Detecting marine pests using environmental DNA and biophysical models

With the spread of marine invasive pests at an all-time high, the need to accurately detect and respond in a timely manner has never been great. Environmental DNA (eDNA) can allow marine invasive pests to be rapidly and accurately detected through little more than a water sample. With the risk of two highly invasive species, the Northern Pacific seastar (Asterias amurensis) and Wakame (Undaria pinnatifida) spreading from Port Phillip Bay to other ports, harbours, and marine protected areas along the Victoria coast increasing through natural dispersion, as well as vectors such as commercial and recreational shipping improved methods to detect these species were needed. The EcoGenetics Lab with MSEaC Lab, Parks Victoria and the Department of Jobs, Precincts and Regions recently published in Science of the Total Environment, the further validation and use of two eDNA assays to target both A. amurensis and U. pinnatifida. This involved laboratory decay trials to determine the rate eDNA from these two species will decay in the water, recharacterising the invasive distribution along the Victorian coastline using eDNA and combining the decay rates and positive detections with advanced biophysical modelling to determine a potential ‘footprint’ of where the eDNA release may have occurred. This study has helped to improve the tool kit available to management authorities to detect and respond to invasive species to prevent their establishment.

To read more head to https://doi.org/10.1016/j.scitotenv.2021.151666