SF scientists fight climate doom with lab-grown coral breakthrough

A lab at the California Academy of Sciences in San Francisco’s Golden Gate Park is the first in the nation to create a unique lifeline for corals suffering from rapid climate change. 

Rebecca Albright, a longtime coral reef scientist at the academy, said her team is creating baby corals to help mitigate their devastating and widespread decline. Over the past three decades, more than 50% of the coral reefs around the world have been lost, mostly over the past 10 years, Albright said. If changes aren’t made soon, 90% to 99% of the coral reefs that are remaining could be deteriorated by 2050, she said. 

“We know we’re on a bad trajectory,” Albright told SFGATE. “… If we are having these losses, the main way we get recovery is through growth and reproduction.”

Albright said the academy’s work comes because of the “urgency of the global coral reef decline” and the fact that ocean waters have “started to become inhospitable.” The main problem is an increasingly widespread process called coral bleaching (zooxanthellae), which is a stress response when the ocean gets too warm due to climate change, Albright said. The coral expels its algae to protect itself and the animal turns white and starves to death. 

Albright said the starvation occurs because coral feeds off algae that live inside their tissue and photosynthesize. And in a lot of places where corals live, they have limited options for food.

“If you think of an iconic coral reef, you usually picture super clear water, bright sunlight, shallow and like this beautiful place. The reason the water is so clear is that there’s not a lot of nutrients or stuff living in the water column,” Albright said. “That’s why it’s bad. [Coral bleaching] is compromising their primary food supply and leading them down this road of starvation if the stressors are not removed.”

Scientists are worried because these “bleaching events” are becoming more common, happening more frequently and affecting more parts of the world. 

There have been four global coral bleaching events on record and two in the last decade, according to the National Oceanic and Atmospheric Administration. The most current event was confirmed on April 15, 2024, and is still ongoing, impacting approximately 84% of the world’s coral reefs as of Aug. 31. It has been documented in at least 83 countries and territories. 

Amid the growing concern, Albright said creating baby corals could prevent the existing corals from starving to death. At Cal Academy’s Steinhart Aquarium, scientists have been studying how to help corals reproduce, collaborating with Roatan Marine Park in Honduras, where researchers have planted more than 3,000 baby corrals. Albright said they are using the “scientific opportunity” of having the deepest and second-largest display of living coral reefs in the world to create “more resilient” coral babies. 

“A lot of those will die, and that’s just part of the process,” she said. “So part of the reason why corals make so many babies is knowing that a lot of them will get predated upon or overgrown or just not survive at the end.” 

The corals, which are almost three months old, are “very tiny” at this point and difficult to see. But Albright said a team will travel to the reef next month when the corals are bigger to learn how many have survived. 

Though there aren’t many coral reefs on the West Coast, with the closest being mostly near Baja California, Albright said it’s important for the public to understand that they are “critical ecosystems” to millions of people, even those who aren’t close to them.

“To a large extent, I think that coral reefs are a little bit out of sight, out of mind. Everybody thinks they’re gorgeous, they’re beautiful, but don’t really understand, other than their beauty, why they’re important,” she said. 

Coral reefs help provide coastal protection against floods, hurricanes and storms, while also providing economic benefits to fisheries and tourism. 

“The most cost-effective, easiest thing that we could do is just protect them from being gone in the first place and it will be felt worldwide,” Albright said. “It’s not just people that are proximate to them that will reap that impact.”