Monitoring bloom-forming Aphanizomenon using environmental DNA metabarcoding: Method development, validation, and...

Area of Science:

• Environmental Science
• Ecology
• Molecular Biology

Background:

• Harmful algal blooms (HABs) are a significant global environmental issue.
• Accurate monitoring of bloom-forming genera is vital for HAB management.
• Traditional methods are labor-intensive and require expertise, limiting large-scale surveillance.

Purpose of the Study:

• To develop Aphanizomenon-specific PCR primers.
• To validate environmental DNA (eDNA) metabarcoding for field-based monitoring of Aphanizomenon.
• To identify environmental drivers of Aphanizomenon distribution.

Main Methods:

• Development and testing of novel Aphanizomenon-specific PCR primers.
• Application of eDNA metabarcoding for monitoring in 37 freshwater sites.
• Statistical analysis correlating eDNA sequence abundance with microscopic cell counts and environmental variables.

Main Results:

• Newly developed primers demonstrated high sensitivity and specificity for Aphanizomenon.
• eDNA metabarcoding showed significant correlations with microscopic cell density in spring and summer.
• Key environmental drivers identified include temperature, total nitrogen, dissolved oxygen, and total phosphorus.

Conclusions:

• eDNA metabarcoding with novel primers provides an accurate, efficient, and high-throughput tool for Aphanizomenon bloom monitoring.
• This method overcomes limitations of traditional techniques for large-scale surveillance.
• Understanding environmental drivers aids in predicting and managing Aphanizomenon blooms.