Conservation: Using 61,000 marine surveys to protect the sunflower sea star

January 18, 2021
Mary Ellen Amodeo
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The significant loss of sunflower sea stars and other predators has allowed populations of purple urchin to explode – resulting in a significant decline in kelp forests in recent years. A recent study led by Oregon State University, The Nature Conservancy, and dozens of other conservation groups equipped IUCN to list the Critically Endangered species. (Photo courtesy of The Nature Conservancy and Janna Nichols)

The Nature Conservancy and Oregon State University researchers have enabled the International Union for Conservation of Nature (IUCN) analyzed 61,000 surveys to list the sunflower sea star (Pycnopodia helianthoides) as Critically Endangered. The listing means heightened awareness and resources to focus on recovering a species that is essential to marine ecosystems throughout its range from Baja, Mexico all the way to the tip of the Aleutian Islands.

From Oregon Public Broadcasting: Oregon State University Research Associate and lead analysis author Sarah Gravem said the past few years is what she calls a perfect storm of ecosystem destruction that first started off with the sea star wasting in 2013. Then a year later the marine heatwave came through and the increase of sea urchins.

“Between the sea stars being gone, the urchins increasing and having lots of babies, and the kelp being killed, that’s left the situation where we have just urchins everywhere,” she said.

Gravem said now that the species has been listed as critically endangered, it gives researchers and conservation groups an opportunity to develop a roadmap to begin to recover the species.

Species360 Conservation Science Alliance is pleased to join those enabling this study, on behalf of our aquatic and zoological community.

Here is a summary of how the study was conducted, and what researchers found:

Oregon State University, along with The Nature Conservancy and dozens of conservation groups, led a groundbreaking study that found 90.6% of the species population has been wiped out and estimated as many as 5.75 billion animals died from the disease since the die-off began. This has led the International Union for Conservation of Nature (IUCN) to list the sunflower sea star (Pycnopodia helianthoides) as critically endangered.

The study used more than 61,000 surveys from 31 datasets and showed no signs of the population’s recovery in any region it is known to be located since the outbreak began. 

Sunflower sea stars are an important predator of sea urchins and, with the significant loss of these sea stars and other predators throughout their range, purple urchin populations have now exploded in many regions. This overabundance of urchin is linked to a significant decline in kelp forests in multiple regions in recent years. Kelp forests are already facing increased pressure from marine heatwave events and, taken together, these threats contribute to an uncertain future for kelp forest ecosystems which provide critical habitat for thousands of marine animals and support coastal economies.

“The loss of this important predator has left an explosion of purple urchins unchecked and has contributed to devastated kelp forests along the West Coast, making this ecosystem more vulnerable and less resilient to the stressors it’s already facing,” said Norah Eddy, Associate Director of The Nature Conservancy’s California Oceans Program.

Read more about the study at Oregon Public Broadcasting.