They're abundant in this area, but hard to count reliably. We outline a procedure for estimating the population sizes so that we can determine whether they're increasing or dwindling. We must both listen for their calls and visually confirm them.
Previous analysis showed this area to have reduced macroinvertebrate biodiversity, an important measure of ecosystem health. New observations indicate that conditions have improved; report includes methods and results of sampling.
A web-enabled database that provides for the capture, curation, integration, and delivery of bioassessment data collected by USGS, principally macroinvertebrate, algae, fish, and supporting habitat data from rivers and streams.
Manual for research program on the nesting habits of sea turtles of the Virgin Islands, with descriptions of species, nesting behavior, observation methods, record keeping, tagging, and tissue sample collection. (PDF file, 121 pp.)
Population size, foaling, deaths, age structure, sex ratio, age-specific survival rates, and more over a 14 year time span. This information will help land and wildlife managers find the best maintenance and conservation strategies.
Sixty-five sampling sites, selected by a statistical design to represent lengths of perennial streams in North Dakota, were chosen to be sampled for water chemistry and mercury in fish tissue to establish unbiased baseline data.
Sixty-five sampling sites, selected by a statistical design to represent lengths of perennial streams in North Dakota, were chosen to be sampled for fish and aquatic insects (macroinvertebrates) to establish unbiased baseline data.