Publications

Level II scour evaluations follow a process in which hydrologic, hydraulic, and sedient-transport data are evaluated to calculate the depth of scour that may result when given discharge is routed through a bridge opening. the results of the modified Levell II analysis for structure I-70-104-5128 on Interstate 70 crossing Brandywine Creek in Hancock County, Indiana, are presented. The...

No abstract available.

We investigate groundwater flow near cooling plutons with a computer program that can model multiphase flow, temperatures up to 1200°C, thermal pressurization, and temperature‐dependent rock properties. A series of experiments examines the effects of host‐rock permeability, size and depth of pluton emplacement, single versus multiple intrusions, the influence of a caprock, and the impact...

The documented presence of two large (~100-km diameter), possibly coeval impact craters of late Eocene age, requires modification of the impact-kill curve proposed by David M. Raup. Though the estimated meteorite size for each crater alone is large enough to have produced considerable global environmental stress, no horizons of mass mortality or pulsed extinction are known to be...

This paper summarizes the results of a comparative bathymetric study encompassing 150 km of the Louisiana barrier-island coast. Bathymetric data surrounding the islands and extending to 12 m water depth were processed from three survey periods: the 1880s, the 1930s, and the 1980s. Digital comparisons between surveys show large-scale, coherent patterns of sea-floor erosion and accretion...

In 1993, great blue heron (Ardea herodias; GBH) eggs were collected from 10 colonies on the upper Mississippi River (UMR). They were then artificially incubated until pipping and analyzed for mercury, selenium, and organochlorines. Livers of embryos were analyzed for hepatic microsomal ethoxyresorufin-O-dealkylase (EROD) activity and four measures of oxidative stress. Brains were...

No abstract available at this time

We examined the diet composition and prey selection of 1,875 recently released American shad (Alosa sapidissima) larvae (approximately 18-d old). Larvae were collected in the Juniata River, Pennsylvania, during June in 1991 and 1992. Chironomid pupae were selected by shad larvae and were the major component in the diet in 1991 (50%) and 1992 (96%). Chironomid larvae, the second-ranked...

No abstract available.

Red drum reared from captive-spawned eggs were used in a 2 × 4 factorial experiment comparing eight diets with soybean oil (SBO) or menhaden oil (MHO) added to a basal diet (about 3.4% lipid from practical ingredients) at 1.5, 5.2, 9.0, or 12.7%. Triplicate groups of 20 early juveniles (mean 0.4 g) were stocked in 1000 litre fiberglass tanks supplied with filtered estuarine water (17–26...

The relationship between allozyme genotype and survival of nymphs of the mayfly Isonychia bicolor (Walker) when exposed to acute mercury concentrations was tested in laboratory experiments. The probability of survival and individual times-to-death were found to be significantly different among genotypes at the glucose phosphate isomerase locus, but not at the phosphoglucomutase locus...

Accurate detection of Aeromonas salmonicida subsp. salmonicida (the cause of furunculosis disease) in covertly infected salmonids is difficult and is a cause of concern for those involved in fish health inspection and resource management programs. In this study, we examined populations of brook trout Salvelinus fontinalis, Atlantic salmon Salmo salar, and lake trout Salvelinus namaycush...