Off the coast of Ishigaki Island in Japan’s Okinawa Prefecture, divers are undertaking new efforts to document manta ray populations in an area renowned for its rich marine biodiversity. Okinawa, a subtropical archipelago located more than three hours southwest of Tokyo and closer to Taipei, is home to some of the most diverse coral reef ecosystems in East Asia. The region supports over 6,000 marine species, including 340 species of reef-building corals, roughly 70 percent of all coral species found in the Pacific Ocean. These ecosystems are sustained by the Kuroshio Current, a major oceanic current known for fostering biodiversity.

In April, the Professional Association of Diving Instructors (PADI), the world’s largest diving certification organization, launched the Global Shark & Ray Census, a citizen science initiative aimed at collecting detailed data on shark and ray populations worldwide. Okinawa’s dive shops, which have not traditionally monitored local manta populations extensively, were among the first in Japan to engage with the program.

Divers participating in the census record sightings, noting details such as physical scars, pregnancy status, and behavior, while capturing photographic evidence with underwater cameras. These data are then shared with researchers at James Cook University in Queensland, Australia, for further study. The project builds on similar efforts by the Japan Manta Project, founded by Rika Ozaki, which highlighted the expanded home ranges of reef mantas through photo identification techniques in Australian waters. Findings have shown some mantas traveling more than 1,150 kilometers along the Queensland coast, suggesting previously underestimated migration patterns.

Near Ishigaki’s Kabira Beach, a popular dive site known as Manta City provides ideal conditions for observing manta rays during their courtship behavior. Divers have documented groups of reef mantas engaging in “conga line” style swimming, a form of social interaction typically involving males following a female.

These monitoring efforts are part of a broader trend to combine recreational diving with environmental data collection, thus turning leisure trips into opportunities for marine conservation research. As tourism to Okinawa increases, such initiatives aim to raise awareness of the region’s unique underwater ecosystems and support their protection amid growing human activity.

The data gathered through the Global Shark & Ray Census and other programs will contribute to a more comprehensive understanding of manta ray ecology, informing conservation strategies for these vulnerable marine species in Japanese waters and beyond.