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Endangered Species Essay, Research Paper

White, wild, and wonderful

Before European settlement, as many as 150,000 trumpeter swans populated the Eastern United States. By the end of the 19th century, they were all gone, victims of pioneer settlers who wanted their meat, or of hatters, who wanted their feathers. (Hatters played a surprisingly large role in the conservation movement: their use of feathers from the great blue heron and the bald eagle helped spark the formation of the Audubon Society and the passage of laws protecting migratory birds.)

When the streams, lakes and marshes of the Eastern United States lost the trumpeter swan, they lost a majestic bird whose snowy white feathers contrast with jet-black bills, legs and feet. With a wingspan between 7 and 8 feet, the swan is the largest waterfowl in the United States; males can weigh 35 pounds.

“It’s an absolutely stunning sight, on a fall morning, in the fog, to see this pure white bird with its black bill,” says Sumner Matteson, an avian ecologist with the Wisconsin Department of Natural Resources (DNR) who is participating in a reintroduction project. “In these still mornings, it has one of the most haunting calls you’ll ever hear.”

After two years of false starts, DNR biologists began collecting eggs in Alaska in 1989. The swan’s historic breeding range extends in a wide band from the Bering Sea east through most of Canada and south to Missouri, Illinois, and Indiana. The Alaska population was healthy, and removing 50 eggs per year causes no harm.

The eggs were incubated and hatched at the Milwaukee County Zoo. From there, cygnets (defined) went into one of two programs:

Captive rearing

Cygnets are raised in pens on the shore of a pond for 12 weeks. Then they are allowed to roam the entire pond (with some flight feathers removed, they can’t fly). After two years on the pond, they are transported to wetlands in northern Wisconsin and released.

Decoy rearing

Five days after hatching, cygnets are flown to wetlands in northern Wisconsin, separated into groups of up to 10, and tended by University of Wisconsin-Madison undergraduate interns for the summer. The intern gets to sit inside the blind mounted on an inner tube and linked to a swan decoy. While ushering the cygnets around to feeding spots, the interns can trigger a hidden tape recorder that plays a warning call when a great horned owl, coyote, fox, bear or human is present. The birds must be taught to fear predators, Matteson says.

The work is soggy but satisfying. In return for wading around all summer long, wildlife ecology students inside this blind-decoy contraption get to watch a marsh up close and personal while “baby-sitting” groups of cygnets. Goal: to simulate behavior in the wild that will allow cygnets to survive with little or no human contact. Specifically, the swans must recognize food, fear danger, and come when they hear the “follow me” call. Photo courtesy of Sumner Matteson.

After seven years of releases, Matteson says, the free-living population in Wisconsin has reached 100 birds, and the project is nearing its goal of having 20 nesting pairs in the wild. In addition, Minnesota, Iowa, Michigan, Ohio and Ontario, Canada, are in various stages of reintroducing trumpeter swans.

Despite the success, problems remain. The majestic swans are being poisoned from eating lead shot pellets, which still pollute the bottom of wetlands even years after they were banned. Just a pellet or two, Matteson says, is enough to kill a swan, or sicken it, making the bird easy prey for predators.

And hunters continue to shoot swans, either because they don’t know that the bird is protected by federal law, or because they can’t distinguish swans from smaller birds. (The only white waterbird that can be mistaken for a trumpeter swan is a snow goose. But snow geese are less than half as large. And they have black feathers on their wings; the trumpeter swan’s feathers come only in white.)

Still, the project, which is funded mainly by private donations, is succeeding, says Matteson. “Trumpeters are a symbol of nature’s majesty, and a wonderful vehicle for promoting wetland conservation in the state. They’re ambassadors.”

Here’s what the Fish and Wildlife Service has to say about this fine, feathered friend.

How do you train captive animals that are born to be wild?

Furry or feathery creatures get all the headlines, but plants need help, too.

How serious, overall, is the threat to biodiversity in the United States? A study by the Nature Conservancy, found that “about one-third of U.S. plants and animals are of conservation concern,” meaning they were in some danger of being eliminated from at least part of their ranges.

Despite all the attention devoted to endangered animals, members of the plant kingdom are also imperiled, the report said. “Plants…receive low marks overall, with many of our most beautiful wildflowers in peril,” the report said. “A startling 5,121 flowering plant species are at risk, fully one-third of their total number.”

The threat to plants

percent number

presumed extinct 0.1 17

possibly extinct 1.0 159

critically imperiled 6.3 979

imperiled 9.6 1,486

vulnerable 15.8 2,480

total flowering plants 100 15,495

Source: Priorities for Conservation.

Here’s a letter from Hawaii on work to preserve the state’s critically endangered plants.

Another indication of the rate of plant extirpation (defined) and extinction came from a recent study of Middlesex Fells, a 1,000-acre park north of Boston. Expert botanists who surveyed the park in 1894 found 422 plant species. Less than 100 years later, after a century as a protected park, only 300 of those species were found in the area.

The disappearances were blamed on trails (which open up the forest and allow it to dry out), trampling by visitors and fires. Fragmentation of nearby habitat by roads and development may have prevented plants from being pollinated, or seeds from being dispersed by invertebrates (see Plant Census Raises the Alarm…).

An additional cause of the missing plants was the arrival of 64 exotic plants, whose rapid growth and adaptability allowed them to colonize ground quickly at the expense of the native species. Biologists have come to recognize that these invasive exotic species are a major cause of species extirpations worldwide.

Yet the dramatic disappearance of 122 plant species might have been missed without a careful study, since it equaled “only” a bit more than 1 species per year.

