Least Terns nesting on the Missouri National Recreational River. |
Work was initiated in August on habitat projects to benefit two federally listed bird species, the endangered interior Least Tern and threatened Piping Plover. This work will occur within the 59 mile long segment of the Missouri River designated as the Missouri National Recreational River. The projects are being carried out by the Army Corps of Engineers.
Contractors began work to create three emergent sandbar habitat complexes. One of the complexes will be constructed using hydraulic dredges and the other two will be constructed using mechanical earth moving equipment such as bull dozers, excavators, and scrapers, according to Luke Wallace, a biologist in the Corps' Omaha District, and project manager for the three emergent sandbar habitat projects below Gavins Point Dam..
"The sand used to construct the sandbars will be taken from the adjacent river bed at each location," according to a Corps press release. "Construction will last through fall and winter months with a scheduled completion date of April 15, 2008. Timely completion will ensure the habitat will be in place when terns and plovers return to nest next spring."
"These complexes will be constructed to provide nesting habitat for the least tern and piping plover, two bird species protected under the Endangered Species Act," according to Omaha District Commander Col. David C. Press.
Yearly populations of Terns and Plovers on the Missouri National Recreational River (Data courtesy of the Army Corps of Engineers). |
||
Year |
Least Tern |
Piping Plover |
1998 |
144 |
49 |
1999 |
161 |
141 |
2000 |
206 |
186 |
2001 |
232 |
218 |
2002 |
314 |
260 |
2003 |
366 |
286 |
2004 |
359 |
262 |
2005 |
476 |
340 |
2006 |
383 |
309 |
2007 |
410 |
300 |
"One ESH complex will be constructed at Missouri River Mile 791.5, near Wynot, Neb.," according to the press release. "The other two complexes will be constructed south of Vermillion, S.D., near the Highway 19 Bridge. One of those will be constructed near Missouri River Mile 774, about two miles downstream of the bridge. The other will be constructed at Missouri River mile 777.5, about 1.5 miles upstream of the bridge and adjacent to the Frost Wilderness Game Production Area in South Dakota.
The sandbars created will vary in size, according to Corps officials.
- River Mile 791.5 complex = 40 acres of emergent sandbar
- RM 777.7 complex = 74 acres of emergent sandbar and 15 acres of backwater.
- RM 774 complex = 49 acres of emergent sandbar
The acreages of ESH listed above represent the amount of sandbar habitat that would be exposed above the water surface at a Gavins Point Dam discharge of 25,000 cubic feet per second.
The total cost of all three projects combined is approximately $8.8 million, The Corps said.
Once the project are completed next year, the response of the terns and plovers will be closely watched.
"The sandbars will be monitored weekly during the nesting season," according to Wallace. "Survey crews will locate nests and monitor the nests until the nests are terminated at which time a nest fate will be applied. Crews will monitor the chicks until they fledge. An adult census will be conducted during the nesting season. Vegetation will be monitored to determine species type and growth.
At river mile 777.5, some aquatic habitat will be constructed in conjunction with the sandbar project.
"Sediment from a historic river channel on the Frost property will be used as an alternative borrow source for the complex, resulting in the restoration of a 15-acre backwater connected to the Missouri River," according to the Corps press release. "The backwater will provide habitat for waterfowl, shorebirds, fish and mussels, and will provide new public fishing and hunting opportunities at the Frost Wilderness Game Production Area."
There has been a positive response of the terns and plovers to newly created sandbars that were the result of previous projects by the Corps.
Tern and plover use at previous sandbar habitat creation projects (Data courtesy of the Army Corps of Engineers). |
|||||
Year |
Tern Adults |
Tern Fledglings |
Plover Adults |
Plover Fledglings |
|
River Mile 755 Complex (Ponca) |
|||||
2004 |
84 |
64 |
18 |
23 |
|
2005 |
68 |
12 |
32 |
6 |
|
2006 |
38 |
8 |
8 |
5 |
|
2007 |
68 |
5 |
11 |
0 |
|
RM 761 |
|||||
2005 |
58 |
67 |
42 |
56 |
|
2006 |
40 |
29 |
55 |
55 |
|
2007 |
48 |
20 |
57 |
20 |
|
RM 770 Complex |
|||||
2005 |
80 |
102 |
62 |
76 |
|
2006 |
176 |
47 |
69 |
30 |
|
2007 |
94 |
10 |
73 |
10 |
"The first year of use for each of the created sandbars was very productive for both species," Wallace said. "Since then productivity has decreased though the sandbars still attract large numbers of adults. Generally the nest success has been very good at all three sites with 60-70% of the nests having at least one egg hatch. The poor productivity is probably due to predation by owls, hawks, minks, raccoons.
Newly created sandbar habitat at the Ponca Complex, 2004. Photos courtesy of the Corps of Engineers. |
"The sandbar habitat has also been used by waterfowl and shorebirds and unfortunately the aforementioned raptors," Wallace said.
For safety purposes, public access to construction and staging areas will be restricted, eliminating recreation and hunting opportunities during the construction period, Sept. 1, 2007 through April 15, 2008.
These projects are part of the Corps effort to implement recommendations of the U.S. Fish and Wildlife Service in its Biological Opinion on the Operation of the Missouri River Main Stem System.
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