Progress made to map Abalone habitat impacted by Centrostephanus on the Tasmania’s East Coast
The Institute for Marine & Antarctic Studies (IMAS) as continued to make great progress on mapping Abalone habitat impacted by Centrostephanus on the East Coast Of Tasmania. The principle aim of this project is to map the fine-scale spatial distribution of key abalone and urchin reef habitats using multibeam acoustic imagery. Barrens are the physical representation of impact and therefore understanding their distribution and dynamics is fundamental to strategic decision making, and early intervention in high risk areas.
Since this project began in October 2020 exceptional progress has been made on the fieldwork elements. A preliminary pilot study was run in Wineglass Bay and outside of Maria Island to ensure that the multi-beam acoustic system could collect the data at the resolution required for the full surveys from the contractor’s vessel. In April 2021 the full survey from Sloop Rock (Block 30) to Tasman Island (Block 22) was completed, collecting close to 600 Km of survey lines across the depth range of 10-25 m.
The data from the project thus far makes it possible to identify the extent of the larger centrostephanus barrens.
The next stage of the project is to continue working on the analysis of both the acoustic data and also analysing the video data.
The data will be used to provide an estimate of the change in algal cover over 20 years for key abalone blocks, quantify temporal changes in patch size and density, explore the key environmental drivers of patch size and density, and examine the significance of kelp patch dynamics in the formation of urchin barrens.