雷州半岛灯楼角珊瑚礁的生态特征与资源可持续利用

The coral reef at Dengloujiao, Leizhou Peninsula, northern coast of the South China Sea——its ecology and sustainable development as a resource

分布于雷州半岛西南部灯楼角的珊瑚礁,自海向陆可分为6个生态带,已鉴定出现代活石珊瑚(Scleractinia) 13科2 5属39种3未定种。该珊瑚礁位于热带北缘,附近人口密集,它的发育受自然因素和人类活动双重制约。气候方面,近4 2 a来的温度总体上升有利于本区珊瑚礁的发育,而台风活动对本区珊瑚礁可能有负面的影响;人类活动对本区珊瑚礁的影响表现为旅游业的快速发展与保护行动滞后威胁珊瑚礁、渔业和养殖业影响珊瑚礁、作为建筑材料使用而破坏珊瑚礁等3个方面。作为一种重要的海洋生态资源,本区珊瑚礁若得以科学保护。

The coral reef at Dengloujiao (20°13′N～20°17′N, 109°54′E～20°58′E), Leizhou Peninsula, northern coast of the South China Sea, is the only developed and well preserved coral fringing reef on China's Mainland. It is part of the so-called “coral triangle” of the Southeast Asia (Robert et al, 2002, Science), where numerous important coral species are supposed to be found. The reef flat, dominated by Goniopora and Porites corals, is about 10 km long and 500～1000 m wide (2 km maximum width). From sea to land, six ecological zones can be recognized. They are (1) reef-front living coral zone (10～120 m wide) with dominant Acropora corals growing below the low spring tide; (2) outer reef-flat massive Porites zone (100～150 m wide) dominated by large dead Porites corals; (3) within-reef-flat mixed massive coral zone (~200 m wide) consisting of large dead Porites, Pavona and Favia corals; (4) within-reef-flat mixed dead massive-coral /Goniopora zone (0～120 m wide) with smaller massive corals mixed with branchy Goniopora corals; and (5) inner reef-flat Goniopora zone (100～500 m wide) dominated by dead branchy Goniopora corals with a spatial coverage of >95%. Over these zones, total 13 families, 25 genera, 39species and 3 uncertain species of living Scleractinia are found and listed. Of course, the number of these species should be only the minimum estimation on this reef area because of the just beginning of the ecological investigation. This coral reef area is situated in the northern margin of tropical climate. Due to high-density human activities, the coral reef ecosystem is controlled by both climate changes and human activities. Based on the analysis of the instrumental climate factors in this reef area, the sea surface temperature (SST), including mean annual SST and monthly minimum SST, shows a obvious rising trend over the last 42 years (from 1960 to 2002), which is favorable for the coral reef recovery and development; however, typhoons may impose disturbances on the coral reef by (1) killing living branch corals directly; (2) destroying coral reef frame and causing large rock blocks transportation; and (3) increasing turbidity sedimentation. These phenomena are based on the field observation after the landing of the typhoon Krovanh on this reef site on 25^(th) August 2003. The disturbances from human activities in this area arise mainly in the following three ways: (1) rapid increase of tourism and the lagging of coral reef protection; (2) unscientific fishing and breeding in the coral reef area; and (3) the digging of coral reef rocks as building materials. Coral reefs worldwide are generally considered to be the most biologically productive of all marine ecosystems. Therefore there is great potential for sustainable develop of the coral reef at Dengloujiao if it is scientifically protected.