Evaluating the health of the Chabahar Bay massive corals under the influence of climatic and physical seawater parameters

Nowadays, corals are exposed to bleaching due to climate change and rising water temperatures. On the other hand, the physical parameters of seawater are per-se affected by climate fluctuations. In this study, we aimed to investigate the effect of physical water parameters such as water temperature, salinity, acidity, electrical conductivity as well as climatic parameters such as air temperature and maximum wind speed on the health of massive corals in the Chabahar Bay. For this purpose, the data recorded at Chabahar Bay Hydrographic Field Station, the ECMWF Center Database, and Chabahar Meteorological Station were used. Ten-year monthly color data of the algae coexisting with massive corals have been extracted as a coral health indicator during diving operations using the Coral Watch method. The relationship between variables was also investigated through the Pearson correlation test, multivariate linear regression, and Mann-Kendall trend analysis using SPSS and Minitab software. According to the results, salinity and electrical conductivity showed a significant decreasing trend, while water acidity and air temperature showed a significant increasing trend. Meanwhile, water temperature and wind speed maximum showed insignificant increasing and decreasing trends, respectively. As for the health status of massive corals, there was a significant decreasing trend ending in 2019 (with a color score of 3.54 out of 6) set is in the category of "moderate". In addition, the health of mass corals showed the highest positive correlation with salinity and EC while indicating a negative correlation with maximum wind speed with a level of 0.01. On the contrary, there was no significant correlation between bulk corals' health and water temperature.