2017 - A Year of Discoveries and Science!
In the 10 years of the NHRCP, we have worked hard to contribute to the national and global understanding of the coral reefs and surrounding ecosystems, and 2017 was a bumper year for exciting discoveries and scientific publications. Below is a rundown of some of our favourites!
Coral Predators of Koh Tao
In April we published a paper analysing our EMP data for coral predators between 2006 and 2014, monitoring and observing outbreaks, while also investigating impacts of tourism to coral predator numbers. We observed intriguing differences between the changes in populations of the Drupella snails and Crown of Thorns seastars on the island and highlighted the need to continue and expand our monitoring of situation.
Population dynamics of corallivores (Drupella and Acanthaster) on coral reefs of Koh Tao, a diving destination in the Gulf of Thailand. (Paper available here - Scott et al. 2017)
New Species to Science!
Our research and exploration of the muck habitats have yielded some exciting discoveries in the past, and here are our first two species that we introduced to science. Armina scotti and Armina occulta are two nudibranchs that live exclusively in the muck, feeding on sea pens, and have been recorded sporadically throughout the Indo-Pacific region. Both species were in taxonomic limbo (either waiting to be investigated or compared with other species) and now make up the first two species described from the island!
On the genus Armina (Gastropoda: Heterobranchia: Nudibranchia) in Thailand. (Paper accessible here – Mehrotra et al. 2017)
The Rarest Coral in the World?
What started as an observation of some fuzzy stuff growing at one of our EMP locations, quickly exploded into one of the coolest discoveries of our island. Right now, there are only 5 species (out of hundreds!) of octocoral (traditional “soft” coral) that create a dense aragonite skeleton. Only 2 of these are found in shallow water, the most recently described of these two is Nanipora kamurai, from Japan, in 2015. In-depth investigations of the fuzzy stuff revealed some startling discoveries. Nanipora, the coral that had only been recorded as 8 small colonies in Japan, was abundant at one part of one bay on the island. Koh Tao was now home to the second recorded population, the largest global population (an area about the size of an Olympic swimming pool), and the first recorded population with zooxanthellae symbiosis. We are excited to see what more we can understand about this mysterious skeleton-forming fuzz.
Rare zooxanthellate Nanipora octocoral (Helioporacea) in the Gulf of Thailand. (Paper accessible here – Urgell et al. 2017)
Corallivorous Snail Nurseries
The latest paper to be published is a short documentation of egg capsules belonging to the two types of coral-feeding snail, recorded at the island. Drupella and Epifungium snail eggs clusters were found on dead (Drupella eggs) and living (Epifungium eggs) mushroom corals. Both these snails have been recorded to feed abundantly on mushroom corals in multiple locations, making the act of using these corals and their skeletons as places for their eggs, an even more morbid find. Marine ecosystems can be creepy, Happy Halloween!
In-situ egg deposition by corallivorous snails on mushroom corals at Koh Tao (Gulf of Thailand). (Paper available here – Scott et al. 2017)
Citizen Science Milestone
Towards the end of the year, our monitoring of sea turtle observations around Koh Tao reached its 500th observation! With over 500 sightings of one of over 70 different individual turtles recorded at our island over the past 10 years (and beyond), our understanding our sea turtle residencies on our little island is growing day by day. Additionally, the launch of the whaleshark sighting platform has come at an optimum time, with a high density of whaleshark sightings being recorded this year, we look forward to seeing how many individuals visit our island and hopefully, where they go from here! Have you photographed a sea turtle or whaleshark at Koh Tao? Consider submitting your photos here or here!
A New Frontier in Koh Tao Spawning
We could not have asked for a more perfect end to the season, with the verification of a long theorised phenomenon, a second coral spawning cycle for Koh Tao! Records from other parts of the world, and even other parts of Thailand, have strongly indicated that a second spawning event (after our usual March/April foray) exists at the island, with a couple of indirect confirmations. This year however, we managed to capture the event in the water for our own eyes. This initial find will undoubtedly lead to closer investigations down the line.
2017 has been an incredible year for discovering and understanding our marine world, we hope you will join us next year to see what will undoubtedly be a whole new chapter of discovery for our program and for Koh Tao.
