摘要
自大约15O年前开始有气温记录以来,1998年是所记录到的最热的一年,20世纪90年代是最热的十年。另外,1998年也是有记录以来厄尔尼诺现象最严重的一年。这一现象产生的结果是,海洋中许多地方的水温很高,尤其是位于热带的印度洋的水温常常比正常年份高3～5℃。该区域内的大量珊瑚脱色并死亡,可能是由于高的水温以及其它气象、气候因子共同作用所致。斯里兰卡、马尔代夫、印度、肯尼亚、坦桑尼亚和塞舌尔群岛的珊瑚礁中珊瑚的死亡率较高,许多浅海区甚至高达90%。在位于印度洋其它地方和距海面20米以下的珊瑚礁中,珊瑚的死亡率通常为50%。因此,1998年珊瑚的死亡情况是空前严重的。印度洋的珊瑚褪色对沿海社区的二级社会经济影响可能是长期的和严重的。除了鱼资源可能减少和对旅游造成不良影响外,侵蚀可能成为一个严重的问题,尤其是在马尔代夫和塞舌尔群岛。如果目前已经发现的全球温度升高的趋势继续下去,那么1998年印度洋珊瑚礁上发生的情况在未来一些年内极有可能加剧并在其它的热带海洋区出现。印度洋的珊瑚礁可能是反映全球气候变化潜在影响的一个重要信号,我们应当对这一警告引起注意。
The year 1998, was the warmest year since the start of temperature recordings some 150 years ago. Similarly, the 1990s have been the warmest decade recorded. In addition, 1998 saw the strongest El Nino ever recorded. As a consequence of this, very high water temperatures were observed in many parts of the oceans, particularly in the tropical Indian Ocean, often with temperatures of 3?to 5癈 above normal. Many corals in this region bleached and subsequently died, probably due to the high water temperatures in combination with meteorological and climatic factors. Massive mortality occurred on the reefs of Sri Lanka, Maldives, India, Kenya, Tanzania, and Seychelles with mortalities of up to 90% in many shallow areas. On reefs in other parts of the Indian Ocean, or in waters below 20 m, coral mortality was typically 50%. Hence, coral death during 1998 was unprecedented in severity. The secondary socioeconomic effects of coral bleaching for coastal communities of the Indian Ocean are likely to be long lasting and severe. In addition to potential decreases in fish stocks and negative effects on tourism, erosion may become an acute problem, particularly in the Maldives and Seychelles. If the observed global trends in temperature rises continue, there is an increased probability of a recurrence of the phenomenon observed in 1998 on the coral reefs of the Indian Ocean, as well as in other parts of the tropical oceans in coming years. Coral reefs of the Indian Ocean may prove to be an important signal of the potential effects of global climate change, and we should heed that warning.
