New Research In
Physical Sciences
Social Sciences
Featured Portals
Articles by Topic
Biological Sciences
Featured Portals
Articles by Topic
- Agricultural Sciences
- Anthropology
- Applied Biological Sciences
- Biochemistry
- Biophysics and Computational Biology
- Cell Biology
- Developmental Biology
- Ecology
- Environmental Sciences
- Evolution
- Genetics
- Immunology and Inflammation
- Medical Sciences
- Microbiology
- Neuroscience
- Pharmacology
- Physiology
- Plant Biology
- Population Biology
- Psychological and Cognitive Sciences
- Sustainability Science
- Systems Biology
Using naturally occurring climate resilient corals to construct bleaching-resistant nurseries
Contributed by Stephen R. Palumbi, February 27, 2019 (sent for review December 11, 2017; reviewed by Andrew C. Baker, Les Kaufman, and Nancy Knowlton)

Significance
Coral reefs are threatened by global bleaching, spurring a need to improve upon reef restoration practices. Yet the strong capacity for corals and their symbionts to acclimatize to their local environment has brought into question whether or not corals that are temperature tolerant in one setting will lose that tolerance elsewhere. We show that variation in bleaching resilience among intraspecific colonies is maintained in novel environments for four species, and can be used to construct bleaching-resistant coral nurseries for restoration. By focusing on the host genotype and symbiont genus and its importance in stock selection, we demonstrate a path forward for reef restoration in the face of climate change.
Abstract
Ecological restoration of forests, meadows, reefs, or other foundational ecosystems during climate change depends on the discovery and use of individuals able to withstand future conditions. For coral reefs, climate-tolerant corals might not remain tolerant in different environments because of widespread environmental adjustment of coral physiology and symbionts. Here, we test if parent corals retain their heat tolerance in nursery settings, if simple proxies predict successful colonies, and if heat-tolerant corals suffer lower growth or survival in normal settings. Before the 2015 natural bleaching event in American Samoa, we set out 800 coral fragments from 80 colonies of four species selected by prior tests to have a range of intraspecific natural heat tolerance. After the event, nursery stock from heat-tolerant parents showed two to three times less bleaching across species than nursery stock from less tolerant parents. They also retained higher individual genetic diversity through the bleaching event than did less heat-tolerant corals. The three best proxies for thermal tolerance were response to experimental heat stress, location on the reef, and thermal microclimate. Molecular biomarkers were also predictive but were highly species specific. Colony genotype and symbiont genus played a similarly strong role in predicting bleaching. Combined, our results show that selecting for host and symbiont resilience produced a multispecies coral nursery that withstood multiple bleaching events, that proxies for thermal tolerance in restoration can work across species and be inexpensive, and that different coral clones within species reacted very differently to bleaching.
Footnotes
- ↵1To whom correspondence should be addressed. Email: spalumbi{at}stanford.edu.
Author contributions: M.K.M. and S.R.P. designed research; M.K.M. performed research; M.K.M. and S.R.P. analyzed data; and M.K.M. and S.R.P. wrote the paper.
Reviewers: A.C.B., University of Miami; L.K., Boston University; and N.K., Smithsonian Institution.
The authors declare no conflict of interest.
Data deposition: BioProject accession numbers for Sequence Read Archive of the fastq files are available at PRJNA529901 for Acropora gemmifera, PRJNA529902 for Pocillopora damicornis, and PRJNA529904 for Acropora hyacinthus.
This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10.1073/pnas.1721415116/-/DCSupplemental.
- Copyright © 2019 the Author(s). Published by PNAS.
This open access article is distributed under Creative Commons Attribution-NonCommercial-NoDerivatives License 4.0 (CC BY-NC-ND).
Citation Manager Formats
Sign up for Article Alerts
Article Classifications
- Biological Sciences
- Sustainability Science