Geology topics

Mark E. Brigham

Publications and source records attributed to Mark E. Brigham.

40 records · Page 3Linked to original sources

USGS1996

Comparison of mercury concentrations in liver, muscle, whole bodies, and composites of fish from the Red River of the North

Carp ( Cyprinus carpio ) from four sites and channel catfish ( Ictalurus punctatus ) from one site in the Red River of the North in 1994 were analyzed for total mercury content. In carp, mercury concentrations differed among liver, muscle, and whole bodies (0.11, 0.31, and 0.18 µg/g wet weight, respectively), between large and small size groups, but not location. Mercury distribution in channel catfish tissues differed from that in carp. Liver and muscle tissue had similar mean concentrations; each was higher than whole-body concentrations (0.16, 0.18, and 0.11 µg/g, respectively). Mercury concentrations were not significantly different between the two size groups of channel catfish. Weighted-mean mercury concentrations from seven individual fish agreed closely (usually within 10%) with concentrations determined on physical composites of the same fish. The ratio of mercury in whole bodies to mercury in muscle was similar for both carp and channel catfish. Historical data indicate that this ratio may be applicable to other species and locations. The ratio of mercury in livers to whole bodies and muscle differed between carp and channel catfish, which may reflect physiological differences between different trophic groups.

Minnesota, North Dakota, South Dakota↗

USGS1995

Pesticide amounts are small in streams in the Red River of the North Basin, 1993-94

Pesticides are used extensively in the largely agricultural Red River of the North (Red River) Basin, but, unlike many other agricultural basins, only small amounts are routinely detected in samples from streams in the basin. The pesticides detected comprise less than 2 percent of the amount applied and usually are at concentrations far less than established drinking water standards. Most of the detected pesticides seem to come from sources near the headwaters in the southern part of the basin. Although low, concentrations are related to pesticide application and runoff. Flat land slope, organic soils, pesticide management, and degradation all may limit pesticide contamination that reaches Red River Basin streams.

Open-File Report↗

USGS1994

Pesticides detected in surface waters and fish of the Red River of the North drainage basin

The Red River of the North drainage basin (herein referred to as Red River Basin) within the United States is a study unit under the U.S. Geological Survey (USGS) National Water-Quality Assessment (NAWQA) program. The overall goals of this program, initiated to better define the status and trends of the Nation’s water quality, are to address regional and national water-quality issues in a nationally consistent manner. Pesticide contamination of surface water and fish is one focus of this program. The Red River Basin is about 90,600 square kilometers (km2 ) in area and is composed of rolling prairie with a high density of prairie-pothole wetlands to the west; a very flat glacial lake bed with drainage ditches and meandering streams in the center (Red River Valley Lake Plain); morainal hills with a mosaic of agriculture, lakes, and forest in the southeast; and a flat lake-washed till plain with extensive peatlands in the northeast (fig. 1). Stoner and others (1993) have given a more complete description of the environmental setting of the Red River Basin. Agriculture is a major component of the region’s economy, and is greatest in the Red River Valley Lake Plain. Principal crops are wheat, barley, oats, sunflowers, corn, soybeans, dry beans, potatoes, sugarbeets, alfalfa hay, and other hay. Herbicide, insecticide, and fungicide use depends on crop type and environmental stresses such as crop disease, drought, and periodic insect-pest infestation. This paper focuses on the occurrence, movement, and fate of agricultural pesticides that are applied to crops, but improper disposal, and use of pesticides for household pests, lawn care, golf courses, and home gardening can also result in contamination of the aquatic environment. Furthermore, atmospheric transport is known to transport pesticides to regions far from their source (Kurtz, 1990). Pesticide data have been collected in the Red River Basin by various Federal, State, and local agencies. Tornes and Brigham (1994) recently summarized many of these historical data. This paper summarizes selected data collected as part of the NAWQA program during 1992-93, and briefly compares these data to historical data and to pesticide usage.

Minnesota, North Dakota, South Dakota↗

USGS1992

Increasing rates of atmospheric mercury deposition in midcontinental North America

Mercury contamination of remote lakes has been attributed to increasing deposition of atmospheric mercury, yet historic deposition rates and inputs from terrestrial sources are essentially unknown. Sediments of seven headwater lakes in Minnesota and Wisconsin were used to reconstruct regional modern and preindustrial deposition rates of mercury. Whole-basin mercury fluxes, determined from lake-wide arrays of dated cores, indicate that the annual deposition of atmospheric mercury has increased from 3.7 to 12.5 micrograms per square meter since 1850 and that 25 percent of atmospheric mercury deposition to the terrestrial catchment is exported to the lake. The deposition increase is similar among sites, implying regional or global sources for the mercury entering these lakes.

Science↗