Edwards A J, Clark S, Zahir H, Rajasuriya A, Naseer A, Rubens J
Department of Marine Sciences and Coastal Management, University of Newcastle, Newcastle Upon Tyne NE1 7RU, UK.
Mar Pollut Bull. 2001 Jan;42(1):7-15. doi: 10.1016/s0025-326x(00)00200-9.
The bleaching and subsequent mortality of branching and massive corals on artificial and natural reefs in the central atolls of Maldives in 1998 are examined with respect to sea surface temperature (SST) anomalies. SST normally peaks in April-May in Maldives. The UK Meteorological Office's Global sea-Ice and SST data set version 2.3 b shows that in 1998 monthly mean SST was 1.2-4 S.D. above the 1950-1999 average during the warmest months (March-June), with the greatest anomaly in May of +2.1 degrees C. Bleaching was first reported in mid-April and was severe from late April to mid-May with some recovery evident by late-May. At least 98% of branching corals (Acroporidae, Pocilloporidae) on artificial structures deployed on a reef flat in 1990 died whereas the majority of massive corals (Poritidae, Faviidae, Agariciidae) survived the bleaching. The pre-bleaching coral community on the artificial reefs in 1994 was 95% branching corals and 5% massives (n = 1589); the post-bleaching community was 3% branching corals and 97% massives (n = 248). Significant reductions in live coral cover were seen at all natural reefs surveyed in the central atolls, with average live coral cover decreasing from about 42% to 2%, a 20-fold reduction from pre-bleaching levels. A survey of recruitment of juvenile corals to the artificial structures 10 months after the bleaching event showed that 67% of recruits (> or = 0.5 cm diameter) were acroporids and pocilloporids and 33% were from massive families (n = 202) compared to 94% and 6%, respectively, in 1990-1994 (n = 3136). Similar post-bleaching dominance of recruitment by branching corals was seen on nearby natural reef (78% acroporids and pocilloporids; 22% massives). A linear regression of April mean monthly SST against year was highly significant (p < 0.001) and suggests a rise of 0.16 degree C per decade. If this trend continues, by 2030 mean April SST in the central atolls will normally exceed the anomaly level at which corals appear there are susceptible to mass bleaching.
针对海面温度（SST）异常情况，对1998年马尔代夫中央环礁人工礁和天然礁上分支珊瑚和块状珊瑚的白化及随后的死亡情况进行了研究。马尔代夫的海面温度通常在4月至5月达到峰值。英国气象局的全球海冰和海面温度数据集版本2.3b显示，1998年在最温暖的月份（3月至6月），月平均海面温度比1950 - 1999年的平均值高出1.2 - 4个标准差，5月的异常值最大，为+2.1摄氏度。白化现象于4月中旬首次被报道，4月下旬至5月中旬较为严重，到5月下旬有明显恢复迹象。1990年放置在礁坪上的人工结构上，至少98%的分支珊瑚（鹿角珊瑚科、杯形珊瑚科）死亡，而大多数块状珊瑚（孔珊瑚科、蜂巢珊瑚科、石芝珊瑚科）在白化事件中存活下来。1994年人工礁上白化前的珊瑚群落中，95%为分支珊瑚，5%为块状珊瑚（n = 1589）；白化后的群落中，分支珊瑚占3%，块状珊瑚占97%（n = 248）。在中央环礁所有被调查的天然礁上，活珊瑚覆盖率都有显著下降，平均活珊瑚覆盖率从约42%降至2%，比白化前水平降低了20倍。在白化事件发生10个月后，对人工结构上幼体珊瑚的补充情况进行的一项调查显示，67%的补充个体（直径≥0.5厘米）为鹿角珊瑚科和杯形珊瑚科，33%来自块状珊瑚科（n = 202），而在1990 - 1994年，这一比例分别为94%和6%（n = 3136）。在附近的天然礁上也观察到类似的白化后分支珊瑚在补充个体中占主导地位的情况（78%为鹿角珊瑚科和杯形珊瑚科；22%为块状珊瑚）。4月平均月海面温度与年份的线性回归高度显著（p < 0.001），表明每十年上升0.16摄氏度。如果这种趋势持续下去，到2030年，中央环礁4月的平均海面温度通常将超过珊瑚似乎易受大规模白化影响的异常水平。
