The Eels

Every eel in Lake Champlain was born in the open Atlantic, two thousand kilometers (1,200 miles) away, and drifted here as a transparent, leaf-shaped larva. Every one that lives to breed swims the whole way back, spawns once, and dies. The spawning itself has never been observed.

Press play. The timeline runs through one eel's life, not calendar years.

A chromolithograph of a common eel, olive-brown above and pale below, seen from the side; signed Denton and captioned Common Eel, Anguilla rostrata.
Common eel, Anguilla rostrata. Chromolithograph by Sherman Foote Denton for the Annual Report of the Commissioners of Fisheries, Game and Forests of the State of New York, 1899. A grown female out of this lake averages 543 mm (21 in); this one is drawn life size at about that.
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—kilometers from the Sargasso to this lake, direct
—months adrift as a larva, carried by the current
—years an eel can spend in fresh water before it breeds
—times it makes this journey

The Chambly ladder count, 1997 onward

There is a ladder on the dam at Chambly, on the Richelieu, and the climb has been counted every year since 1997. It is the only long eel count in this basin. The first full season found nearly ten thousand eels; the highest since is 6,476, in 2010.

Two dams on the Richelieu

Between the Atlantic and this lake there are exactly two structures, and both are on the Richelieu. An elver that reaches Sorel and turns south has to get past them both.

Known facts and open questions