Researchers have introduced an innovative tool aimed at safeguarding and nurturing coral reefs by boosting their feeding opportunities.
The new device, known as the Underwater Zooplankton Enhancement Light Array (UZELA), is an automated underwater light that attracts nearby zooplankton, which are tiny organisms that serve as food for coral.
After conducting tests on two types of coral native to Hawaii over six months, the researchers observed that UZELA significantly increased the local density of zooplankton and improved the feeding rates of both healthy and stressed coral. Providing these corals with more food enhances their strength and resilience to various environmental challenges, such as heat stress and ocean acidification.
These findings are particularly noteworthy given the current threats posed by rising ocean temperatures, pushing coral reefs toward potential collapse, according to Andrea Grottoli, the lead author and a professor of earth sciences at The Ohio State University.
“Coral reefs host one-third of all marine species while occupying less than 1% of the ocean’s area,” she explained. “They play a critical role in ocean health, making their loss a significant concern.”
The study has recently been published in the journal Limnology and Oceanography: Methods.
Coral reefs are essential for millions of people, supporting fishing industries and shielding coastal communities from issues like erosion and flooding. Sadly, many climate models predict that at the current warming rate, these crucial ecosystems may be devastated by 2050, threatening the diverse marine life they support.
While the technology from this study serves as a temporary measure against the environmental challenges faced by coral reefs, Grottoli believes it will be beneficial for coral restoration efforts. “It’s like a band-aid for a couple of decades,” she noted. “It can protect certain corals in specific locations, at times.”
The team also discovered that UZELA, which can operate for up to six months on a single battery, optimizes coral feeding by functioning for just one hour after sunset.
Although artificial lighting can disrupt other marine life, researchers may choose not to use the device continuously throughout the year. Nevertheless, the study highlights that using the UZELA to attract zooplankton does not negatively impact the environment or disrupt the natural flow of zooplankton in nearby waters.
“Imagine a column of zooplankton drifting above the coral, instead of being evenly dispersed; UZELA effectively draws them down without diminishing the availability for neighboring corals,” Grottoli explained. “Our findings show that coral positioned near the light can access a concentrated supply of zooplankton, leading to a feeding rate increase of 10 to 50 times.”
This increase translates to an 18% to 68% rise in the metabolic needs that can be satisfied by zooplankton alone, which means enhanced feeding significantly contributes to the overall diet of the coral, promoting its survival and stability.
“The primary goal of this project is to introduce new technology and energy into the success of coral restoration,” Grottoli stated. “It can be strategically used in valuable reefs or for projects that have already received considerable investment.”
UZELA is versatile and can be easily serviced by divers once it is placed in suitable underwater locations.
Interestingly, while the current UZELAs are handcrafted, the team is collaborating with an engineering company in Ohio to redesign the technology for easier mass production. Grottoli anticipates that these improved versions will be ready within the next one to three years.
“We are not addressing climate change quickly enough to save coral, and UZELA won’t provide an instant solution for coral reefs,” she remarked. “However, it represents an exciting opportunity to gain time as we aim for a more sustainable future.”
Co-authors of the study include Shannon Dixon and Ann Marie Hulver from Ohio State, along with Claire Bardin, Claire Lewis, Christopher Suchocki, and Rob Toonen from the University of Hawai’i at Manoa and the Hawaii Institute of Marine Biology.
This research was funded by the University of Hawai’i Foundation, the National Science Foundation, and the Defense Advanced Research Projects Agency.
