(Reuters) - The American eel, a freshwater fish native to the eastern United States that is born and dies in the open ocean, may be at risk of extinction because of climate change, the U.S. Fish and Wildlife Service said on Wednesday.
The agency, which is considering a petition to add the eel to its official list of endangered species, said new scientific evidence, including "statistically significant long-term" declines in the stock of young eels, suggested the snake-like species is in enough peril to warrant federal protection.
The Fish and Wildlife Service said a number of factors were putting pressure on eel populations, including climate-related changes in the ocean that "may be negatively impacting the eel's reproduction rates."
An invasive parasite from Asia has also been implicated in the eel's decline. The parasite infects the eel's swim bladder, an air-filled organ that provides the eel with buoyancy and balance.
The agency, which declined to add the American eel to its endangered list in 2007, said it would initiate an "extensive review" that could ultimately reverse that four-year-old decision and result in the eel's inclusion on the list.
First established in 1974 to protect plants and animals facing extinction in the United States, the endangered species list now contains nearly 1,400 species.
In addition, the Fish and Wildlife Service has issued findings in recent years -- like Wednesday's report on the American eel -- that suggest the list could be vastly expanded to include several hundred more species.
The American eel lives much of its life in freshwater. But it spawns hundreds of miles away from shore in the Sargasso Sea, a seaweed-choked area of the north Atlantic located between the Azores and the West Indies.
When the eggs hatch, it takes years for the larvae to float though the saltwater and reach the freshwater rivers, streams and lakes in the United States -- including the Great Lakes and Mississippi River basin -- where they mature and reach lengths of up to three feet.
They remain here for between 10 to 40 years and then make their way back to the Sargasso Sea, where they spawn and then die.
The Fish and Wildlife Service will now collect information from a host of interested parties before making any decision regarding the eel. A final ruling could be years away because of the backlog in petitions the agency faces.
In 2007, officials at the agency found that while the American eel population was declining in some areas, the overall population was not in danger of extinction.
(Reporting by James B. Kelleher in Chicago; Editing by Greg McCune))