Palau’s spawning events of Moorish Idols and Orange Spine Surgeonfish featured in BBC’s New Series

By: Eustoria Marie Borja

Koror, Palau – The annual blue water spawning events of Moorish Idols (MI) and Orange spine Surgeonfish (OSS) in Palau, along with the high-stakes predator-prey interactions between these fish and grey reef sharks, was highlighted in the BBC series Asia, airing on November 3, 2024

The fascinating research behind these spawning events was detailed in a paper by local marine experts Mandy T. Etpison and Dr.Patrick L. Colin. The study focuses on the aggregation of these fish species during the spawning season, which takes place from December through March, with peaks in January and February. These fish leave the safety of the reef to release their eggs into open water, making them vulnerable to predators like grey reef sharks. The study documents how large numbers of sharks follow the ascending fish, resulting in high predation rates during this critical reproductive phase.

“We were able to learn of these behaviors because of the Palau tour guides that have been in this industry for decades and have observed the aggregation of these fish overtime.  They are the ones in the water all the time, seeing these phenomena that has been there but no one really knew,” said Mrs. Etpison.

The study’s findings drew the attention of the BBC, which decided to include the spawning event in its new series Asia. Though Palau is culturally and politically part of Micronesia, it was included in the series’ Southeast Asia segment due to its geographical proximity to Indonesia. For the past two years, the BBC film crew, led by producer Mark Wheeler, has been coming to Palau to capture this remarkable natural event.

Local guide and safety diver Iked Etpison and his mother Mandy from Neco Marine played an integral role in the project, guiding the BBC crew to key locations such as Siaes Corner and Blue Corner during the spawning season. They ensured the crew captured the moments when Moorish Idols were hunted by sharks—a scene that will be narrated by Sir David Attenborough in the series’ first episode.

The series showcased on Palau’s unique ecological events, which are vital not only for scientific research but also for global awareness around marine conservation. Be sure to watch the first episode of Asia to witness the wonders of Palau’s marine life on a global stage, if you haven’t already.