Publications
Read publications and other informational products to learn more about USGS science occurring in the Mississippi Basin.
Filter Total Items: 5568
Selenium concentrations in the razorback sucker (Xyrauchen texanus): Substitution of non-lethal muscle plugs for muscle tissue in contaminant assessment Selenium concentrations in the razorback sucker (Xyrauchen texanus): Substitution of non-lethal muscle plugs for muscle tissue in contaminant assessment
A single muscle plug was collected from each of 25 live razorback suckers inhabiting the Colorado River basin and analyzed for selenium by instrumental neutron activation. Eight fish from Ashley Creek and three from Razorback Bar exhibited selenium concentrations exceeding 8 μg/g, a level associated with reproductive failure in fish. Concentrations of selenium in eggs and milt were...
Authors
B. Waddell, T. May
Dietary exposure of mink to carp from Saginaw Bay, Michigan. 1. Effects on reproduction and survival, and the potential risks to wild mink populations Dietary exposure of mink to carp from Saginaw Bay, Michigan. 1. Effects on reproduction and survival, and the potential risks to wild mink populations
Carp (Cyprinus carpio) collected from Saginaw Bay, Michigan, containing 8.4 mg total polychlorinated biphenyls (PCBs)/kg and 194 ng of 2,3,7,8-tetrachloro-dibenzo-p-dioxin equivalents (TEQs)/kg, were substituted for marine fish at levels of 0, 10, 20, or 40% in the diets of adult ranch mink (Mustela vison). The diets, containing 0.015, 0.72, 1.53, and 2.56 mg PCBs/kg diet, or 1.03, 19.41...
Authors
S. N. Heaton, S.J. Bursian, J. P. Giesy, D. E. Tillitt, J. A. Render, P. D. Jones, D. A. Verbrugge, T.J. Kubiak, R.J. Aulerich
Postflood occurrence of selected agricultural chemicals and volatile organic compounds in near-surface unconsolidated aquifers in the upper Mississippi River basin, 1993 Postflood occurrence of selected agricultural chemicals and volatile organic compounds in near-surface unconsolidated aquifers in the upper Mississippi River basin, 1993
The historic stream flooding and intense rainfall across the upper Mississippi River Basin during summer 1993 had an immediate effect on near-surface unconsolidated aquifers by raising the water levels closer to the land surface . The objective of this study was to determine if this flooding also had immediate effects on groundwater quality . Water samples were collected during September...
Authors
Dana W. Kolpin, E. Michael Thurman
Effect of increased water depth on growth of a common perennial freshwater-intermediate marsh species in Coastal Louisiana Effect of increased water depth on growth of a common perennial freshwater-intermediate marsh species in Coastal Louisiana
The response of Sagittaria lancifolia to increased water depths of 7.5 and 15 cm was examined in this field study. Water-depth treatments were achieved by digging sods containing one or two individual plants or ramets of S. lancifolia from the marsh, removing sediment from the resulting hole, and replacing the sods in their original location at the appropriate lower elevation. Plants...
Authors
Rebecca J. Howard, Irving A. Mendelssohn
Survey for blood parasites in redheads (Aythya americana) wintering at the Chandeleur Islands, Louisiana Survey for blood parasites in redheads (Aythya americana) wintering at the Chandeleur Islands, Louisiana
We detected no infections with species of Plasmodium, Haemoproteus, Leucocytozoon, Sarcocystis or Trypanosoma in blood smears, liver and spleen impressions, and muscle tissue from 136 redheads (Aythya americana) collected or captured at the Chandeleur Islands, Louisiana (USA), during three winters (1987 to 1990). One bird, a juvenile male, was infected with an unidentified species of...
Authors
Thomas C. Michot, Mary C. Garvin, Earl H. Weidner
A regional monitoring network to investigate the occurrence of agricultural chemicals in near-surface aquifers of the midcontinental USA A regional monitoring network to investigate the occurrence of agricultural chemicals in near-surface aquifers of the midcontinental USA
Previous state and national surveys conducted in the mid-continental USA have produced a wide range in results regarding the occurrence of agricultural chemicals in groundwater. At least some of these differences can be attributed to inconsistencies between the surveys, such as different analytical reporting limits. The US Geological Survey has designed a sampling network that is...
Authors
D.W. Kolpin, D. A. Goolsby
On the measurement of plant competition intensity On the measurement of plant competition intensity
No abstract available.
Authors
James B. Grace
Seagrass distribution in the Northern Gulf of Mexico Seagrass distribution in the Northern Gulf of Mexico
Seagrass ecosystems are widely recognized as some of the most productive benthic habitats in estuarine and nearshore waters of the gulf coast. Seagrass meadows provide food for wintering waterfowl and important spawning and foraging habitat for several species of commercially important finfish and shellfish. Physical structure provided by seagrasses affords juveniles refuge from...
Authors
Lawrence R. Handley
United States Geological Survey activities in Iowa United States Geological Survey activities in Iowa
No abstract available.
Authors
R. G. Middlemis-Brown
United States Geological Survey: Programs in Iowa United States Geological Survey: Programs in Iowa
No abstract available.
Authors
Water Resources Division U.S. Geological Survey
Southeastern freshwater fishes Southeastern freshwater fishes
North America has the richest fauna of temperate freshwater fishes in the world, with about 800 native species in the waters of Canada and the United States. The center of this diversity is in the southeastern United States, where as many as 500 species may exist (62% of the continental fauna north of Mexico). Many coastal marine species also enter fresh waters of the Southeast, and at...
Authors
Stephen J. Walsh, Noel M. Burkhead, James D. Williams