LONDON (AP) - Eels that have been migrating across the Atlantic Ocean to European rivers for hundreds of years are rapidly disappearing from London's River Thames, scientists said Thursday.
Conservationists say they're worried that the slithery creatures
are not returning to the capital, where they have been most well
known in the form of a traditional dish. Jellied eel - stewed eels
in a spiced jelly made from the stewing juices - is a cockney
specialty from London's East End dating back centuries.
Less than 50 European eels were found in eel traps placed the
river last year - a 98 percent drop from 1,500 of the fish found in
2005, records at the Zoological Society of London indicated.
The decline was likely a combined result of changes in ocean
currents due to climate change, man-made structures such as dams,
and the presence of certain parasites, said Matthew Gollock, a
Thames conservationist at the organization. It was difficult to
pinpoint what caused the change because there wasn't enough data on eel populations, he said.
"We just don't know enough," Gollock said. "Eels are
mysterious creatures at the best of times, but we are very
concerned about the rapid disappearance of the species in the
The critically endangered migratory fish - found in rivers
across Europe from Sweden to north Africa - has a long and complex
life cycle. After spawning in the North Atlantic Ocean, the eels'
tiny eggs are carried thousands of miles (kilometers) by sea
currents to European rivers, where they settle and mature for up to
20 years. The eels then swim back 4,000 miles (6,500 kilometers) to
where they came from, to spawn and die.
The eels also have been disappearing from other European rivers,
Gollock said - a change that could have a domino effect on other
species up and down the ecosystem chain.
The water quality of the Thames, which runs through central
London, has improved in the past 50 years, but it remains a fragile
estuary, Gollock said.
"It's quite a precarious ecosystem and the fast removal of any
species - whether it is a fish or a plant - is going to upset the
balance," he said.