Conference Proceeding

Field observations of impacts of local stressors on the thermally-robust coral Porites

Dr. Ranjeet Bhagooli ,
The massive coral Porites spp. has been reported to be thermally tolerant to bleaching linked to climate changedriven ocean warming. However, impacts of local stressors on Porites spp. are yet to be thoroughly understood. This study aimed at comparing the status of Porites spp. at two sites: Albion (AL) and Flic-en-Flac (FEF) around Mauritius Island. Environmental conditions were characterized using underwater temperature and light data loggers, and quantifying nitrate and phosphate levels in October 2012. Density of live Porites spp. colonies was ~1.5-fold higher at AL than at FEF. Temperature (23.5-28.2oC) and light (0.0-3350.8 μmol quanta m-2s-1) during the month of October 2012 tended to be more fluctuating and higher at FEF than AL. Seawater nitrate and phosphate levels were ~12.8- and 2.9-folds, respectively, higher at FEF than at AL. Percentage colonies predated by gastropods and injured through fish bites were ~8.9- and 1.9-folds, respectively, higher at FEF than at AL. While at FEF 16.9±4.8% of the Porites spp. colonies were invaded by the boring sponge Terpios hoshinota at AL no such invasion was observed. Approximately ~11.9-fold higher percentage colonies showed pink pigmentation responses (PPR) at FEF compared to AL. Percentage colonies with unusual localized bleaching conditions (ULBC) were ~27.5-fold higher at FEF than at AL. Photo-physiological functioning was significantly reduced for fish bites and PPR while in ULBC it declined both at the adjacent and affected tissues. These findings indicate that local stressors are not sparing the thermally-tolerant coral Porites spp. at FEF and might have coral management and conservation implications.

Published: 28 July 2017

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Copyright: © 2017 Ranjeet Bhagooli. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.