A comparison between the 2010 and 2016 El-Ninō induced coral bleaching in the Indonesian waters

Global Colloquium on GeoSciences and Engineering 2017

Wouthuyzen, Sam^1 ; Abrar, M.^1 ; Lorwens, J.^2

LPKSDMO Pari Island, LIPI, Coremap LIPI, Jl. Raden Saleh 43, Jakarta

10330, Indonesia^1

UPT Marine Biota Consevation Biak, LIPI, Bosnik-Biak Timur, Biak, Papua

98152, Indonesia^2

关键词: Aqua MODIS;    Coral bleaching;    Indonesians;    Normal condition;    Ocean temperature;    Sea surface temperature (SST);    Small variations;    Waterbodies;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/118/1/012051/pdf
DOI  :  10.1088/1755-1315/118/1/012051

来源: IOP

【 摘 要 】

Severe coral bleaching events are always associated with El-Nin phenomenon which caused a rise in ocean temperature between 1-2°C and that they potentially kill the corals worldwide. There were at least four severe coral bleaching events occurred in the Indonesian waters. This study aims to compare the coral bleaching events of the 2010 and 2016 and their impact on corals in Indonesian waters. Long-term (2002-2017) remotely sensed night time sea surface temperature (SST) data acquired from Aqua MODIS Satellite were used in the analysis. Here, we calculated the mean monthly maximum (MMM)of SST as SST in normal condition in which coral can adapt to temperature; the differences between high SST in each pixel during coral bleaching events of the 2010/2016 and MMM SST, called hot spot (HS); and how long has HS occupied a certain water body, called degree of heating weeks (DHW, °C-week) and then mapped it. Results show that the MMM SST for the Indonesian waters is 29.1°C. Both bleaching events of 2010 and 2016 started and finished in the same periods of Mar-Jun and they nearly have the same pattern, but bleaching magnitude of the 2016 was stronger than 2010 with the mean SST about 0.4°C higher in May-June. The percentage of impacted areas of strong thermal stress on corals of Alert-1 plus Alert-2 status was higher in 2016 (39.4%) compared to 2010 (31.3%). Coral bleaching events in the 2010 and 2016 spread in almost all Indonesian waters and relatively occurred in the same places but with small variation in the bleaching sites that was caused by the strength/weakness of El-Nin and upwelling phenomenon as well as the role of Indonesian through flow (ITF).