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OTTAWA — It takes ladders to help them up the St. Lawrence River and trucks to haul them back down, but conservation officials with the Ontario government and Ontario Power Generation are determined to do all they can to help the endangered American eels.
The eels’ existence is jeopardized, in part, by hydroelectric generating stations that impede their migration up and down the St. Lawrence.
This month, Ontario Power Generation unveiled an improved eel ladder at its Saunders Generating Station near Cornwall, and Ontario’s Ministry of Natural Resources announced nearly $200,000 in funding to help the beleaguered fish, whose numbers have plummeted since the mid-1980s.
“It’s a very important species in the balance of the Upper St. Lawrence ecosystem, even though people say, ‘Eww! It’s an eel’,” said biologist Ron Threader, a senior environmental adviser with Ontario Power Generation.
“We know very little about the biology of the creature. We know what we see, we know what we study, but there’s an awful lot we don’t know, and they’ve been around since a long time before humans.”
The MNR grants include:
- $47,000 to the Lanark, Ottawa, Prescott/Russell and Pembroke stewardship councils to monitor the eels’ movement,
- $41,500 to the Ontario Waterpower Association to develop best-practice guidelines with regard to hydro-electric generation, and
- $103,000 to Plenty Canada to assess American eel abundance in the Ottawa River watershed.
They’re just part of larger recovery efforts that include the Ontario, Quebec, and federal governments, as well as the international community.
“We’re trying to enhance the population and support it any way we can,” said Threader.
American eels hatch in the Sargasso Sea in the middle of the Atlantic Ocean and undertake a multi-year migration toward freshwater lakes and rivers in eastern North America. Some of them swim up the St. Lawrence and end up in Lake Ontario and surrounding waterways, where they spend most of their adult lives before entering a mature, “silver” phase, when they return to the Sargasso Sea to spawn and die.
Historically, the abundant eels in Lake Ontario were a source of food for the aboriginal population, and later the basis of a thriving commercial and recreational fishery. But in the mid-1980s, scientists noticed a drastic decline in the eel population.
Although the reasons for the decline remain unknown, one contributing factor might be the two hydro dams on the St. Lawrence River that form barriers to the eels’ migratory path — Hydro Québec’s Beauharnois Generating Station and OPG’s Saunders Generating Station at Cornwall.
Although eel ladders have long existed on the dams to help the young eels swim upstream, until this summer, the ladder at Saunders dropped the eels directly into the current just above the dam. This caused many of them to get swept back downstream and over the dam, said Threader.
That’s now been fixed with a 300-metre extension of the ladder, unveiled earlier this month.
Adult eels swimming downstream to spawn also have a problem with the generating stations: about 25 per cent of them get swept into the hydro dams’ turbines, where they are injured or die, said Edwin de Bruyn, the Ontario and Great Lakes area director for the Department of Fisheries and Oceans.
Last year, OPG began an initiative to capture about 2,000 adult “silver” eels from Lake Ontario and transport them downstream in trucks to release them beneath the Beauharnois dam.
Though trucking eels may seem like an extreme measure, there is no way yet to modify existing hydro dams to make them safe for eels migrating downstream, Threader said.
“Simply from a biodiversity standpoint, it’s an important species for us to recognize that, we, as humans, are having an impact (on),” said de Bruyn.
It’s hoped that these local efforts may help not only the Lake Ontario eels, but the broader population of North American and even European eels, whose life cycles appear to be intimately connected.
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