Heat Attenuation and Nutrient Delivery by Localized Upwelling Avoided Coral Bleaching Mortality in Northern Galapagos During 2015/2016 ENSO

Authors

Bernhard Riegl, Nova Southeastern UniversityFollow
Peter W. Glynn, University of Miami
Stuart Banks, Conservation International - Ecuador
Inti Keith, Charles Darwin Research Station - Galapagos, Ecuador
Fernando Rivera, Instituto Nazca de Investigaciones Marinas - Santa Elena, Ecuador
Mariana Vera-Zambrano, Conservation International - Galapagos, Ecuador
Cecilia D'Angelo, Coral Reef Laboratory - Southampton, United Kingdom
Joerg Wiedenmann, Coral Reef Laboratory - Southampton, United Kingdom

Document Type

Article

Publication Date

8-2019

Publication Title

Coral Reefs

Keywords

Coral bleaching, ENSO, Galapagos, Upwelling, Nutrients, Reef resilience

ISSN

0722-4028

Volume

38

Issue/No.

4

First Page

773

Last Page

785

Abstract

Despite a very strong El Niño Southern Oscillation in 2015/2016, no coral mortality associated with bleaching was observed at the northern Galapagos (Ecuador) Islands of Darwin and Wolf. From March 2016 to March 2018, coral cover and health as well as water chemistry (NO₃⁻ and PO₄³⁻) and temperature were recorded. A marked heat anomaly reached 30 °C at Wolf in February 2016, but peak temperatures were attenuated after 2 d by a 4 °C drop. Temperature patterns at three depths (10, 15, and 20 m) and a subsequent and persistent phytoplankton bloom suggest topographically driven upwelling as the source of colder water and dissolved inorganic nutrients—both of which helped corals endure the heating episode. Consequently, no mortality and only partial bleaching were recorded in March 2016. Partially bleached corals contained numerous healthy zooxanthellae in deeper tissue layers. A continuous temperature record from 2012 to 2014 suggests that such upwelling events are common, inducing temperature fluctuations of up to 6 °C within 24 h during the observation period. Events at Wolf in 2016 suggest local upwelling reduced coral stress by relieving heat and by delivering nutrients required by corals to retain their regular temperature tolerance.

Comments

©Springer-Verlag GmbH Germany, part of Springer Nature 2019

Additional Comments

Eastern Tropical Pacific Seascape Transition Phase grant #: CI CI240-560; NSF grant #: OCE-1447306, OCE-9314798; NERC grant #: NE/K00641X/1; European Research Council prgoram #: FP/2007-2013/ERC Grant Agreement No. 311179

NSUWorks Citation

Bernhard Riegl, Peter W. Glynn, Stuart Banks, Inti Keith, Fernando Rivera, Mariana Vera-Zambrano, Cecilia D'Angelo, and Joerg Wiedenmann. 2019. Heat Attenuation and Nutrient Delivery by Localized Upwelling Avoided Coral Bleaching Mortality in Northern Galapagos During 2015/2016 ENSO .Coral Reefs , (4) : 773 -785. https://nsuworks.nova.edu/occ_facarticles/1063.

ORCID ID

0000-0002-6003-9324

ResearcherID

F-8807-2011

DOI

10.1007/s00338-019-01787-8