| FishBase | Complete | Literature | Reference | |||
|---|---|---|---|---|---|---|
| Species | Families | Species | Families | |||
| Marine | 621 | 86 | No | 568 | 90 % | Allen, G.R. and R.C. Steene, 1988 |
| Freshwater | 1 | 1 | No | 5 | Allen, G.R. and R.C. Steene, 1988 | |
| Total | 621 | 86 | No | |||
| Conservation | The marine fish fauna is well known and consists primarily of reef-associated species. It may be best described as a slightly impoverished Indo-Malayan one. This impoverishment is primarily due to the oceanic position of the island, its small size and the consequent low diversity of habitat. Freshwater fishes of Christmas Island are few. Those most commonly encountered are introduced exotics which include members of the genus Gambusia, Xiphophorus, Poecilia and Sarotherodon. The only known native species include a freshwater eel ( Anguilla sp.) taken from a shallow stream at Dolly Beach, a small brown fish in Lost Lake Cave, and the freshwater gudgeon Eleotris fusca. Presently, the relatively small population of the island and the current low level of exploitation of its reef resources minimize the need for detailed conservation measures. However, this will change as phosphate mining declines and the development of tourism proceeds is anticipated. The following information is to be sought: - Contact(s) for further information. |
| Geography and Climate |
Christmas Island is located in the northeastern Indian Ocean, south of Indonesia. It is approximately 290 km south of Java and 850 km northeast of the Cocos Islands. It is about 22 km in its greatest length (straight-line distance between Egeria Point and North East Point), with the overall shape resembling a dog with its head facing towards the east.
Total area is 135 sq km; land: 135 sq km, water: 0 sq km (Ref. 30539).
The coastline is extremely irregular consisting primarily of sheer rocky cliffs which on the average are 10-20 m in height. At many localities on the north coast the coastal cliffs plunge vertically (where they are sometimes undercut) and then continue for another 2-5 m below the surface. These cliffs are composed of highly eroded limestone and contain many interesting caverns and ledges which extend below the surface. Most of the beaches (10-12 in number) are nothing more than narrow strips of sand which are exposed only at low tide.
Inland, the island rises steeply with an initial series of coastal terraces. Most of the interior consists of relatively gentle sloping hills with a maximum elevation of about 361 m above sea level. The island is covered everywhere, except on the steep cliffs and where phosphate mining has occurred (phosphate being a major natural resource, Ref. 30539), by a dense canopy of tropical jungle.
Christmas Island has tropical climate; heat and humidity moderated by trade winds (Ref. 30539). Ref. Allen, G.R. and R.C. Steene, 1988 |
| Hydrography |
Most of the submarine coast around Christmas Island consists of a relatively narrow shelf of coral reef varying in width from about 20 to 100 m. In Flying Fish Cove there is a well-developed fringing reef in shallow water adjacent to the shore, which is sometimes exposed during low tide. This shallow reef extends for about 20-50 m before plunging abruptly to a depth of 3-5 m, and then there is a gradual descent to the upper edge of the outer reef slope. The outer, seaward slope plunges quickly to deep water around the entire coastline.
An extensive elevated terrace, about 3-4 m in width and perched about 2-3 m above mean sea level, is present at North West , Egeria and Steep Points. The terrace contains a number of large pools with depths of 0.2-1 m and harbours a rich collection of fishes.
There are no brackish estuaries, silty bays and protected lagoon environments.
Although an abundance of subterranean water is present, there is very little suitable habitat to support fish life. It consists mainly of a few springs and very small, gradient creeks. Ref. Allen, G.R. and R.C. Steene, 1988 |