These sea stars were nearly wiped out — but B.C. researchers say fiords provided refuge

Researchers from British Columbia have made a groundbreaking discovery that could have significant implications for the critically endangered sunflower sea star. The fiords of the Central Coast have been identified as a possible refuge for these sea stars, which have been devastated by sea star wasting disease in recent years.

The sunflower sea star is listed as critically endangered due to a mass die-off that has wiped out nine out of 10 sea stars since 2013 along North America’s West Coast. This decline has had far-reaching effects on marine ecosystems, as sunflower sea stars play a crucial role in controlling sea urchin populations. Without them, sea urchins have flourished and decimated kelp forests, further destabilizing marine ecosystems.

After years of diving along B.C.’s Central Coast, researchers have found healthy adult colonies of sunflower sea stars in the fiords. The mortality rate of sea stars in these fiords is significantly lower than in other parts of the ocean, leading scientists to suspect that the cooler water temperatures in the fiords may be a factor in their survival.

Alyssa Gehman, a scientist with the Hakai Institute and the University of British Columbia, co-authored a paper on the findings. She explained that the cold water temperatures in the fiords may be creating a refuge for the sea stars, protecting them from the warmer waters where sea star wasting disease thrives.

Jeff Sha, an aquarium biologist at the Vancouver Aquarium, highlighted the importance of temperature in the spread of the disease, noting that higher temperatures make it harder for infected sea stars to recover. The researchers believe that the unique oceanographic conditions in the fiords, including Arctic outflow and glacial runoff, may be creating a more hospitable environment for the sea stars.

The implications of this discovery are significant for recovery efforts aimed at restoring sunflower sea star populations. By understanding the role of temperature in the spread of sea star wasting disease, researchers can better design conservation strategies to protect these critical species. There is hope that by raising disease-resistant sea stars in laboratories and reintroducing them to the ocean, we can help restore balance to marine ecosystems that have been disrupted by the decline of sunflower sea stars.

As climate change continues to impact ocean temperatures, it will be crucial to monitor the viability of fiords as refuge habitats for the sunflower sea stars. By studying the unique conditions in these fiords and their role in protecting sea stars, researchers can inform conservation efforts and ensure the survival of this critically endangered species.