Migration secrets of eels revealed

London, September 26 (ANI): A team of biologists, using satellite tags, has revealed the migration secrets of eels, as to where they go and what they do after leaving their rivers.

The European eel's migration to the Sargasso Sea to spawn is one of nature's great unsolved mysteries.

According to a report by BBC News, scientists using satellite tags have tracked 22 eels, revealing what they do in the first 1,300km of an epic 5,000km migration.

Using this method, biologists hope the whole journey to the Sargasso Sea will soon be revealed.

The tracking study provides unique insights into the migratory behaviour of the European eel (Anguilla anguilla), including the direction and depth the eels swim.

It's one of the last great remaining biological mysteries because the spawning site has been found in the Sargasso Sea, but no adult eels has ever been found in the ocean.

"It's exciting data because no-one has managed to do this before," said Dr David Righton from the Centre for Environment, Fisheries and Aquaculture Science (CEFAS) in Lowestoft, UK, a member of the multinational team that undertook the study.

"People have often speculated about which direction eels may take, how they might travel, so what we've been able to show is which of those speculations are actually right," he added.

In 2006, the team attached miniaturized pop-up satellite tags to 22 large adult eels which they released from the coast of Galway, western Ireland.

The tags record not only the location of the eel, but also the daily activity of the eel, recording speed, depth and direction.

The tags are set to "pop off" after six months and float to the ocean surface, sending data via satellite back to the research team.

"We found the direction the eels take wasn't a straight line from the west coast of Ireland towards the Sargasso Sea, but it was to the south of that, as if they were heading toward the Azores," Dr Righton explained.

"So basically, they are heading towards the conveyor belt ocean current which will help propel them toward the Sargasso Sea," he said.

"That implies some navigational ability. It also suggests they are not just going the shortest distance; they are going the most efficient distance," he added.

The researchers also found the eels swim too slowly to get to the Sargasso Sea by the April spawning period.

The researchers suggest this means the eels may gain speed and travel efficiency by entering the ocean currents that begin west of Africa and continue as part of the subtropical gyre system that flows to the Caribbean. (ANI)