|Total||No||620||0 %||Zajonz, U., M. Khalaf and F. Krupp, 2000|
Since most estuaries are separated from the sea by gravel or sand berms and only become temporarily connected to the sea after flash floods during the rainy seasons or by storm surges (i.e. temporarily open and closed estuaries, TOCEs), for long periods during the year, the in- and out-ward migrations of post-larvae, juveniles and mature fishes between freshwater, brackish and marine environments are usually limited (Ref. 117436).
The coastal fish assemblages are reported as being highly diverse and enriched by species of adjacent biogeographic regions consistent with the archipelago’s position at ‘biogeographic crossroads’ as postulated by various authors (Ref. 117436).
The fish assemblages of the archipelago are of an Indo-Pacific origin, with zoogeographic affinities to the Red Sea, southern Arabia, East Africa, other parts of the Western Indian Ocean and the wider Indo-Pacific and many of which are 'Arabian' endemics (Ref. 37631).
|Geography and Climate||
The Archipelago (12°30? N; 54°00? E) lies in the north-western corner of the Indian Ocean, at the junction between the Gulf of Aden and the Arabian Sea. Included are the main island of Socotra, and the three smaller islands of Samha, Darsa and Abd al-Kuri, and various rocky stacks. The islands have seasonally variable environment as a result of the alternating monsoon seasons in the northern Indian Ocean driven by the Inter-Tropical Convergence Zone (ITCZ): the weak and wet winter or north-east monsoon (November to February) and the forceful and dry summer or south-west monsoon (May to September) (Ref. 117436)
The Archipelago is situated in the vicinity of four major biogeographic units of the circum-Arabian seas: the Eritrean, South Arabian and Persian sections of the Arabian subprovince (sensu KLAUSEWITZ 1989) and the Western Indian Ocean subprovince (Ref. 37631).
There are no estuaries or lagoons found on the islands of Darsa, Samha and Abd al-Kuri. On the other hand, Socotra Island has approximately 30 estuaries which vary greatly in terms of morphology, water regime and ecological conditions, and one intertidal lagoon. The monsoons contribute to creating particular estuarine environments with marked seasonal river flow, salinity
and temperature regimes.
Ref. Lavergne, E., U. Zajonz, F. Krupp, F. Naseeb and M.S. Aideed, 2016