Comparing Bacterial Community Compositions in Flourishing and Degraded Pocillopora verrucosa Colonies in the South China Sea

Abstract

Lyu, Y.; Zhang, Q.; Gao, Y.; Chen, Z.; Bai, S., and Zhou, J., 2020. Comparing bacterial community compositions in flourishing and degraded Pocillopora verrucosa colonies in the South China Sea. In: Hu, C. and Cai, M. (eds.), Geo-informatics and Oceanography. Journal of Coastal Research, Special Issue No. 105, pp. 176–180. Coconut Creek (Florida), ISSN 0749-0208.The apparently healthy and degraded colonies of Pocillopora verrucosa were collected from Yongle Islands in the South China Sea (SCS). The coral-associated microbial communities were investigated. The prokaryotic α-diversity was greater in flourishing than in degraded samples. A significant difference in prokaryotic communities was found between flourishing and degraded samples at detected site. At the genus level, Rhodococcus was most commonly found in the healthy samples, and Ruegeria was the most abundant in degraded corals. For the environmental factors, temperature, TOC, PO43–, and NH4+ were the factors most associated with changes in the microbial structure. Functional predictions indicated that degraded coral featured enhanced microbial nitrogen metabolism and sulfur-cycle abilities and decreased carbon and methanol metabolism. The results here suggest that bacterial communities and functions are strongly linked to degenerative progression. These results imply that it is urgent to protect the corals in the SCS.