Iijima Mariko, Yasumoto Jun, Iguchi Akira, Koiso Kiyomi, Ushigome Sayaka, Nakajima Natsuki, Kunieda Yuko, Nakamura Takashi, Sakai Kazuhiko, Yasumoto-Hirose Mina, Mori-Yasumoto Kanami, Mizusawa Nanami, Amano Haruna, Suzuki Atsushi, Jimbo Mitsuru, Watabe Shugo, Yasumoto Ko
Geological Survey of Japan, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba, Ibaraki 305-8567, Japan.
Faculty of Agriculture, University of the Ryukyus, 1 Senbaru, Nishihara, Nakagusuku, Okinawa 903-0213, Japan.
R Soc Open Sci. 2021 Mar 17;8(3):201214. doi: 10.1098/rsos.201214.
To test the hypothesis that terrestrial runoff affects the functions of calcareous sediments in coral reefs and hampers the development of corals, we analysed calcareous sediments with different levels of bound phosphate, collected from reef areas of Okinawajima, Japan. We confirmed that phosphate bound to calcareous sediments was readily released into ambient seawater, resulting in much higher concentrations of phosphorous in seawater from heavily polluted areas (4.3-19.0 µM as compared with less than 0.096 µM in natural ambient seawater). Additionally, we examined the effect of phosphate released from calcareous sediments on the development of coral juveniles. We found that high phosphate concentrations in seawater clearly inhibit the skeletal formation of coral juveniles. Our results demonstrate that calcareous sediments in reef areas play a crucial role in mediating the impact of terrestrial runoff on corals by storing and releasing phosphate in seawater.
为了验证陆地径流会影响珊瑚礁中钙质沉积物的功能并阻碍珊瑚生长这一假设，我们分析了从日本冲绳岛珊瑚礁区域采集的、结合磷含量不同的钙质沉积物。我们证实，结合在钙质沉积物中的磷很容易释放到周围海水中，导致污染严重地区海水中的磷浓度大幅升高（4.3 - 19.0微摩尔，而自然环境海水中低于0.096微摩尔）。此外，我们研究了钙质沉积物释放的磷对珊瑚幼体生长的影响。我们发现，海水中的高磷浓度明显抑制了珊瑚幼体的骨骼形成。我们的结果表明，珊瑚礁区域的钙质沉积物通过储存和释放海水中的磷，在调节陆地径流对珊瑚的影响方面发挥着关键作用。
