environmental artist Wyland, who painted the whale mural at Underground Atlanta, returns to Atlanta for the first time in nearly 15 years to paint an 8’ x 25’ mural at the Georgia Aquarium. The painting will kick off the Wyland Foundation’s 4th annual Clean Water Challenge Tour, with stops by Wyland to paint in the Rockies, Great Lakes, Chesapeake Bay and everywhere in between. All part of the National campaign to raise awareness on need to preserve clean water.
Botanical gardens - those quiet sanctuaries where folks go to stroll amongst flower and trees, contemplating the fate of the world - or escaping from it for a few precious minutes. Not exactly a place that you would consider as a hotbed of invasive species activity, now would you?
As expected, the botanical garden community is not particularly pleased with Hulme's research and conclusions. Stephen Blackmore, head of the Royal Botanic Garden Edinburgh, U.K., says that while botanical gardens may have been interested in introducing non-native species - but lax in protocols - in the past, today they are much more mindful of the consequences and that it is home gardeners and the horticultural trade that probably deserve greater inspection.
The Palm Springs Aerial Tramway takes passengers more than 8,500 feet up into the San Jacinto Mountains, part of the Santa Rosa and San Jacinto Mountains National Monument. 
Sharks have amazing skin - sleek and smooth when felt in one direction, as rough as sandpaper when felt in another. Shark skin is built on denticles, rather than scales, which is similar to the compounds that also make up the predator's teeth. In many species of pelagic, or open ocean, sharks, the skin is tightly woven and very hydrodynamic, making it impervious to many but not all of the ocean parasites that are floating about looking for a host and a free ride.
In tropical environments, the cleaner wrasse, or bluestreak wrasse, is known for staying in one area, establishing a "cleaning station" where large fish will hover patiently while the cleaner wrasse goes about its work - an oceanic car wash of a sort. In colder climates, fish like the senorita, another type of small wrasse, perform the same function. Oliver suspects that, while not all species of shark are able to literally stop and hover while getting a grooming, he did see evidence of sharks coming in close and getting a beneficial once-over by resident cleaner fish."It's like a lion at a waterhole with an antelope. Its thirst takes precedence over the natural order of things. The grey reef shark could easily take a bite out of a thresher, or a ray, but doesn't, which shows the necessity for these cleaners" said Oliver.
Not all sharks will swim to sea mountains or coastal reefs to take part in this kind of dermatological hygiene. Makos and white sharks can be observed with long, hair-like streamers along the edges of their fins - the telltale sign of established parasites. But it is another fascinating aspect of behavior in the ocean environment that even pelagic animals, like some species of shark, have come to recognize and take advantage of what the reef fish community has to offer other than being a source of prey.
Read more about shark cleaning in the BBC News.
Dead Zones - an alarming term used to describe aquatic areas where oxygen levels are so greatly reduced as to push out or kill most fish, plants, and shellfish. It's a dramatic descriptor for the extreme end result of two much more complex processes: eutrophication and hypoxia. While both of these can occur naturally, they are also increasing with greater frequency due to man-made causes.
However, eutrophication is often caused by the introduction of fertilizers and treated or untreated sewage. And when this happens there begins a series of cascading disturbances that can ultimately lead to a dead zone. Everything from increased nitrogen which upsets the proper balance of dissolved nitrogen and oxygen levels; the expanded growth of algae and phytoplankton which can reduce sunlight, upsetting the process of photosynthesis that produces oxygen and impacting bottom dwelling creatures; a feedback loop that is generated by more decaying plant material from the increase algal growth - all begin to enter into the picture at varying degrees.
