Mapping spatial variation in coastal and shelf midwater productivity in Tasmanian waters with single-beam acoustics

Supervisory Team:

Myriam Lacharité, Neville Barrett, Mary-Anne Lea

Brief project description:

The distribution of marine pelagic predators, such as seals, and seabirds, coupled with fishery catches suggests the waters in coastal to shelf waters around Tasmania are more productive in some regions than others. However, no attempt has been made to comprehensively map or quantify these patterns. A common remote-sensing approach to map the underlying productivity in ocean waters has been the use of mid-water column acoustics to develop an index of likely biomass of meso-pelagic species (large zooplankton through to fish schools) based on target strength, depth distribution and spatial coverage. This project will collate and analyse several mid-water acoustic survey datasets including: historical data collected by ships of opportunity by IMOS, upcoming targeted surveys planned to be undertaken off southern Tasmania by IMAS in and near the Tasman Fracture Marine Park, and upcoming voyage from the RV Investigator to the southern and western Tasmanian shelf. The study area of the project will focus on southern Tasmanian waters and any relationships with shelf-incising canyons and associated upwelling (to inform Parks Australia of the biological oceanography of the Tasman Fracture Marine Park). However, the overall data collation should also allow spatial comparisons of productivity at state-wide scales, and relationships with the distribution of key marine predators, further informing management of marine resources and natural values in Tasmania.

This project is suitable for Honours or Masters research projects, as well as a stepping platform for a more detailed PhD exploring this important area at a range of temporal and spatial scales.

Skills students will develop during this research project:

The student should have some experience in the handling of spatial data in GIS and an interest in developing acoustic data processing skills. The project will further develop GIS skills, manipulation and analysis of spatial data. The student will have the opportunity to develop skills in ArcGIS/QGIS, EchoView (acoustic data processing software) and the R programming environment to quantify metrics of mid-water biomass. The student will also develop collaborative skills while working with CSIRO and IMAS staff. There may also be some opportunity for fieldwork, involving acoustic data acquisition.

Authorised by the Executive Director, Institute for Marine and Antarctic Studies
November 3, 2022