Exploiting bivalves, specifically the Pacific Oyster, as a natural eDNA sampling platform

Brett Bolte^1,2,3,4, Carmel McDougall^3,4, Andrew Bissett¹, Pascal Craw¹, James Wynne⁴, Kylie Pitt^2,4,6, David Beale⁷

¹CSIRO Environment, Hobart, Australia, ²Blue Economy CRC, Launceston, Australia, ³Griffith University School of Environment and Science, Nathan, Australia, ⁴Australian Rivers Institute, Nathan, Australia, ⁵CSIRO Agriculture and Food, Hobart, Australia, ⁶Coastal and Marine Research Centre, Gold Coast, Australia, ⁷CSIRO Environment, Ecosciences Precinct, Dutton Park, Australia

Filter feeding organisms, specifically bivalves are some of the most successful organisms within the aquatic environment and are regularly found to be invasive within waterways globally. Further, they are some of the most prolific biofouling species, especially within aquaculture farms, causing decreased water flow, oxygen and in some cases, death of stock. This is largely due to their successful suspension feeding behaviours allowing them to be efficient in their collection of food, along with surrounding environmental DNA (eDNA) sized particles. This ability to collect and potentially accumulate eDNA within their bodies allow them to be ideal candidates for natural samplers, or organisms which can accumulate DNA from their feeding/foraging behaviours. eDNA utilises DNA shed in the environment to infer the presence of an organism(s) and has been shown to successfully compliment and replace direct monitoring methods. Several eDNA concentration methods are currently used across different environments, which are optimised for the target organism(s) and the specific research question. Bivalves as natural samplers offer the potential to be a concentration medium for DNA which may be highly suitable for detection of metazoan, microbe and phytoplanktonic communities, especially where mechanical filtration is difficult. Additionally, these samplers offer a further biomonitoring platform for the early detection of potential pathogens which are of concern for the aquaculture industry, namely Vibrio spp., Neoparamoeba perurans, Alexandrium catenella and Tenacibaculum spp.