广东大亚湾石珊瑚群落的分布及动态变化

2006年6月对位于南海北部亚热带的大亚湾和大鹏湾石珊瑚群落的分布、种类和覆盖率进行了调查,结果显示大亚湾共有石珊瑚24种,以秘密角蜂巢珊瑚(Favites abdita)为优势种,总覆盖率为20%,大鹏湾有石珊瑚21种,以精巧扁脑珊瑚(Platygyra daedalea)为优势种,总覆盖率为7.9%。大亚湾石珊瑚群落健康状况良好,但生长稀疏,群落密度低,空间结构简单,生长带窄;与1964年、1983年、1984年和1991年的调查结果相比,覆盖率从76.6%下降到20%,优势种从枝状的霜鹿角珊瑚(Acropora Pruinosa)转变成块状或皮壳状的秘密角蜂巢珊瑚,群落生态退化严重,主要原因可能是人为破坏活动对珊瑚本身以及生长环境造成的压力所致,包括过度捕捞、盗采珊瑚、沿岸施工和水体污染等,建议采取相应的保护措施。

Distribution and Status of Scleractinian coral communities in the Daya Bay, Guangdong

The Daya Bay,close to Hong Kong and Shenzhen,faced with the South China Sea,is one of the large bays along the coast of Guangdong Province,with two nuclear power stations standing in its southwest.Increasing human activities are bringing stress to the living environment of the coral communities at this area.For understanding the current status of coral communities and their response to global climatic change and human activities,ecological survey methods are used to investigate the coral communities in the Daya Bay.The distribution,species and cover ratios of scleractinian coral communities in the Daya Bay in June,2006 are documented quantitatively.The results show that there are 24 species of scleractinian corals in the Bay with Favites abdita as dominant species,the cover ratios of total living coral are 20%;while in the Dapeng Bay as frame of reference,where there are 21 coral species and 7.9% in cover ratio of living coral,with Platygyra daedalea as dominant species.Compared with historical records occurred in 1964,1983,1984 and 1991,the coral communities in Daya Bay are experiencing dramatically degradation,namely the species decreasing,the density becoming sparse,the structure simplifying,coral growth ratio and living coral cover descending,and the dominant species changing. The likely reasons are human activities,including over-fishing,picking unlawfully the corals,coastal development,water pollution,et al.Corresponding measures for protection should be taken.However,global warming may avail coral to recover with the rising of SST in the subtropical zone.