Old Dominion University Biology Associate Professor, Daniel Barshis, and a team of international and U.S.-based researchers have been awarded six grants totaling $7 million to assess the impacts of climate change and determine the resilience of coral reefs in American Sāmoa along with the Caribbean and the Great Barrier Reef. This combination of funding will enable one of the most comprehensive examinations of coral climate change resistance and susceptibility across the entire complexity of the coral genome and the entire depth range of coral reef ecosystems. The funding is a blend of recent grants awarded by the Paul G. Allen Family Foundation, the National Oceanic and Atmospheric Administration (NOAA), the National Park Foundation, Revive & Restore, SOFAR Aqualink, and the Paul M. Angell Family Foundation. These grants also fund two postdoctoral researchers at ODU: Veronica Radice, Ph.D. and Nicolas Evensen, Ph.D.
"This research is geared towards identifying the corals with the best chance of surviving climate change and discovering what genetic mechanisms might be responsible for their exceptional survival," said Barshis. "It is our hope we can then use these corals in active restoration efforts to seed the reef with corals that may be able to help reefs persist over the next few decades." American Sāmoa has some of the more stress resistant corals in the world, and the team of researchers are hoping to learn why these corals are doing so well, while other corals are dying around the world.
Coral reefs hold tremendous ecological, financial, and social value, sustaining approximately one billion people worldwide through food, coastal protection, and income from fisheries and tourism. Yet these ecosystems are rapidly declining due to climate change, namely due to warming ocean temperatures. When corals are subjected to temperatures above their normal limits, corals expel the microalgae living in their tissues that provide the corals with essential nutrients, in a process termed coral bleaching. While corals can recover from bleaching when temperatures cool back down, elevated seawater temperatures have caused unprecedented levels of coral mortality in recent years.
Recent research into patterns of coral survival and mortality has highlighted the potential existence of naturally resilient corals. A $4-million grant awarded by the Paul G. Allen Family Foundation seeks to identify these naturally resilient corals and study the physiological and molecular underpinnings that help them survive exceptionally high temperatures.
The grant, dubbed the 'global search', also includes collaborators Christian Voolstra from the University of Konstanz, Germany, Iliana Baums from Penn State University, Jake Valenzuela and Nitin Baliga from the Institute for Systems Biology in Seattle, Washington and Line Bay from the Australian Institute of Marine Science located in Townsville, Queensland, Australia. Together, these global researchers will investigate reefs across the tropics, from the Caribbean to the Great Barrier Reef.
The NOAA funding includes a $2.4 million grant for the Deep Coral Reef Ecosystem Studies (Deep-CRES) program of American Sāmoa. This collaborative four-year research program includes scientists Tony Montgomery, Ph.D. from the U.S. Fish and Wildlife Service, Ken Longenecker, Ph.D. and Rich Pyle, Ph.D. from the Bernice P. Bishop Museum, Robert Toonen, Ph.D. from the Hawai'i Institute of Marine Biology, and Randy Kosaki, Ph.D. from NOAA Papahānaumokuākea Marine National Monument. The project will examine the understudied deeper, mesophotic ("middle light") reefs of American Sāmoa between ~40m/130ft and 100m/328ft depths, which represent 79% of the nearshore marine habitat. The research will focus on improving knowledge of the mesophotic reef environment and its corals and fishes with the aim to help resource managers develop strategies to protect these unique ecosystems. Further, the team will research the genetic mechanisms of thermal tolerance of these mesophotic corals thanks to funding from the National Park Foundation, which is supporting a postdoctoral fellowship to work with scientists from the National Park of American Sāmoa.
An additional Wild Genomes grant from Revive & Restore will produce genomes for two coral species that occur primarily at tropical and subtropical regions between depths of 100-feet to 490-feet of the ocean's surface. These genomes will serve as important references for the transcriptome (gene expression) research related to coral thermal tolerance.
The research team will also begin long-term, real-time monitoring of seawater temperatures across shallow to mesophotic reefs thanks to 'smart' buoys granted from SOFAR Aqualink. "Current standard temperature monitoring only provides a 'hindsight' view of past thermal history, yet it is critical to monitor marine heatwaves in real time so scientists can be prepared to study the effects of coral bleaching especially in understudied mesophotic reefs," said Barshis.
Lastly, a sixth grant from the Paul M. Angell Family Foundation will support a Genome Wide Association Study (or GWAS) to directly link the genetic composition of corals to their thermal tolerance capacities to determine what genes may be responsible for thermal resilience.
Linking all these projects together, Barshis and his team will be using a novel experimental system called the Coral Bleaching Automated Stress System (or CBASS for short) to identify stress resilient corals. The system was first developed by Barshis and Steve Palumbi, as well as Tom Oliver, while working in American Samoa 16 years ago. The CBASS has since been redesigned to be an ultra-portable, experimental stress system bringing the "lab to the reef", as most coral reef locations around the globe are far from well-developed experimental research facilities. "The CBASS is a really innovative tool that can be used to identify heat tolerant corals in a fraction of the time, and at a fraction of the cost, of traditional experimental systems," said Barshis. "We're very excited to be returning to American Sāmoa where all this work began and demonstrate the full value of the CBASS to coral reef science."
This will only be accomplished by coordination of a large team of multinational researchers, local resource management agencies, and highly trained technical scuba divers working together to investigate the resilience of this critically threatened group of organisms so important for biodiversity and sustaining human populations throughout the world's tropical regions.