Design and Validation of an Open-Close Device for Integrated Environmental DNA Sampling Detects A Depth Gradient in...

Area of Science:

• Marine Biology
• Environmental Science
• Molecular Ecology

Background:

• Environmental DNA (eDNA) sampling is revolutionizing biomonitoring.
• Existing survey technologies can be adapted for novel eDNA collection methods.

Purpose of the Study:

• To design and test an integrated eDNA sampler for deep-water transects.
• To assess the efficacy of a novel open-close device (OCD) for eDNA capture.
• To compare different eDNA processing methods and validate detections with existing survey data.

Main Methods:

• Manufactured a high-density polyethylene open-close device (OCD) attachable to a deep tow camera system.
• Deployed the OCD with active carbon sponges for eDNA capture at depths up to 6000m.
• Compared three eDNA processing techniques (water filtration, sponge extraction, sponge rinse filtration) and validated fish detections against trawl data.

Main Results:

• Successfully collected integrated eDNA samples using the OCD sampler in the Gascoyne Marine Park.
• Detected a substantial number of fish taxa (193), with most detections aligning with expected depth ranges and trawl survey data.
• Identified optimal methods for eDNA processing from the sampler, enhancing data reliability.

Conclusions:

• The developed OCD sampler is a viable tool for deep-water eDNA biomonitoring.
• This technology offers advancements in ecological metrics and understanding of deep-sea ecosystems.
• Further research can optimize eDNA capture efficiency and processing methodologies for broader oceanographic applications.