Metal toxicity affects predatory stream invertebrates less than other functional feeding groups

Area of Science:

• Environmental toxicology
• Ecotoxicology
• Aquatic ecology

Background:

• Heavy metal contamination poses risks to aquatic ecosystems.
• Assessing ecosystem effects is crucial for risk assessment.
• Understanding metal impacts on invertebrates is vital.

Purpose of the Study:

• Correlate dissolved metal toxicity with invertebrate community structure.
• Identify reliable indicators for heavy metal pollution.
• Establish effect concentrations for copper and zinc.

Main Methods:

• Compiled data from Australian streams with heavy metal contamination.
• Analyzed relationships between metal toxicity and invertebrate communities.
• Calculated predator ratio and assessed its correlation with metal toxicity.

Main Results:

• Dissolved metal toxicity positively correlated with the proportion of predators (predator ratio).
• Effect threshold ranges for copper (2.6–26 μg/L) and zinc (62–617 μg/L) were identified.
• Heavy metals negatively affected taxa richness.

Conclusions:

• The predator ratio is a potential indicator for dissolved metal toxicity.
• SPEAR metals can be developed using the predator ratio.
• Current guideline limits for metals may need re-evaluation.