涠洲岛滨珊瑚中的生物侵蚀及其环境指示意义
摘要
The negative impacts of water pollution and eutrophication on coral reefs at Weizhou Island in the northern South China Sea have been preliminarily affirmed, but quantitative research examples supporting these effects are still lacking. Here, we analyzed the species and bioerosion intensity of boring organisms in samples of <italic>Porites </italic>corals collected at Weizhou Island as well as the relationship between eutrophication and bioerosion to assess the impacts of local pollution on corals and coral reefs. The observed bioeroders included bivalves (<italic>Lithophaga</italic> spp.), sponges (<italic>Cliothosa</italic> spp. and <italic>Cliona</italic> spp.), barnacles, and sipunculid and polychaete worms. Additionally, traces of micro-bioerosion were observed. The most important borers were filter-feeding bivalves (<italic>Lithophaga</italic> spp.), especially south of the island, where the environment has been heavily impacted by intensive human activities and eutrophication. Bioerosion intensity in corals collected from the south was significantly higher than that in corals collected from the north. Eutrophication stimulated boring organisms and subsequently caused the bioerosion intensity to increase significantly, which subsequently threatened local coral survival, calcium carbonate accumulation, and reef framework development. The results of this study also suggested that the bioerosion intensity of macrobioeroders, especially boring bivalves and sponges, can be interpreted as an indicator of chronic exposure to decreased water quality in coastal coral areas, especially those lacking water quality monitoring activities.