(CNS) The Central Caribbean Marine Institute (CCMI), which has been monitoring coral bleaching around Cayman since June, has found that a potential devastation to local coral reefs due to the rise in ocean temperatures this summer was averted by a drop in sea temperature at the end of last month. In September sea temperatures passed 87 degrees F, the point at which coral bleaching begins.
Assistant Director of Research at CCMI, Dr Kristi Foster, said the Caribbean has experienced prolonged high temperatures since 2009, causing bleaching around the region.
“Unexpected but welcome relief arrived in Little Cayman during early October in the form of storms and high winds that churned the water, cooling it down. This has halted the bleaching progress and we are hopeful that anything that has survived to this point will recover,” she said.
Different species have handled the event differently; lettuce corals, for example, are more susceptible and were most affected. Scientists have been particularly concerned about staghorn and elkhorn corals, which are already endangered, but research so far shows that they appear, around Little Cayman at least, to be stable at this point, with as many as 90% appearing to be still healthy.
National Oceanic and Atmospheric Administration (NOAA) scientists have been predicting this phenomenon for more than a year. They had warmed that El Nino would bring steadily increasing temperatures, attributed to climate change, that would result in the third global coral bleaching event on record. This scenario has now been confirmed, with coral bleaching reported across the Caribbean, the North and South Pacific and the Indian Oceans since the summer of 2014.
CCMI, which is based at the Little Cayman research Centre, started to monitor coral bleaching with data loggers deployed at various depths around Little Cayman. Surveys will be conducted through next summer to gauge the extent of the bleaching event and recovery, CCMI said in a release Friday.
Coral bleaching is one of many threats and pressures on reefs the world over. Coral colonies are made up of thousands of genetically identical individuals called polyps. Polyps have microscopic, colourful algae, called zooxanthellae, living in their tissues that carry out photosynthesis and provide energy to their coral hosts, which helps reef-building corals create reef structures. Bleaching occurs when these symbiotic algae are expelled by the coral due to changes in water temperature, light or nutrients.
The pressure local reefs are under from bleaching is intensified by local fishing and coastal development. The combination of factors threatening the reefs is a major motivating factor in the Save Cayman campaign opposing government’s plans to dredge and destroy many acres of ancient coral reef in George Town.
With the coral already battling climate change, a decline in reef cleaning and supporting fish, as well as the destruction directly and indirectly from smaller scale coastal development, the potential loss of some 35-acres of ancient reef in and around George Town Harbour is devastating for the local reef system. With almost no hope of any meaningful relocation and the time it takes for new coral to form, the future survival of the reefs in Cayman, and in turn its tourism product, remain under serious threat.