Attachment	Fish and Wildlife

Issues concerning fish and wildlife within the Middle Loup River Basin were raised during scoping. These issues are grouped under the major categories below:

Affected Environment

Fish and Wildlife Abundance and Distribution

Fish.--Sherman Reservoir is habitat to a variety of fish species including walleye, bluegill, green sunfish, crappie, channel catfish, northern pike, yellow perch, common carp, and freshwater drum. The Nebraska Game and Parks Commission (NGPC) is responsible for fisheries resource management at Sherman Reservoir. NGPC has stocked a variety of fish over the past 12 years, including walleye, northern pike, white bass, white crappie, largemouth bass, channel catfish, and freshwater drum.

A limited number of standard fish community surveys have been done on Sherman Reservoir in the past; however, historical information on fishing pressure, catch, and harvest is completely lacking for the reservoir. Walleye are considered the most sought-after sport fish in Sherman Reservoir. A study done in 1995 by NGPC shows that walleye populations within the reservoir are beginning to increase due to the production of big year classes in 1991 and 1992. The reservoir is currently part of a Statewide walleye stocking evaluation project receiving walleye on a biyearly basis.

Red shiner, fathead minnow, river carpsucker, and channel catfish dominate the fish communities within the Loup River. There are some species present that exhibit more limited distributions, including brassy minnow, longnose dace, and pearl dace (NGPC, 1997).

The pallid sturgeon, the only listed endangered fish species within the Middle Loup River Basin, is discussed under the heading "Protected Species," below.

Wildlife

Mammals found frequently throughout the Middle Loup River Basin include the deer mouse, white-footed mouse, meadow vole, pocket gopher, eastern mole, badger, raccoon, and eastern cottontail rabbit. Big game present in the basin include white-tailed and mule deer.

Birds within the basin include an abundance of meadowlark, mourning dove, and barn swallow. Various species of waterfowl and shorebirds-- including mallards, geese, and sandpipers--utilize habitat within the basin as well. There are six species of rare birds which include the great blue heron, Swainson's hawk, northern harrier, sedge wren, common snipe, and swamp sparrow. The whooping crane, piping plover, bald eagle, and interior least tern, all threatened or endangered species, are also found within the basin.

Protected Species.--Threatened and endangered species known to occur within the Middle Loup River Basin include the whooping crane, piping plover, bald eagle, and interior least tern.

The pallid sturgeon (Scaphirhynchus albus) is one of the largest and rarest fishes in North America. This species was federally listed as an endangered species on September 6, 1990 (55 F.R. 4001) (Fish and Wildlife Service, 1990). Pallid sturgeon require large, turbid, free-flowing river habitat with rocky or sandy substrate (Gilbraith et al., 1988). Their small eyes and large barbels allow for successful feeding in turbid water conditions (Keenlyne, 1989). Pallid sturgeon feed on fish and aquatic invertebrates (Carlson et al., 1985). The decline of the pallid sturgeon population is attributed to habitat modifications and other factors, including dam construction, stream channelization, and flow alterations.

The range of the pallid sturgeon is large, extending over 3,550 miles of river including the Missouri River from Fort Benton, Montana, to its confluence with the Mississippi River to the mouth of the Mississippi.

Irrigation Operations.-- The Middle Loup River Basin has a relatively good number of natural community sites and provides habitat for a number of rare species, migratory species, and many common species for the area. Without these sites, species that are now common can quickly become rare or threatened. Thus, any actions or changes in management regime that would threaten these sites on a basinwide or even local scale should be prevented. The natural communities that remain in the basin are impacted by the flow regimes imposed by the existing water use projects. Under the current streamflow conditions, these sites are able to maintain their relatively high quality in conjunction with existing management practices of grazing, haying, etc. A variety of habitats are present within the basin. They include meadows, woodlands, marsh, and wetland areas.

Land Use

Sherman Reservoir.-- The approximately 2,868-acre surface area of Sherman Reservoir provides productive fish habitat. Shoreline habitat consisting of willows and various other vegetation provides needed habitat for several species of fish such as largemouth bass and green sunfish. Deep, open water habitat is present for species such as walleye and freshwater drum. However, the reservoir has been subjected to large releases of water to satisfy agricultural needs, resulting in shoreline erosion. The continued erosion can cause clear water and vegetation to be replaced by windswept, muddy water and can change fish communities due to the loss of productive habitat. As the reservoir continues to erode from drawdowns, there will be less available shoreline habitat for those species that require it for survival.

Loup River.-- Habitat parameter characteristics of the Loup River are typical of rivers found in similar agriculturally impacted areas of Great Plains grassland ecosystems, tending to be relatively shallow, primarily sandy bottoms, and exhibiting low current velocities that are impacted by strong rain events (NGPC, 1997). Throughout the 1995-96 water year, mean flows were under 1,000 cubic feet per second (cfs) from the months of April through November, with the lowest average flows occurring in July (54.1 cfs). December through March offered the highest flows, with February flows averaging 2,179 cfs (U.S. Geological Survey, 1997).

Canals.-- Canals used for diversion of irrigation waters may act as migration barriers to channel catfish. Both the Sherman Feeder Canal downstream of the Arcadia Diversion and the Sargent Canal downstream of the Milburn Diversion may be limiting the migratory movement of channel catfish as well as the recruitment of year classes of channel catfish, common carp, green sunfish, white sucker, and shorthead redhorse. Such barriers to fish movement can result in isolated subpopulations throughout the system, especially during low water years (NGPC, 1997).

Habitat

Wildlife management areas exist near Sherman Reservoir, as well as other areas throughout the basin. These wildlife management areas are of particular importance for the preservation of wildlife habitats. Wildlife areas are managed by NGPC.

Approximately 97 percent of land in Nebraska (NGPC, 1991) is privately owned. This means that the bulk of the potential wildlife habitat within the basin is controlled privately. Nebraska has specific programs which encourage wildlife management on private property. Through Nebraska's Wildlife Habitat Improvement Program, landowners can receive assistance to improve habitat on their own land.

Much of the privately owned land throughout the basin is irrigated land for agricultural needs. Drawdowns of Sherman Reservoir for irrigation can result in significant impacts to fish recruitment, brood stock, and aquatic organisms. It has been shown that reservoir storage ratios have a direct effect on species abundance; low storage ratios can result in loss of shoreline habitat, which can inhibit successful fish rearing. This decrease in the amount of littoral zone results in less habitat and available forage for feeding young.