Environmental DNA metabarcoding of lake fish communities reflects long-term data from established survey methods

Area of Science:

• Ecology
• Molecular Biology
• Environmental Monitoring

Background:

• Organisms release environmental DNA (eDNA) into aquatic ecosystems.
• eDNA analysis is a rapidly advancing technique for biodiversity assessment.
• Few studies have validated eDNA's ability to represent entire aquatic communities.

Purpose of the Study:

• To assess the qualitative and quantitative accuracy of eDNA for monitoring fish communities in large lakes.
• To compare eDNA metabarcoding results with long-term gill-net survey data.
• To evaluate eDNA's potential as a complementary biodiversity monitoring tool.

Main Methods:

• Collected 78 water samples from three large UK lakes (Windermere, Bassenthwaite, Derwent Water).
• Utilized eDNA metabarcoding targeting mitochondrial 12S and cytochrome b regions.
• Compared eDNA detection and abundance proxies (sequence reads, site occupancy) with gill-net data.

Main Results:

• eDNA detected 14 out of 16 historical fish species in Windermere, significantly more than gill-net surveys.
• eDNA metabarcoding demonstrated high species sensitivity and detection capabilities.
• eDNA abundance proxies (sequence reads, site occupancy) showed consistent correlation with established survey abundance estimates.

Conclusions:

• eDNA metabarcoding accurately describes fish communities in large lakes, both qualitatively and quantitatively.
• eDNA is a highly sensitive tool for species detection, surpassing traditional methods in this study.
• eDNA holds significant potential as a complementary method for ecological and biodiversity monitoring.