Scientists at the Marine Megafauna Foundation and Murdoch University have discovered a large number of manta rays in the waters of Komodo National Park, a UNESCO World Heritage Site in Indonesia, suggesting that the area may be key to the regional recovery of this vulnerable species.
The reef manta ray (Mobula alfredi), which can grow up to 5.5 m (18 ft) wide, tends to live and feed in shallow, coastal habitats. They also go to "cleaning stations" on coral reefs to let parasites or dead skins be picked up by small fish. Courtship behavior can also be observed near cleaning stations. In Komodo National Park, manta rays are present all year round, challenging the famous Komodo dragon, the megafauna most sought after by tourists.
The scientists worked with groups of divers serving in Komodo National Park to look for identifying photos of manta rays visiting the park's waters and submitting them to MantaMatcher.org, a crowdsourced online database of manta rays and other fish. Most of the photos come from four of the more than 20 locations frequently visited by tourist boats. The researchers, with the support of the local diving community, were able to identify more than 1,000 individual manta rays from more than 4,000 photographs.
Individual manta rays are identified by their distinctive, and sometimes striking, abdominal patterns. The researchers saw the potential to engage the public in data collection and partnered with software company WildMe to develop an online wildlife database platform (MantaMatcher.org) to match and classify manta rays from different populations around the world.
The increase in the number of people engaged in scuba diving, snorkeling and the advent of inexpensive underwater cameras mean that photos and videos taken by the public during the holidays can be used to rapidly and economically scale up data collection. These photographs and accompanying time and location information are then used to construct an observational history of individual manta rays, which can then be analyzed with statistical motion models. These models can predict the likelihood that manta rays will live or travel between specific locations.