research projects | biodiversity | meiobenthos | coral ecology | fish ecology | fossil reefs | behavior
     
 
 

Community Ecology of Pleistocene Reefs in around Dahab and in Ras Mohammed National Park (Egypt) - Prof. Dr. Wolgang Kiessling

Our study aims to assessing the ecological stability of Pleistocene coral reefs during times of major climatic change. Coral reefs are thought to be especially sensitive to environmental change but yet they persisted through the Pleistocene ice ages with their major impact on eustatic sea level and climate. We intend to do detailed quantitative studies on fossil reef terraces exposed in Ras Mohammed National Park and those exposed north of Dahab. Line transects and bulk sampling will be performed to analyze the composition of each terrace. Statistical analyses will then allow evaluating the ecological change through the ice ages.

  Ras Mohammed
 
 

Small group project:

Pleistocene coral reefs of the Canyon / Blue Hole,
eastern coast of the Sinai peninsula, Egypt

by Vanessa Julie Roden, Raphael Fritz, Manuel Gonzales Rivero & Ana Teresa Herrera

Abstract

A Pleistocene fossil reef on the eastern coast of the Sinai Peninsula, near Dahab, was examined. Three layers of slightly different fossil content could be distinguished. The top layer could not be studied in detail due to its inaccessibility, so estimations were made. It contains approximately 30 % red coralline algae, 60 % corals and 10 % of other invertebrates. About half of the corals were of the genus Porites, a third were of the genus Acropora, and the genera Platygyra, Favia and Tubularia make up another sixth of the total coral abundance in the top layer. To obtain a more accurate distribution of the taxa in the middle and lower layers, six or five laterally distributed areas of 1 m2 each were defined, respectively, and the distribution of species was examined. About 35 % of the visible area in the middle layer is made up of corals of the genus Porites, and less than ten percent each of the genera Favia, Platygyra and Acropora. Invertebrates total approximately 5 %. In the lower layer, 40 % of the area is covered by Porites, and about 5 % by Favia and Platygyra. No Acropora was seen in the lower layer. Invertebrates only make up 2 % of the lower layer. No lateral change in fossil abundance could be observed. Following coral genera were found in lower abundance, either within one or more of the layers, or in the rubble that had eroded out of the wall: Lobophyllia, Fungia, Favia, Blastomussa, Goniastrea, Pocillopora and Podobacia. The most abundant species of bivalves is Trachycardium lacunosum Reeve; a total of 21 species of bivalves were found during this study. The most abundant gastropod genus is Turbo; 21 gastropod species were found. Many echinoid spines of the species Heterocentrotus mammilatus Linnaeus were found. By observing the degree of recrystallization within the echinoid spines, it was possible to conclude that the top layer is the oldest and the lower layer the youngest.

 

Ras Mohammed

Ras Mohammed

Ras Mohammed