Coral reefs provide many benefits to society, including storm protection to shorelines, tourism, and supporting sport and commercial fisheries. They are also crucial for biodiversity, providing a home to 25% of marine life while occupying less than 1% of the ocean floor. However, the rapid decline of coral reefs around the world has significantly reduced those benefits.

A team consisting of mechanical science and engineering professors Amy Wagoner Johnson (EIRH/RBTE) and Gabriel Juarez, and civil and environmental engineering professor Rosa Espinosa-Marzal (EIRH) have been awarded a continuing National Science Foundation (NSF) Convergence Research grant to work on coral recruitment and survival.

To reproduce, swimming coral larvae — the size of a grain of rice — must successfully find a substrate to attach to, settle and grow. From there, the larvae transform into juvenile coral and continue to grow into adult corals. However, relatively little is known about how coral reef surfaces influence coral larvae attachment and growth. Through a collaboration with expertise in materials engineering, fluid physics, microbiology, and coral reproduction, studies will be done to promote coral larval settlement for increased survival.

“The bottleneck is having good settlement and then getting the juvenile corals to survive out in the wild,” said Wagoner Johnson. “If we can develop materials that will help larvae settle and grow better, and help keep algae and bad biofilms off, then we hope that that will provide the tools to successfully regenerate reefs by assisted sexual reproduction.”
 
To achieve their goal, researchers will engineer and test suitable materials and measure the release of active molecules that encourage settlement. Wagoner Johnson and Espinosa Marzal will design and develop materials to encourage larval settlement while Juarez will investigate the influence of fluid forces on larval settlement.
 
“Larvae can sense their local environment and they actually display a preference for certain substrate features. In the ocean, the fluid motion is at least 10 times larger than the larval swimming speed, which makes it extremely difficult for larvae to sense and respond to their environment in real-time,” said Juarez. “It’s like trying to land an aircraft on a moving runway.”
 
Since the coral species studied release sperm and egg only once or twice a year, the researchers have a limited window to test substrate samples on coral larvae and measure their response to the release of active chemicals. Once data is collected and analyzed, the research team will study the materials more in-depth, modify the composition of the materials and plan for the next season of experiments.
 
The ultimate goal is to encourage natural coral restoration and sustainability through limited artificial intervention. Besides having important, long-term societal and economic impacts, the research will also help establish a new discipline geared towards engineers, paving the way for the future generation of scientists.

“Restoration of reef ecological function can yield cleaner water, more sustainable food supplies, and healthier and more resilient coastal cities. Hence, in addition to the fundamental knowledge generated in this collaborative project, this is a project with a huge environmental impact,” said Espinosa-Marzal. “This project is at my heart because we, as a team, can do something useful for our society. There’s a lot to do and it’s all very exciting.”

The research team also includes current postdoctoral researcher Joaquin Yus Dominguez, former postdoctoral researcher Mark Levenstein (now at Centre CEA Paris-Saclay), Linda Wegley Kelly (University of California-San Diego, Scripps Institution of Oceanography), Forest Rohwer (San Diego State University), and Kristen Marhaver (CARMABI Research Station, Curacao).

On September 23rd, the Urbana-Champaign Satellite Reef installation, the culmination of coral reefs crocheted by the University of Illinois Urbana-Champaign community members, will be celebrated at the Siebel Center for Design. Launched by the School of Art & Design at the University of Illinois Urbana-Champaign, the Urbana-Champaign Satellite Reef is part of the global Crochet Coral Reef project co-conceived by Margaret Wertheim, who looks at the intersection of math, art and science. Wertheim will give a talk sponsored by the Center for Advanced Study at the Spurlock Museum at 4 pm on the 23rd, followed by a reception for the opening of the crochet coral reef at 6 pm at the Siebel Center for Design. Research sponsored by the NSF will be featured in poster format at the exhibit.