Is global warming concentrating Mercury in Arctic food-chain?
March 17, 2008
A Euronews report on contamination of the arctic food chain with high concentrations of methylmercury, a highly toxic form that builds up in fish and the animals that eat them.
European researchers are taking a close look at polar precipitation, trying to understand more about concentrations of mercury at the North Pole. It’s part of a wide range of research projects undertaken for the “International Polar Year.” Scientists are looking into how and why the highly toxic heavy metal is finding its way into the food chain.
Ice crystals, mercury implicated in Arctic pollution
University of Michigan report:
Frost flowers. Diamond dust. Hoarfrost.
These poetically named ice crystal forms are part of the stark beauty of the Arctic. But they also play a role in its pollution, according to a new study by scientists at U-M, the Cold Regions Research & Engineering Laboratory and the University of Alaska.
After collecting and analyzing hundreds of samples from the Alaskan Arctic, the researchers determined ice crystals that form from vapor clouds billowing up from cracks in sea ice help concentrate mercury from the atmosphere, and certain types of crystals are more efficient than others. Their results appear in the cover article for the March 1 issue of Environmental Science & Technology.
“Previous measurements had shown that in polar springtime, the normally steady levels of mercury in the atmosphere drop to near zero, and scientists studying this atmospheric phenomenon had analyzed a few snow samples and found very high levels of mercury,” says Joel Blum, the John D. MacArthur Professor of Geological Sciences. “We wanted to understand what’s controlling this mercury deposition, where it’s occurring and whether mercury concentrations are related to the type and formation of snow and ice crystals.”
Mercury is a naturally occurring element, but some 150 tons of it enter the environment each year from human-generated sources, such as incinerators, chlorine-producing plants and coal-fired power plants, in the United States. Precipitation is a major pathway through which mercury and other pollutants travel from the atmosphere to land and water, says lead author Thomas Douglas of the Cold Regions Research & Engineering Laboratory in Fort Wainwright, Alaska.
Once mercury from the atmosphere is deposited onto land or into water, micro-organisms convert some of it to methylmercury, a highly toxic form that builds up in fish and the animals that eat them. In wildlife, exposure to methylmercury can interfere with reproduction, growth, development and behavior and may even cause death. Effects on humans include damage to the central nervous system, heart and immune system. The developing brains of young and unborn children are especially vulnerable.
Dream underwater filming rig
March 15, 2008
In an dream underwater filming world I would put together a rig which would give me extra mobility and speed, increase my bottom-time and shoot HD format footage with lights, all contained in the one unit. Although this is theoretical, the equipment (separates) is out there to do it. The Seabob high-powered underwater scooter will take you down to 40m at speeds of nearly 20km/h. Fit this out with a lightweight O2ptima FX rebreather and a Gates XL-H1 housing with lights and I reckon you’re pretty much there.
For ‘Aliens’ fans out there, now imagine adding a personal 360-degree sonar device with a 200/300m range and your ready to go!
Sea Cucumber Inspires Nano-Material
March 14, 2008
Scientists have created a breakthrough substance that can change in seconds when exposed to liquid, shifting from hard plastic to soft and back again, and that has a wide range of potential medical applications.
The material — inspired by the skin of sea cucumbers — has astounding “mechanical morphing characteristics,” according to an article published in the latest issue of Science.
Researchers said a plethora of possible biomedical applications exist for the malleable new material, including as part of “artificial nervous systems” for patients with Parkinson’s disease, stroke or spinal cord injuries.
Sea cucumbers, found on ocean floors around the world, have leathery skin, an elongated, cucumber-like shape, and a consistency that can be either gelatinous, stiff and rigid, or anything in between.
This “switching effect” in the tissue of the sea cucumber is derived from a distinct nanocomposite structure in which highly rigid collagen nanofibers are embedded in a soft connective tissue.
Now the school of engineering at Case Western Reserve University and researchers at the Louis Stokes Cleveland Department of Veterans Affairs Medical Center have succeeded after years of effort in mimicking the unusual architectural structure of the sea creatures.
Hammerhead in need of protection
March 14, 2008
Over-fishing and demand for shark fins, an expensive delicacy, have pushed one of the world’s iconic animals towards the brink of extinction, say experts.
The scalloped hammerhead shark is to be added to the official endangered species list this year, under the heading “globally endangered”.
Their plight has been discussed at the American Association for the Advancement of Science annual meeting.
It was told that enforcement of marine reserves would aid shark protection.
The observation takes account of new research that shows hammerhead and great white sharks patrol fixed routes in the ocean, gathering at hotspots to mate or feed.
Dr Julia Baum, a marine ecologist at the Scripps Institution of Oceanography, US, and a member of the World Conservation Union (IUCN), said excessive fishing was putting many of the ocean’s “most majestic predators” at risk of extinction.
Speaking at the Boston meeting, she said: “Sharks evolved 400 million years ago, and we could now lose some species in the next few decades – so that would be just a blink of an eye in evolutionary time.”
She said conservation concern for sharks had been mounting for several years, and it was now critical that there was effective management action in order to restore and conserve their numbers.
Russia: Archangel bloody seal pup cull halted
March 13, 2008
The blood of baby seals stains the snow red during the traditional cull in the Archangel region of northern Russia each March. But the slaughter of thousands of seals, many only a few days old, has been halted this year amid protests by celebrities and environmental groups, and calls for hunting to be outlawed.
Officials in Archangel insisted that the cull had been cancelled to protect the hunters, not the seals, because ice sheets close to the White Sea were too thin to walk on.
The decision, however, came at a time of heightened protests by animal rights groups. Russian television broadcast a demonstration in Archangel by a group of celebrities and prominent journalists against the practice.
Hunters were shown clubbing baby seals with ice picks, leaving them to bleed to death before they were skinned for their white fur. One report showed a seal struggling for life in icy water surrounded by its own blood.
