Standard Presentation Australian Marine Sciences Association Annual Meeting 2023

Relationships between geomorphology and biodiversity in the Ribbon Reef Canyon system, GBR (#332)

Kate Whitton 1 , Jody Webster 1 , Robin Beaman 2 , Mardi McNeil 3 , Rachel Przeslawski 4 , Luke Nothdurft 3 , Jacquomo Monk 5 , Ariell Friedman 6 , Zhi Huang 7
  1. Geocoastal Research Group, School of Geosciences, University of Sydney, Sydney, NSW, Australia
  2. College of Science & Engineering, James Cook University, Cairns, QLD, Australia
  3. School of Earth, Environmental & Biological Sciences, Queensland University of Technology, Brisbane, QLD, Australia
  4. Department of Primary Industries, Fisheries Research, Huskisson, NSW, Australia
  5. Institute for Marine and Antarctic Studies, University of Tasmania, Hobert, TAS, Australia
  6. Australian Centre for Field Robotics, University of Sydney, Sydney, NSW, Australia
  7. Geoscience Australia, Canberra, ACT, Australia

SSubmarine canyons have ecological importance as they host unique species, control sediment and nutrient pathways, and act as refugia for shallow ecosystems on the continental shelf. Canyon morphology, substrate type, oceanography, and biodiversity of benthic macrofauna were compared across three canyon types in the Ribbon Reef Canyon (RRC) to determine how variations in canyon geomorphology affect biodiversity. Data was collected from the Schmidt Ocean Institute R/V Falkor 200802 which included multibeam (bathymetry and backscatter), remotely operated vehicle (ROV) imagery, oceanographic variables, and geological samples (https://doi.org/10.5281/zenodo.7274769). The study focused on three canyon types on the basis of shelf-connectivity: shelf-connected (type 1a), reef-blocked (type 1b), and slope-confined (type 2). The study looked at macrofaunal distribution within and along submarine canyons between 300 and 1800 m depth in the RRC. The study hypothesised that canyons with greater shelf-connectivity would feature greater signs of disturbance, habitat heterogeneity, and biodiversity. Type 1a canyons had the greatest canyon morphological complexity, sediment activity, habitat heterogeneity, and taxonomic abundance. There were no significant differences in taxonomic richness between canyons. There were variations in taxonomic assemblages between canyons but these were influenced by a small number of local samples within each ROV transect.