Report on how mercury (Hg) was examined in top-predator fish, bed sediment, and water from streams that spanned regional and national gradients of Hg source strength and other factors thought to influence methylmercury bioaccum. Sampled settings include stream basins that were agr¿l, urbanized, undeveloped, and mined. Predator fish were targeted for collection, and composited samples of fish were analyzed for total Hg (THg), as most of the Hg found in fish tissue is MeHg. Samples of bed sediment and stream water were analyzed for THg, MeHg, and characteristics thought to affect Hg methylation, such as loss-on-ignition and acid-volatile sulfide in bed sediment, and pH, dissolved organic carbon, and dissolved sulfate in water. Illus.

Pollution is undesirable state of the natural environment being contaminated with harmful substances as a consequence of human activities so that the environment becomes harmful or unfit for living things; especially applicable to the contamination of soil, water, or the atmosphere by the discharge of harmful substances. In addition to the harm to living beings, both present or future and known or unknown, pollution cleanup and surveillance are enormous financial drains of the economies of the world. This book focuses on issues and developments critical for the field.

This edited volume collects population and metapopulation models for a wide variety of species, focusing on the use of models in population-level risk assessment for toxins. Each chapter of Demographic Toxicity describes the application of a population model to one species, with the aim of demonstrating how various life history characteristics of the species are incorporated into the model, how ecotoxicological impacts are modeled, and how the results of the model has been or can be used in risk assessment. The model in each chapter is implemented in RAMAS software, which uses matrix modeling of population dynamics. RAMAS software is believed to be the most powerful tool ever invented for this task.Demographic Toxicity includes a CD that contains a demo version of the program and the data files for each species. The book explains how to use these specific tools for modeling, analysis, and interpretation of data. Demographic Toxicity provides a major review of current knowledge on population dynamics in different species, representing both terrestrial and aquatic environments.