Endangered fish swept through spillway, returned to river

NEW ORLEANS (AP)—For more than two sweltering August weeks, state and federal biologists worked to rescue endangered fish swept out of the Mississippi River during a flood fight that lasted for months. They waded or leaned out of boats with dip nets and went neck-deep into canals with seins to net endangered pallid sturgeon.

The endangered sturgeon and flat-billed, open-mouthed cousins called paddlefish were among untold numbers of fish carried out of the Mississippi River by water rushing through the Bonnet Carre Spillway while it was open for a record 123 days to protect New Orleans levees from high water. Both are ancient species, closely resembling fish known only from fossils, with hard plates armoring scale-less skin and cartilage rather than bones.

Now crews were working to return those found alive to the river. The Army Corps of Engineers, the U.S. Fish and Wildlife Service and Louisiana Department of Wildlife and Fisheries worked together on the project.

They measured and tagged 17 pallid sturgeon and 208 closely related shovelnose sturgeon before releasing them, said K. Jack Killgore, a research fisheries biologist with the Corps’ Engineer Research and Development Center Environmental Laboratory in Vicksburg, Mississippi.

He said about 10 paddlefish, “ram ventilators” which swim open-mouthed to force water past their gills while straining out the plankton they eat, also were rescued. The International Union for Conservation of Nature considers paddlefish vulnerable to extinction.

The excursion was both an assessment of the spillway’s effects on endangered and threatened species and a more general look at the spillway’s species diversity.

“We’ve probably documented about 70 species of fish in that spillway,” Killgore said. “Most are probably from the Mississippi River, but some are probably from Lake Pontchartrain,” into which the spillway empties.

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