Technical report

File type: PDF

McKenna S, Carter A, Smit N, McMahon K, and Coles R (2023). An inventory of northern Australia’s seagrass data. Report to the Reef and Rainforest Research Centre, Cairns, Queensland.



Northern Australia has globally significant seagrass habitat that provide well-documented ecological services, including providing a food resource that underpins the survival of dugong and green sea turtles. Key to understanding, managing, mitigating risk and establishing monitoring of these habitats is reliable data on this resource. Recent National Environmental Science Program projects have provided a synthesis of 35 years of seagrass data from the Great Barrier Reef and a 40-year synthesis for Torres Strait and the Gulf of Carpentaria. However, seagrass data for the majority of Northern Territory waters and northern Western Australian waters were not included and remain disparate and not available in an easily accessible database. To begin addressing this, we have created an inventory of projects between Cape Arnhem (Northern Territory) and Ningaloo Reef (Western Australia), where seagrass data is available for inclusion in a synthesis or could be available with further evaluation. This inventory is the first stage in expanding the seagrass data synthesis to cover all of northern Australia. We identify knowledge gaps in the available seagrass data which will assist in designing seagrass mapping and monitoring priorities across northern Australia.

This inventory compiles projects that were undertaken from 1971–2022 that either have information on seagrass habitat or, with further evaluation, seagrass information that could be extracted. The inventory includes information on the location of the seagrass/project area, the data custodian and the date data were collected. It describes the spatial information available and key seagrass information collected (i.e., percent cover, species, above-ground biomass). It includes information on the availability of the data for public use or, if data is not publicly available, the potential for a pathway to make it available.

This inventory identifies at least 49 projects between Cape Arnhem and Ningaloo Reef that have collected seagrass data. Projects that have contributed to the approval processes for larger dredging campaigns, like the Pluto, Wheatstone, Gorgon and Cape Lambert Projects have been grouped together. These projects were part of a data-sharing agreement with the Western Australian Marine Science Institution Dredging Science Program. Individual projects and datasets that contribute to these larger projects will need to be ‘unpacked’ with further resources and consultation.

Of the 49 projects identified in this inventory, 19 are publicly available. For the projects with access constraints, 26 have the potential for negotiations to enable them to be included in a data synthesis, albeit with some caveats. The information included in some projects and datasets we have listed was not able to be confirmed within the timeframe and resources for this project and will require further investigation.

Most project data have spatial information and can be incorporated into a spatial synthesis similar to that for the Great Barrier Reef, Torres Strait and Gulf of Carpentaria. We also identified projects where seagrass habitat was not a target of the project, but additional seagrass information could be extracted to include in a future synthesis.

The inventory in this report provides a valuable resource to underpin:

  • Creation of a seagrass data synthesis between Cape Arnhem (Northern Territory) and Ningaloo Reef (Western Australia).
  • Identification of knowledge gaps to guide future mapping and monitoring efforts for northern Australia.
  • Regional planning in northern Australia.