High Temperature Damages Persian Gulf Coral Species

An unprecedented rise in seawater temperature in the summer has caused the extensive bleaching of coral species on several Persian Gulf islands.

According to the latest remote sensing images, water temperature has reached a record high level.

"For the first time in 35 years, the temperature of Kish Island waters has reached 35 degrees Celsius, while it exceeded this figure and hit a record high of 36 degrees Celsius in Kharg and Kharku islands," Keivan Kabiri, a faculty member at the Iranian National Institute of Oceanography and Atmospheric Science, IRNA reported.

To assess the resilience of corals to the recent rise in water temperature, a research team at the institute, measured the index of Degree Heating Weeks for the summer.

Degree Heating Weeks show how much heat stress has accumulated in an area over the past 12 weeks by adding up any temperature exceeding the bleaching threshold (5-5.3) during that time period. The result showed that the DHW index hit an unprecedented high of 12, exceeding the previous high of 10 in 1998.

"We expected irreversible bleaching among most Persian Gulf coral species this summer and the field study and direct observations of corals at the site lent credence to our prediction," Kabiri said. The sudden increase in water temperature over recent years, driven by global warming, has caused the extensive bleaching of Persian Gulf corals, which threatens the unique biodiversity of the region.