Development and evaluation of sediment quality guidelines based on benthic macrofauna responses.

Area of Science:

• Environmental Science
• Ecotoxicology
• Marine Biology

Background:

• Sediment quality guidelines (SQGs) are crucial for assessing contamination risks to benthic macrofauna.
• The correlation between toxicity-based SQGs and actual benthic community condition remains insufficiently documented.

Purpose of the Study:

• To compare the efficacy of five toxicity-based SQG approaches against a novel benthos-based SQG approach.
• To evaluate their performance in predicting changes in benthic community condition.

Main Methods:

• Applied five toxicity-based SQG methods (Effects Range Median, Logistic Regression Modeling (LRM), SQGQ1, Consensus, California LRM) and a new benthos-based Chemical Score Index (CSI) to Southern California data.
• Matched chemical concentrations, amphipod mortality, and benthic macrofauna abundance data.
• Calculated summary metrics and classified stations into four biological effect categories.

Main Results:

• All SQG approaches showed significant correlations with sediment toxicity and benthic community condition.
• Toxicity and benthic condition measures exhibited similar sensitivity and specificity to contamination levels.
• The National LRM, California LRM, and CSI demonstrated high agreement with benthic categories.

Conclusions:

• The benthos-based Chemical Score Index (CSI) consistently outperformed other SQG indices across all association measures for both toxicity and benthic data.
• This suggests CSI is a superior tool for assessing sediment contamination impacts on benthic communities.