Open AccessA Pilot Study on Zinc Isotopic Compositions in Shallow‐Water Coral Skeletons
Author(s) -
Xiao Hangfang,
Deng Wenfeng,
Wei Gangjian,
Chen Jiubin,
Zheng Xinqing,
Shi Tuo,
Chen Xuefei,
Wang Chenying,
Liu Xi,
Zeng Ti
Publication year - 2020
Publication title -
geochemistry, geophysics, geosystems
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.928
H-Index - 136
ISSN - 1525-2027
DOI - 10.1029/2020gc009430
Subject(s) - coral , porites , zooxanthellae , reef , coral reef , hermatypic coral , oceanography , geology , ecology , environmental science , biology , paleontology , symbiosis , bacteria
The trace metal element zinc (Zn) participates in coral metabolic processes and therefore accumulates in their skeletons. These metabolic processes are largely controlled by the changes of environment in which they live, so Zn isotopic compositions (δ 66 Zn) in coral skeletons may possibly serve as potential tracers for climate and environmental changes. In this study, we first reported the δ 66 Zn in shallow‐water coral skeletons by investigating with monthly resolution δ 66 Zn values in the skeleton of a modern Porites coral 10AR2 from the Great Barrier Reef of Australia, and the bulk skeletal δ 66 Zn values of several coral species from the Luhuitou Reef of Hainan Island in the northern South China Sea. Correlations between δ 66 Zn and other climate and environmental proxies (Sr/Ca, δ 18 O, and δ 13 C) and instrumental environmental variables (sea surface temperature, river runoff, and chlorophyll a ) are poor, suggesting that the effects of external environmental changes on monthly variations in δ 66 Zn in coral skeletons are not significant. However, significant interspecific differences in the skeletal δ 66 Zn of corals growing under identical external environments may suggest the occurrence of biologically controlled δ 66 Zn fractionation during coral skeletons formation. In addition, the monthly δ 66 Zn in the 10AR2 coral skeleton roughly decreases with increasing temperature, which is in agreement with the recent finding that δ 66 Zn in coral tissues and zooxanthellae increases with increasing temperature and can serve as a proxy for thermal stress in corals. We thus suggest that the complicated coral internal biological processes hinder the use of skeletal δ 66 Zn as a climate and environmental proxy.