GO-eFISH: Generating best practise for the use of eDNA for marine fish biodiversity analyses

Traditional morphological or image-based classification of marine taxa is time-consuming, requires specialist knowledge and is near impossible for certain life forms (e.g. fish eggs). An alternative approach that has lately received a great deal of interest is the use of so-called environmental DNA or 'eDNA'; the DNA signature that animals leave behind either through shedding skin cells, reproductive stages or through decomposition. eDNA offers the opportunity to study the population structures of fish communities, regardless of life stage, and without the need to catch and count manually. This vital data supports fish stock assessment and fisheries management (_e.g._ spawning areas, seasons, recruitment, simultaneously for multiple fish species), and will aid in our understanding of drivers of change.

At Applied Genomics, we have developed technologies that can automatically collect large quantities of eDNA from the marine environment and have developed protocols to semi-quantify fish species abundance. Making use of the weekly sampling taking place at the Western Channel Observatory long-term biodiversity monitoring site, researchers at the Plymouth Marine Laboratory have been collecting smaller water DNA samples since 2012\. Working together, our aim is to compare the data on fish taxa derived from DNA methods with those from conventional catch-and-count methods in order to refine our DNA methodologies, improving the technology readiness of Applied Genomics' automated large volume eDNA sampler. At the same time, we will provide detailed insight into changes to the seasonal structure of fish populations over time at the Western Channel Observatory.