White Paper - Dredging Activities: Marine Issues

Characterizing Marine Resource Dredging Effects in Washington State

This paper synthesizes the extent and nature of scientific information about how dredging activities in Washington State potentially affect habitats and key ecological functions supporting recruitment and sustainability of estuarine and marine organisms. A companion paper addresses the same issues in freshwater environments. We present conceptual tools to identify criteria for assessment of potential impacts associated with dredging activities. Identified impacts include: animal injury, behavioral effects, the effects of removing a measured amount of productivity from the landscape, and ecosystem-scale changes due to changes in estuarine circulation. Potential dredging effects are discussed as direct behavioral effects and long-term or cumulative effects. Long-term effects are approached from a landscape ecology perspective with the goal of facilitating the identification of critical regions in a given estuarine or marine landscape area and better identify critical habitat functions and the changes associated with dredging that could affect the realized functions of those habitats.

Information pertaining to the disposal of contaminated sediments is provided in a brief overview of disposal mechanisms and decision-making and a bibliography providing access to extensive literature specific to disposal and contaminated sediments.

This paper describes the existing federal and state regulatory framework regulating dredging and disposal activities. Federal and state authorities under the Clean Water Act, the Rivers and Harbors Act of 1899, the Ocean Dumping Act, and applicable state laws are summarized. Prohibited Work Periods (existing and proposed), Hydraulic Code Rules, Habitats of Special Concern, Tidal Reference Areas, and Technical Provisions Applicable to Dredging Activities are also presented.