Researchers warn: replant or perish
Hervey Bay’s coral reefs could face an uncertain future unless action is taken to revegetate the banks of the flood-prone Mary River and improve the quality of water hitting the Great Sandy Straits.
University of Queensland PhD candidate Ian Butler has called on the government to improve the vegetation along the banks of the river and consider introducing a 50 to 100 metre “buffer zone” along the shore line to help stabilise the eroding banks and reduce the amount of silt and fertilizer being washed into the waterway during times of flood.
Mr Butler, who has been studying how inshore coral reefs along the state’s coast have changed over the past 10,000 years, says almost 60 per cent of the corals from the Bay have been lost since the flood events earlier this year.
This is largely due to water contaminated with silt and sediment being washed downstream from the Mary River and settling in and around the coral – blocking its access to sunlight and a clean environment.
Mr Butler said while the coral around Hervey Bay had recovered relatively well from the flood event in the 90s, the impact of climate change – which could see more floods occurring in a shorter space of time – posed serious concerns that the coral may not have the capacity to fully recover before the next natural disaster.
“In theory it can grow back, the only question is if it is going to in the future,” Mr Butler said.
With 85 per cent of the Mary River’s banks eroding, Mr Butler believes the government needs to revisit the discussions it was having 20 years ago and reassess its land and river management.
“It is a tough issue but it is one that needs to be done,” Mr Butler said.
“A bit more attention needs to be put on the Mary River in terms of having it functioning well and the water quality.
“Flooding happens everywhere.
“Disturbance happens and corals do suffer because of it.”
Last year Reef Check Australia received funding to establish five reef health monitoring sites along the Hervey Bay and Woongarra coastline.
After initial observations, Reef Check Australia community engagement officer Jodi Salmond said while sites along Big Woody Island, Gataker’s Reef and ESA Park had recorded a heavy silt load, they did show positive signs of growth.
Ms Salmond said given the floods and the environment the corals live in, the growth was a pretty impressive discovery.
Though the surveys conducted by Reef Check Australia was building on the information conducted by previous studies and helping to create a baseline of information for future use, Ms Salmond said it would be a while before they would be able to see how the reef health may be changing.
Member for Hervey Bay Ted Sorensen was not available for comment.