Cryopreserved Seastar Larvae May Facilitate the Recovery of Key Species

In a groundbreaking achievement, researchers have successfully frozen and revived sea star larvae, marking a significant advance in conservation efforts aimed at restoring an endangered keystone species.

Since 2013, Coastal Star Wasting Syndrome has been devastating populations of sunflower stars (Pycnopodia helianthoides) and giant pink stars (Pisaster brevispinus) along the North American west coast. The decline of these predators has resulted in a major surge in sea urchins, decimating 97% of the kelp forests in Northern California.

Currently, the sunflower star is considered functionally extinct in California, sparking extensive efforts to cultivate these creatures for eventual reintroduction into their natural habitat.

In January 2025, a giant pink star was birthed at the Pacific Aquarium in Long Beach, California. Just two days later, its larvae were dispatched to the San Diego Zoo Wildlife Alliance, where they were immersed in liquid nitrogen and stored at -200°C. The following month, they were transported approximately 700 kilometers north to the Sunflower Star Institute in Monterey Bay.

Upon careful thawing, the giant pink star larvae resumed their development, settling on the seabed and transitioning into a boy shape. “No one has ever successfully frozen a sea star at the larval stage and achieved this,” researchers noted.

The successful cultivation of cryopreserved larvae represents a significant milestone for conservationists, as it opens up avenues for reintroducing genetically diverse sunflower stars back into California’s waters. “The larval cycle of the giant pink star closely resembles that of the sunflower stars,” explained Bank, “after which we will move forward with sunflower star rearing.”

Over the past 15 years, marine ecosystems in the North Pacific have faced a growing tide of environmental challenges. “It’s a daunting narrative involving climate change, ocean heat waves, and ecosystem collapse,” remarked Andrew Kim from the Sunflower Star Institute. “However, within Pycnopodia, there lies hope for recovery.”