Chlordane: effects on several estuarine organisms.

Area of Science:

• Environmental Toxicology
• Marine Biology
• Chemical Ecotoxicology

Background:

• Chlordane is a persistent organic pollutant with known environmental risks.
• Understanding the toxicity of chlordane to marine organisms is crucial for ecological risk assessment.

Purpose of the Study:

• To determine the acute and chronic toxicity of technical grade chlordane to key marine species.
• To establish lethal concentration values (LC20) and effective concentration values (EC50) for various marine invertebrates and fish.

Main Methods:

• Dynamic marine toxicity testing using standard protocols.
• Exposure of eastern oysters, pink shrimp, grass shrimp, sheepshead minnows, and pinfish to measured chlordane concentrations.
• Flow-through tests to assess chronic effects on sheepshead minnow embryos and fry over 28 days.

Main Results:

• 96-hour LC20 values for pink shrimp, grass shrimp, sheepshead minnows, and pinfish were determined.
• The 96-hour EC50 for eastern oysters was established.
• Sheepshead minnow fry exhibited reduced survival in concentrations above 7.1 µg/L, while embryos showed no adverse effects.

Conclusions:

• Chlordane exhibits varying levels of acute toxicity across different marine species.
• Chronic exposure to chlordane significantly impacts sheepshead minnow fry survival, indicating developmental toxicity.
• These findings highlight the ecological risk posed by chlordane contamination in marine environments.