期刊
CORAL REEFS
卷 22, 期 4, 页码 357-369出版社
SPRINGER-VERLAG
DOI: 10.1007/s00338-003-0323-4
关键词
coral bleaching; skeleton; Porites; oxygen isotopes; carbon isotopes; photosynthesis; skeletogenesis
Severe coral bleaching occurred throughout the tropics in 1997/98. We report high-resolution skeletal oxygen isotope (delta(18)O) and carbon isotope (delta(13)C) microprofiles for bleached corals from Pandora Reef, Great Barrier Reef, and Ishigaki Island, Japan, in order to examine the ability of Porites corals to record clear signals of bleaching. Analysis of the annual cycle in delta(18)O revealed abrupt reductions in skeletal extension immediately after the 1997-98 summer temperature maximum, indicating that bleaching inhibits coral calcification. Skeletal delta(13)C in the Ishigaki corals showed lower values during bleaching, indicating depressed coral metabolism associated with a reduction in calcification. In contrast, microprofiles of skeletal delta(13)C from the shaded sides of Pandora Reef corals exhibited little change, possibly because algal photosynthesis was already slow prior to bleaching, thus subduing the C-13-response to bleaching. Comparison of delta(18)O microprofiles from bleached corals with instrumental temperature records showed that Porites corals can recover following 5 months with little skeletogenesis. The results indicate that isotopic microprofiling may be the key to identifying gaps in coral growth that are diagnostic of past bleaching events. We have tested this hypothesis using blue UV fluorescent bands to guide us to coral skeleton where isotope microprofiling identifies bleaching events in 1986, 1989, and 1990. These events, detected by proxy, suggest that coral bleaching may have occurred more commonly on Ishigaki Island than previously recorded.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据