Format

Send to

Choose Destination
J Photochem Photobiol B. 2017 Jan;166:12-17. doi: 10.1016/j.jphotobiol.2016.11.003. Epub 2016 Nov 8.

Effect of UV radiation on the expulsion of Symbiodinium from the coral Pocillopora damicornis.

Author information

1
State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, Fujian, China.
2
Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China; Tropical Marine Biological Research Station in Hainan, Chinese Academy of Sciences, Sanya, China.
3
State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, Fujian, China; School of Biological Sciences, Monash University, Clayton, Victoria 3800, Australia.
4
State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, Fujian, China. Electronic address: ksgao@xmu.edu.cn.

Abstract

The variation in density of the symbiotic dinoflagellate Symbiodinum in coral is a basic indicator of coral bleaching, i.e. loss of the symbiotic algae or their photosynthetic pigments. However, in the field corals constantly release their symbiotic algae to surrounding water. To explore the underlying mechanism, the rate of expulsion of zooxanthellae from the coral Pocillopora damicornis was studied over a three-day period under ultraviolet radiation (UVR, 280-400nm) stress. The results showed that the algal expulsion rate appeared 10-20% higher under exposure to UV-A (320-395nm) or UV-B (295-320nm), though the differences were not statistically significant. When corals were exposed to UV-A and UV-B radiation, the maximum expulsion of zooxanthellae occurred at noon (10:00-13:00), and this timing was 1h earlier than in the control without UVR. UVR stress led to obvious decreases in the concentrations of chl a and carotenoids in the coral nubbins after a three-day exposure. Therefore, our results suggested that although the UVR effect on algal expulsion rate was a chronic stress and was not significant within a time frame of only three days, the reduction in chl a and carotenoids may potentially enhance the possibility of coral bleaching over a longer period.

KEYWORDS:

Coral; Expulsion; Pocillopora damicornis; Ultraviolet radiation

[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center