|Taxonomic and sclerochronological studies of Kenyan reef corals|
Melles, A. (1991). Taxonomic and sclerochronological studies of Kenyan reef corals. MSc Thesis. Vrije Universiteit Brussel: Brussel. 83 pp.
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VLIZ: Non-open access 246986
|Document type: Dissertation|
Coral reefs; Taxonomy; ISW, Kenya, Coast, Nyali [Marine Regions]; Marine
Taxonomic and sclerochronological studies were carried out along the Kenyan coast at four sites : Nyali, Bamburi North, Bamburi South and Malindi during November 1990. In total 76 species belonging to 35 genera have been identified. The status of Kenyan coral diversity is not yet well established due to paucity of taxonomic information in contrast to other localities in the Indo-Pacific. The results of the present study are compared with previous surveys from Kenya. All studies so far conducted have not exhaustively covered the reefs along the Kenyan coast, especially reef slopes. Surveys down to 23 m revealed typical slope-inhabiting species such as Echinophyllia aspera, Oxypora lacera, Mycedium elephantotus and Gyrosmilia interrupta. The latter is restricted to the western Indian Ocean. Anomastrea irregularis and Plesiastrea versipora are reported for the first time for Kenya, even though they occur in adjacent localities. Zoogeographically speaking, Kenyan reef corals are similar to a certain degree with regard to their diversity to adjacent reefs such as those of Madagascar and the Mascarenes. Latitudinal variation, probably as a function of seawater temperature, is evident from currently-known distribution of corals south from South Africa till north to Kenya. Longitudinal variation is less pronounced due to generic homogeneity across western Indian Ocean. Results of growth and isotopic studies of corals employing sclerochronology are presented for the first time for the region with the aim of discussing coral growth and stressing the multidisciplinarity of coral reef studies. Linear growth of Porites lutea, along with isotopic oxygen and carbon composition, is discussed in light of environmental variables. Porites lutea exhibits a pair of annual density bands known as high and low density bands. High density bands form during optimal growth conditions such as higher temperature and reduced stress. An increase in temperature lowers the delta oxygen-18 of coral carbonate and such reductions were found to be associated with high density bands. Thus, isotopic and growth studies by sclerochronological techniques complement each other in asserting the seasonality of coral growth versus ambient variables.
- Kenyan reef corals sampled in November 1990, more