For the Anindilyakwa people of the Groote Archipelago in the Gulf of Carpentaria, when the dry season winds blow from the southeast they bring marine debris, sometimes from thousands of kilometres away.
Rangers collect several tonnes of debris each year to protect marine life and keep the beaches clean.
Later in the year, leading up to the wet season, the Anindilyakwa Sea and Land Rangers monitor fish species using underwater cameras, and turtle nesting activities to protect the four threatened species in the region.
Ghost nets are abandoned, lost or discarded fishing nets, often many hundreds of metres in length that can drift significant distances across the ocean.
Due to ocean currents they congregate in large densities in the Gulf of Carpentaria.
The nets cause injury or death to marine species that become entangled in them, including turtles, sharks, dolphins and dugongs.
In a bid to help clear the Gulf of Carpentaria of marine debris, Charles Darwin University (CDU) is working with Anindilyakwa Sea Rangers on a project that will use long-distance uncrewed autonomous aircraft (drones) to identify and map the distribution of ghost nets across nearly 960km of NT coastline.
CDU’s project, which has received funding of almost $400,000 from the Australian government as part of the Ghost Nets Innovative Solutions Grants, will use drones and artificial intelligence software to identify and quantify the volume of marine debris along remote and difficult to access coastlines.
Professor Hamish Campbell, from CDU’s North Australia Centre for Autonomous Systems, said the project will provide immediate environmental benefits across the Gulf.
“Ghost nets are a significant threat to marine wildlife and coastal bushtucker,” he said.
“A major challenge for ghost net removal is that nets come ashore along vast tracts of Northern Territory coastline, which are tended to by small communities with limited resources.
“Consequently, ghost nets are not generally detected and retrieved for prolonged periods, if at all, which increases their impact upon wildlife and raises the chances of them being re-floated and deposited elsewhere.”
Professor Campbell said the project will provide accurate data to help clean-up efforts.
Throughout the project, drones will collect information with a high-resolution hyperspectral sensor, powerful technology that provides detailed information about the composition and characteristics of objects and surfaces in a way that is impossible with conventional imaging systems.
The aircraft will fly at low altitudes to survey the 45 islands within the Groote Archipelago.
Artificial intelligence software will be used to develop coastal aerial imagery with NACAS partnering with CDU’s Northern Territory Academic Centre for Cybersecurity and Innovation.
As part of the project, abundance distribution maps illustrating ghost net locations and size will be created and provided to the Anindilyakwa Land and Sea Rangers to assist with retrieval operations.
Lingiari MP Marion Scrymgour said it was encouraging to see CDU apply state-of-the-art technology to marine conservation to get rid of more ghost nets.
“This project, funded by the Australian government, will complement the work of the Anindilyakwa Sea Rangers,” she said.
“We are also funding a dedicated vessel, located on Groote Eylandt, which is specially fitted out to locate and retrieve ghost nets.
“Every year ghost nets kill hundreds of marine species, including animals that are culturally very important and or endangered, such as turtles, dugongs and dolphins.
“It’s heartening to see a multi-pronged effort emerging that will really make a difference in this area.”
Australian Associated Press