Natural England - European eel

European eel

Anguilla anguilla

We all recognise the eel’s smooth, snake-like shape, but these familiar fish lead amazing lives. Eels are the only European fish to leave the coast to spawn in the sea – the opposite to salmon, which travel upstream to spawn in freshwater. European eels migrate to their spawning grounds in the Sargasso Sea, off the coast of North America. Migration is greatest on dark, moonless nights, and usually starts in flood water following heavy rain.

Travelling eastwards on ocean currents, the returning young change into transparent 'glass eels' as they reach the shallow waters close to the continent, eventually arriving on the Atlantic coast of Europe, after a journey that can take as long as three years. They enter inshore waters as young 'elvers', where they live under rocks, in crevices, or in the mud on the bed of estuaries, coastal lagoons, rivers, and lake ponds.

Elvers and adult eels are fished commercially, and over-harvesting has contributed to the massive decline in eel numbers, as have pollution, hydropower dams and parasites. The quantity of juvenile eels returning to the coast has been reduced to no more than 5% of the numbers recorded in the 1970s. The number of adults is thought to have declined by 80% in the past 60 years.

The eels do not begin to undertake spawning migrations until the males are at least six years old, and the females even older. Once in decline, their numbers take a long time to recover, as is the case with other long-lived, slow growing animals.

Other common names

Common eel

Brief description of European distribution

The distribution of the eel is widespread in Europe, being found from Iceland and North Cape in the north, to the coasts of Morocco in the south, and the Black Sea in the east.