Patterns in Reef Structure, Coral and Fish Communities, and Their Degradation in the Red Sea - Implications for Management and Restoration
International Conference on Scientific Aspects of Coral Reef Assessment, Monitoring, and Restoration, Ft. Lauderdale, April 16, 1999.
Coral Community Structure, Fish Community Structure, Dynamite Damage, Ship Grounding
This study investigated reef degradation due to ship groundings and destructive fishing techniques on 68 Egyptian Red Sea reefs. Sixty-five percent of reefs had signs of dynamite damage, mostly in leeward areas (58%). Significant changes in coral and fish community composition within dynamited sites were observed. Coral cover decreased, the amount of bare substratum, and rubble increased, fish communities decreased in species richness and abundance, dominance shifted from territorial grazers (Pomacentridae) to vagile grazers (Scaridae and Acanthuridae). Eight grounding sites of cargo or passenger vessels were investigated (using 1m sample squares), 7 on windward reefs, 1 leeward. Damage was similar to that caused by dynamiting and depended on speed of the vessel and the angle of impact. Stable meteorological and oceanographic conditions result in a stable pattern of coral communities (windward Acropora, leeward Porites). Most damage by dynamite and anchoring is on leeward, near-climax Porites reef slopes or Porites carpets. Calculated regeneration of such communities is slow, in the order of several hundred years. Most ship groundings were on windward Acropora reefs with faster regeneration periods, however also in excess of 100 years. Rehabilitation efforts have respect the natural community pattern and coral transplants into damaged areas would have to mimic the previously existing community. Restocking of naturally k-dominated areas (Porites reefs) with species further on the r-side of the scale, like Acropora should be avoided since this could preclude the re- establishment of a mimick of the original community within the desired time-frame due to competitive processes.
Riegl, Bernhard, "Patterns in Reef Structure, Coral and Fish Communities, and Their Degradation in the Red Sea - Implications for Management and Restoration" (1999). Oceanography Faculty Proceedings, Presentations, Speeches, Lectures. 80.
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