Marine park rangers from Queensland Parks and Wildlife Service (QPWS) and researchers from James Cook University (JCU) TropWATER have seen widespread regrowth of seagrass within the Great Sandy Marine Park during recent surveys.
The marine park off the Cooloola and Fraser Coast is showing positive signs of recovery from multiple flood events that impacted the region in early 2022.
The team of rangers and researchers have been carrying out regular surveys since the floods to monitor changes to the marine park’s seagrass meadows.
JCU TropWATER’s Associate Professor Michael Rasheed said the most recent results show widespread recovery of seagrass, in many sections of the marine park.
“We have seen big increases in the deepwater seagrasses in the middle of Hervey Bay as well as substantial expansion of intertidal seagrasses in the Great Sandy Strait that were devastated following the floods of 2022.”
While the recovery is promising, recent JCU dugong surveys reveal that the initial loss of seagrass meadows has taken a significant toll on green turtle and dugong populations in the region, with seagrass serving as their main food source.
Senior Ranger Daniel Clifton said the Great Sandy Marine Park was a major hotspot for dugongs in Queensland, meaning the overall health of the marine ecosystem played a crucial role in sustaining populations of these threatened animals.
“The Great Sandy Marine Park’s seagrass meadows are a critical part of the marine ecosystem to support local sea turtle and dugong populations,” Ranger Clifton said.
“By monitoring the abundance of seagrass across the park, we get a better picture of the health of the wider marine ecosystem in the area.
“These latest results show that the area is recovering from the 2022 floods, but it doesn’t mean that our work to protect these threatened animals ends here.
“On top of the seagrass surveys, we are taking immediate and long-term action to support dugong and marine turtle populations now and well into the future.”
QPWS and JCU are leading additional projects to monitor the health of seagrass in the area, including examining light availability within the Great Sandy Strait, a herbivory exclusion study looking at how marine life feeding on seagrass impacts recovery, and seagrass seed bank availability.
Professor Rasheed said while the regrowth of the meadows is a positive sign, the resilience of the seagrass meadows to future impacts was still uncertain.
“We are really interested in the health of seagrass meadow’s seed bank, which is the repository of seeds in the sediment that influences the ability of the meadows to recover and remain healthy in the event of further impacts.
“Understanding the health of the seed bank is key to figuring out how resilient these meadows are against future pressures, such as intense feeding from dugongs and the possibility of more flooding in the years ahead.”
“The reality of climate change means we need to continue to regularly monitor these seagrass meadows and to develop potential restoration methods. This will allow us to quickly respond to damaged or lost meadows to ensure we have these important ecosystems into the future.”
The Department of Environment and Science (DES) is delivering $3.5 million worth of biodiversity conservation grants for state agencies, non-government organisations including JCU, community and Indigenous groups for projects including seagrass management through the joint Australian-Queensland government funded Disaster Recovery Funding Arrangements.
This is part of a $38.9 million environmental recovery program which aims to improve the condition of flood-affected catchments and associated biodiversity.
DES is also increasing the proportion of marine national park (green) zones within the Great Sandy Marine Park from 3.9 per cent to 12.8 per cent, contributing to a total of 28.6 per cent of the marine park being in highly-protected (green and yellow) zones to conserve the park’s marine life, including dugongs.
These changes will include the removal of commercial large mesh gillnets and ring nets, which pose a threat to dugongs and other marine life, from the yellow zones within Baffle Creek, Elliott River, Burrum River system, the Great Sandy Strait and Tin Can Inlet.
Across Queensland’s marine parks network, rangers enforce ‘Go Slow’ zones which prohibit recreational boat users from traveling on the plane in known dugong and turtle habitat, or risk receiving an on-the-spot $619 fine or higher penalties in court.
Within the Great Sandy Marine Park, the extent of these Go Slow zones will be increased to provide more comprehensive protection for turtles and dugongs.
QPWS is investigating the establishment of a comprehensive and ongoing monitoring program for seagrass in the Great Sandy Marine Park.
