Macrobioerosion of dead branching Porites, 4 and 6 years after coral mass mortality

Marine Ecology Progress Series

T. R. McClanahan¹  M. Carreiro-Silva¹ 

关键词: Calcium carbonate;    Climate disturbance;    Kenya;    Marine protected areas;    Monitoring;    Pollution;    Reef framework;    Thermal anomaly;   

DOI  :  10.3354/meps09726

学科分类：海洋学与技术

来源: Inter-Research

【 摘 要 】

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.

【 授权许可】

Unknown