VOA慢速英语2009年-SCIENCE IN THE NEWS - On Chesapeake Bay, a（在线收听）

VOICE ONE:

This is SCIENCE IN THE NEWS in VOA Special English. I'm Bob Doughty.

VOICE TWO:

And I'm Shirley Griffith. Today we tell about efforts to save an island in the American state of Maryland. Poplar Island lies about fifty-five kilometers south of Baltimore, in the Chesapeake Bay. This historic waterway opens into the Atlantic Ocean.

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VOICE ONE:

People sailing on the Chesapeake Bay often comment about the beauty of the area's water and wetland birds. Uncounted birds have lived in the area for centuries.

But by nineteen ninety, an island important to the birds was sinking. Winds, water and time had reduced Poplar Island to only a few pieces of land. All the land together measured only one and one half hectares. Sometimes, water threatened to cover all of what remained. Birds lost areas where they traditionally lived and reproduced.

But now birds are returning to the island. Poplar Island is in the process of rebirth.

VOICE TWO:

Many birds make a home on Poplar Island today. The island now measures four hundred sixty-one hectares, about the same size as in the eighteen eighties. The birds will have even more space in the future. The island is expected to grow by another two hundred thirty-three hectares.

Poplar Island shows what can happen when many people and organizations cooperate.

In nineteen ninety-four, engineers and government agencies joined to plan a possible rescue of Poplar Island. The United States Army Corps of Engineers, the Maryland Port Administration and other groups became partners in the effort. Environmental activists and people who live near the island supported the campaign.

VOICE ONE:

The planners thought a Poplar Island rescue could help the port of Baltimore. They wanted to find a new place to put material dug up from shipping channels leading to the port. Each year, container ships carry thousands of tons of goods to Baltimore. The ships need deep waters for the trip. The shipping channels must be dredged, or cleared, of silt, a fine-particle material.

One plan called for dropping the dredged material in deep waters. But environmental activists and people who lived along the coastline objected. They said the dredged material would reduce water quality. So, the planners asked, why not re-use the material to rebuild Poplar Island? The planners believed the idea would meet the needs of the port of Baltimore. A rebuilt island also would help return thousands of water birds to the Chesapeake Bay.

VOICE TWO:
　
An Osprey nest

The project was approved in nineteen ninety-six. The following year, the Army Corps of Engineers signed a Project Cooperation Agreement with the state of Maryland. The agreement called for the Army engineers to lead the rescue of the island.

Experts would return grasses, plants and trees to Poplar Island. Underwater plants would recover, leading more birds to return. The birds would build nesting areas and produce young on the island. And, the island could provide an example for other areas interested in similar projects.

Work started in nineteen ninety-eight. The project is now called the Paul S. Sarbanes Ecosystem Restoration Project at Poplar Island. The name honors Mister Sarbanes, the Senator who led the campaign for the project in the United States Congress.

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VOICE ONE:

Kevin Brennan leads the Poplar Island project. He says the project will cost six hundred sixty-seven million dollars. The federal government has paid most of the money, sharing the cost with the state. Completion is expected by about twenty thirty-four.

Much work has already been done. Flat-bottom boats have carried eighteen million cubic yards of dredged material to the island. When a boat arrives, the material is cleaned and dried. Machinery pumps the dry material onto the island. Then it is shaped to build up the land. About forty hectares have been completed.

The Chesapeake Bay sometimes flows over the wetlands, which cover half the land. Plantings in the wetlands help hold down the soil against the forces of erosion, like wind and water.

VOICE TWO:
　
Terrapins

In June, volunteers placed seventy-six thousand spartina plants in a wetlands area. Spartinas are a kind of saltmarsh grass. They traditionally are a home for wild birds and prevent erosion.

The volunteers placed the plants about five centimeters into the soil to prevent rising and falling water levels from pulling them out. Volunteers also built barriers to keep hungry geese from eating the spartina.

Students from the Marriotts Ridge High School in Maryland volunteered for the project. Besides planting, the students also released terrapins on the island. The terrapins joined thousands of other turtles there. The National Aquarium in Baltimore helped organize the release with other groups.

VOICE ONE:

Later in June, prisoners also worked on the island. They are part of a state program called Maryland Correctional Enterprises. The program is meant to help prisoners develop work skills for the time after they serve their sentences.

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At one time, poplar trees must have grown on Poplar Island. But there are no poplars there now. Instead, northern pines and hardwood trees will rise on the higher half of the land, which is called Upland.

Even dead trees have found their way to the island. Trees thrown away after the winter holidays are part of the recycling process. Kevin Brennan of the Poplar Island Project says ducks like to build their homes on the dead trees.

Winter brings workers and machinery to the island. But the noise does not seem to frighten the birds.

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VOICE ONE:

March seventeenth is the day many Americans celebrate Saint Patrick's Day. Mister Brennan says ospreys also mark that day. Every year, he says, ospreys return to Poplar Island to build their homes on March seventeenth.

The project leader says some of the birds place pieces of wood on heavy machinery like bulldozers. Workers remove these sticks to use the machinery. But when the workers return the next day, the birds have replaced the sticks.

Mister Brennan says about one hundred seventy kinds of birds use the island for a nesting place. Sometimes a heron can be seen standing on one thin leg, motionless.

Sandpipers, snowy egrets and eagles also are among the many kinds of birds of Poplar Island. They share the territory with animals like white tailed deer, river otters and mice.

VOICE TWO:

No people live on the island now. And no one will live there when the project is completed. But it was not always unpopulated. Native American tribes once grew vegetables like beans and corn throughout the Chesapeake coastal plain.

The first known European settlement on Poplar Island was established in the sixteen thirties. Around that time England gave the land to Richard Thompson, a trader and explorer. For a few years, the settlement grew.

Then tragedy struck. One day Thompson returned to Poplar Island from a trip and made a horrible discovery. Some settlers had been murdered. But the crime did not stop people from continuing to live on the island.

VOICE ONE:

Later, British troops occupied Poplar Island during the War of Eighteen Twelve. Historical records say a trader bought the island in eighteen forty-four. He wanted to keep one thousand cats there to produce black cat fur. But the animals escaped to the mainland when waters on the Chesapeake Bay froze in December.

Until the early nineteen hundreds, Poplar Island had mail service, a store and a school. But nature was cruel. By the nineteen twenties, erosion from winds and weather had removed a large part of the land.

VOICE TWO:

Still, some politicians bought the island in the early nineteen thirties. They thought the wildlife and distance from Washington, D.C. would make a good place for people wishing to get away from the city. They built a clubhouse on a piece of land that had separated from the main island.

Presidents Franklin D. Roosevelt and Harry Truman used Poplar Island and nearby Jackson Island for holidays. The clubhouse burned down in nineteen forty-six, and the island continued to erode.

Recently, a Maryland woman who remembers going to Poplar Island years ago returned on a guided visit. She said it was wonderful that life had returned to an interesting part of Chesapeake Bay.

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VOICE ONE:

This SCIENCE IN THE NEWS was written by Jerilyn Watson. Our producer was Brianna Blake. I'm Bob Doughty.

VOICE TWO:

And I'm Shirley Griffith. Listen again next week for more news about science in Special English on the Voice of America.