GESAMP: Long-Term Consequences of Low-Level Marine Contamination: An Analytical Approach - UNEP Regional Seas Reports and Studies No. 118

This report examines the potential long-term ecological consequences of persistent low-level chemical contamination in marine environments and proposes an analytical approach for evaluating such effects. It discusses conceptual and methodological challenges in identifying subtle ecological changes caused by contaminants in complex marine ecosystems, where natural variability and limited baseline data complicate interpretation. The document develops principles based on toxicological concepts, including dose–response relationships and exposure over extended periods, and applies them through case studies involving nutrients, chlorinated hydrocarbons, tributyl tin, and petroleum hydrocarbons. These cases illustrate biological responses from cellular to community levels and inform the development of analytical frameworks linking contaminant exposure with ecological effects and monitoring indicators for detecting environmental change.