Fish kill in lake raises concerns

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wwltv.com

Posted on May 23, 2011 at 6:16 PM

Bill Capo / Eyewitness News

NEW ORLEANS -- Word spread quickly on the Northshore that there was a fish kill, which led to worries it was connected to the rush of fresh water from the Mississippi River into the lake since the opening of the Bonnet Carre Spillway two weeks ago.

"Now all this water is in from the spillway," said Lacombe resident Chris Waguespack. "That was our concern too, because it has reached here now."

Scientist Dr. John Lopez of the Lake Pontchartrain Basin Foundation found 20 to 30 fish killed in Faciane's Canal, which empties into Lake Pontchartrain, but he was surprised that it was not the small fish that he usually sees in an event like this.

"But it is unusual that there are large black drum, 20 or 30 pounds, just a few of those, and mostly large catfish, maybe two, three, five pounds," said Lopez.

So is this the sign of things to come from the torrent of river water emptying into the lake? Lopez said he is not worried by this fish kill, though he does think a lack of oxygen caused it.

"This appears to be isolated, and a small number of fish. It is a little unusual the nature of it. But this canal does dead end, so it probably is a lack of circulation."

But Lopez said the flood of Mississippi River water rushing into the lake has now displaced almost all of the normally brackish water here.

"Probably 80 to 90 percent. This morning I had reports from Wildlife and Fisheries that the water moving through Rigolets and Chef is about .8 parts per thousand. That is not quite pure river water, but it is getting pretty close."

Lopez believes the river water will drive many marine species out of the lake, making it a tough summer for commercial and recreational fishermen.

"I don't think we'll see much brown shrimp, maybe some white shrimp late," Lopez said. "Some crab, but it is probably going to be overall a slow year."

But the ultimate question for the fishermen, whether they are commercial or recreational fishermen is, when will the lake get back to normal after the Spillway closes?

"Six or eight months out, so September, October, November, the lake should be back to normal," Lopez said.

He added that conditions seem right for a large algae bloom to form in the lake after the Spillway closes, probably in July or August, and last about a month.

 

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