Gaps in seagrass knowledge

Northern Australian seagrass habitats are highly valuable natural resources, supporting fisheries, cultural heritage, and threatened species such as dugong and turtles. But there are significant gaps in our knowledge of the abundance and distribution of seagrass in the region – primarily because of the challenges in recording seagrass over the vast area of northern Australian waters.

Region-wide seagrass mapping is needed to understand the ecosystems present and the marine animals they support. These maps can then be used to establish monitoring programs where they are needed and inform management decisions for marine parks, Indigenous Protected Areas, and Sea Country.

Regional mapping can also be used to identify how marine habitats may be changing and to understand resources in the region.

Building a map of seagrass habitats

We are building a comprehensive map of seagrass across northern Australia, from the north of Western Australia to the east coast of Queensland, in partnership with Indigenous Rangers and Traditional Owners.

This project will provide publicly accessible datasets to:

• Support regional planning, including Indigenous-led management planning for Sea Country and seagrass restoration.

• Assist management of protected species that rely on these habitats including turtles and dugongs.

• Inform monitoring design for marine parks and Indigenous Protected Areas.

• Model climate change impacts, risks, dispersal, and connectivity between seagrass habitats.

• Provide baseline data for the development of blue carbon accounting.

Our team is using a combination of complementary methods to address the unique challenges of working across large areas of remote northern Australia.

Synthesising data

We are synthesising existing seagrass data across northern Australia to identify where monitoring is needed and to ensure data are accessible and reusable. Records are available from the 1880s to the present, with incomplete coverage across the region.

We have published our syntheses of seagrass data for the Great Barrier Reef World Heritage Area and Torres Strait and the Gulf of Carpentaria. Our synthesis of seagrass data for northern Western Australia and the Northern Territory is currently under development.

Filling gaps on-the-ground

Our researchers are mapping seagrass and other seafloor habitats across northern Western Australia, the Tiwi Islands, South East Arnhem Land, the Gulf of Carpentaria, Torres Strait, and the eastern coast of Queensland.

We use boat surveys for subtidal sites using drop cameras, sled tows, and Van Veen grabs. For intertidal sites, we use a combination of helicopter surveys, drone surveys, and walking transects.

We are recording habitat types and the biodiversity that these ecosystems support, such as fish, dugongs, and turtles. So far, our team has recorded seafloor habitats with more than 20 Ranger groups across northern Australia.

Extending knowledge

We are gaining a better understanding of seagrass distribution and changes over time through:

• Drones.

• Satellite imagery.

• Modelling, including identifying areas with high potential for seagrass to target for future mapping and monitoring.

We have published our modelling of seagrass habitat and community diversity for the Great Barrier Reef World Heritage Area.

Project details

This project is led by Dr Alex Carter and Dr Catherine Collier in collaboration with Charles Darwin University and Edith Cowan University, with funding from the National Environmental Science Program Marine and Coastal Hub, the Northern Territory Government, Parks Australia, Torres Strait Regional Authority, Great Barrier Reef Foundation, and the Queensland Government.

This work is in partnership with Karajarri Traditional Lands Association, Tiwi Resources, Northern Land Council, Yugul Mangi Rangers, Numbulwar Numburindi Rangers,  Namultja Aboriginal Corporation, Mabunji Aboriginal Resource Indigenous Corporation, Wellesley Islands Land Sea Social Economic Development, Carpentaria Land Council Aboriginal Corporation, Gangalidda-Garawa Rangers, Normanton Rangers, Seven Rivers Aboriginal Corporation, Kaurareg Native Title Aboriginal Corporation, Torres Strait Regional Authority Land and Sea Management Unit, Wuthathi Aboriginal Corporation, and Girringun Aboriginal Corporation.