11 July 2007

Release of Reservoir Water Washes Away Eggs and Young of Terns and Plovers

[Least Terns on Missouri River. Courtesy of Wikipedia.] By James Ed. Ducey

As water releases from Gavins Point dam have been increased in recent days, Least Tern and Piping Plover eggs and young are being washed from sandbars of the Missouri National Recreation River, along the border of northeast Nebraska.

The increase in water flowing from the dam reservoir is being made by the Army Corps of Engineers to allow a single towboat to navigate the river channel to Blair, in order to retrieve alfalfa pellets used as stock feed. Excell Marine Corp. operates the tow boat and four barges.

The rate of release of the dam water had been 17,700 cubic feet per second in June, with an increase to 22,000 cfs by July 12th.

At least 81 plover eggs, 84 tern eggs and 29 pre-flight tern chicks will be washed away once the release rate is again stabilized, according to information supplied by the Nebraska Game and Parks Commission.

A number of eggs and chicks had already been destroyed, according to information kept by the Corps, which has been monitoring 166 plover and 270 tern nests this season along this stretch of the river.

"Waiting three weeks would have allowed the birds to grow large enough to fly," said Gene Zuerlein, fisheries biologist with the Commission. "The people in Blair knew in advance when the pellets are needed, and could have considered other transportation options. They use barges because it is an inconvenience to use rail cars."

The current flooding of tern and plover habitat is an ongoing event, which happens nearly every year, according to Zuerlein, fisheries biologist with the Commission.

Flooding of nests by water releases is known to have washed away birds or eggs, dating back to the early 1980s, as noted during Commission surveys of both species.

"Millions of dollars have been spent to refurbish the river for fish and wildlife," said Zuerlein. "Agencies should have had an opportunity to protect the resource." He suggested that the barge shippers could have asked for help with options other than river shipping to avoid impacts to the breeding birds.

Least Terns are an endangered species, with the Piping Plover classified as threatened.

An incidental take permit from the Fish and Wildlife Service allows the Corps to destroy the nests and eggs, since both species are protected by the Migratory Bird Treaty Act. The permit allows up to 295 plovers to be "taken" each year, and 180 terns in a three year period.

The action also violates a Nebraska law against the destruction of nests and eggs.

"State law prohibits illegal taking of bird eggs and young," according to Ted Blume, chief wildlife enforcement officer of the Nebraska Game and Parks Commission. "The attorney general would render a legal opinion to determine if under state law, this taking would be illegal given the current circumstances."

There has been a continual decline in barge traffic along the Missouri river since the late 1970s, with no barge trips in 2005 and 2006 between Sioux City and Omaha, according to information at the Commission's fisheries office.

Zuerlein suggested people concerned with the loss of terns and plovers should "get informed first" and contact their congressional delegation in Nebraska, and especially in Missouri, to express their opinion.

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