"European eels (Anguilla anguilla) have a long and complex life cycle. They are a migratory, catadromous fish, feeding and growing in fresh water but returning to the sea to spawn. Their spawning grounds are believed to be in the Sargasso Sea resulting in a 4,000 mile migration from the UK.

"Once spawned, eel larvae (leptocephali) are carried by oceanic currents back to continental shores where they are distributed into waterways throughout Europe."