Two undergraduate students in the University of Hawaiʻi at Mānoa’s Global Environmental Science (GES) degree program have conducted original research on coral’s tolerance to changing ocean conditions and the vulnerability of human communities in Hawaiʻi to inundation from projected sea level rise—contributing new knowledge to their respective fields.

Can coral adapt to ocean acidification?

Mia Delano, a senior in the GES program, works with Rob Toonen and Chris Jury at the Hawaiʻi Institute of Marine Biology to understand coral growth rates and the potential for adaptation as ocean water becomes more acidic.

Climate change is leading to a more acidified ocean, changing the way calcifying creatures like corals grow. Because corals are the basis for vast, complex ecosystems, researchers are investigating how reefs might change and evolve in the future.

Delano studied eight species of Hawaiian corals that constitute more than 97 percent of reef cover in Hawaiʻi for their variability in tolerance to acidic water. Delano also investigated whether any of this variation in coral response could be based on genetics. During a six-week experiment, all species showed a reduced growth rate in more acidic water. And all species showed that much of the variation seen in coral response to acidic conditions is genetic and therefore can be passed on and lead to adaptation over generations.

“Three species in particular showed a high variability in growth rate between colonies, meaning that some colonies were significantly more tolerant to acidic environments than were others within these species,” reported Delano. “Many scientists have previously predicted that corals won’t adapt to acidification, and we could face a global extinction event. However, my research indicates that some adaptation has already occurred in some species, and that the possibility of further adaptation across distinct species is also possible.

“My favorite aspect of the GES program has been participating in such groundbreaking research and becoming familiar with a topic that I am so curious and excited about,” said Delano. “After graduation I plan to attend graduate school and hopefully continue my research career.”

Are coastal communities in Hawaiʻi ready for sea level rise?

Kaitlyn Nelson, who graduated in December with a dual major in GES and ethnic studies from UH Mānoa, studied the relative vulnerability of communities in Hawaiʻi to inundation from projected sea level rise in the next century.

Nelson and mentor Justin Hospital who leads the socioeconomics program for NOAA ’s Pacific Islands Fisheries Science Center, determined relative risk factors of inundation for each community in Hawaiʻi to estimate physical hazard risk and estimated a community’s adaptation capacity. By combining these two assessments, Nelson was able to determine which communities were most vulnerable as sea level rises.

Kekaha-Waimea area on Kauaʻi and Honolulu on Oʻahu exhibited the highest risk of inundation to sea level rise.

“Interestingly, communities that exhibit higher inundation risk exhibit lower vulnerability scores on average, which suggests that communities that are at risk of inundation may have relatively high adaptation capacity,” said Nelson. “However, the inundation risk of Honolulu is somewhat concerning because of its importance to the statewide marine economy.”

By determining which communities experience relatively higher vulnerability, adaptation efforts could be prioritized for high risk communities.

“My favorite aspect of my GES research project was extending my learning,” said Nelson. “I was able to study something that was so different from my coursework but still required a lot of the background knowledge from my classes. It was exciting and challenging to work on a project that required a lot of independent thinking and problem-solving.”

Having graduated just weeks ago, Nelson is deciding whether to stay in Hawaiʻi and work as a community youth coordinator or teach at a high school in San Francisco.

Preparing students for the future

The Global Environmental Science program at the UH Mānoa School of Ocean and Earth Science and Technology trains high-quality students to be knowledgeable in Earth-system science and think creatively about the challenges facing communities and natural resources now and in the future. As a GES degree requirement, each student performs original scientific research, writes a research thesis and presents findings publically. Mentors include SOEST faculty—global leaders in the fields of ocean, earth and space science. Throughout the GES degree program, students are engaged in fieldwork, laboratory work and field trips, and have access to deep ocean and coastal research vessels, SOEST’s world-class Hawaiʻi Institute of Marine Biology and an active volcano.

—By Marcie Grabowski