Ms Darcy Philpott1, Dr Cecilia Villacorta-Rath2, Dr Paul York1, Professor Michael Rasheed1, A/Prof Nathan Waltham2
1James Cook University, Cairns, Australia, 2James Cook University, Townsville, Australia
Biography:
Darcy is originally from the UK where she completed a MSc in Marine Environmental Management from the University of St. Andrews. She has worked as a marine biologist in various locations worldwide, including teaching fish survey techniques to aspiring marine conservationists in the Bahamas and the Seychelles.
More recently, she worked as a Marine Scientist on Ascension Island, one of the world’s largest marine protected areas, where she contributed to a variety of marine projects. Darcy is currently undertaking a PhD on fish and prawn nurseries in recovering seagrass meadows in Cairns, utilising beam trawling and eDNA metabarcoding techniques.
Abstract:
Seagrass meadows are amongst the most productive ecosystems on Earth, but present unique challenges when assessing biodiversity due to the variability in environmental and ecological conditions amongst sites. Traditional monitoring methods can be inconsistent in capturing this variability. Environmental DNA (eDNA) metabarcoding has emerged as a promising tool for for measuring marine species diversity, though its effectiveness in tropical regions remains underrepresented. Implementing novel monitoring methods focusing on specific indicators, such as the presence of different trophic groups, is crucial for understanding how seagrass meadows respond to environmental change.
This study investigates the applicability of eDNA metabarcoding in a highly turbid tropical seagrass meadow. We evaluate the suitability of two eDNA capture methods: filtration through different pore sizes (5, 10, and 20 µm) and whole water samples preserved in a buffer. Additionally, we analyse the minimum number of replicates required for reliable species detection. The selection of appropriate primers is also critical: we tested two sets of teleost fish primers targeting the 16S and CO1 region and a crustacean primer targeting the 16S region, to maximise species detection at the study site.
This aims of this research are to establish an efficient and reliable eDNA metabarcoding method for monitoring fish and prawn assemblages in a highly turbid seagrass habitat. This research will advance our ability to assess biodiversity and understand ecological responses to environmental changes in these tropical ecosystems.