Severe coral bleaching of Siderastrea stellata at the only atoll in the South Atlantic driven by sequential Marine Heatwaves

Author(s)

Tainá L. Gaspar ^[1] ; Juan P. Quimbayo ^[2] ; Renan Ozekoski ^[3] ; Lucas T. Nunes ^[4] ; Anaide W. Aued ^[5] ; Thiago C. Mendes ^[6] ; Amana G. Garrido ^[7] ; Bárbara Segal

Affiliation

^[1] Universidade Federal de Santa Catarina. Departamento de Ecologia e Zoologia. Laboratório de Ecologia de Ambientes Recifais - Brasil

^[2] Universidade de São Paulo. Centro de Biologia Marinha - Brasil

^[3] Universidade Federal de Santa Catarina. Departamento de Ecologia e Zoologia. Laboratório de Ecologia de Ambientes Recifais - Brasil

^[4] Universidade Federal de Santa Catarina. Laboratório de Macroecologia e Biogeografia Marinha - Brasil

^[5] Universidade Federal de Santa Catarina. Departamento de Ecologia e Zoologia. Laboratório de Ecologia de Ambientes Recifais - Brasil

^[6] Universidade Federal de São Paulo. Instituto do Mar - Brasil

^[7] Universidade Federal do Rio de Janeiro. Programa de Pós-Graduação em Biodiversidade e Biologia Evolutiva - Brasil

• Document type: Journal article
• Source: Biota Neotropica; v. 21, n. 2 2021-04-12.

Abstract

Abstract: Threatened by global warming and extreme climatic events, such as El Niño Southern Oscillation (ENSO) and Marine Heatwaves (MHW), coral reefs worldwide faced the worst bleaching and mortality event between 2014 and 2017, induced by the 2015/2016 ENSO. We evaluated the impacts of ENSO and MHW episodes on bleaching and mortality frequencies of Siderastrea stellata at Rocas Atoll, Southwestern Atlantic, using visual censuses conducted in 2016, 2017 and 2019. Bleaching rate varied significantly along the sampling period (11.71% in 2016, 1.52% in 2017, and 88% in 2019), but mortality was always less than 4%. Bleaching events in Atlantic reefs have been constantly associated with ENSO, until these recent events of the last two years. We suggest that MHW were probably the primary driver of the observed bleaching, especially in 2019, when much higher bleaching rates were observed than in ENSO periods. Although Southwestern Atlantic massive corals are considered more resistant to thermal stress than reefs corals worldwide, the strong events registered since 2019 highlight the need for continuous monitoring to better understand coral bleaching dynamics and improve predictions on the effects of global change in the region. (AU)

• FAPESP's process: 18/21380-0 - Climate drivers of reef fish functional diversity in the Atlantic Ocean
• Grantee: Juan Pablo Quimbayo Agreda
• Support Opportunities: Scholarships in Brazil - Post-Doctoral