Seagrass meadows are among the most productive coastal ecosystems globally, supporting high biodiversity and providing critical habitat, refuge, and nursery grounds for fish. However, characterising fish communities across broad spatial scales remains challenging, particularly in turbid and logistically complex environments such as ports. Environmental DNA (eDNA) metabarcoding offers a powerful alternative to traditional survey methods, enabling non-invasive, scalable biodiversity assessments.
This study applies a standardised eDNA metabarcoding workflow to assess fish assemblages across seagrass habitats within major Australian ports spanning a tropical to subtropical gradient in Queensland, including: Weipa, Cairns, Townsville, Bowen, and Gladstone. Within each port, multiple seagrass meadows (2-3 per location), representing different seagrass species, were sampled to capture habitat variability.
To address challenges associated with high turbidity, water samples were filtered sequentially through 10 µm and 1.2 µm membranes to capture DNA. Fish diversity was assessed using three complementary primers (MiFish, 16S and COI) to maximise taxonomic coverage and compare performance.
This study aims to characterise spatial variation in fish assemblage composition across ports and latitudes and to assess environmental drivers of fish communities. These findings will provide insights into the application of eDNA metabarcoding for monitoring fish communities in turbid coastal habitats.