About Jellyfish lake
Jellyfish Lake, Ongeim’l Tketau (OTM), is located in Palau, an island nation near the Philippines. One of over 50 marine lakes in Palau, Jellyfish Lake is a 30 m deep basin that is indirectly filled with seawater from the ocean. The lake is connected to the ocean through a series of cracks and crevices through the encircling limestone that are so small that creatures in the lake are isolated from the ocean and nearby marine lakes. Organisms such as Mastigias spp. that were trapped in the lake when the sea level dropped thousands of years ago were able to evolve in quiet isolation, “developing a lake-specific suite of genetic, physical, and behavioral characteristics.” Jellyfish Lake derives its name from two jellyfish species; golden jellyfish, Mastigias papua etpisoni, and the less common moon jellyfish, Aurelia spp.
About the Jellyfish of Jellyfish lake
The fragile, transparent moon jellyfish generally spend the daylight hours feeding on plankton. In contrast, the golden jellyfish rely on an obligate symbiosis with microscopic algae that live inside their body to get the energy they need. The algae convert sunlight to sugar which provides energy for both the algae and the jellyfish. In return the jellyfish dedicate their life to tending the algae. The golden jellyfish make a 1 km long, daily migration following the sun. Millions of golden jellyfish swim east in the morning and west in the afternoon to maximize their exposure to the sun. At night the jellyfish must dive down to the bacterial layer that decomposes dead organisms to get nutrients that the algae need. This layer lacks oxygen and has high concentrations of poisonous hydrogen sulfide, so the jellyfish cannot stay long or they will suffocate and die. Although the jellyfish can also acquire energy by capturing zooplankton, they are dependent on the algae for survival, and so they are forced to make this treacherous daily journey.
Please, please check out the national geographic videos hyperlinked on the next post. They are excellent videos that show this daily migration and the dangers the jellyfish face if they stray too close to the shore. I was unable to embed them on the blog, but they are really worth a look.
The experience of a lifetime
Believe it or not you can actually swim with these jellyfish as their sting is mild and often undetetable; however you may feel their sting if an oral arm comes in contact with sensitive skin like around your mouth. I personally would love the opportunity to do this at least once before I die.
References:
Coral Reef Research Foundation. (1991). Jellyfish Lake Information Sheet. Retrieved from http://www.coralreefresearchfoundation.org/CRRFassets/Reports/OTM_FactSheet.pdf
Word count (428)
Word count (428)
