El Niño Southern Oscillation (ENSO) events are known to bring high sea surface temperatures and in turn cause coral bleaching. The Fall 2015 ENSO event has had record breaking temperatures and has been severely detrimental to Pacific coral reef ecosystems. To gauge the effect this ENSO event would have on the Caribbean, this study looked at the frequency and severity of bleaching and paling, during this ENSO event. The bleaching was measured along a 2 m wide by 10 m long transect. Coral colonies along the transect were observed once a week for four weeks and the water temperature was recorded hourly. At the end of data collection, the overall number of corals experiencing bleaching was recorded and the percent difference in paling and bleaching from week to week was measured. At the end of the four weeks it was found that 60 out of 192 coral colonies were experiencing some form of bleaching. By the fourth week there was no significant increase in bleaching, and paling had significantly increased until week four. This trend followed the decrease of water temperature from week one to week three with signs of coral recovery, but there was also evidence of water temperature starting to increase again by week four.. This study shows the resilience of Bonairean reefs and that this ENSO event may have a lesser affect on the Caribbean coral reefs compared to the Pacific.
This student research was retrieved from Physis: Journal of Marine Science XVIII (Fall 2015)19: 47-52 from CIEE Bonaire.