El Niño

Coral bleaching in the Bonaire National Marine Park 2016-2020

STINAPA report

Mass coral bleaching is becoming more frequent and widespread and poses a major threat to coral reefs worldwide. Mass coral bleaching is a response to thermal stress triggered by high Sea Surface Temperatures (SSTs) or ultraviolet radiation attributed to changing regional and global climate patterns. Since 2016, STINAPA Bonaire has surveyed the severity of coral bleaching in the Bonaire National Marine Park at 10 sites on the leeward coast. Each year, corals exhibited signs of thermal stress including paling, partial bleaching, and fully bleaching, but no mortality. Since 2016, the year with the lowest percentage of corals affected was 2018 (9%) and the year with the highest percent of corals affected was 2020 (61%). Corals deeper in the water column were more susceptible to thermal stress in all years, but susceptibility trends by site were not consistent throughout the study. While addressing the global-scale causes of coral bleaching is daunting, STINAPA Bonaire monitors the severity of coral bleaching and helps develop local management strategies that may improve the resistance and resilience of coral reefs in the Bonaire National Marine Park to climate change.

Date
2021
Data type
Research report
Theme
Research and monitoring
Geographic location
Bonaire
Image

Global synchrony of an accelerating rise in sea surface temperature

The oceans have shown a recent rapid and accelerating rise in temperature with, given the close link between temperature and marine organisms, pronounced effects on ecosystems. Here we describe for the first time a globally synchronous pattern of pulsed short period (~1 year long) emanations of warm sea surface temperature anomalies from tropical seas towards the poles on the shelf/slope with an intensification of the warming after the 1976/1977, 1986/1987 and 1997/1998 El Niños. On the eastern margins of continents the anomalies propagate towards the poles in part by largely baroclinic boundary currents, reinforced by regional atmospheric warming. The processes contributing to the less continuous warm anomalies on western margins are linked to the transfer of warmth from adjacent western boundary currents. These climate induced events show a close parallelism with the timing of ecosystem changes in shelf seas, important for fisheries and ecosystem services, and melting of sea-ice.

 

Date
2012
Data type
Scientific article
Theme
Research and monitoring