Ashley Kidd, a conservation project manager at the Sunflower Star Laboratory in Monterey Bay, joined a Zoom call a bit late, excited to share some unexpected news. Just 12 minutes before, a planned spawning of critically endangered sunflower sea stars had begun, three days ahead of schedule. Kidd and her team were set to travel to an aquarium in Alaska to help with the spawning process and collect samples for their conservation efforts.
The mission is part of a broader initiative to revive the sunflower sea star population, a species that plays a critical role in maintaining the health of kelp forests along the Pacific Coast. These vibrant sea stars, which can have up to 24 arms and weigh as much as a small dog, have faced severe declines due to a mysterious disease linked to a marine heat wave that began in 2013. This disease wiped out an estimated 5.75 billion sunflower sea stars, leading to a staggering 94% decrease in their global population. California alone lost about 99% of its sunflower sea stars, prompting their listing as critically endangered in 2020.
The decline of sunflower sea stars has had a domino effect on the ecosystem. These sea stars are natural predators of purple urchins, which have exploded in numbers without their natural predators. In California’s North Coast, the unchecked urchin population has devastated kelp forests, with 96% of them disappearing in the last decade. Kelp is vital for sequestering carbon and providing habitat for diverse marine life, so the loss of these forests has significant ecological and economic implications.
Kidd expressed optimism about the spontaneous spawning event, as it allows the team to hit the ground running when they arrive in Alaska. The plan involves collecting sperm from male sea stars and bringing back live specimens and larvae to California. This is crucial because the captive breeding efforts have produced young sea stars, but they lack genetic diversity due to limited breeding pairs. The team hopes that by introducing new sea stars from Alaska, they can enhance the genetic pool and improve the chances of successful reintroduction into the wild.
Recent successes in breeding sunflower sea stars in captivity have raised hopes for the species’ recovery. A significant milestone was achieved last year when the Birch Aquarium at UC San Diego successfully induced spawning for the first time in California. This breakthrough demonstrated that researchers can facilitate breeding at a scale that could support reintroduction efforts.
However, releasing these lab-raised stars into their natural habitat is still a few years away. Scientists need to address various challenges, including understanding the nature of the sea star wasting disease and how to build resilience among the stars. Experts estimate that it could take three to five years before sunflower sea stars can be reintroduced to the Pacific.
The stakes are high. If the sunflower sea star population can be revived, it could help restore balance to the ecosystem, allowing kelp forests to recover and thrive once again. Kelp forests are not only essential for marine biodiversity but also play a significant role in combating climate change by capturing carbon at rates much higher than terrestrial forests. As researchers work diligently to save this keystone species, the future of California’s coastal ecosystems hangs in the balance.