More than one million tons of sludge are to be dumped close to the Great Barrier Reef after authorities in Australia approved plans to discard industrial dredge spoil.

Sediment scooped up from the sea floor during maintenance work at nearby Hay Point Port will be ditched under a permit granted by the Great Barrier Reef Marine Park Authority (GBRMPA).

“Dumping dredged sludge into world heritage waters treats our reef like a rubbish tip,” said Larissa Waters, a senator for The Greens party.

The plans have been approved barely a week after warnings that filthy water from recent floods in Queensland could cause irreparable damage to the reef by blocking sunlight and preventing photosynthesis which the coral relies on to survive.

Although sludge dumping in the area is largely illegal, a loophole in the ban – it does not cover the discarding of waste created during port maintenance work – means the new permit can be granted.

Dirty water threatens the Great Barrier Reef Show all 20 1 /20 Dirty water threatens the Great Barrier Reef Dirty water threatens the Great Barrier Reef Months after scientists warned that it is at greater risk than ever, the Great Barrier Reef is facing a new challenge: dirty water. AFP/Getty Dirty water threatens the Great Barrier Reef Run-off from the recent floods in Australia is spreading out from the coast with the potential to smother the fragile reef. Matt Curnock / Reuters Dirty water threatens the Great Barrier Reef The floodwater is thick with sediment from the shore and scientists fear that this may block out the sun, preventing photosynthesis for the algae that the coral relies on to survive. AFP/Getty Dirty water threatens the Great Barrier Reef Dr Frederieke Koon from the Australian Institute of Marine Science however, has told the BBC that the floodwater contains nutrients that have boosted algae growth in some areas, turning the water "a thick blanket of green". Matt Curnock / Reuters Dirty water threatens the Great Barrier Reef Despite such benefits in some areas, the fear is that the floodwater will contain pesticides that could prove extremely damaging and due to a lack of wind, it isn't dispersing. Matt Curnock / Reuters Dirty water threatens the Great Barrier Reef Dr Koon added that "a bit of wind and wave action can break the plumes up quite quickly, but we have literally had no wind so they're just sitting there hanging". Matt Curnock / Reuters Dirty water threatens the Great Barrier Reef Fears over the future of the reef have been building in recent years, with the US National Oceanographic and Atmospheric Administration forecasting in October 2018 that the entire 130,000 miles square system is at high risk of bleaching. Matt Curnock / Reuters Dirty water threatens the Great Barrier Reef These aerial photos show the murky water spreading across the reef. Matt Curnock / Reuters Dirty water threatens the Great Barrier Reef A handout photo taken by Matt Curnock on February 13, off Townsville. 2019 and released on February 15 shows sediment (R) approaching Central Great Barrier Reef from recent unprecedented rain and flooding around Cape Cleveland, off Townsville. - Runoff from recent floods in northern Australia is flowing onto parts of the Barrier Reef, scientists said on February 14, starving coral of light and providing fodder for the predatory crown-of-thorns starfish. (Photo by MATT CURNOCK / Matt Curnock / AFP) / --EDITORS NOTE--- RESTRICTED TO EDITORIAL USE - MANDATORY CREDIT "AFP PHOTO / Matt Curnock" - NO MARKETING - NO ADVERTISING CAMPAIGNS - DISTRIBUTED AS A SERVICE TO CLIENTS - NO ARCHIVESMATT CURNOCK/AFP/Getty Images AFP/Getty Dirty water threatens the Great Barrier Reef Sediment-filled water is seen in the Great Barrier Reef, Australia February 13, 2019 in this picture obtained from social media on February 15, 2019. MATT CURNOCK/TROPWATER JCU/via REUTERS THIS IMAGE HAS BEEN SUPPLIED BY A THIRD PARTY. MANDATORY CREDIT. NO RESALES. NO ARCHIVES. Reuters Dirty water threatens the Great Barrier Reef Sediment-filled water is seen in the Great Barrier Reef, Australia February 13, 2019 in this picture obtained from social media on February 15, 2019. MATT CURNOCK/TROPWATER JCU/via REUTERS THIS IMAGE HAS BEEN SUPPLIED BY A THIRD PARTY. MANDATORY CREDIT. NO RESALES. NO ARCHIVES. Matt Curnock / Reuters Dirty water threatens the Great Barrier Reef Sediment-filled water is seen in the Great Barrier Reef, Australia February 13, 2019 in this picture obtained from social media on February 15, 2019. MATT CURNOCK/TROPWATER JCU/via REUTERS THIS IMAGE HAS BEEN SUPPLIED BY A THIRD PARTY. MANDATORY CREDIT. NO RESALES. NO ARCHIVES. Matt Curnock / Reuters Dirty water threatens the Great Barrier Reef Sediment-filled water is seen in the Great Barrier Reef, Australia February 13, 2019 in this picture obtained from social media on February 15, 2019. MATT CURNOCK/TROPWATER JCU/via REUTERS THIS IMAGE HAS BEEN SUPPLIED BY A THIRD PARTY. MANDATORY CREDIT. NO RESALES. NO ARCHIVES. Matt Curnock / Reuters Dirty water threatens the Great Barrier Reef A handout photo taken by Matt Curnock on February 13, off Townsville. 