三亚红塘湾珊瑚礁生态系统健康评价与影响因素分析

Health evaluation and influencing factors of the coral reef ecosystem in the Hongtang Bay,Sanya

为了解和掌握三亚红塘湾珊瑚礁生态系统的健康状况及其影响因素,2017年3月采用断面监测法调查了三亚红塘湾海域珊瑚的物种多样性、覆盖率和补充量等指标,并采用健康指数(CI)对红塘湾珊瑚礁生态系统进行了评估。结果表明,红塘湾造礁石珊瑚共鉴定11科25属55种,优势种是多孔鹿角珊瑚(Acropora millepora)、风信子鹿角珊瑚(A.hyacinthus)、平展蔷薇珊瑚(Montipora solanderi)、叶状蔷薇珊瑚(M.foliosa);软珊瑚主要种有豆荚软珊瑚Lobophytum sp.、短指软珊瑚Sinularia sp.、肉芝软珊瑚Sarcophyton sp.以及柳珊瑚目一种;造礁石珊瑚平均覆盖率为14.58%,平均珊瑚补充量为0.15个·m^-2,软珊瑚平均覆盖率为0.17%,珊瑚主要分布在1~4 m水深,水深6 m以外有零星的造礁石珊瑚或柳珊瑚分布;目前该区域珊瑚礁生态系统的健康状况平均处于很好级别,但与历史调查数据比较呈下降趋势,主要受水体环境中悬浮物及叶绿素a增加、围填海悬浮泥沙以及大型藻类增多等因素影响。

To understand and master the health status and influencing factors of the coral reef ecosystems,and give a basic data and theoretical research for the coral reef survey and research in Sanya,Hainan,a cross-sectional monitoring method was used to investigate the species diversity,coverage and recruitment of the coral reef by setting up 12 coral survey stations in the Hongtang Bay,Sanya,in March 2017.And coral reef ecosystem was evaluated by the guidelines from Assessment of the Health of Coastal Marine Ecosystems(HY/T 087-2005);the evaluation indexes were pH value,chlorophyll a,turbidity,active phosphate and inorganic nitrogen,and the coral reef ecosystem in the Hongtang Bay was evaluated by condition index(CI).Results showed that there were 11 families,25 genera and 55 species of coral reef in the Hongtang Bay.And the coral reef dominant species were Acropora millepora,Acropora hyacinthus,Montipora solanderi,Montipora foliosa,The main morphological groups were clump,branch and leaf.Soft corals mainly were Lobophytum sp.,Sinularia sp.,Sarcophyton sp and one Gorgonacea.The average coverage of coral reef was 14.58%,average coral recruitment was 0.15 ind.·m^-2,and the average coverage of soft coral was 0.17%.The distribution of corals in the Hongtang Bay was semi-continuous along the coast,and the distribution width along the coast was mostly 100 to 300 m,main types of sediment were fine sand,small rocks and coral fragments,and as the water depth increases,the distribution of corals decreases.Corals were mainly distributed in the water depths of 1 to 4 m,and there were scattered coral reef or Gorgonacea in the water depth more than 6 m.The coral reef water environment in the Hongtang Bay was healthy,but the concentration of suspended matter and Chlorophyll-a in the water environment was high,and the value assigned was low.The average health status of the region’s coral reef ecosystems was currently at a good level based on qualitative estimation criteria,but showed a downward trend as the number species of coral reef decreased from 57 to 55,and the coverage of coral reef decreased from 17.33%to 14.58%;coverage of soft corals decreased from 2.01%to 0.17%,and the recruitment of coral reef decreased from 0.22%to 0.17%,compared to historical survey data.It was mainly affected by the increase of suspended matter and chlorophyll a,suspended sediment in reclamation and the increase of macro algae.