Passive air sampling detects environmental DNA transfer from water into air

Area of Science:

• Environmental DNA (eDNA) research
• Aquatic ecology
• Biomonitoring technologies

Background:

• Environmental DNA (eDNA) is typically studied in separate water and air reservoirs.
• eDNA is known to cross the air-water boundary, but this has not been systematically studied.
• Understanding eDNA transfer across interfaces is crucial for comprehensive environmental monitoring.

Purpose of the Study:

• To investigate the feasibility of sampling aquatic environmental DNA (eDNA) from the air.
• To evaluate passive air sampling methods for detecting aquatic life.
• To assess the air-water interface as a source of genetic information for biomonitoring.

Main Methods:

• Deployed passive air samplers (filters and water trays) alongside water samples and visual counts.
• Quantified eDNA concentrations in air (copies/cm²/day) and water (copies/L) using quantitative PCR.
• Analyzed airborne eDNA signals in relation to Coho salmon counts over a six-week period.

Main Results:

• Passive air collectors successfully detected airborne eDNA from aquatic species.
• Airborne eDNA concentrations were significantly lower than water concentrations but covaried with salmon counts.
• Sampler design and orientation influenced eDNA recovery rates.

Conclusions:

• The air-water interface is a viable source of quantifiable aquatic genetic information.
• Simple, passive air samplers can detect aquatic eDNA, offering a low-cost biomonitoring solution.
• Airborne eDNA monitoring holds promise for conservation, resource management, and public health.