"Education, arts and social sciences, natural and technical sciences in the United States and Canada".

As debates over how relative risk can be used to shape landscape-scale environmental management intensify, Regional-Scale Risk Assessment demonstrates the capabilities of RRM using nine case studies in the Pacific Northwest, Pennsylvania, Brazil, and Tasmania. The authors use a process of ranking and filters to interrelate different kinds of risks

Recently, environmental scientists have been required to perform a new type of assessment-ecological risk assessment. This is the first book that explains how to perform ecological risk assessments and gives assessors access to the full range of useful data, models, and conceptual approaches they need to perform an accurate assessment. It explains how ecological risk assessment relates to more familiar types of assessments. It also shows how to organize and conduct an ecological risk assessment, including defining the source, selecting endpoints, describing the relevant features of the receiving environment, estimating exposure, estimating effects, characterizing the risks, and interacting with the risk manager. Specific technical topics include finding and selecting toxicity data; statistical and mathematical models of effects on organisms, populations, and ecosystems; estimation of chemical fate parameters; modeling of chemical transport and fate; estimation of chemical uptake by organisms; and estimation, propagation, and presentation of uncertainty. Ecological Risk Assessment also covers conventional risk assessments, risk assessments for existing contamination, large scale problems, exotic organisms, and risk assessments based on environmental monitoring. Environmental assessors at regulatory agencies, consulting firms, industry, and government labs need this book for its approaches and methods for ecological risk assessment. Professors in ecology and other environmental sciences will find the book's practical preparation useful for classroom instruction. Environmental toxicologists and chemists will appreciate the discussion of the utility for risk assessment of particular toxicity tests and chemical determinations.

In spite of the growing importance of Species Sensitivity Distribution models (SSDs) in ecological risk assessments, the conceptual basis, strengths, and weaknesses of using them have not been comprehensively reviewed. This book fills that need. Written by a panel of international experts, Species Sensitivity Distributions in Ecotoxicology reviews

U.S. mariculture production of bivalve molluscs-those cultivated in the marine environment-has roughly doubled over the last 25 years. Although mariculture operations may expand the production of seafood without additional exploitation of wild populations, they still depend upon and affect natural ecosystems and ecosystem services. Every additional animal has an incremental effect arising from food extraction and waste excretion. Increasing domestic seafood production in the United States in an environmentally and socially responsible way will likely require the use of policy tools, such as best management practices (BMPs) and performance standards. BMPs represent one approach to protecting against undesirable consequences of mariculture. An alternative approach to voluntary or mandatory BMPs is the establishment of performance standards for mariculture. Variability in environmental conditions makes it difficult to develop BMPs that are sufficiently flexible and adaptable to protect ecosystem integrity across a broad range of locations and conditions. An alternative that measures performance in sustaining key indicators of ecosystem state and function may be more effective. Because BMPs address mariculture methods rather than monitoring actual ecosystem responses, they do not guarantee that detrimental ecosystem impacts will be controlled or that unacceptable impact will be avoided. Ecosystem Concepts for Sustainable Bivalve Mariculture finds that while performance standards can be applied for some broad ecosystem indicators, BMPs may be more appropriate for addressing parameters that change from site to site, such as the species being cultured, different culture methods, and various environmental conditions. This book takes an in-depth look at the environmental, social, and economic issues to present recommendations for sustainable bivalve mariculture.

Are the nation's ports adequate for our present and future needs? This volume points out that no significant new deep-water construction has occurred for a decade, and provides the information and analysis needed to goad the ports and the federal government into action. The book asks three questions: Is additional port construction and maintenance dredging needed now or over the next 20 years? What would prevent dredging if it is needed? What alternatives could make additional dredging possible? The book identifies several problems in dredging ports, including the long interval between a decision to deepen a port and the time the alterations are complete. The United States needs to speed port construction to meet changing needs, and the committee recommends that we prepare for future needs by dredging now.

How can environmental regulators use information on 48-hour toxicity tests to predict the effects of a few minutes of pollution? Or, at the other extreme, what is the relevance of 96-hour toxicity data for organisms that may have been exposed to a pollutant for six months or more? Time to event methods are the key to answering these types of questi