A diverse group of researchers—led by molecular ecologist Kate Quigley—have begun a first-of-its-kind initiative. They’re doing impressive work to fight coral bleaching at Ningaloo Reef in Western Australia. Quigley has dedicated almost a decade of his life to the science and art of selective coral breeding. He works with master’s student Alexandra Kler Lago from the University of Bremen and Chris Fulton, principal research scientist at the Australian Institute of Marine Science. Their groundbreaking studies show how selective breeding methods can strengthen coral defenses against increasing ocean temperatures.
The project is extensively sampling parent corals from the southern section of Ningaloo Reef. It is particularly focused on the few that are actually doing better in higher temperatures, called “on-average hot reefs.” To simulate the corals’ natural environment, the team stores the corals in dark conditions to induce their annual spawning cycle. They want to breed future generations to be able to handle climate change stressors. The urgency for such measures is underscored by alarming reports indicating that every part of the Western Australian coast is exhibiting signs of coral bleaching.
The Process of Selective Breeding
Quigley and her team employed techniques originally pioneered at the GBR. They modified these techniques to suit Ningaloo Reef’s distinct conditions. In an elaborate process, the researchers separated coral gametes by sex. They had previously identified them according to their heat tolerance as parentals, as hot and cool. This very detailed artistic process enabled them to produce compound results that would hopefully add to the resistance to heat for their lineage.
“We collected parent corals, so ‘mum’ and ‘dad’ corals from an on-average hot reef,” – Dr. Kate Quigley
After sorting the gametes, the team performed multiple crossing experiments. In a remarkable finding, Quigley noted that “after only one round or one generation of breeding, we were actually able to double the heat tolerance of the baby corals.” The research suggests that Acropora tenuis corals with at least one “hot” parent, particularly a mother from a warmer environment, exhibited twice the capacity to survive elevated temperatures of up to 35.5 degrees Celsius.
The Challenges Faced by Researchers
Doing this type of research came with a number of logistical challenges for Kler Lago and her team. To do this, they carried parent corals loaded with seawater from the reef to their on-land laboratory. Usually, they took long journeys wading through knee-deep waters with heavy buckets.
“We actually had to go to the shallow part with buckets and then carry them filled with water to the trucks,” – Alexandra Kler Lago
To test their hypotheses, the team created large, specialized coolers with pumping systems to keep water at consistent temperatures. This level of detailed planning reflects their absolute focus on making sure the corals are getting the best possible conditions for growth.
The team rotated rearing these baby corals under strong light and current conditions. They took care of them until they reached a size equivalent to adolescent corals. They then put them through environmental stress tests meant to test their durability against heat and other elements.
“We reared up these baby corals to essentially become teenager corals, and we put them through a stress test,” – Dr. Quigley
The Urgent Need for Action
These results from this study come at a particularly crucial moment, as coral reefs around the world are experiencing increased rates of coral bleaching. Quigley expressed her concerns, stating, “Bleaching, once upon a time, was an extreme event … it’s becoming far too regular.” This is the team’s work, a glimpse at the amazing potential that new coral breeding methods open up. It goes beyond that, pushing for faster and stronger action in general on climate change.
“We absolutely need emissions reductions to happen immediately in order for these techniques to have a meaningful impact,” – Dr. Quigley
Andrew “Twiggy” Forrest, who will deliver these findings at the upcoming United Nations Ocean Conference. He’ll explain why this research is so important to restoring coral populations around the globe. Quigley and her team are doing amazing things to help safeguard the world’s marine biodiversity. Collectively, their work addresses the growing threats and tests that climate change continues to bring.
