Grottoli’s research focuses on three areas of research:
1- determining what drives resilience in corals in the face of climate change,
2- reconstructing oceanographic conditions in the past based on coral skeletal isotope and trace metal records, and
3- the impact of land-use on the delivery of carbon to small tropical and temperate rivers.
Grottoli currently has two ongoing research projects related to coral resilience and climate change funded through the Division of Oceanography at the National Science Foundation and a third funded through the USGS-CESU program. She is also the director of the NSF-funded Coral Bleaching Research Coordination Netowork.
1) Will corals recover from bleaching under ocean acidification conditions?
In October 2014 and 2015, the sea surface temperature surrounding O’ahu (Hawaiʻi) reached 30°C. The result of this ~2°C increase above mean monthly maximum temperatures was a coral bleaching event across the entire length of the Hawaiian Archipelago in both years. The two most dominant species on Hawaiian coral reefs, Montipora capitata and Porites compressa, were among the most impacted species with high spatial variability in bleaching. Bleaching is a stress response in corals whereby they lose their symbiotic algal partners and turn white. Prolonged bleaching can lead to disease and death. By the end of this century, bleaching events are expected to become annual events and the oceans are predicted to be twice as acidic as today. Ocean acidification is caused by the dissolution of excess atmospheric CO2 into the surface ocean and has been linked to decreases in coral calcification and reduced health. My team is conducting research in Hawaii in collaboration with Dr. Rob Toonen and Dr. Peter Marko at the University of Hawaii to determine if ocean acidification slows down recovery rates of corals following natural bleaching two years in a row. We are also determining if feeding can offset any negative effects of ocean acidification following bleaching. Fieldwork was conducted throughout 2014 and 2015 and analyses are in progress. Results of this research would inform coral reef managers as to which species or reef regions are more resilient to global change conditions and better targets for protection.
2) Phenotype and genotype of coral adaptation and acclimatization to global change
Coral reefs are among the most diverse ecosystems on the planet, housing an estimated 25% of marine species. Global climate models predict that by the end of this century, tropical seawater temperatures are expected to be up to 3°C warmer than they are today and at least twice as acidic, which threatens the long-term survival of coral reef ecosystems. Elevated temperature and ocean acidification have been shown to cause reduced coral growth rates and increased coral disease and mortality rates. To date, the assumption has been that corals will not be able to adapt because the rates of anthropogenically driven ocean acidification and climate change are too high. My team is conducting a two-year long experiment in Hawaii in collaboration with Dr. Rob Toonen to determine if coral experimentally reared corals can acclimate or are pre-adapted to global change conditions expected at the end of this century. If they can acclimate, how fast? How do adaptations differ among species and geographic locations? Answers to these questions are key to developing strategic coral conservation and management plans. To address these questions, eight species of Hawaiian corals are being studied using a two-part approach: 1) a survey of natural corals found across natural temperature and acidity gradients and 2) a two-year long mesocosm study which will expose corals collected in part 1 to temperature and acidity conditions expected at the end of this century. Photos from the field are here .
3) Persistence of the threatened Acropora palmata coral in Dry Tortugas National Park
The precipitous loss of the reef building coral Acropora palmata in the western Atlantic is of high concern. Once a dominant reef framework building coral throughout the Caribbean, this coral is now listed as threatened. However, ongoing research shows that A. palmata in the Dry Tortugas calcifies more and has a higher survival rate than the same genets of A. palmata elsewhere in the Florida Keys (Kuffner unpubl data). Yet, the underlying reason for the site-specific success of A. palmata in the Dry Tortugas is unknown. This research aims to determine if the biological processes of nutrition or oceanographic conditions underlie the greater growth and survivorship success of A. palmata in the Dry Tortugas. Results of this research will help to divulge what conditions enhance A. palmata success, and which genetic strains of A. palmata are best suited for which environments. Together, these findings will provide valuable information for effectively restoring A. palmata on a regional scale and the ecosystem function and services this species provides by protecting coastal communities and economic stability through reef fisheries and tourism. This is collaborative work between Dr. Andrea Grottoli at the Ohio State University and Dr. Ilsa Kuffner at the U.S. Geological Survey as part of the ongoing permitted research in the Florida Keys National Marine Sanctuary (FKNMS-2016-085-A1), Dry Tortugas National Park (DRTO-2019-SCI-005), and Biscayne National Park (BISC-2019-SCI-0010).
Past research have included the following:
- the interactive effect of elevated temperature and ocean acidification on corals
- the effect of repeat bleaching on Caribbean coral adaptation and acclimation
- the effect of bleaching on the acquisition, allocation, and utilization of carbon in bleached and recovering corals
- the effect of land-use on the concentration and isotopic character of organic and inorganic carbon in tropical and temperature streams
- the history of land-use change in tropical streams as recorded in coral skeletal records
- paleoceanography of the western tropical Pacific using coral, sclerosponge, and gorgonian isotope and elemental records
- coral skeletal cadmium-based paleoceanography of upwelling in the eastern tropical Pacific
Results from past research are published and can be viewed through the Publications link on the right-hand toolbar.