Heatwaves and a decrease in turbidity drive coral bleaching in Atlantic marginal equatorial reefs

Frontiers in Marine Science

Marine Science

Sandra Vieira Paiva¹  Carlos Eduardo Peres Teixeira¹  Caroline Costa Lucas¹  Anne Larisse Gurgel¹  Sergio Rossi²  Marcus Davis Andrade Braga³  Marcelo Oliveira Soares⁴  Francisco Carlos Júnior⁵ 

[1] Institute of Marine Sciences (LABOMAR), Federal University of Ceará (UFC), Fortaleza, Brazil;Institute of Marine Sciences (LABOMAR), Federal University of Ceará (UFC), Fortaleza, Brazil;Institut de Ciència i Tecnologia Ambientals (ICTA), Universitat Autònoma de Barcelona (UAB), Cerdanyolla del Vallés, Barcelona, Spain;Dipartimento di Scienze e Tecnologie Biologiche e Ambientali (DISTEBA), Via Monteroni s/n, Università del Salento, Lecce, Italy;Institute of Marine Sciences (LABOMAR), Federal University of Ceará (UFC), Fortaleza, Brazil;Mar do Ceará, School Dive, Fortaleza, Brazil;Institute of Marine Sciences (LABOMAR), Federal University of Ceará (UFC), Fortaleza, Brazil;Reef Systems Group, Leibniz Centre for Tropical Marine Research (ZMT), Bremen, Germany;Center for Marine and Environmental Studies (CMES), University of the Virgin Islands, Saint Thomas, US Virgin Islands;Mar do Ceará, School Dive, Fortaleza, Brazil;

关键词: coral bleaching;    turbidity;    coral reef;    marine heatwave;    marginal reef;   

DOI  :  10.3389/fmars.2023.1061488

 received in 2022-10-04, accepted in 2023-02-02,  发布年份 2023

来源: Frontiers

【 摘 要 】

Tropical reefs can occur naturally under suboptimal environmental conditions, where few reef-building corals thrive. These unique reefs are especially important for understanding resistance to global warming, but they are understudied. We studied a coral bleaching event that occurred in turbid reefs (~ 19 m deep) in the equatorial southwestern Atlantic. Mass bleaching was observed in 91% of the Siderastrea stellata colonies in 2020, whereas only 7.7% of the colonies were bleached in 2019 and 10.9% in 2022. The year 2020 had the highest heat stress recorded in this century in this region according to the degree of heating weeks such as 17.6°C-week. In the first semester of 2020, the region also underwent three marine heatwaves (MHWs) above the average temperatures (1.3, 1.5, and 2.0°C). The lowest turbidity and wind speed matched long-lasting, repeated, and severe MHWs. These reef-building corals are dominant under moderate turbid waters and high sea temperature (26–29°C), however they are near the maximum tolerance limit. In this regard, these low-latitude reefs are warming twice as fast (0.2°C/decade) as other regions (e.g., Abrolhos and Coral Coast) (0.1 to 0.13°C/decade) in the South America reef system demonstrating that they cannot be considered climate-change refugia. These results suggest that even turbid marginal reefs and tolerant corals are highly susceptible to mass bleaching, especially when heatwaves and a decrease in turbidity occur simultaneously.

【 授权许可】

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Copyright © 2023 Lucas, Teixeira, Braga, Júnior, Paiva, Gurgel, Rossi and Soares