Toxicological Assessment of Aquatic Ecosystems: Application to Watercraft Contaminants in Shallow Water Environments

• Published in: Journal of coastal research 2002-10, p.179-191
• Main Author: Winger, Parley V.
• Format: Article
• Language: English
• Subjects: Animal reproduction; Biochemistry; Chemical hazards; Contaminants; Fresh water; Green chemistry; Sediments; Toxicity; Toxicology; Water pollution
• ISSN: 0749-0208; 1551-5036

Recreational boating and personal watercraft use have the potential to adversely impact shallow water systems through contaminant release and physical disturbance of bottom sediments. These nearshore areas are often already degraded by surface runoff, municipal and industrial effluents, and other anthropogenic activities. For proper management, information is needed on the level of contamination and environmental quality of these systems. A number of field and laboratory procedures can be used to provide this much needed information. Contaminants, such as metals, pesticides, polychlorinated biphenyls, and polycyclic aromatic hydrocarbons, entering aquatic environments generally attach to particulate matter that eventually settles and becomes incorporated into the bottom sediments. Because bottom sediments serve as a sink and as a source for contaminants, environmental assessments generally focus on this matrix. While contaminant residues in sediments and sediment pore waters can reflect environmental quality, characteristics of sediments (redox potential, sediment/pore-water chemistry, acid volatile sulfides, percent organic matter, and sediment particle size) influence their bioavailability and make interpretation of environmental significance difficult. Comparisons of contaminant concentrations in pore water (interstitial water) and sediment with water quality criteria and sediment quality guidelines, respectively, can provide insight into potential biological effects. Laboratory bioaccumulation studies and residue concentrations in resident or caged biota also yield information on potential biological impacts. The usefulness of these measurements may increase as data are developed relating in-situ concentrations, tissue residue levels, and biological responses. Exposures of test organisms in situ or to field-collected sediment and pore water are additional procedures that can be used to assess the biological effects of contaminants. A battery of tests using multispecies and/or various life stages with different sensitivities to contaminants may offer a more conservative assessment of toxicity than single species testing. Using a "weight of evidence" approach, the Sediment Quality Triad produces a robust evaluation of habitat quality and includes a measure of contaminant concentrations in the sediments, an assessment of sediment/pore-water toxicity to laboratory animals, and an evaluation of in-situ biological assemblages. Field and laboratory procedures