Green groups are calling on authorities to scrap major dredging projects near the Great Barrier Reef after a study found the practice can harm coral.
New research linking coral diseases to dredging has sparked renewed debate over the potential impact of the practice on the Great Barrier Reef.
An Australian Research Council study of a Western Australian dredge project found dredge plume stressed coral, making it more prone to chronic diseases.
In light of the report, environmental groups are calling on the federal government to reconsider major developments along Queensland’s coast.
In particular they want approval for the expansion of Abbot Point coal port, which involves dumping dredge spoil in the marine park, revoked.
However, the firm carrying out the works says the study shouldn’t be used to criticise past or planned dredging projects near the reef.
“The dredging operations (on the east coast) occur many kilometres from the nearest coral reefs, unlike the close proximity of the coral reef which is the subject of this study,” North Queensland Bulk Ports spokesman Kevin Kane said.
He says the firm will continue to work on dredge programs to ensure impacts are avoided or mitigated.
Queensland Resource Council chief executive Michael Roche says any impacts are temporary and localised.
Studies had already shown that the biggest cause of coral disease was the crown-of-thorns starfish and cyclones, he says.
WWF-Australia spokesman Richard Leck says the impacts of dredging would be far worse on the east coast.
“When you introduce another big source of pollution into an already degraded environment the impact could be a lot more severe,” he said.
Alternatives such as using existing ports that are running below capacity should be looked at, he says.
Australian Marine Conservation Society spokeswoman Felicity Wishart says port authorities can’t be trusted to monitor the impacts of dredge plume.
“Basically they need to stop dumping in the reef’s waters, establish a plan to address stopping any unnecessary dredging and put a halt to any new dredging,” she said.
Greens environment spokeswoman Larissa Waters wants the federal government to revoke its approval for Abbot Point.
Queensland Environment Minister Andrew Powell said it would be irresponsible to compare dredge projects in WA to those off the Queensland coast.
“The Queensland government has consistently said it will be guided by science when it comes to protecting the Great Barrier Reef,” he told AAP.
The reef is one of the best managed world heritage sites in the world and dredging projects are subject to strict environmental conditions, he says.
The study by the Australian Research Council’s Coral Reef Studies Centre of Excellence compared 11 reefs and thousands of coral near Barrow Island, off Western Australia, where a seven million cubic metre dredging project took place.
Lead author marine scientist Joe Pollock said twice as much coral disease was recorded in areas where dredged sediment had drifted and settled.
Turbidity meant there was less light for photosynthesis and sediment on the coral interfered with their ability to feed.
“So they have less energy coming in, they’re expending more energy and what we’ve shown here is that chronic stress can lead to disease,” he told AAP.