“Shirasu” is a shallow-water shoal that emerges at low tide off the ruins of Hara Castle in Minami-Shimabara City, Nagasaki prefecture. The castle figured prominently as the last bastion of the Shimabara rebellion in the 17th century and is today part of the UNESCO World Heritage sites “Hidden Christian Sites in the Nagasaki Region.” “Shirasu” shoal is a touristattr action and is accessible by boat.
The research team, led by Associate Professor Aki Kato and her PhD student, Mr. Min-Khant-Kyaw, surveyed the shoal and found that it is almost entirely composed of a seaweed bed formed by spherical calcareous red algae (coralline algae). In their research, 10 species of coralline algae were found including two species described for the first time. The full technical report was published in Phycologia 63: 520-533 (2024; link provided below).