3D modelling dives into coral conservation

The Hydrous' vice-president, Ms Smalley- Norman, says 3D models can measure coral growth more accurately than conventional tools.
The Hydrous' vice-president, Ms Smalley-Norman, says 3D models can measure coral growth more accurately than conventional tools.

3D technology is set to change the way people live, and a new software that was developed here promises to make it accessible to most people. Audrey Tan looks at how this software is making its mark vividly at home and abroad.

ReMake is a type of software developed here by technology firm Autodesk, and it is making waves abroad... and underwater.

A marine conservation group based in the United States, The Hydrous, has been using the technology for at least two years to create 3D models of corals during its expeditions to places such as the Maldives.

"We have been using the technology as a better way for scientists to measure coral size and growth," Ms Yasmeen Smalley-Norman, vice-president of The Hydrous, said while she was in Singapore last month to attend the Asia Dive Expo.

Coral growth is usually measured in a two-dimensional way, with tape measures, rugosity chains or grid-like structures made of PVC pipes called quadrats. For instance, scientists typically use PVC quadrats to measure coral bleaching - a phenomenon when corals expel the symbiotic micro-algae living in them due to warming sea surface temperatures - by simply counting the number of bleached squares on the grid.

"It is a 2D method of measuring something that is 3D - it is inaccurate as it relies a lot on the human eye. The quadratsare also potentially damaging as they are laid on the coral reefs," Ms Smalley-Norman said.

But with the 3D models, it is easier to say with certainty the amount of coral affected by bleaching.

Such measurements help scientists understand the impact of climate change on coral reefs, which are not only tourist spots, but also fish nurseries, she added.

The technology could also help agencies that oversee marine protected areas assess the area over time. For instance, Singapore's National Parks Board could use it to track changes in the 40ha Sisters' Islands Marine Park, located south of the mainland.

"If the technology is used to establish a baseline of each coral now, at a point soon after the marine park was established, and if similar measurements could be made over time, then we can see how the protection is working, and also compare them with areas which are not protected," Ms Smalley-Norman said.

As the technology is compatible with simple point-and-shoot cameras, it could be used easily by citizen scientists, she added.

Dr David Kline, an associate project scientist at the Scripps Institution of Oceanography in San Diego, has worked on projects involving 3D imaging and coral reef conservation.

He told The Straits Times that 3D surveying techniques are a critical advancement in coral reef surveying methods. "Traditional surveying methods obtain only a 2D representation of reefs. But their three-dimensional structure is critical to their function of serving as a home to the incredible biodiversity found there."

Mr Jerker Tamelander, head of the United Nations Environment Programme's Coral Reef Unit, agreed. But he said that 3D technology does not capture "biotic cover" - it does not measure the presence, abundance and diversity of mobile species, including fish. But if the technology is combined with such biological data, valuable information on coral reef structural complexity and changes over time can be gained.

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A version of this article appeared in the print edition of The Straits Times on May 13, 2016, with the headline 3D modelling dives into coral conservation. Subscribe