Publications

No abstract available

The activity of the erythrocyte enzyme δ-aminolevulinic acid dehydratase (ALA-D) was measured in 35 catostomids (black redhorse, Moxostoma duquesnei; golden redhorse, M. erythrurum; northern hogsucker, Hypentelium nigricans) collected from three sites on a stream contaminated with Pb-, Cd-, and Zn-rich mine tailings and from an uncontaminated site upstream. Enzyme activity was expressed...

No abstract available.

No abstract available.

The Dakota aquifer in northwest Iowa consists of sandstones in the Dakota Formation. It underlies most of the study area and is the most extensive source of ground water in the area. Individual sandstone beds are from less than 10 to more than 150 feet thick. The cumulative thickness of sandstone is more than 200 feet throughout much of the area. The aquifer is confined by overlying...

Water resources data for the 1983 water year for Iowa consists of records of stage, discharge, and water quality of streams; stage, contents, and water quality of lakes and reservoirs; and water levels in wells. This report contains discharge records for 116 gaging stations; stage and contents for 7 lakes and reservoirs; water quality for 17 gaging stations; and water levels for 90...

No abstract available.

Variation in the birth size of offspring of the terrestrial isopod, Armadillidium vulgare, was observed in laboratory experiments and in field populations. In the laboratory, larger offspring were produced when the mother's food supply was reduced. In field populations, larger offspring were produced during the summer, a period of reduced food availability. Smaller offspring are produced...

This report documents the results of a study of the cost-effectiveness of the stream-gaging program in Iowa. Data uses and funding sources were identified for the 122 surface-water stations (including reservoir, lake, stage only, and miscellaneous stations) operated by the U. S. Geological Survey in Iowa. There are 110 continuous streamflow stations currently being operated in Iowa with...

Distinguishing forested wetland from dry forest using aerial photographs has been handicapped because photographs often do not reveal the presence of water below the tree canopies. Images obtained during the summer months of 1978 by the Seasat satellite's L-band (23-cm) radar reveal forested wetland as patterns of high radar reflection in the Atlantic coastal plain between Maryland and...

No abstract available.

Adult spawning behavior and emigration of larvae of the endangered cui-ui Chasmistes cujus were studied in a natural side channel of the lower Truckee River. External radio-tags placed on eight apparently did not affect spawning behavior. Cui-uis spawned in clusters of two to seven fish; usually a single female was flanked by two males. Each spawning act lasted 3–6 seconds, and...