Coral reefs in the Anthropocene Ocean: novel insights from skeletal proxies of climate change, impacts, and resilience
Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Oceanography at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution February 2021. Anthropogenic emissions of greenhouse gases are driving rapid changes in ocean conditio...
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Massachusetts Institute of Technology and Woods Hole Oceanographic Institution
2021
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ftwhoas:oai:darchive.mblwhoilibrary.org:1912/26540 2023-05-15T17:51:58+02:00 Coral reefs in the Anthropocene Ocean: novel insights from skeletal proxies of climate change, impacts, and resilience Mollica, Nathaniel R. Cohen, Anne L. Guo, Weifu 2021-02 https://hdl.handle.net/1912/26540 en_US eng Massachusetts Institute of Technology and Woods Hole Oceanographic Institution WHOI Theses https://hdl.handle.net/1912/26540 doi:10.1575/1912/26540 doi:10.1575/1912/26540 Coral reef Climate Proxy Thesis 2021 ftwhoas https://doi.org/10.1575/1912/26540 2022-10-22T22:57:09Z Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Oceanography at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution February 2021. Anthropogenic emissions of greenhouse gases are driving rapid changes in ocean conditions. Shallow-water coral reefs are experiencing the brunt of these changes, including intensifying marine heatwaves (MHWs) and rapid ocean acidification (OA). Consequently, coral reefs are in broad-scale decline, threatening the livelihoods of hundreds of millions of people. Ensuring survival of coral reefs in the 21st century will thus require a new management approach that incorporates robust understanding of reef-scale climate change, the mechanisms by which these changes impact corals, and their potential for adaptation. In this thesis, I extract information from within coral skeletons to 1) Quantify the climate changes occurring on coral reefs and the effects on coral growth, 2) Identify differences in the sensitivity of coral reefs to these changes, and 3) Evaluate the adaptation potential of the keystone reef-building coral, Porites. First, I develop a mechanistic Porites growth model and reveal the physicochemical link between OA and skeletal formation. I show that the thickening (densification) of coral skeletal framework is most vulnerable to OA and that, under 21st century climate model projections, OA will reduce Porites skeletal density globally, with greatest impact in the Coral Triangle. Second, I develop an improved metric of thermal stress, and use a skeletal bleaching proxy to quantify coral responses to intensifying heatwaves in the central equatorial Pacific (CEP) since 1982. My work reveals a long history of bleaching in the CEP, and reef-specific differences in thermal tolerance linked to past heatwave exposure implying that, over time, reef communities have adapted to tolerate their unique thermal regimes. Third, I refine the Sr-U paleo-thermometer to enable monthly-resolved sea surface ... Thesis Ocean acidification Woods Hole Scientific Community: WHOAS (Woods Hole Open Access Server) Pacific Woods Hole, MA |
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Open Polar |
collection |
Woods Hole Scientific Community: WHOAS (Woods Hole Open Access Server) |
op_collection_id |
ftwhoas |
language |
English |
topic |
Coral reef Climate Proxy |
spellingShingle |
Coral reef Climate Proxy Mollica, Nathaniel R. Coral reefs in the Anthropocene Ocean: novel insights from skeletal proxies of climate change, impacts, and resilience |
topic_facet |
Coral reef Climate Proxy |
description |
Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Oceanography at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution February 2021. Anthropogenic emissions of greenhouse gases are driving rapid changes in ocean conditions. Shallow-water coral reefs are experiencing the brunt of these changes, including intensifying marine heatwaves (MHWs) and rapid ocean acidification (OA). Consequently, coral reefs are in broad-scale decline, threatening the livelihoods of hundreds of millions of people. Ensuring survival of coral reefs in the 21st century will thus require a new management approach that incorporates robust understanding of reef-scale climate change, the mechanisms by which these changes impact corals, and their potential for adaptation. In this thesis, I extract information from within coral skeletons to 1) Quantify the climate changes occurring on coral reefs and the effects on coral growth, 2) Identify differences in the sensitivity of coral reefs to these changes, and 3) Evaluate the adaptation potential of the keystone reef-building coral, Porites. First, I develop a mechanistic Porites growth model and reveal the physicochemical link between OA and skeletal formation. I show that the thickening (densification) of coral skeletal framework is most vulnerable to OA and that, under 21st century climate model projections, OA will reduce Porites skeletal density globally, with greatest impact in the Coral Triangle. Second, I develop an improved metric of thermal stress, and use a skeletal bleaching proxy to quantify coral responses to intensifying heatwaves in the central equatorial Pacific (CEP) since 1982. My work reveals a long history of bleaching in the CEP, and reef-specific differences in thermal tolerance linked to past heatwave exposure implying that, over time, reef communities have adapted to tolerate their unique thermal regimes. Third, I refine the Sr-U paleo-thermometer to enable monthly-resolved sea surface ... |
author2 |
Cohen, Anne L. Guo, Weifu |
format |
Thesis |
author |
Mollica, Nathaniel R. |
author_facet |
Mollica, Nathaniel R. |
author_sort |
Mollica, Nathaniel R. |
title |
Coral reefs in the Anthropocene Ocean: novel insights from skeletal proxies of climate change, impacts, and resilience |
title_short |
Coral reefs in the Anthropocene Ocean: novel insights from skeletal proxies of climate change, impacts, and resilience |
title_full |
Coral reefs in the Anthropocene Ocean: novel insights from skeletal proxies of climate change, impacts, and resilience |
title_fullStr |
Coral reefs in the Anthropocene Ocean: novel insights from skeletal proxies of climate change, impacts, and resilience |
title_full_unstemmed |
Coral reefs in the Anthropocene Ocean: novel insights from skeletal proxies of climate change, impacts, and resilience |
title_sort |
coral reefs in the anthropocene ocean: novel insights from skeletal proxies of climate change, impacts, and resilience |
publisher |
Massachusetts Institute of Technology and Woods Hole Oceanographic Institution |
publishDate |
2021 |
url |
https://hdl.handle.net/1912/26540 |
geographic |
Pacific |
geographic_facet |
Pacific |
genre |
Ocean acidification |
genre_facet |
Ocean acidification |
op_source |
doi:10.1575/1912/26540 |
op_relation |
WHOI Theses https://hdl.handle.net/1912/26540 doi:10.1575/1912/26540 |
op_doi |
https://doi.org/10.1575/1912/26540 |
op_publisher_place |
Woods Hole, MA |
_version_ |
1766159270069403648 |