南海中沙群岛两海域造礁石珊瑚物种多样性与分布特点

Species diversity and scleractinian corals distribution at two shoals of Zhongsha Islands,South China Sea

2014年6月,采用截线样带法进行了南海中沙群岛两海区造礁石珊瑚种质资源分布调查.通过现场调查、对调查影像调查资料和采获样品分析,本次调查共获记录石珊瑚30种,其中中北暗沙7种,主要优势种为鬃棘表孔珊瑚(Montipora hispida),漫步暗沙30种,主要优势种为巨枝鹿角珊瑚(Pocillopora eydouxi);统计分析表明,漫步暗沙海域石珊瑚覆盖率为(66.35±17.21)%,其中健康石珊瑚、半白化石珊瑚、白化石珊瑚覆盖率分别为(53.80±17.96)%、(2.85±4.65)%、(9.70±13.15)%;中北暗沙域石珊瑚覆盖率为(7.34±6.05)%,调查海域未发现白化石珊瑚.分析结果表明可能由于海流和水深等因素差异导致了漫步暗沙与中北暗沙海域的石珊瑚种类和物种多样性存在显著差异.研究认为,调查海区造礁石珊瑚多样性较低,覆盖度差异大,应加强对中沙群岛珊瑚礁及其生态系统的监控,保护日益衰退的珊瑚礁资源.

Species diversity and distribution status of the scleractinian corals were surveyed by belt transect method at Zhongsha Islands in the South China Sea in June 2014. Based on the image data and field sample analysis, 30 species of scleractinian corals are recorded. Among them 7 species are from the shoal Zhongbei Ansha where domi- nant species is Montipora hispida and 30 species are from the shoal Manbu Ansha where dominant species is Pocil- lopora eydouxi. Statistical analysis shows that scleractinian coral coverage rate at Manbu Ansha is （66.35 ± 17.21 ） % , among which health scleractinian coral, half moderately bleached scleractinian coral and the bleached scleractinian coral are account for （53.80 ± 17.96） %, （2. 85 ± 4. 65 ） % and （91 70 ± 13.15 ） %, respectively. However, the coverage rate in Zhongbei Ansha is around （7.34 ± 6.05 ） % , where there was none of bleached scleractinian. The analysis shows that the deference of species composition may have affected by factors such as wa- ter depths and currents. The scleractinian coral coverage rates of 2 shoals are remarkably different and the species diversity is quite low. It is necessary to strengthen the monitoring on the coral reef and its ecosystems which should be better protected from the gradually recession of coral resources.