海南三亚鹿回头造礁石珊瑚生长变化与人类活动的影响

采用全球珊瑚礁监测网络(GCRMN)推荐的永久样方法首次在国内开展珊瑚礁生长的监测和研究。在海南三亚鹿回头岸礁区建立了10个珊瑚礁永久样方,分别于2003年12月、2004年4月、2004年9月和2005年4月开展了4次造礁石珊瑚生长的现场监测,并对周边人类活动进行了相关调查。研究发现,鹿回头东北部岸礁区4个样方的珊瑚覆盖率稳定增长,珊瑚生长良好,监测期间的珊瑚生长覆盖率平均为3.1%,珊瑚死亡覆盖率平均为1.3%;中部和南部岸礁区5个样方的珊瑚覆盖率明显下降,珊瑚出现衰退,衰退范围有明显扩大,珊瑚生长覆盖率平均为2.2%,珊瑚死亡覆盖率平均达到7.9%。珊瑚新个体的繁殖数量极少,平均新生珊瑚数量近1个/m2,新生珊瑚覆盖率对珊瑚生长覆盖率的贡献较低。人类活动对鹿回头岸礁区珊瑚生长的影响主要有两类:一是捕捞、炸鱼、船只抛锚、潜水等物理破坏;二是沿岸养殖场和旅游餐馆污水排放产生的水质污染,导致珊瑚生长机理的破坏。其中,水质污染是造成中部和南部岸礁区样方珊瑚死亡的主要原因,与沿岸养殖场和餐馆的分布、排污时间以及排污量有密切关系。

Growth variations of scleratinan corals at Luhuitou, Sanya, Hainan Island, and the impacts from human activities

Adopting permanent quadrat method recommended by Global Coral Reef Monitoring Network(GCRMN),we firstly carried out monitoring and researching on coral growth at the fringing reef area of Luhuitou,Sanya,Hainan Island.By establishing ten permanent quadrats,scleratinan coral growth was measured in Dec.2003,Apr.2004,Sep.2004 and Apr.2005,respectively.Human activities along the coast and their impacts on corals were also investigated over this period.The results show a steadily increasing trend over the study period at the northeastern reef area and a declining trend at the central and southern areas.The average living coral cover in the four quadrats at the northeastern reef area is 3.1% and dead 1.3%;while in the five quadrats at the central and the southern areas the average living coral cover is 2.2% and dead 7.9%.Coral recruitment in the ten quadrats is less than 1 colony /m2 averagely and it contributes little to the total coral growth cover.During the study period,two types of human impacts on the coral growth were identified,they are from physical damage and seawater pollution.The former results from catching fish,bombing fish,boat anchoring,scuba diving,etc.;and the later is mainly caused by sewage discharging from the aquafarms and restaurants along the coast and it directly resulted in the observed coral death in the quadrats at the central and southern area.The pollution degree strongly correlates with the amount of discharging of the nearby aquafarms and restaurants.