The Coral Triangle, one of the planet’s most diverse reef regions, is under siege.

The area, spanning the waters of Indonesia, Malaysia, Papua New Guinea, the Philippines, the Solomon Islands and Timor-Leste, is home to 75 per cent of the world’s known coral species. It sustains 3,000 species of reef fish and the livelihoods of over 120 million people. But over 85 per cent of its reefs are threatened by rising temperatures, ocean acidification, pollution and unsustainable fishing, according to the World Resources Institute.

Chiahsin Lin’s love for the ocean led to a career in marine biology. Currently working as head of the Department of Planning and Research at Taiwan’s National Museum of Marine Biology and Aquarium, he fears that future generations may never get to see living reefs.

Scientists warn that reefs worldwide could decline by 70-90 per cent with 1.5°C of global warming. In October, researchers said that rising global temperatures have pushed warm water coral reefs – found in tropical, shallow and sunny waters – into a long-term decline. This signals the Earth reaching its first climate tipping point linked to greenhouse gas emissions.

To give coral reefs a chance to survive, scientists are turning to cryopreservation – freezing coral cells, larvae and sperm to be used for future reproduction.

Lin is leading an effort to build a network of cryo-repositories in the Coral Triangle. It aims to preserve larvae from corals that could be used for reef restoration when the environment becomes suitable for their deployment. This is when conditions improve to the point where the larvae, when released, can survive and support coral growth.

“The more coral banks, the more possibilities coral can survive, and the more diversity [is preserved],” Lin says.

But the work is far from easy, and progress has been slow, with only a tiny fraction of larvae surviving the cryopreservation process.

Freezing Coral Larvae for the Future

For around two decades, scientists around the world have been freezing coral materials in liquid nitrogen at temperatures as low as -196°C, notes coastal science publication Hakai. Metabolic and biological processes stop at these extreme temperatures, allowing cells and larvae to be stored for years and later thawed for reef restoration activities. This could mean raising corals that can better withstand climate stress, or to restore reefs where corals have died off.

Read the full article about freezing coral larvae by Gaea Katreena Cabico at Eco-Business.