Predicting and managing the future of Ongeim’l Tketau (Jellyfish Lake), Palau in a changing climate

Underwater image of hundreds of pale yellow jellyfish with clear bells and short bundles of stingers floating in green-tinged water
Golden jellyfish sometimes abound in Jellyfish Lake, generating a remarkable, and safe, sight for visitors. (Photo: CCby3.0, Lukas)

Tourism is a large component of the Koror State and Palau economies, whose impacts ripple through all levels of the community. Jellyfish Lake, locally known as Ongeim’l Tketau (OTM), is an iconic tourism site and an important area of biodiversity. It is home to the unique Golden jellyfish subspecies found nowhere else in the world. Populations of this jellyfish within OTM have varied over past decades from ~30 million to zero, with the collapse sometimes lasting multiple years (Patris et al., in prep). Scientific monitoring of OTM has produced a basic understanding of the climate conditions associated with the natural variation of Golden jellyfish numbers, usually related to the El Niño and La Niña cycles (Martin et al., 2005, Patris et al., 2020).

To make this information more accessible to the public and local agencies, we will develop a ‘Conditions Assessment and Forecast” (CAF) tool for Jellyfish Lake. The CAF tool will allow Koror State and the national government to present a unified message to the public regarding OTM’s current Golden jellyfish status and its forecast, six months into the future. This is especially timely as tourists return to Palau, post‐Covid, and tour operators and Palau Visitor’s Authority will be able to use the tool for market planning.

We will also develop a culturally sensitive, place‐based “Invasive Alien Species Educational Outreach Strategy” for OTM, to help preserve the resilience of the lake and its jellyfish population from invasive threats. The strategy will involve actions that local communities, tour operators and tourists can take to control and prevent introduction of non‐native species into the lake. Protecting the lake from future introductions of invasive species promotes the resilience of Jellyfish Lake in a changing climate.





Romina King
Associate Professor of Geography, University of Guam


Sharon Patris
Research Biologist, Coral Reef research Foundation