On the brighter side, amateur and professional botanists in New York State have rediscovered 61 rare plants that had not been seen for at least 15 years in the state. The “Lazarus” species included nine grasses, 13 sedges, seven aquatic plants, and 32 wildflowers (including two orchids). The average length of time since the last sighting was 46 years.

What about the genetics of species reintroductions?

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Big trouble in the deep blue sea

POSTED 4 MARCH 1999. In Florida, new disease with medieval names like black band disease, white plague and white pox are devastating corals. Reefs, a bedrock of marine biodiversity, have been silently suffering for years — only more slowly. A new study by James Porter of the University of Georgia found a 446 percent increase in the number of diseased sites — and a 244 percent increase in the number of sick coral species — between just 1996 and 1998.

Another threat to ocean ecosystems and coastal economies is the rise of invasive exotic species. On the Pacific Coast, European green crabs are on an underwater march toward Puget Sound, where they threaten productive shellfish beds. The crabs are soldiers in an army of aquatic intrusions that earlier brought the disastrous zebra mussel to the Great Lakes.

In North Carolina, fish, fishing people and scientists alike are being stricken by nerve diseases caused by “red tide” algae.

The algal toxin undermines the ability of fish and shellfish to protect themselves. It makes people confused and forgetful, and can cause month-long headaches.

It’s not just new maladies that are plaguing the ocean. Old diseases like cholera are responding to the warmer sea temperatures and rising sea levels of global warming.

Feeling crabby

The great blue ocean. A healing, healthy cloak on our watery planet. A limitless resource that’s immune to human destruction.

That’s not quite the picture we took away from 1999 meeting of the American Association for the Advancement of Science in Anaheim, Calif., this January. Before you read this Why File on emerging oceanic hazards, read this caution: Swimming and surfing may never be the same.

Packing for the beach? Where disease-causing viruses are concerned, “flush and forget” is not the safest solution…

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Hepatitis A virus. Courtesy of the Centers for Disease Control. .

Didn’t swim in the water

The chamber of commerce might not tell you, but ocean water can be hazardous to your health. Don’t believe us? Check the evidence. Windsurfers who fall more often get sick more often. Among surfers, and canoeists and swimmers, “More exposure leads to more disease.” That’s the word from Joan Rose, a microbiologist with the University of South Florida Department of Marine Science.

Rose, who studies contamination of shoreline water, says a disturbing number of pathogenic viruses appear in those waters, causing infections of the skin, eye, ear and stomach. Most illnesses are transitory, but in a small percentage of cases, damage to the heart, liver or other organ causes long-term disease.

More than 100 enteric (gut) viruses can move from human feces to wastewater. Viruses are much smaller than bacteria, and that “allows rapid transmission through soil and water,” Rose says. The seaside villains include hepatitis A, a cause of serious liver disease; and coxsackie B, which is thought to attack the heart.

Don’t touch that fork!

Coastal populations are soaring. Beaches are a favorite vacation destination. And shellfish is popular food. Adding it up, scientists warn about more disease from water-borne viruses.

Why do they pick on shellfish when discussing diseases associated with the ocean? Because those poor oysters or clams resting on the ocean floor make a living by patiently extracting nutrients from seawater. That filtering mechanism makes shellfish beds targets for invading toxins and viruses, and excellent indicators of water pollution.

It also makes them questionable food.

How are human viruses entering near-shore waters? A major culprit is antiquated — or non-existent — sewage treatment. In Florida, where Rose works, septic tanks, designed to degrade sewage a bit before it seeps into the subsurface soil and rock, quickly leak into groundwater.

At least in Florida, septic tanks — not to mention the even more primitive “cesspits” don’t work. If you flush something down a toilet today, you can find it tomorrow in the nearby ocean.

Don’t touch that plunger!

Rose’s scientific technique was simplicity itself. Her research group grew a harmless virus, then flushed it down toilets in homes with septic tanks or cesspits. Over the next week or so, they sampled the nearby ocean for the virus, using a test able to detect one viral particle in 10 liters of water.

In some studies in the Florida Keys, the marker viruses were found within 24 hours in shellfish beds a mile offshore. The movement was propelled by heavy rain and “tidal pumping,” the motion of the groundwater caused by tides. In another study, open shellfish beds in Charlotte Harbor, Fla., were contaminated with infectious human waste. That’s according to Erin Lipp, a graduate student in marine sciences at the University of South Florida.

As evidence gathers about the presence of viruses in the near-shore waters, the dispute is shifting from science to politics. The best way to clean up is to build sewers and a modern sewage treatment plant, which kills most pathogens in sewage. Since that’s expensive — one Florida estimate came to $10,000 per household — scientists are trying to pin down the risk and help regulators focus on the worst sources first.

Costly cleanup

The “worst go first” approach focuses on older homes with rudimentary sewage “treatment.” The U.S. has already banned cesspits, says Rose.

Still unknown is how much cleanup will make a difference. Would, for example, cleaning up half the sewage reduce viral contamination enough to matter, or is a much greater reduction required?

Scientists trying to prevent ocean-borne disease are running up against antiquated regulations. D. Jay Grimes, director of the Institute of Marine Sciences at the University of Southern Mississippi, says the present approach to assuring clean water — counting harmless bacteria t

at originate in the human intestines — misses the point. “We have predicted the risk based on fecal coliforms,” he says. “But they don’t correlate with viruses, most bacteria, fungi, protozoa or helminths,” all known causes of human disease.

Rather than rely on indirect indications, Grimes says regulators should identify pathogens directly with molecular biological techniques.

Can scientists assess ocean-borne diseases without flushing a toilet?

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1999, University of Wisconsin, Board of Regents.


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