Investigation of the causes of bleaching, fracture and displacement of corals in Chabahar Bay

In the present study, the relationship between environmental factors and human activities on the status of coral reef in the southeastern zone of Chabahar Bay (Shahid Beheshti Port) was investigated during the years of 2012-2018. The study methods were included direct observation (diving operations), Line Transect and Coral Watch. The studies showed that the amount of sedimentation in the region had an increasing trend during the sampling years (p < 0.05). The highest and lowest sedimentation rates were measured in summer 2015 and winter 2012, respectively (p < 0.05). The transparency of water during the sampling seasons had a decreasing trend (p < 0.05). The highest and lowest levels of transparency were measured in winter 2013 and summer 2015, respectively (p < 0.05). Water temperature during the sampling period increased from 22.2 ° C in 2012 to 26 ° C in winter 2018 (p < 0.05). The study of human activities in the region showed that during the dredging the sea operation, a lot of mud and silt was deposited in the corals growing area and covered the seabed. After this event, the corals lost their zooxanthella and separated from their seabed after bleaching. It seems that the probable reason for these results is the occurrence of stress due to human activities in the region, which in general has caused a critical situation in the health status of corals in the region.