Friday, July 20, 2018

Fish Tale

Dragonfly enters the St. Ours Lock.
We're always on the lookout for conservation stories. In Quebec, the spotlight is on an unusual fish. It's found nowhere else but this province. Meet the . . .

Copper Redhorse

Cool name, eh? As we checked out the next leg of our journey--south from the Saint Lawrence River toward Lake Champlain on the Richelieu River—we were intrigued by the mention in our cruising guide.

"At the St. Ours lock, be sure to walk across the dam to see the fish ladder constructed for the copper redhorse."

Ok then!

What's in the Name?

So let me tell you a little bit about this fish. It has cousins: Canada is also home to the pleasingly named silver redhorse, shorthead redhorse, and river redhorse. Taxonomically these fish may seem less glamorous--they’re members of a group popularly called "suckers."

Quite an unusual color, almost koi-like! Photo credit: Oceans and Fisheries Canada
Th is a BIG, powerful sucker, however--it can live for 30 years and grow to more than 10 lbs.  And its scales are quite an unusual copper color. It hangs out in shallow water-grass beds along the shores of the St. Lawrence and the Richelieu. Nowhere else.

And where most suckers, um, suck detritus from the bottom, the copper redhorse, curiously for a North American freshwater fish, subsists on an elegant French diet of small snails, which it crushes with tooth-like mouthparts. Also curiously for a fish, females don't reproduce till they're 10 yrs old.

Uneasy Coexistence

Everywhere on the Richelieu we saw big expanses of lawn, rip-rap 
on the shore, sediment stirred up by passingboats . . . none of this looks
good for the copper redhorse.
This life history makes it vulnerable. The rivers where it lives transect the most densely populated part of Quebec. 

The sediment stirred up by fast-moving boats (moorons?  speediots?) chokes the shallow water where copper redhorses hang out.

Pesticide run-off from farming is also a problem. And dams isolate populations, preventing genetic flow.  

Biologists estimate the copper redhorse population at only a few hundred fish. A fish-rearing and restocking program is underway.

A Ladder for Fish

So back to the St. Ours Lock. It was a hot day, and a sweaty slog across the road topping the modern hydro dam next to the lock. But as the guide promised, worth the trip.

The Vianney-Legendre fish ladder, named for a distinguished fish researcher, was built in 2001 so copper redhorses could reach their spawning grounds in the Chambly rapids (now included in a wildlife preserve), above the dam.

I'd seen fish ladders before, but they were designed as a straight line of concrete cells, each a little higher than the next--clearly a ladder. The snail-shell design of this ladder--can you see how the cells spiral around?--seemed to do a better job of offering fish small, quiet pools to rest in during the strenuous climb.

Citizens in Action

Translation: No wake! Slow down. This is copper redhorse habitat
Besides the fish ladder, the preserve, and the breeding program, other actions are in place to help this oddball fish. Nature Conservancy Canada has campaign to revegetate and naturalize the river banks.

Many people who live along the river are pitching in, working to improve riverbanks and posting signs to warn boaters to travel responsibly.

Great work, Quebec-ers, and bonne chance, copper redhorse!

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