OCEANOGRAPHERS from the Australian Institute of Marine Science teamed up with the Australian Maritime Safety Authority last November to track coral spawn slicks on the Great Barrier Reef.

The Cairns-based AMSA Challenger jet aircraft was used to deploy self-locating datum marker buoys with satellite tracking technology into the sea near Darley Reef off Townsville and Hope Reef off Bowen, to help track the movement of coral spawn slicks.

AMSA principal advisor aviation assets Mike Wytcherley said they took the opportunity to combine the tracking buoy drop with marine research during a recent audit flight.

“SLDMBs are typically used by the Safety Authority to calculate surface drift and validate search areas in search and rescue operations,” he said.

“The real-time GPS feeds from the buoys give us vital information and are an effective tool in determining where we start searching for people and vessels missing at sea.”

AIMS oceanographer Craig Steinberg said the real-time information from the buoys revealed that the slicks had floated 52km in five days.

Mr Steinberg said the on-water observations found small slicks could form and move quickly across the reef, or dissipate if the wind created whitecaps.

“We want to better understand the connectivity of reefs so we know how they can be protected,” he said. “To do this we can observe surface currents using these satellite buoys in order to gather this information, which is quite rare.”

While AMSA undertook the deployment from the air, AIMS marine biologist Dr Andrew Heyward was on the water watching close-up.

Dr Heyward said most coral species released buoyant egg and sperm bundles after dark, in the spectacular annual spawning event that typically occurs four to six nights in November, after the full moon.

Dr Heyward said floating spawn slicks could contain several million coral larvae per square metre.