Abstract
Keywords: Kenya, Tanzania, fringing reef, reef platform, sediment, sea-level change, climatevariability, shoreline change, Late Pleistocene, Holocene Sea-level changes through the Quaternary era have provided recurrent opportunities for the biosphere to significantly shape the coastal geomorphology of eastern Africa. Key agents in this shaping have been the calcium carbonate-fixing biota that have constructed the ocean-facing fringing reefs and produced the extensive backreef sediments that form the limestone platforms, cliffs and terraces that characterise these coasts. Today\'s reefs comprise tough, algal-clad intertidal bars composed largely of coral rubble derived from their ocean front. They provide protection from wave attack to the inshore platforms with their sediment veneers and their beach and beach plain sands that are susceptible to erosion. If the eastern African coasts are subjected to the rise of sea-level that is predicted at the global scale during the coming century, the protective role of the reef bars will be diminished if their upward growth fails to keep pace. Favourable ocean temperatures and restraint in the destructive human pressures impacting the reef ecosystems will facilitate such growth. Western Indian Ocean Journal of Marine Science Vol.2(1) 2003: 1-14
Highlights
Today’s eastern coast of Africa from Egypt to northern Mozambique is a reef coast, mostly without a significant continental shelf
This paper examines the contemporary coastal processes and ecosystems on the fringing reef coasts of Kenya and Tanzania in the context of their geological history
The fringing reef coasts of Kenya and Tanzania, comprising platforms with bars at their ocean margins, are modifications of a geomorphology created during the Pleistocene period by the extensive coastal accretion and partial erosion of calcium carbonate sediments occurring as limestones
Summary
Today’s eastern coast of Africa from Egypt to northern Mozambique is a reef coast, mostly without a significant continental shelf. The fringing reefs and platforms, and their associated coastal landforms including terraces, are the products of a complex Quaternary sequence of accretion and erosion of biogenic reef and backreef sediments composed of calcium carbonate, in response to sea-level variation. Of particular importance are the biota that have contributed to the building of rigid fringing reefs at the ocean margin, thriving in the turbulent conditions of breaking ocean swell It is this defensive bulwark, produced by the upward accretion of these fringing reefs in response to episodic rises of sea-level, that has provided the backreef, lagoonal protection for the biogenic production of carbonate sediments as well as the accommodation necessary for the long-term. The paper incorporates field observations made by the author on the coasts of Kenya and Tanzania during the period 1991–2002
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
