Researchers Find Promising Results for Sunflower Sea Star Recovery in Monterey Bay National Marine Sanctuary

By: Rachel Plunkett

November 13, 2026

For the first time in years, sunflower sea stars are crawling across the seafloor of Monterey Bay National Marine Sanctuary. And these critically endangered predators could play an important role in restoring California's declining kelp forests.

In 2026, researchers from Sunflower Star Laboratory and several partner organizations temporarily introduced laboratory-reared sunflower stars into the sanctuary as part of a study investigating their potential to help restore kelp forest ecosystems. The project marks the first time laboratory-reared sunflower stars have been temporarily released into California's nearshore waters.

A Keystone Predator in Decline

Sunflower sea stars (Pycnopodia helianthoides) are voracious predators that help maintain balance in kelp forest ecosystems by feeding on sea urchins. But following a devastating outbreak of sea star wasting disease beginning in 2013, sunflower star populations collapsed along much of the West Coast.

Without these predators, sea urchins can graze unchecked, contributing to the transformation of once-thriving kelp forests into underwater barrens.

To investigate whether reintroducing sunflower stars could help reverse this trend, researchers placed 16 laboratory-reared sea stars in enclosed experimental pods within an urchin barren in Monterey Bay National Marine Sanctuary.

Over the month-long experiment, researchers observed that sunflower stars readily consumed urchins, including the food-deprived urchins commonly found in barrens. The sea stars also influenced the behavior of nearby urchins. Within three feet of the experimental cages, 99% of adult urchins moved away, suggesting that even the presence of these predators could help reduce grazing pressure on kelp.

Taking Restoration Research Into the Field

Following the enclosed experiments, researchers conducted 18 temporary, closely supervised releases to observe how the young sunflower stars behaved on the open seafloor.

During the temporary sunflower sea star reintroductions, divers accompanied the stars during excursions lasting up to two hours, documenting their movements, feeding behaviors, and interactions with surrounding marine life. These observations will help researchers develop methods for future reintroductions.

The fieldwork also revealed an important challenge: Two of the 16 stars developed symptoms of sea star wasting disease and subsequently died. Diagnostic testing detected a bacterium associated with the disease in one of the stars, providing valuable information about potential risks to future restoration efforts.

Connecting Research to Sanctuary Management

The research brings together Sunflower Star Laboratory, Reef Check Foundation, Monterey Bay Aquarium, Moss Landing Marine Laboratories, California State University, Monterey Bay, Hopkins Marine Station, the California Department of Fish and Wildlife, and other collaborators.

Monterey Bay National Marine Sanctuary supports the research through permitting and oversight, while also collaborating with Sunflower Star Laboratory on education, outreach, and community science. Sanctuary volunteers visit the laboratory to learn about the ecological relationships among sunflower stars, urchins, and kelp forests, helping them share this conservation story with the public.

Protecting and restoring Monterey Bay's iconic kelp forests is an important sanctuary management priority. Understanding how sunflower stars influence urchin populations, survive in natural habitats, and potentially support kelp recovery can inform future restoration strategies and resource management.

Although permanent reintroductions remain a future goal, these early findings represent a promising step toward restoring a critical predator—and the ecological balance of California's kelp forests.

Rachel Plunkett is the content manager and senior writer/editor for NOAA's Office of National Marine Sanctuaries

Lisa Uttal is the media coordinator for NOAA's Monterey Bay National Marine Sanctuary