Goby Lake
Encyclopedia
Goby Lake is a marine lake located on Koror
Koror
Koror is the state comprising the main commercial centre of the Republic of Palau. It consists of several islands, the most prominent being Koror Island ....

 island in Palau
Palau
Palau , officially the Republic of Palau , is an island nation in the Pacific Ocean, east of the Philippines and south of Tokyo. In 1978, after three decades as being part of the United Nations trusteeship, Palau chose independence instead of becoming part of the Federated States of Micronesia, a...

. There are about 70 other marine lakes located throughout the Rock Islands and Koror. Goby Lake 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
Jellyfish Lake
Jellyfish Lake is a marine lake located on Eil Malk island in Palau. Eil Malk is part of the Rock Islands, a group of small, rocky, mostly uninhabited islands in Palau's Southern Lagoon, between Koror and Peleliu. There are about 70 other marine lakes located throughout the Rock Islands. Jellyfish...

, Clear Lake (Palau)
Clear Lake (Palau)
Clear Lake is a marine lake located on Eil Malk island in Palau. Eil Malk is part of the Rock Islands, a group of small, rocky, mostly uninhabited islands in Palau's Southern Lagoon, between Koror and Peleliu. There are about 70 other marine lakes located throughout the Rock Islands...

, Uet era Ngermeuangel
Uet era Ngermeuangel
Uet era Ngermeuangel 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 Ongael
Uet era Ongael
Uet era Ongael is a marine lake located on Ongael island, Koror, in Palau. There are about 70 other marine lakes located throughout the Rock Islands and Koror...

.

Golden jellyfish

Clear Lake is connected to the ocean through fissures and tunnels in the limestone of ancient Miocene
Miocene
The Miocene is a geological epoch of the Neogene Period and extends from about . The Miocene was named by Sir Charles Lyell. Its name comes from the Greek words and and means "less recent" because it has 18% fewer modern sea invertebrates than the Pliocene. The Miocene follows the Oligocene...

 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 nakamurai and possibly other species in the lake have evolved to be substantially different from their close relatives living in the nearby lagoons. Lake is rich with several species of fish, including goby, giving to lake its name.

Lake stratification

The deepest - north-eastern - part of Goby Lake is stratified
Stratification (water)
Water stratification occurs when water masses with different properties - salinity , oxygenation , density , temperature - form layers that act as barriers to water mixing...

 into two layers, an oxygenated upper layer (mixolimnion) and a lower anoxic
Hypoxia (environmental)
Hypoxia, or oxygen depletion, is a phenomenon that occurs in aquatic environments as dissolved oxygen becomes reduced in concentration to a point where it becomes detrimental to aquatic organisms living in the system...

 layer (monimolimnion). The oxygen concentration in the lake declines from about 6 mg/l at the surface to zero at 10 meters (at the chemocline
Chemocline
A chemocline is a cline caused by a strong, vertical chemistry gradient within a body of water. A chemocline is analogous to a thermocline, the border at which warmer and cooler waters meet in an ocean, sea, lake, or other body of water...

). Stratification is persistent and seasonal mixing does not occur. The lake is one of about 200 saline meromictic
Meromictic
A meromictic lake has layers of water that do not intermix. In ordinary, "holomictic" lakes, at least once each year there is a physical mixing of the surface and the deep waters...

 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, the most renowned one is Jellyfish Lake
Jellyfish Lake
Jellyfish Lake is a marine lake located on Eil Malk island in Palau. Eil Malk is part of the Rock Islands, a group of small, rocky, mostly uninhabited islands in Palau's Southern Lagoon, between Koror and Peleliu. There are about 70 other marine lakes located throughout the Rock Islands. Jellyfish...

.

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK