Tidal Waterways

Dae-Min Kim

* See The Map of Administrative Divisions of South Korea

  ! To find names of waterways in the pictures you are looking at, please place your mouse cursor on a picture and wait a few seconds !

- Tidal Lagoons, Coastal Springs of the Jeju Island, Creeks of Tidal Mudflats.

1. Tidal Lagoons : In South Korea, lagoons are located near small stream estuaries, behind barrier beaches, and on the East Sea coast, often adjacent to open sea. Although these tidally influenced communities harbor relatively few plant species, they are highly productive. They also occur behind barrier islands - long, narrow, sandy islands that run parallel to the coast. The landward sides of barrier islands are often bordered by extensive salt marshes including lagoons and tidal flats. At the same time these tidal lagoons support several freshwater fish including Carassius auratus, Rhynchocypris percnurus, Misgurnus anguillicaudatus, and Pungitius kaibarae, they also support a lot of estuary and marine species, including Mugil cephalus, Acanthopagrus schlegeli, Terapon jarbua, and many goby species, and several anadromous species, including Tribolodon hakonensis and Salangichthys microdon.
For a couple of recent decades, most of these lagoons, occuring along East Sea coast, have been partly to fully reclaimed and now suffering from eutrophication.
 

* The following map shows the distribution of tidal lagoons in South Korea

2. Coastal Springs of the Jeju Island: Coastal springs are waters that come out of underground aquifer forming clear and sunlit creeks with non-vegetated bottoms. They mainly dot along the sea shore of Jeju Island, an dormant volcanic island, on South Sea of South Korea. Jeju Island has many valleys with annaul precipitation over 2,000mm and hills with volcanic groups around Mt. Halla(1950m /6398 feet), the highest mountain in South Korea (the highest mountain in the Korean Peninsula is Mt. Baekdoo, located in North Korea and 2744m/9003 feet high.). Jeju island's streams tend to be underflows from middle to lower reach near sea shore, due to its geological characteristic that this island consists of basaltic stones. 
These coastal springs support several species of estuary or marine goby species, which prefer warm and shallow waters, including Chaenogobius spp., Mugilogobius fontinalis, Chasmichthys spp., and Bathygobius fuscus. The natives of Jeju Island have traditionally maintained friendly ties with coastal springs, key sources of freshwater supply. 
The following two pictures show coastal springs used as "public baths" for Jeju's fisherwomen - traditional female divers.

* The following map shows the distribution of coastal springs of the Jeju Island.

3. Creeks of Tidal Mudflats: Tidal mudflats, mud-bottomed intertidal zones, are mostly occurred in estuary and shallow bays. The Yellow Sea, long and narrow bay located between northeastern China and South Korea, boasts its size which is well known as the world largest mudflats with four other areas in the world, including southeastern coast of Canada, eastern coast of U.S, estuary of Amazon River, and the North Sea in northwestern Europe. Due to the movement of water currents and their sculpture, the oceanic topography of the Yellow Sea, western South Korea's coastal water is much shallower than northeastern China. This geographic features have created such a large body of muddy sediment in South Korea.
 There are numerous creeks that are shorter than 20km(12.5 miles)-long and originated in gentle hill terrain around the Yellow Sea coast. They mostly do not harbor riffles or torrential headwaters but silty runs with low current. The intertidal zone gets deeper from south to north and it is about 9m(30 ft) deep in Incheon, northwestern coastal city of South Korea. Therefore, a large number of creeks in northwestern coastal area usually get almost more than twice longer when the intertidal zones are fully exposed. These creeks are nice home of various goby species including mudskippers(Boleophthalmus ssp. and Periophthalmus ssp.), Anguilla japonica, Trachidermus fasciatus, and Takifugu niphobles, and ideal dinning place for a lot of bird species.

* The following map shows the distribution of the creeks running through tidal mudflats.