Effluent toxicity test using developmental stages of the marine polychaete Hydroides elegans

Area of Science:

• Marine Biology
• Environmental Toxicology
• Ecotoxicology

Background:

• The US Environmental Protection Agency (USEPA) has developed bioassay methods using coastal invertebrates for toxicity testing.
• These methods are globally applied but underexplored in Asian coastal waters.
• Hydroides elegans, a common marine invertebrate, offers potential for toxicity assessments.

Purpose of the Study:

• To establish and validate a bioassay using Hydroides elegans gametes for monitoring coastal water quality in India.
• To assess the sensitivity of H. elegans early life stages to effluents and environmental samples.
• To explore the utility of H. elegans as a bioindicator for marine pollution.

Main Methods:

• Utilized gametes of Hydroides elegans for bioassays.
• Exposed H. elegans embryos and larvae to varying concentrations of industrial/domestic effluents and coastal water samples from India's east coast.
• Monitored fertilization success, embryo development rates, and larval morphology.

Main Results:

• Seawater from Ennore station significantly reduced H. elegans development percentage.
• A 25% effluent concentration caused complete developmental arrest in H. elegans embryos.
• Observed morphological abnormalities indicated defects in early embryonic cell differentiation.

Conclusions:

• Fertilization and early development of H. elegans serve as sensitive indicators for rapid pollution bioassays.
• Toxicity tests with early life stages of H. elegans are effective for detecting low-level pollutants due to high sensitivity and assay simplicity.
• This bioassay is suitable for assessing coastal water quality in Asian regions, particularly along the east coast of India.