The 'seasquatch' has returned: A lost predator could save California's dying kelp forests

Nature · Published 3 October 2026 Swipe more like this →

In short: After vanishing from California waters a decade ago, the sunflower sea star—a voracious predator essential to kelp forest health—has been rediscovered. This elusive 'seasquatch' offers a glimmer of hope for ecosystems devastated by an explosion of sea urchins, which have decimated coastal seaweed habitats since the star's disappearance.

A decade ago, a mysterious epidemic combined with a severe marine heatwave caused sunflower sea stars, or Pycnopodia helianthoides, to effectively vanish from the California coast. These creatures are formidable predators, capable of growing up to 24 arms and spanning three feet in width. As they hunt, they move at a speed of three feet per minute, using thousands of tube feet to capture and consume purple sea urchins. Without these stars to keep urchin populations in check, the urchins insatiably devoured the region's kelp forests, leading to a collapse of over 90 percent of these vital underwater habitats in certain areas by 2017.

The loss of these ecosystems was profound, as kelp forests provide critical shelter for diverse species ranging from plankton to migrating gray whales, while also sequestering atmospheric carbon. For years, researchers and citizen scientists searched for any remaining survivors, often feeling like cryptozoologists hunting for a myth. This search finally yielded results in June 2025, when a research team discovered a small, healthy population of sunflower sea stars in a protected cove off the coast of Sea Ranch, California. The discovery included both adults and juveniles, suggesting that successful reproduction is occurring in the wild.

Following this breakthrough, a collaborative effort dubbed 'Pycnopalooza' brought together 25 scientific divers from eight institutions to survey the area. Using an underwater grid system and innovative environmental DNA (eDNA) technology, the team documented 18 sunflower sea stars. Researchers are now analyzing genetic samples from these individuals to determine if they possess a natural resilience to the sea star wasting disease that caused the initial population crash. If this population is indeed resistant, it could provide the foundation for broader restoration efforts, potentially allowing the state's kelp forests to recover from years of degradation.

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