Marine debris on north Australian beaches doubles in a decade; foreign fishers may be to blame, researchers say
Trash from the sea washing up on Arnhem Land’s once-pristine beaches has doubled in the last decade.
Researchers say there is up to three tonnes of marine debris per kilometre along 11 monitored beaches in northern Australia, and that much of it is related to fishing activity, some of it illegal.
Karen Edyvane from the Australian National University’s North Australia Research Unit has been monitoring Top End beaches for 12 years, and she told ABC Radio Darwin on Tuesday that they are recording “extraordinary” amounts of rubbish.
“North Australian shores have recorded some of the highest levels of marine debris — particularly fishing-related debris — not only in Australia but the world,” she said.
Ms Edyvane said it is currently the worst it has ever been.
Local Indigenous ranger groups and conservation volunteers have been working with researchers for almost two decades to monitor 11 beach sites for marine debris, and they have found that Cape Arnhem is registering the highest volume of rubbish.
“What has been recorded, particularly last year, is twice the amount of litter — debris — than we were recording 10 years ago,” Ms Edyvane said.
The bulk of debris was fishing material, she found.
“It’s not just the fishing nets and the buoys and the baits and the lures and so forth, but also the fact that when you’re on a boat … for weeks at a time you also need to eat, need to shampoo,” she said.
“Many of the fishermen smoke and use lighters, and many of them wear thongs, and we see a lot of thongs.”
Gas cylinders, bottles, lighters litter sand
The situation is so bad at Cape Arnhem because the south head trade winds and currents move in circles, pulling the debris onto beaches.
Ranger groups say the culturally significant beaches have become a dumping ground. (Supplied: Blue Douglas)
North-east Arnhem Land resident Blue Douglas painted a vivid picture of the debris he found on a once-pristine beach:
“The beach was literally littered with plastic baskets, cigarette lighters, bottles in particular — shampoo bottles, oil bottles — and the sad thing is about a lot of these things, when you pick them up, they’ve obviously been punctured in some way to ensure that when they’re thrown off the side of the boat they sink,” he said.
“A lot of the oil bottles, the caps, there’s been holes punctured in them, the shampoo bottles have had a slice put through the centre of them.
“There were empty steel gas cylinders — which I’ve never seen in past years — which surprised me.
“Bottle tops, squid lures, bits of net, rope, you could go on for an hour just describing what was there.”
Foreign fishers to blame: researchers
Although the finger has previously been pointed at Indonesia, Ms Edyvane said researchers had not yet been able to establish an oceanographic link between the western parts of Indonesia and the rubbish washing up in the Gulf of Carpentaria.
But she said the area was adjacent to some of the largest fisheries in south-east Asia, and nearly all of them were located in the Arafura Sea, “intimately connected” with the Gulf.
“It’s a global hotspot for illegal fishing and that illegal fishing activity,” Ms Edyvane said.
“In the Arafura Sea in Indonesian waters, industrial-scale fishing has doubled in the last 10 years.
“And when we look at our foreign fishing vessel sightings we get from border security, we know that the sightings of fishermen on the border of Australia has [quadrupled] in that time, too.”
She said that in 2000, authorities were sighting up to 9,000 foreign fishermen in Australia’s border regions, whereas in 2012 it was close to 37,000.
She said, however, that it was difficult to pinpoint how much of the marine debris related to illegal foreign fishing.
Fishermen from Indonesia and other parts of Asia are thought to be responsible for much of the debris. (ABC News: Samantha Hawley)
Turtles drowning in ghost nets
The debris is having a major impact on marine wildlife as well as affecting it when broken down into the food chain, Ms Edyvane said.
“Along the north Australian coastline we have some of the most globally significant populations of marine megafauna, particularly turtles, and they’re the ones affected by driftnets and derelict fishing nets,” she said.
She quoted a study which found that in the five years between 2005-2010, up to 15,000 turtles had been entangled in up to 9,000 ghost nets.
“That’s a lot of turtles potentially caught and drowned in those nets, huge impact,” she said.
Ms Edyvane said Australia and Indonesia were working together to fight illegal fishing, and she urged consumers to buy sustainably sourced food to encourage supermarkets and MPs to put Australian fisheries at the forefront.
“Australia fisheries are well regulated and have very good environmental track records,” she said.
Turtles often become tangled in ghost nets and other forms of marine rubbish. (Supplied: Ghostnets Australia)