Genetic connectivity, adaptation, and phenotypic plasticity of corals and anemones under thermal stress

dc.contributor.author Rivera, Hanny Elizabeth
dc.date.accessioned 2019-02-05T21:27:22Z
dc.date.available 2019-02-05T21:27:22Z
dc.date.issued 2019-02
dc.description Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Applied Ocean Science & Engineering at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution February 2019. en_US
dc.description.abstract Under global climate change, our oceans are warming at an unprecedented rate. Increased temperatures represent a severe source of stress for many marine organisms. This thesis aims to understand how corals and anemones respond to changing temperatures across different timescales and investigates mechanisms that can facilitate persistence in light of environmental change, from selection and adaptation across generations to phenotypic plasticity within a single individual’s lifespan. In this context, I explore three case studies of thermal stress in corals and anemones. I begin with massive Porites lobata corals from the central Pacific. Here, reefs that are most affected by El Niño, such as Jarvis and the northeast Phoenix Islands maintain genetic diversity indicating recruitment from nearby reefs may occur. Yet, they show significant genetic differentiation (FST) from farther areas, suggesting this dispersal may be limited. Thermal variability in this region may also favor plasticity over adaptation, as we do not find differences in bleaching histories among genetic groups. Next, I investigate genetic connectivity and adaptation to chronically elevated temperatures across a natural temperature gradient within the Palauan archipelago. Combining genetic data and historical growth measurements from coral cores, I find that Palau’s warmest reefs harbor unique genetic subpopulations of Porites lobata and find evidence for a genetic basis of their higher thermal tolerance. Lastly, I explore if parents can modulate parental effects to increase the thermal tolerance of their offspring over short time scales, using the estuarine anemone Nematostella vectensis. Indeed, I find parents exposed to increased temperatures quickly produce more thermally tolerant larvae. In fact, offspring from these Massachusetts parents show thermal thresholds that are indistinguishable from more southern populations. This thesis highlights the ability and potential of corals and anemones to persist under variable conditions over different timescales. Nevertheless, a compelling effort to reduce rates of warming worldwide will be imperative to the survival and integrity of key marine ecosystems such as coral reefs. en_US
dc.description.sponsorship Funding for this research came from the National Science Foundation (Awards OCE-1537338, OCE-1605365, OCE-1220529, and OCE-1031971), the Link Foundation, Bermuda Institute of Ocean Sciences Grants-in-Aid, the Tiffany & Co. Foundation, the Nature Conservancy, the Dalio Foundation, Inc., through the Dalio Explore Fund, and Ray Dalio through the WHOI Access to the Sea Fund, all to Anne Cohen; and a Gordon and Betty Moore Foundation grant (#4033) to Ann Tarrant. Funding to H. Rivera was provided by the Charles M. Vest Presidential Fellowship, the National Defense Science and Engineering Graduate Fellowship, American Association for University Women’s American Dissertation Fellowship, MIT’s Martin Family Foundation Fellowship, the Gates Millennium Scholars Program, WHOI’s Coastal Ocean Institute Grants, WHOI’s Grassler Family Foundation Grants, WHOI’s Ocean Ventures Fund, the MIT-BIOS Fund, and the MIT-WHOI Academic Programs Office. en_US
dc.identifier.citation Rivera, H. E. (2019). Genetic connectivity, adaptation, and phenotypic plasticity of corals and anemones under thermal stress [Doctoral thesis, Massachusetts Institute of Technology and Woods Hole Oceanographic Institution]. Woods Hole Open Access Server. https://doi.org/10.1575/1912/23630
dc.identifier.doi 10.1575/1912/23630
dc.identifier.uri https://hdl.handle.net/1912/23630
dc.language.iso en_US en_US
dc.publisher Massachusetts Institute of Technology and Woods Hole Oceanographic Institution en_US
dc.relation.ispartofseries WHOI Theses en_US
dc.subject Global warming
dc.subject Corals
dc.subject Anemones
dc.subject Marine organisms
dc.subject Thermal stresses
dc.subject Marine ecology
dc.title Genetic connectivity, adaptation, and phenotypic plasticity of corals and anemones under thermal stress en_US
dc.type Thesis en_US
dspace.entity.type Publication
relation.isAuthorOfPublication c45325b8-32ae-474e-a4da-c19e14da395a
relation.isAuthorOfPublication.latestForDiscovery c45325b8-32ae-474e-a4da-c19e14da395a
Files
Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
Rivera_Thesis.pdf
Size:
16.26 MB
Format:
Adobe Portable Document Format
Description:
Rivera_Thesis
License bundle
Now showing 1 - 1 of 1
No Thumbnail Available
Name:
license.txt
Size:
1.89 KB
Format:
Item-specific license agreed upon to submission
Description: