Dr Joel Williams1, Dr Tim Ingleton2, Dr David Harasti3, Dr Nicole Hill1, Dr Alan Jordan1, Dr Neville Barrett1
1IMAS, University Of Tasmania, Hobart, Australia, 2NSW Department of Planning and Environmnet, Lidcombe, Australia, 3NSW Department of Fisheries, Nelson Bay, Australia
Temperate mesophotic reefs are located at depths of 30-150m and are a transition zone from algal dominated reefs to sessile invertebrate dominated reefs. It is expected that the structure of the fish assemblage would also change with depth. There’s a large knowledge gap of inter and intra reef variability in fish assemblage structure, including seasonal patterns of abundance of fish at mesophotic depths. Several of the newly established Australian Marine Parks recognised these mesophotic reefs as key ecological features. Through the support of the NESP Marine Biodiversity Hub we collected baseline mapping, habitat and fish abundance data for the Hunter Marine Park on the mid-north coast of NSW. Using joint species distribution models, we were able to investigate assemblage level seasonal variability, environmental drivers, species-species interactions, and trait-based patterns of fish distribution at mesophotic depths. We found minimal seasonal variability in the fish composition of rocky reefs in the Hunter Marine Park. Species composition was primary associated with reef structure, with upper mesophotic high relief reefs being biodiversity hotspots. These results highlight the need for monitoring programs to stratify sampling across depths and habitats if trends in biodiversity through time are the core metrics of interest to marine park managers.
Presentation Slides – Joel Williams
Biography:
Joel is a quantitative ecologist at IMAS University of Tasmania. Joel’s worked on a range of project that include marine park monitoring, biodiversity mapping, underwater video, BRUVs, ROV. Joel passion is collecting statistically robust data from the field and bringing back to the office to model and visualise in a way that can be used by managers and understood by the public.
