Red Sea Surveys
Presently only little is known about the distribution of species and habitats along the coasts of the Red Sea. A South-North gradient of ecologically important oceanographic features such as the depletion of nutrients and the rise of salinity towards the North in contrast to dropping temperatures in the opposite direction consequently trigger the regional differences in species composition. For mapping of these specific and particularly valuable habitats, it is necessary to know the species distribution along these gradients in detail. At present detailed information is available from the northern Red Sea only, especially the Sinai area and from older expeditions to the Dahlak Archipelago of the Eritrean coast.
The aim of the present project is to understand biodiversity gradients along the Red Sea basin that can be ideally tackled at the Saudi Arabian coast, which stretches from the Gulf of Aqaba to the more productive southern Red Sea waters that get regular, though seasonally variable, nutrient influx from the adjacent Indian Ocean.
A series of surveys has been planned to achieve these goals. The first one took place in spring 2011 Further ones in 2012 and 2013 covering all seasons.
The KAU-SRI Red Sea surveys focused on the shallow water fauna including all environment types, like beaches, rocky shores, mangroves and coral reefs. Both the shore fauna and the sublitoral one reachable by snorkeling and scuba-diving are sampled. The first survey took place on 27.3.-22.4.2011. The material collected is under study by participants, wherever possible in joint work between members of the two partner organizations wherever possible and by international specialists. The second survey concentrated on the southern part of the Saudi-Arabian Red Sea coast and was undertaken in the period of 2.2.-12.3.2012. The third survey was restricted to the north and was undertaken in the period of 7.-28.6.2013, i. e. in summer.
The numbers of collected species have been quite substantial. The following table gives details based upon preliminary identifications and may be used as a key to the diversity of the animal groups collected in the surveys:
| Taxon | Total species collected |
|---|---|
| Sponges | 754 |
| Stony corals | 540 |
| Soft corals | 180 |
| Polychaetes | 997 |
| Crustaceans | 940 |
| Molluscs | 2156 |
| Bryozoans | 508 |
| Echinoderms | 127 |
| Fishes | 1277 |
| Total | 7479 |