It took scientists 100 years to track these eels to their breeding ground

The life of a European eel isn’t an easy one. They’re critically endangered, must travel up to 10,000 km to get to their spawning point and then when they get there they probably die.  

But they’re also incredibly difficult to keep track of. In the 1920s a Danish biologist named Johannes Schmidt, discovered the Sargasso Sea – due east of North America – had eel larvae. He spent the next 20 years trying to confirm his finding. But in the century since, researchers have been unable to sample either eggs or spawning adults.

Now, a team from Europe has published a paper in Scientific Reports that shows the first direct evidence of adult European eels migrating to the Sargasso Sea to breed. This provides vitally needed information on the life cycle of these slippery suckers.

“The European Eel is critically endangered, so it is important that we solve the mystery surrounding their complete life-cycle to support efforts to protect the spawning area of this important species,” says project lead Ros Wright from the UK Environment Agency.

“This is the first time we’ve been able to track eels to the Sargasso Sea … Their journey will reveal information about eel migration that has never been known before.”

The team attached satellite tags to 26 female eels that were in rivers in the Azores archipelago – an autonomous region of Portugal in the North Atlantic Ocean – and then waited.