Restoring eels in the Ottawa River (Feb. 25, 2017)

//Restoring eels in the Ottawa River (Feb. 25, 2017)

Photo of Nick Lapointe explaining eel life cycle
Our speaker, Nick Lapointe, was himself once a member of the Macoun Club, so he was confident of having a knowledgeable audience. “What is the eel’s scientific name?” Anguilla rostrata. “Where to they start from when they hatch? “The Sargasso Sea! “Where is that? “ Bermuda. “Where do they go to grow up? “ Rivers that empty into the Atlantic Ocean.

Macoun members who have been around long enough already knew the answers because we had heard about eels from Lauren Stoot on November 2, 2014. And even some of our newest members could answer Nick’s questions from their own general knowledge. But we very quickly got beyond that. There are hints that somehow the young eels “know“ which river they should ascend. We learned that in all the species’ range (from Greenland to the northern part of South America), the Ottawa-River eels grow to be the biggest (5 feet, or 1.5 metres) and oldest (50 years) before returning to the sea. The enormous number of eggs the huge Ottawa-River eels produced meant that they constituted a quarter of the species’ reproduction. The implication for conservation is that this watershed is of outsized importance.

Photo of boy touching model of eel

Historical records show the American Eel was once the dominant fish species in the Ottawa River, but almost none are left. What happened? It wasn’t over-fishing, even though eels had been a major resource taken by native people in Ontario. It wasn’t pollution. It wasn’t habitat loss, either. The trouble – and it isn’t too late to remedy it – is a series of barriers to the twice-in-a-lifetime migration of eels. In a pattern opposite to that of salmon, young eels migrate up the Ottawa, and mature eels migrate down in order to complete their life cycle. Four all but impassable hydro-electric dams bar upstream travel, and their turbines constitute a generally lethal route downstream. The second of the four is right in downtown Ottawa.

The dams were built mainly between 1900 and 1960 to generate electricity. That was before wildlife such as fish were taken into account. It is expensive to retrofit them, but the organization Nick is working for (the Canadian Wildlife Federation) has been working with the dams’ owners. The Ottawa Hydro dam will soon accommodate eels traveling in both directions. The owners of the others want proof that the dams are the central problem in the eel’s population crash, and even that eels still travel up and down the Ottawa River. Nick is involved in the natural history research necessary to demonstrate these most basic facts.

2017-05-18T20:36:10+00:00 February 27th, 2017|Macoun Field Club|

About the Author:

Naturalist. Macoun Club member 1965-74; Macoun Club leader since 1985.

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