Isochoric vitrification set to revive Hawaiian stony corals

Cryopreservation technique

Now, researchers have developed a new cryopreservation technique that helped revive cm-scale coral fragments using mL-scale isochoric vitrification. 

The study emphasized: “We demonstrate coral viability at 24 h post-thaw using a calibrated oxygen-uptake respirometry technique, and further show that the method can be applied in a passive, electronics-free configuration.”

In simple terms, the technique involves strategic bleaching and cooling coral fragments using liquid nitrogen. This process allows the coral to be preserved in a "glassy state." The coral can later be revived by slowly warming the samples and reintroducing filtered seawater.

A team of scientists from Texas A&M University stated that the process allowed the corals to cool rapidly at nearly -321 degrees Fahrenheit (196 degrees Celsius) without forming ice lethal to coral and most biological matter.

Dr. Matthew Powell-Palm, lead author on the project, explained: 

“Compared to other emergent vitrification techniques — which frequently require lasers, electromagnetic implements, or other high-tech laboratory equipment — our isochoric vitrification approach is exceedingly fieldable. It requires no moving parts or electronics, and the protocol can be implemented by a field technician with no background in thermodynamics." 

He added, “This is essential to the practicality of any conservation technique because when this is deployed in real marine field stations, the high-tech lab infrastructure common to many laboratories will not be available. From a purely technological perspective, the technique is simple, rugged, and ready for the field.”

Aiming long-term growth

Alluding to a ready prototype that employs a coral cryopreservation pipeline, this setup offers a foundation for important actions to manage stress after thawing and start long-term growth.

The team of researchers successfully preserved and revived one species of coral, and it just about managed to stay alive for up to 24 hours after being thawed. 

Scientists are aiming to achieve the long-term survival of the corals by reducing the overall stress placed on the species and will continue to deploy the technique into real-world conservation efforts.

The statement by the university said that these findings pave the way towards an approach that can be rapidly deployed around the world to secure the biological genetic diversity of our vanishing coral reefs.

Without coral reefs as part of our ecosystem, coastlines would remain unprotected, and as a result, so would cities and homes – not to mention the impact on food security.

According to the study, the value of coral reefs is estimated at $10 trillion annually. Despite the species'  global economic and social significance, they continue to deteriorate, posing a threat to most life on Earth, particularly impacting nations that rely on reefs for their resources, even though they might not have many resources themselves, such as Hawaii.

The study was published on 23 August in the journal Nature.

Abstract:

Corals are under siege by both local and global threats, creating a worldwide reef crisis. Cryopreservation is an important intervention measure and a vital component of the modern coral conservation toolkit, but preservation techniques are currently limited to sensitive reproductive materials that can only be obtained a few nights per year during spawning. Here, we report the successful cryopreservation and revival of cm-scale coral fragments via mL-scale isochoric vitrification. We demonstrate coral viability at 24 h post-thaw using a calibrated oxygen-uptake respirometry technique, and further show that the method can be applied in a passive, electronics-free configuration. Finally, we detail a complete prototype coral cryopreservation pipeline, which provides a platform for essential next steps in modulating post-thaw stress and initiating long-term growth. These findings pave the way towards an approach that can be rapidly deployed around the world to secure the biological genetic diversity of our vanishing coral reefs.