CONTAMINANT RESIDUES IN SANDHILL CRANES KILLED UPON STRIKING POWERLINES IN CENTRAL NEBRASKA

In 1989 and 1990, 58 sandhill cranes (Grus canadensis) were collected along the central Platte River in Nebraska during a study of mortality caused by powerline impact. Brains were assayed for acetylcholinesterase activity; gut contents were analyzed for residues of 25 organophosphate and 6 carbamate compounds; and livers were analyzed for 20 inorganics (including lead, mercury, and boron) and 22 organochlorine chemicals. Brain acetylcholinesterase activities appeared to be within normal ranges, and no measurable organophosphate or carbamate residues were found in the gut contents of 5 birds with the lowest brain enzyme activities. Heptachlor epoxide, oxychlordane. p,p\u27 -DDE, and hexachlorobenzene were detected in livers. Inorganics were generally below concern levels and were similar to levels found in a previous study of greater sandhill cranes in the Rocky Mountain population. Applications of these data to other investigations of contaminants in sandhill cranes are also discussed

Metal and organic residues in addled eggs of least terns and piping plovers in the Platte Valley of Nebraska

The threatened piping plover and the endangered interior least tern breed on the Platte River in Nebraska from the city of North Platte to the confluence with the Missouri River at Plattsmouth (Faanes 1983, Sidle et a/1988). Major riverine nesting areas are the reaches from Lexington to Grand Island and from Columbus to Plattsmouth (Fig 1). Nesting habitat is sparsely vegetated or unvegetated islands, sandbars, or shorelines of the river. An additional and important habitat is on the banks and islands within sand pits made by sand and gravel operations along the river. In the initial nest of the year, piping plovers usually lay four eggs, and least terns lay two or three and sometimes four eggs. Piping plovers will commonly renest if the initial nesting attempt is unsuccessful; least terns will renest infrequently if the initial attempt is unproducti ve. When renesting, piping plovers usually lay three to four eggs, and least terns lay two eggs. Least terns feed primarily on small fish (Anderson and Hubert 1988). Piping plovers feed on small aquatic invertebrates and terrestrial insects

A CONTAMINANTS EVALUATION OF THE BIG BLUE RIVER IN SOUTHEASTERN NEBRASKA

We collected three composite fish and three composite sediment samples from the Big Blue River in southeastern Nebraska to determine the presence of agricultural chemicals or other contaminants. Inorganic analyses consisted of individual analyses for arsenic, selenium, and mercury, as well as an ICP scan for other elements. Organic analyses included organochlorines, polynuclear aromatic hydrocarbons, organophosphate and carbamate pesticides, and chlorphenoxy acid herbicides. Arsenic was detected in the sediment samples, but not in the fish samples. Selenium was detected in one of three sediment samples and in all fish samples. Mercury was not detected in sediment samples, but was detected in all fish samples. Organic compounds detected in composite fish samples include BHC compounds, chlordane compounds, DDT and its metabolites, and anthracene. Outside of oil and grease, organic compounds were not detected in any sediment sample

A SURVEY OF ELEMENTAL CONTAMINANTS AND ORGANOCHLORINES AT NORTH PLATTE NATIONAL WILDLIFE REFUGE, NEBRASKA, 1993.

The North Platte National Wildlife Refuge (Refuge) is located 8 miles northeast of Scottsbluff, in Nebraska\u27s Panhandle. It was established by Executive Order in 1916, and was managed by the Bureau of Reclamation (BR) until 1986, when primary jurisdiction was granted to the U.S. Fish and Wildlife Service (Service). The 2,909 acre Refuge includes three reservoirs: 1) Lake Alice, 2) Winters Creek Lake, and 3) Lake Minitare (Figure 1). Water levels in all three reservoirs are managed by BR for irrigation and Lake Minitare is managed as a State Recreation Area under a lease agreement with the Nebraska Game and Parks Commission. The primary purpose of the Refuge is to provide sanctuary for migratory birds, but habitat for migrating bald eagles, waterfowl production, and compatible recreation are important management goals (USFWS, 2001). Twenty bald eagles and over 200,000 waterfowl concentrate on the Refuge during migration and over 200 species of birds have been observed on the Refuge. Irrigation supply water from the North Platte River is the primary source of water for all three Refuge reservoirs, which are interconnected by surface water. Lake Alice receives water from the Interstate and Highline canal, and discharges to the Supply canal and Hersche drain. Winters Creek Lake is fed by the Supply canal and also discharges to the Supply canal, with the inflow and outflow separated by approximately 200 meters. Lake Minitare receives water primarily from the Supply canal with secondary input from the Highline canal and discharges into the Lowline canal and Alliance drain. Land use in the drainage is primarily agricultural; with corn, soybeans, and sugar beet production the predominant row crops. In addition, alfalfa production and grazing areas support cattle ranching within the Refuge’s watershed