Coral Taxonomy and Local Stressors Drive Bleaching Prevalence Across the Hawaiian Archipelago in 2019

The Hawaiian Archipelago experienced a moderate bleaching event in 2019—the third major bleaching event over a 6-year period to impact the islands.

The HCBC was established to coordinate bleaching monitoring efforts across the state between academic institutions, non-governmental organizations, and governmental agencies to facilitate data sharing and provide management recommendations. In 2019, the goals of this unique partnership were to:

1) assess the spatial and temporal patterns of thermal stress;

2) examine taxa-level patterns in bleaching susceptibility;

3) quantify spatial variation in bleaching extent;

4) compare 2019 patterns to those of prior bleaching events;

5) identify predictors of bleaching in 2019; and

6) explore site-specific management strategies to mitigate future bleaching events.

Both acute thermal stress and bleaching in 2019 were less severe overall compared to the last major marine heatwave events in 2014 and 2015.

Our findings illustrate how detrimental effects of local anthropogenic stressors, such as tourism and urban run-off, may be exacerbated under high thermal stress. In light of the forecasted increase in severity and frequency of bleaching events, future mitigation of both local and global stressors is a high priority for the future of corals in Hawai‘i.

Winston M, Oliver T, Couch C, Donovan MK, Asner GP, et al.. 2022. Coral taxonomy and local stressors drive bleaching prevalence across the Hawaiian Archipelago in 2019. PLOS ONE 17(9): e0269068.  https://doi.org/10.1371/journal.pone.0269068.