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Updated: Jul 25, 2026
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A Flow-through Exposure System for Evaluating Suspended Sediments Effects on Aquatic Life
Published on: January 9, 2017
Toxicity testing, risk assessment, and options for dredged material management
Wayne R Munns1, Walter J Berry, Theodore H Dewitt
1NHEERL Atlantic Ecology Division, US Environmental Protection Agency, Narragansett, RI 02882, USA. munns.wayne@epa.gov
Marine Pollution Bulletin
|July 26, 2002
Summary
Current dredged material disposal evaluations assess sediment toxicity individually, limiting cumulative risk assessment for aquatic ecosystems. An ecological risk assessment approach focusing on disposal sites can better evaluate risks from multiple disposal events.
Area of Science:
- Environmental toxicology
- Ecological risk assessment
- Aquatic ecosystem management
Background:
- US programs evaluate dredged material discharges using tiered testing and bioassays for sediment toxicity.
- Current methods assess each dredging project's sediments separately, hindering evaluation of cumulative risks to aquatic organisms.
- This siloed approach limits understanding of overall impacts on water column and benthic communities near disposal sites.
Purpose of the Study:
- To review current US toxicity testing protocols for dredged material.
- To propose an ecological risk assessment framework for evaluating cumulative impacts of dredged material disposal.
- To enable a more holistic management approach for dredged material disposal activities.
Main Methods:
- Review of existing US toxicity testing and evaluation protocols for dredged material.
- Application of ecological risk assessment principles to disposal sites.
- Incorporation of temporal and spatial risk components into the assessment framework.
Main Results:
- Current protocols inadequately address cumulative risks due to project-specific sediment analysis.
- A disposal site-focused ecological risk assessment can better capture risks from multiple disposal events.
- The proposed approach integrates temporal and spatial considerations for a comprehensive risk evaluation.
Conclusions:
- A shift towards disposal site-focused ecological risk assessment is needed for accurate evaluation of dredged material impacts.
- This approach facilitates a more comprehensive understanding of risks to receiving aquatic ecosystems.
- The framework supports holistic management strategies for dredged material disposal, considering cumulative effects.
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