This is the VOA Special English ENVIRONMENT REPORT.
American scientists are concerned about an invasion of fish called Asian swamp eels. The eels have been found mostly in the southeastern United States. But scientists fear that they may soon spread to other waters in North America.
Asian swamp eels can grow up to one meter long and weight more than one-half kilogram. They eat all kinds of sea life, including small fish, frogs, shrimp, crayfish and insects. Experts say the eels eat everything they can find. They have no natural enemies, except alligators.
Asian eels can survive in extreme conditions. They can survive in cold or warm waters. They can live in fresh water or salt water. They can live without food or water for months at a time. They can even breathe air and move across dry land. The Asian eels reproduce in an unusual way. They are females at birth. As they get older, they become males. One eel can lay as many as one-thousand eggs.
The eels come from eastern Asia. In Asia, the eel is a popular food. Scientists do not know how Asian eels reached North American waters. But they think the eels were imported for sale as pets or as food. Then they were released or escaped into waterways.
The swamp eels were first discovered several years ago in the state of Georgia. Other populations were later found in widely separated areas in Florida and off Florida's Gulf coast.
A new population of swamp eels has been found near Everglades National Park in Florida. This park contains six-hundred-thousand hectares of rare plants, animals and fish. It is a protected natural park system. The eels have not been found in Everglades National Park. But experts say they could reach the area soon.
Scientists are worried about the fish populations in the Everglades and in other Florida waterways. They say the fish populations could decrease sharply if the eels invade the area. Without fish, birds and other animals would starve.
Scientists are trying to find ways to control the Asian swamp eels. They say the eels are not affected by poisons. Even explosives do not kill them. Scientists say the eels can be killed by hitting them. But the eels are difficult to catch. Experts from local and national fish and wildlife agencies are working with researchers to find ways to deal with the eels.
This VOA Special English ENVIRONMENT REPORT was written by Cynthia Kirk.