2019 and released on February 15 shows sediment (bottom) approaching Central Great Barrier Reef from recent unprecedented rain and flooding around Cape Cleveland, off Townsville. - Runoff from recent floods in northern Australia is flowing onto parts of the Barrier Reef, scientists said on February 14, starving coral of light and providing fodder for the predatory crown-of-thorns starfish. (Photo by MATT CURNOCK / Matt Curnock / AFP) / --EDITORS NOTE--- RESTRICTED TO EDITORIAL USE - MANDATORY CREDIT "AFP PHOTO / Matt Curnock" - NO MARKETING - NO ADVERTISING CAMPAIGNS - DISTRIBUTED AS A SERVICE TO CLIENTS - NO ARCHIVESMATT CURNOCK/AFP/Getty Images AFP/Getty Dirty water threatens the Great Barrier Reef Sediment-filled water is seen in the Great Barrier Reef, Australia February 13, 2019 in this picture obtained from social media on February 15, 2019. MATT CURNOCK/TROPWATER JCU/via REUTERS THIS IMAGE HAS BEEN SUPPLIED BY A THIRD PARTY. MANDATORY CREDIT. NO RESALES. NO ARCHIVES. TPX IMAGES OF THE DAY Matt Curnock / Reuters Dirty water threatens the Great Barrier Reef Sediment-filled water is seen in the Great Barrier Reef, Australia February 13, 2019 in this picture obtained from social media on February 15, 2019. MATT CURNOCK/TROPWATER JCU/via REUTERS THIS IMAGE HAS BEEN SUPPLIED BY A THIRD PARTY. MANDATORY CREDIT. NO RESALES. NO ARCHIVES. Matt Curnock / Reuters Dirty water threatens the Great Barrier Reef Sediment-filled water is seen in the Great Barrier Reef, Australia February 13, 2019 in this picture obtained from social media on February 15, 2019. MATT CURNOCK/TROPWATER JCU/via REUTERS THIS IMAGE HAS BEEN SUPPLIED BY A THIRD PARTY. MANDATORY CREDIT. NO RESALES. NO ARCHIVES. Matt Curnock / Reuters Dirty water threatens the Great Barrier Reef Sediment-filled water is seen in the Great Barrier Reef, Australia February 13, 2019 in this picture obtained from social media on February 15, 2019. MATT CURNOCK/TROPWATER JCU/via REUTERS THIS IMAGE HAS BEEN SUPPLIED BY A THIRD PARTY. MANDATORY CREDIT. NO RESALES. NO ARCHIVES. Matt Curnock / Reuters Dirty water threatens the Great Barrier Reef Sediment-filled water is seen in the Great Barrier Reef, Australia February 13, 2019 in this picture obtained from social media on February 15, 2019. MATT CURNOCK/TROPWATER JCU/via REUTERS THIS IMAGE HAS BEEN SUPPLIED BY A THIRD PARTY. MANDATORY CREDIT. NO RESALES. NO ARCHIVES. Matt Curnock / Reuters Dirty water threatens the Great Barrier Reef Sediment-filled water is seen in the Great Barrier Reef, Australia February 13, 2019 in this picture obtained from social media on February 15, 2019. MATT CURNOCK/TROPWATER JCU/via REUTERS THIS IMAGE HAS BEEN SUPPLIED BY A THIRD PARTY. MANDATORY CREDIT. NO RESALES. NO ARCHIVES. Matt Curnock / Reuters

“Government policy needs to change to ban all offshore dumping, so GBRMPA is not allowed to permit the reef’s waters to be used as a cheaper alternative to treating the sludge and disposing of it safely onshore,” Ms Waters told The Guardian.

But North Queensland Bulk Ports Corporation, which runs Hay Point, said such action caused little environmental damage.

“Just like roads, shipping channels require maintenance to keep ports operating effectively,” the corporation said in a statement posted online. “Maintenance dredging involves relocating sediment which travels along the coast and accumulates over the years where our shipping operation occurs.

Under threat: the world's reef-building corals. Figures from statista.com (Independent)

“Importantly, our assessment reports have found the risks to protected areas including the Great Barrier Reef Marine Park and sensitive habitats are predominantly low with some temporary short-term impacts to [some bottom-dwelling] habitat possible.

Support free-thinking journalism and attend Independent events