MEPS 176:11-15 (1999)  -  doi:10.3354/meps176011

Damage and recovery of four Philippine corals from short-term sediment burial

Ineke Wesseling1, André J. Uychiaoco2, Porfirio M. Aliño2, Therese Aurin2, Jan E. Vermaat1,*

1Department of Environmental Science and Water Resources, International Institute for Infrastructural, Hydraulic and Environmental Engineering (IHE), PO Box 3015, 2601 DA Delft, The Netherlands
2Marine Science Institute, University of The Philippines, Diliman 1101, Quezon City, The Philippines
*Addressee for correspondence. E-mail:

ABSTRACT: Recovery of corals after full burial with littoral sediment (16% silt, 46% fine sand and 38% coarse sand; 28% CaCO3) was monitored in 2 field experiments at the reefs off Lucero, Bolinao (Pangasinan, NW Philippines), from April to May 1996. In the first experiment at 2 m depth, Porites was buried for 0, 6, 20 and 68 h; a second experiment was done at 5 m depth and 4 common taxa (Porites, Galaxea, Heliopora and Acropora) were buried for 20 h. At 2 m depth, Porites was not affected by 6 h burial compared to the controls that were not buried. Increasing burial time had increasingly more serious effects. Burial for 20 h resulted in increased discoloration of the coral tissue. After 68 h of burial, up to 90% of the tissue bleached in the first days. About 50% of this tissue disappeared subsequently and bare coral skeleton became exposed or were covered with algae. After a few weeks, however, recovery took place: the bare areas were recolonized from surrounding surviving tissue or from highly retracted polyps in the affected area. In the corals that had been buried for 20 h no more significant differences from the controls were observed after 3 wk. For those that were buried for 68 h, this was the case after 4 wk. At 5 m depth, all Acropora died after the 20 h burial treatment, but the other taxa recovered in a comparable way to the Porites in the first experiment at 2 m depth. It is concluded that complete burial will cause considerable whole-colony mortality in at least Acropora, and thus may result in a permanent loss of coral taxa from reefs that are subject to such intense sedimentation events. Less sensitive taxa incur substantial damage but significant recovery was observed after a month.

KEY WORDS: Siltation · Partial mortality · Tissue necrosis · Bleaching · Porites · Acropora · Galaxea · Heliopora · SE Asia

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