Cook Islanders on front line of world coral reef challenge

Monday 18 September 2017 | Written by Chris Taylor | Published in Local


Cook Islanders on front line of world coral reef challenge
Scientists use underwater cameras and laser technology to make 3D photo mosaics of the reef PHOTO : Waitt Foundation. 17091422

Two Cook Islanders have recently been involved in a project that is using cutting edge technology to examine coral reefs around the world.

Rarotonga-based Marine Scientist Dr Teina Rongo and research assistant James Kora of local environmental NGO Korero O Te 'Orau, have just spent three weeks working with researchers from Southern California-based Scripps Institute of Oceanography on their “100 Island Challenge”.

The programme is a collaboration of scientists from around the globe who are carrying out a large-scale investigation on how coral reefs are responding to oceanographic, human activities, and climate change and variability.

The “100 Island Challenge” will run over a five-year period, with the aim of revisiting islands surveyed within an interval of two years to assess changes in fish and coral communities.

Rongo and Kora, who have both also previously worked at Climate Change Cook Islands (CCCI) and led the recent long-term coral reef monitoring survey for Rarotonga in 2016, were part of the benthic (ocean floor) community assessment team on this research cruise to French Polynesia’s Tuamotu archipelago (Tikehau, Rangiroa, Takapoto) and the Line Islands (Millenium, Vostok, Flint).

The programme uses 3D imaging technology that will allow scientists to track the growth of coral colonies as well as changes in species composition and reef complexity within a 100sqm plot at each site surveyed.

Over 2,000 individual ocean floor photographs measuring depth and width are subsequently “sewn” together to create a 3D photo mosaic reef community showcasing the colours and complexity on the reef.

The software also allows scientists to virtually examine and measure individual corals from their office thousands of kilometres away. While the technology and concept has been around for some time, especially in archaeology and other land-based fields, its application on coral reefs is still new, and the “100 Island Challenge” is the first to use this technology on coral reef communities.

The high tech project is run by the labs of Dr Stuart Sandin and Dr Jennifer Smith from the Scripps Institute of Oceanography, along with many partners and collaborators.

Rongo and Kora have been at the forefront of this exciting venture and have gleaned some interesting insights by learning to use the new technology.

Rongo says coral bleaching associated with the recent El Niño event in 2015 seemed to affect coral reefs closer to the equator, where bleaching was noticeably more severe in the Line Islands than in the higher latitude islands in the Tuamotus. A similar trend has been noted in the Cook Islands, with more severe bleaching occurring in the northern group compared with the southern group.

The study zeroed in on the uninhabited Millennium Island in the Line Islands (Kiribati), known as one of the most pristine reefs in the world, which was found to be severely bleached by the recent El Niño event. Studying Millennium can help scientists understand how reefs recover without human factors, such as nutrient overloading, coastal development, and overfishing.

Rongo is a big supporter of the new 3D mosaic photo technology as it speeds up the process of collecting lots of data in a limited amount of time. He believes that by seeing the reef through this technology, it will help people appreciate reefs and hopefully influence how they use them in the future.

“We tend to just see reef systems as a provider of food and opportunities for economic growth. We don’t appreciate them because we can’t see them,” says Rongo.

As a scientist, he’s seen people switch off when shown a graph of changing reef systems. However, take those same individuals through a journey of a virtual 3D map of the reef, and they can fully comprehend changes and see first-hand dying or flourishing reefs.

But there is still no substitute to getting up close and personal with corals in the field, even for an experienced scientist.

For the Scripps researchers, Rongo’s extensive traditional and local knowledge of reefs throughout the Cook Islands was an important contribution that assisted in painting a complete picture of these ecosystems and the relationship with those who use the resources.

Rongo’s ability to speak Cook Islands Maori was useful in the Tuamotus to understand how things have changed over the years regarding marine resource use for the indigenous populations residing there, which was similar to the work he has carried out throughout the Cook Islands while at CCCI.

Like the Cook Islands, residents in the Tuamotus are also experiencing a decline in the marine resources they have relied on in the past.

Other recent expeditions in the “100 Island Challenge” include the Mariana Islands, Kingdom of Tonga, and Jamaica.

This particular research trip of Scripps Institute of Oceanography was a collaboration with the Waitt Foundation and included researchers from The Nature Conservancy - Hawaii, CRIOBE in French Polynesia, and Cook Islands Korero O Te ‘Orau, represented by Rongo and Kora.

Rongo hopes the Cook Islands will be included in the “100 Island Challenge”, so we can use the technology as part of our monitoring efforts for Marae Moana.

He also sees the technology as a tool for raising the awareness of coral reefs in the Cook Islands, so that a balance between economic growth and the environment can be achieved.