Macrobioerosion of dead branching Porites, 4 and 6 years after coral mass mortality
Carreiro-Silva, M.; McClanahan, T. R. (2012). Macrobioerosion of dead branching Porites, 4 and 6 years after coral mass mortality. Mar. Ecol. Prog. Ser. 458: 103-122. dx.doi.org/10.3354/meps09726 In: Marine Ecology Progress Series. Inter-Research: Oldendorf/Luhe. ISSN 0171-8630; e-ISSN 1616-1599, more | |
Keywords | Bioerosion Porites bernardi Gravier, 1909 [WoRMS] ISW, Kenya, Coast, Watamu Marine/Coastal | Author keywords | Calcium carbonate, climate disturbance, Kenya, marine protected areas, monitoring, pollution, reef framework, thermal anomaly |
Authors | | Top | - Carreiro-Silva, M.
- McClanahan, T. R.
| | |
Abstract | Internal bioerosion by macroborers (polychaetes, sipunculans, bivalves, and sponges) was investigated in dead Porites branches collected from 8 coral reefs along the Kenyan coast, 4 and 6 yr after the 1998 mass mortality of corals. Levels of nutrients, benthic cover, and numbers of grazing and invertebrate-eating fish and sea urchins were measured and evaluated for their influence on macrobioerosion. The macroboring community composition was influenced by the grazer composition on each reef; worms were the major macroboring agent where sea urchin biomass was high, and sponges were the dominant agent where herbivorous fish biomass was high. Bivalves accounted for a small proportion of the internal bioerosion and were not measurably influenced by consumers or water quality. The total macrobioerosion rates in Porites branches ranged from 534 +/- 70 to 1134 +/- 44 g CaCO3 m(-2) (4 yr after the coral death) and 837 +/- 111 to 2149 +/- 314 g CaCO3 m(-2) (6 yr after the coral death). The macrobioerosion rates were linearly and positively correlated with chlorophyll a concentrations (chl a) in the water column 4 and 6 yr after the coral death. Sponge boring rates were also positively correlated to chl a 6 yr after coral death but not after the initial 4 yr. Consequently, the macrobioerosion rates responded to nutrient status, but the community of borers changed with the dominant grazers, which in turn were influenced by fisheries management. |
|