Spur and Groove coring at Heron Island Reef

Last week Stephanie Duce and Belinda Dechnik from the Geocoastal Research Group (GRG) teamed up with fellow PhD student James Sadler from UQ to conduct an underwater coring campaign of the spur and grooves at Heron Island Reef in the southern Great Barrier Reef. To our knowledge these spur and grooves have never been cored before and they provided beautiful but challenging targets.

We used a handheld drill, with a 70 cm long barrel, powered by air from a dive tank to collect cores along the tops and into the walls of spurs. Overall, a total of 14 short cores (up to 60 cm in length) were collected from three sites on the windward and leeward sides of the reef. The framework of the spurs proved to be relatively unconsolidated with some holes having to be abandoned only a few centimeters in as they became too rubbly or sandy to continue (given the limited drill power and time and air restrictions).

These cores will be logged to identify the coral and algal assemblages and dated to determine their age. This will help us understand how spur and grooves have formed and evolved at Heron Reef. It is hoped they will also provide insight into reef platform growth throughout the Holocene.

In another exciting new development for the GRG, we (with Jody-“Mr 3D”-Webster leading the charge) have discovered Agisoft! This software allows us to stitch numerous photos together creating spectacular 3D images, for example the transect along a coral spur below. Stay tuned for more as we explore cool applications for this software.

Acknowledgements: This work was funded by a Danielle Simmons Award from the Australian Coral Reef Society  and a Heron Island Research Scholarship. Many thanks to the excellent staff at Heron Island Research Station for their help.

We were lucky to have fine weather although strong winds and swell limited our ability to access the windward side of the reef.

We were lucky to have fine weather although strong winds and swell limited our ability to access the windward side of the reef.

James Sadler with a peice of core from the wall of a spur near "Libby's Lair"

James Sadler with a peice of core from the wall of a spur near “Libby’s Lair”

James, the corer, takes off his fins and wears two weight belts so he has good control over the drill.

James, the corer, takes off his fins and wears two weight belts so he has good control over the drill.

James and Steph working on a core into a spur wall near Harry's Bommie. Spurs in this location are up to 3 m tall and 5 m wide, separated by wide rubbly grooves.

James and Steph working on a core into a spur wall near Harry’s Bommie. Spurs in this location are up to 3 m tall and 5 m wide, separated by wide rubbly grooves.

James delivering a nice peice of core.

James delivering a nice peice of core.

The team with a nice peice of core through a Platygyra (Brain) coral

The team with a nice peice of core through a Platygyra (Brain) coral

3D

3D mosaic along the top of a spur near Harry’s Bommie

Heron sun sets are a sight to behold!

Heron sun sets are a sight to behold!

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