Publications

Abstract not supplied at this time

Design of a device to freeze soils to prevent compaction, dewatering, and loss of flocculent material and allow soil sampling.

Isla del Coco lies at 5 degrees 32'N latitude, 87 degrees 04'W longitude and is the sole peak of the Cocos Ridge exposed above sea level. This isolated island formed approximately 2 million years ago. It rises 575 m above the surface of the sea and covers 46 km2 (Castillo et aI., 1988). Five hundred km to the NNE is Costa Rica; 630 km SSW are the Galapagos Islands; 650 km to the E is...

Abstract not supplied at this time

A statistical analysis of the age composition of striped bass Morone saxatilis harvested in Albemarle Sound and the Roanoke River, North Carolina. indicated that in 1988–1992 the population experienced a relatively high rate of total mortality. Age-3 and older fish were estimated to have been fully vulnerable to fishing mortality and to have experienced a total instantaneous mortality...

U.S. Geological Survey's Biological Resources Disicipline scientists have developed a procedure that could save commercial producers of triploid grass carp between $2000 and $3000 per pond. Since 1983, triploid grass carp have been commercially available for managing aquatic weeds that can cause water quality problems, replace native plants, or impede recreational and commercial use of...

We used morphological characteristics to determine the sex of California Gulls (Larus californicus) nesting at Bamforth Lake, Wyoming. Using univariate and multivariate techniques, we evaluated sexual dimorphism in five external measurements taken from 614 California Gulls: bill length, bill depth, head-bill length, tarsus length, and body mass. Males were significantly larger than...

Abstract not supplied at this time

Rates of direct denitrification were measured using 15N isotope tchniques in intact sediment cores from fringe and basin mangroves in Terminos Lagoon, Mexico. Sediments were injected with 15NO3- and the distribution of 15N was measured over time in the head space, overlying water, and sediments. Experiments included an investigation of spatial variation in denitrification rates by...

The areal extent and temporal patterns of sediment deposition in delta marshes and shallow water bodies of Louisiana associated with the passage of Hurricane Andrew were determined from sediment traps, marker horizons, and benchmarks deployed for other studies. Data were collected over different time scales from 11 sites representing salt, brackish, and intermediate marshes, shallow...

No abstracts available.

At 20 sites, incorporating mixtures of black, red, and white mangroves, canopy reflectance spectra were derived from high resolution spectral data taken from a helicopter platform. Canopy characteristics were predicted from the canopy reflectance spectra by using measured and estimated data as inputs into a light-canopy interaction model within a optimization routine. Pertinent to...