Investigation of the effect of physical parameters of seawater on the health of branching corals in Chabahar Bay

Background and Objectives: Coral ecosystems, like other natural habitats, are under the influence of global warming. Every year we see the bleaching of corals in different parts of the world. Since the physical parameters of seawater are affected by meteorological phenomena, so in this study using ten-year data of oceanographic buoys, the effect of physical parameters of seawater including water surface temperature, salinity, acidity and electrical conductivity on the phenomenon of bleaching of branching corals in Chabahar Bay was investigated. Methods: For this purpose, the trend of multi-year data of marine parameters was determined by non-parametric Mann-Kendall test. In the next step, the Pearson correlation test showed the correlation between seawater parameters and choreographed Zooxanthellae algae color score data as a coral health index produced by the authors during long-term diving operations using the Coral Watch method. Findings: The results of this study showed that among the four parameters: water surface temperature, electrical conductivity, acidity and salinity, the highest correlation and the most effective independent variable in multivariate regression between coral health and seawater parameters is concern to EC. Conclusion: Due to the insignificance of the increasing trend of water surface temperature in previous years and the existence of a significant negative correlation at the level of 0.01 between the health status of corals and water surface temperature, fortunately, the branching corals of Chabahar Bay have been in good condition. As human and sea pollutants are controlled in the coming years. We will see the survival of this valuable ecosystem.