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Non-Climate Environmental Concerns |
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Male Bass Across Region Found to Be Bearing Eggs
Pollution Concerns Arise In Drinking-Water Source
By David A. Fahrenthold Washington Post Staff Writer September 6, 2006;
Abnormally developed fish, possessing both male and female characteristics, have been discovered in the Potomac River in the District and in tributaries across the region, federal scientists say -- raising alarms that the river is tainted by pollution that drives hormone systems haywire.
The fish, smallmouth and largemouth bass, are naturally males but for some reason are developing immature eggs inside their sex organs. Their discovery at such widely spread sites, including one just upstream from the Woodrow Wilson Bridge, seems to show that the Potomac's problem with "intersex" fish extends far beyond the West Virginia stream where they were first found in 2003.
The cause of the abnormalities is unknown, but scientists suspect a class of waterborne contaminants that can confuse animals' growth and reproductive systems. These pollutants are poorly understood, however, leaving many observers with questions about what the problems in fish mean for the Potomac and the millions of people who take their tap water from it.
"I don't know, and I don't think anybody knows, the answer to that question right now: Is the effect in the fish transferable to humans?" said Thomas Jacobus, general manager of the Washington Aqueduct, which processes Potomac water to provide drinking water for residents of the District, Arlington County and Falls Church.
Jacobus, like others at area utilities, said there was no evidence that tap water taken from the Potomac was unsafe to drink. They said humans should be far less susceptible to the river's pollution than fish, because people are not exposed constantly to the water, our hormone systems work differently, and our larger bodies should require higher doses of any pollutant to cause problems. As research on the fish continues, other scientists across the region are trying to determine whether Potomac water or mud can affect human cells. This research, including tests at West Virginia University that examine whether cells react as if estrogen or estrogen mimics are present, has not reached any solid conclusions. ...
Pollutants that mimic hormones have emerged as a worldwide concern in the past decade, blamed for problems in animals as diverse as alligators, minnows and polar bears. Although scientists say the research is in its infancy, they have identified a large array of pollutants that might affect animals, including human estrogen from processed sewage, animal estrogen from farm manure, some pesticides and additives to soap.
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| Vanishing Island |
A New Guinea island is disappearing below the water |
| "There used to be two rows of houses," said Mickey Tarabi, a wood carver in his 50s, nodding toward the crystal blue sea. "The first one has been moved, and the second one will be gone soon." |
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The failure of last year's Pacific upwelling killed seabirds from California to British Columbia. Scientists had hoped the change was just a natural temperature fluctuation in what is known as the California Current.
But the return of higher ocean temperatures and scarce food resources this year has scientists wondering whether last year's erratic weather was not a fluke but the emergence of a troubling trend.
The Farallones present a special case. Researchers have kept Cassin's auklet counts there every day since 1967. Never before have they seen such a drop-off in numbers. That decline comes as California ocean temperatures hover three to five degrees above average.
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Timeline Says Climate Is Culprit
This much is clear: most of North America's largest mammals, including the woolly mammoth, disappeared about 13,000 years ago, as the last ice age came to an end. Why that happened, however, is a subject of great debate.
Some scientists think climate change was responsible, causing a shift in vegetation that favored certain animals over others. Others blame people, who arrived on the continent around the same time.
Humans may have hunted the mammals to extinction, the so-called overkill hypothesis. They may have brought diseases that had the same cataclysmic effect. Or they may have only wiped out the mammoths, a "keystone" grazing species whose disappearance could have had a ripple effect by altering vegetation.
While it won't end the debate, R. Dale Guthrie of the University of Alaska has compiled an extensive fossil timeline for the period that argues in favor of climate change, at least in what is now Alaska and the Yukon. The findings are in the May 11 issue of the journal Nature.
The research involved radiocarbon dating of many fossils of two extinct mammals, the Eurasian wild horse and mammoth, as well as others that survived the period, like bison and wapiti. The findings show that surviving species actually increased in number in the early part of human influx, even though there is evidence that they were hunted.
That argues against overkill. And horses became extinct in the region well before mammoths — a pattern that argues against the mammoth as a keystone species, and against the disease hypothesis (which would have caused simultaneous extinctions).
Instead, Dr. Guthrie suggests, climate-induced changes in vegetation from grassy steppes to a more tundralike terrain with woody plants was probably the major cause of the extinctions. NYTimes
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Something is Damaging Frogs on a Global Scale "The frogs are sending an alarm call to all concerned about the future of biodiversity and the need to protect the greatest of all open-access resources - the atmosphere," write the scientists, Andy Dobson, a Princeton University ecologist, and Andrew R. Blaustein, a zoologist at Oregon State University.
More than 110 species of brightly colored harlequin frogs, in the genus Atelopus, once lived near streams in the tropics of the Western Hemisphere, but about two-thirds of them have vanished since the 1980's.
Frog PDF deformed frogs
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Changing climate changes habitat and behavior. For example, as the climate warms, bird begin nesting earlier. Earlier nesting means that birds will be a week or so older when the time come to migrate south, which may improve their odds of survive their first winters. The changing climate, however, may impair the extent to which a bird’s life cycle is synchronized with its food supply. While birds can adjust to warmer temperatures by flying to more northern areas in any given year, the vegetation upon which they (or the insects they eat) rely may take decades or longer to adjust (see forests).
In some cases, the habitat upon which birds rely may not only fail to migrate north, it may be threatened in its current location. The loss of estuarine beaches caused by rising sea level would decrease available habitat for the least tern, an endangered species; the loss of these beaches also would decrease feeding areas for shore birds that rely on horseshoe crabs and other organisms found in inter-tidal areas By decreasing estuarine fish and shellfish populations, the loss of coastal wetlands would decrease available food supplies; and the loss of wetlands would also decrease available habitat. The loss of Louisiana’s wetlands could have a particularly adverse impact on international migratory birds that travel along the Mississippi flyway.
Similarly, the decline in prairie potholes would decrease duck populations. The prairie potholes in the northern Great Plains are responsible for breeding 50-80% of the nation’s duck population. A drier climate would decrease the amount of open water ponds in this region, with a commensurate reduction in duck populations. Scientists at the University of Michigan and Ducks Unlimited have estimated that a 1°C (2°F) warming would decrease duck populations by about 25 percent if rainfall were to remain constant
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Washington Post
Mountaintop removal is in again, and dumping the mountain tops into streambeds is protected, thanks to a small wording change to federal environmental regulations.
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The U.S. Department of Energy
The DOE's mission is "to advance the national, economic, and energy security of the United States; to promote scientific and technological innovation in support of that mission; and to ensure the environmental cleanup of the national nuclear weapons complex."
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Environment: One in four Americans live within four miles of a Superfund toxic waste site. Nine years after the expiration of the polluter pays fees, the Superfund trust fund is now bankrupt, with the number of cleanups falling significantly, and taxpayers, rather than polluting industries, footing the entire bill (U.S PIRG).
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http://zfacts.com/p/47.html | 01/18/12 07:16 GMT
Modified: Tue, 10 Oct 2006 03:37:38 GMT
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