Publications

We conducted two 90 day chronic toxicity studies with two endangered fish, razorback sucker and bonytail. Swim-up larvae were exposed in a reconstituted water simulating the middle Green River. The toxicant mixture simulated the environmental ratio and concentrations of inorganics reported in a Department of the Interior study for the mouth of Ashley Creek on the Green River, and was...

We developed a key to identify wings of hybrids between American Black Ducks (Anas rubripes) and Mallards (A. platyrhynchos). Material for analysis included review of historical descriptions dating from the late 1700's, older museum collections in Europe and North America, wings collected from hunters in North America and Great Britain, birds banded in Canada and the United States, and a...

The water quality in rivers and streams and in selected aquifers in eastern Iowa and part of southern Minnesota is described and illustrated. Major ions, nitrogen and other nutrients, and pesticides and some of their breakdown compounds were analyzed in both surface and ground water. Biological communities that included fish, invertebrates, and algae, were described in relation to stream...

Relations between neurotoxicants and changes in physiological parameters and behavior were investigated in larval rainbow trout (RBT; Oncorhynchus mykiss) exposed to sublethal concentrations of two organophosphate pesticides (OPs). Fish were exposed to diazinon and malathion in static-renewal experiments. After exposures for 24, 96, or 96 h, followed by 48 h of recovery, individual RBT...

Surface water quality was monitored at 19 stations (2-4 week intervals) in six drainage basins of Big Thicket National Preserve of east Texas between 1996 and 1999. The parameters monitored were temperature, dissolved oxygen, pH, conductivity, current speed, light attenuation, chlorophyll a and concentrations of ammonium, ortho-phosphate, nitrate and nitrite. The best water quality (low...

No abstract available.

No abstract available.

Fish community data were collected by the U.S. Geological Survey (USGS) at 12 sites in 1996 in the Wapsipinicon, the Cedar, the Iowa, and the Skunk River Basins in eastern Iowa. The study was done as part of the National Water-Quality Assessment (NAWQA) Program of the USGS. This report presents an evaluation of the fish communities, the composition and conditions of the fish communities...

Cogongrass (Imperata cylindrica), an invasive perennial introduced from Southeast Asia, is currently spreading throughout the southeastern United States from Florida to Louisiana. In the U.S., cogongrass is generally not considered a wetland species, although it’s range is expanding in regions with high wetland abundance. The objective of this study was to determine if excessive soil...

Wetlands exist in a transition zone between aquatic and terrestrial environments which can be altered by subtle changes in hydrology. Twentieth century climate records show that the United States is generally experiencing a trend towards a wetter, warmer climate; some climate models suggest that his trend will continue and possibly intensify over the next 100 years. Wetlands that are...

Sediment-quality guidelines (SQGs) have been published for polychlorinated biphenyls (PCBs) using both empirical and theoretical approaches. Empirically based guidelines have been developed using the screening-level concentration, effects range, effects level, and apparent effects threshold approaches. Theoretically based guidelines have been developed using the equilibrium-partitioning...

No abstract available.