PERTH waters recently hosted a milestone for a WA-based program, with the launch of an underwater drone acting as a crucial monitoring tool of one of the world’s most accessible near-shore reefs, the Ningaloo.
The “ocean glider” program, a 16-year collaboration between the University of WA and Integrated Marine Observing System, successfully completed its 400th mission along the Rottnest continental shelf.
Gliders provide near-live data to researchers, oceanographers and government agencies, giving them an understanding of the ocean’s health, a stepping stone to combating carbon emission effects.
• The ocean glider team celebrate their 400th launch.
One of their achievements has been the discovery of a network of “underwater rivers” that encircles the entire continent.
The glider program is conducted across Australia, with Perth’s launching from Two Rocks and monitoring the Leeuwin Current.
UWA Ocean Institute senior researcher Christine Hanson said the Leeuwin Current acts as the parent of lesser northward flowing counter-currents, the Capes Current and the Ningaloo Current.
“The gliders provide high-resolution measurements of ocean temperature, salinity, oxygen and other parameters,” Dr Hanson said.
The overreaching goal is to monitor the Leeuwin Current for marine heatwaves and sudden increases of productivity, otherwise known as seasonal upwelling.
“Seasonal upwelling is particularly important off Ningaloo, as this brings up cool water and high nutrients that support the reef,” Dr Hanson said.
Recent monitoring of the Leeuwin Current found a noticeable increase in water temperature at Ningaloo Reef, fluctuating up to three to four degrees from its long-term average.
Event-based sampling off Ningaloo consequently discovered a “warm water layer” covering the reef itself.
Dr Hanson said these two factor led her to believe the reef was in “critical danger”.
She said coral bleaching events such as those which had affected the “huge tourist attraction” in the past were undoubtedly going to occur again, and she’s not optimistic that changes are being made by decision-makers that can turn the situation around.
“Will large-scale changes actually be made to global emissions to, in time, curb where things are headed – it’s unclear,” Dr Hanson said.
by CHARLOTTE TROTTER