Fish community dynamics in remote northern Australia: the role of habitat and seascape

Associations between fish and benthic habitats are shaped by structural complexity, resource availability, and positioning within the larger seascape. In the remote Gulf of Carpentaria in northern Australia, there is very little scientific information on how fish communities interact with their habitats within a heterogeneous seascape, despite their ecological and cultural value. This is the first study of how habitat characteristics and seascape configuration influence demersal fish communities in Marra Sea Country in the southwestern Gulf of Carpentaria. Baited remote underwater video stations were used to observe species richness, relative fish abundance, and community structure at 95 sites. We determined that site (seagrass, algae, benthic macroinvertebrate (BMI) cover, and depth) and seascape characteristics (distance to reef (km), distance to major river mouth (km), distance to habitat-forming seagrass meadows (km), and distance to Kurrulinya (km) (Maria Island)) influence fish species richness and relative abundance. We also found that the three major habitats in Marra Sea Country (bare substrate, benthic macroinvertebrates, and seagrass meadows) support statistically distinct fish communities, with community differences in seagrass and BMI being driven by specific associated species, while community differences in bare substrate are driven by the presence of both BMI- and seagrass-associated species. Our results indicate that both habitat type and seascape configuration are important for determining fish assemblage distributions. Variation in fish assemblages across benthic habitats and their spatial arrangement underscores the need for seascape-scale management to support marine conservation in Marra Sea Country and other tropical ecosystems.

Estuarine, Coastal and Shelf Science

Estuarine Coastal And Shelf Science

344

0272-7714

N/A

N/A

14