Photosynthetic response of Persian Gulf acroporid corals to summer versus winter temperature deviations.

摘要: With on-going climate change, coral susceptibility to thermal stress constitutes a central concern in reefconservation. In the Persian Gulf, reefs are confronted with high seasonal variability water temperature, and both hot cold extremes have been associated episodes of bleaching mortality. Using physiological performance as measure health, we investigated common acroporid, Acropora downingi, near Hengam Island where temperature oscillates seasonally range 20.2–34.2 °C. series two short-term experiments comparing response summer versus winter conditions, exposed corals during each season (1) corresponding average extreme levels static environment, (2) progressive deviation from annual mean toward value beyond dynamic environment. We monitored four indictors performance: net photosynthesis (Pn), dark respiration (R), autotrophic capability (Pn/R), survival. Corals warming showed decrease ultimately died, while cooling were not affected their photosynthetic Coral Pn/R was lower at warmer level within eachseason, compared winter. maximum displayed < 1, inferring that could support basal metabolic needs under this Our results suggest Gulf A. downingi is sensitive temperatures endured summer, therefore its populations may be impacted by future increases temperature.