Uet era Ngermeuangel

Uet era Ngermeuangel Big Jellyfish Lake Ngermeuangel Lake
Location	Koror, Palau
Coordinates	7°19′25″N 134°30′31″E / 7.32361°N 134.50861°E / 7.32361; 134.50861Coordinates: 7°19′25″N 134°30′31″E / 7.32361°N 134.50861°E / 7.32361; 134.50861
Lake type	Meromictic
Basin countries	Palau
Max. length	0.290 km (0.180 mi)
Surface area	4.3 ha (11 acres)
Max. depth	40 m (100 ft)
Frozen	never
Islands	none
Settlements	none

Uet era Ngermeuangel (Ngermeuangel Lake, Big Jellyfish Lake) is a marine lake located on Koror island in Palau. There are about 70 other marine lakes located throughout the Rock Islands and Koror. Uet era Ngermeuangel is notable for endemic subspecies of golden jellyfish and is one of five marine lakes in Palau used for several scientific researches in evolutionary biology the other lakes being Jellyfish Lake, Clear Lake (Palau), Goby Lake, Uet era Ongael.

Golden jellyfish

Uet era Ngermeuangel is connected to the ocean through fissures and tunnels in the limestone of ancient Miocene reef. However the lake is sufficiently isolated and the conditions are different enough that the diversity of species in the lake is greatly reduced from the nearby lagoon. The golden jellyfish Mastigias cf. papua remeliiki^[1] and possibly other species in the lake have evolved to be substantially different from their close relatives living in the nearby lagoons. In the lake there is living also jellyfish Aurelia sp.

Lake stratification

Uet era Ngermeuangel is a deep, comparatively ancient (15 - 12 thousand years) lake, stratified into two layers, an oxygenated upper layer (mixolimnion) and a lower anoxic layer (monimolimnion). The oxygen concentration in the lake declines from about 6 mg/l at the surface to zero at 18 meters (at the chemocline) ^[2]. Stratification is persistent and seasonal mixing does not occur. The lake is one of about 200 saline meromictic lakes that have been identified in the world. However most of these lakes are of freshwater origin. Permanently stratified marine lakes are unusual, but in Palau there are eleven other permanently stratified marine lakes^[3], the most renowned one is Jellyfish Lake.

References

1. ^ Dawson M, MIchael. "Five new subspecies of Mastigias (Scyphozoa: Rhizostomeae: Mastiigidae) from marine lakes, Palau, Micronesia". http://www2.eve.ucdavis.edu/mndawson/MND/assets/PDFs/2005Dawson_JMBA_M.pdf/. Retrieved 2010-02-11. ^{[dead link]}
2. ^ "Coral Reef Research Foundation". http://www.coralreefresearchfoundation.org. Retrieved 2010-02-11. 
3. ^ Stratified marine lakes of Palau (Western Caroline Islands) Physical Geography 19: 175-220, William Hamner, Peggy Hamner

External links

• Wondermondo: Uet era Ngermeuangel - marine lake of jellyfishes