Latest news with #Gehman
Hamilton Spectator
13-06-2025
- Science
- Hamilton Spectator
BC's sunflower sea stars are now endangered, but rays of hope remain
Sunflower sea stars clinging to life in BC's cold-water fjords are officially on the edge of extinction, a scientific advisory panel is warning. A once-abundant predator of the sea floor along the Pacific coast, stretching from Alaska to Baja California, Pycnopodia helianthoides, has been assessed as endangered by the federal Committee on the Status of Endangered Wildlife in Canada (COSEWIC). While disheartening, the decision isn't unexpected and could offer a margin of hope for the survival of the massive, vibrant sea star, said Alyssa Gehman, marine ecologist with the Hakai Institute. The only type of its genus, an adult sunflower star Pycnopodia (which comes in a variety of purple, orange or pinks) is one of the largest, fastest sea stars in the ocean, often reaching a metre wide with 16 to 24 arms. It has 15,000 tube feet that suspend it off the seafloor and allow it to move more than a metre per minute when on the prowl for prey, Gehman said. 'They kind of look like a hovercraft moving towards their food.' The species has suffered catastrophic population declines of 80 to 90 per cent in the last decade due to a marine epidemic known as sea star wasting disease that causes white lesions on the many-armed creatures before rapidly reducing them to mush. The wasting syndrome surfaced in 2013 along with spiking ocean temperatures caused by climate change, Gehman said. The disease attacks other types of sea stars as well, but it's decimated the sunflower variety, pushing them into virtual extinction in California and Mexican waters. Pockets of sunflower sea stars have found some refuge from the disease tucked away in the deep, cold inlets of the BC central coast, Gehman said. However, those remaining populations aren't immune to outbreaks and their chances of survival remain fragile. 'While [being endangered] is clearly bad news, the silver lining is that COSEWIC's acknowledgment might finally generate momentum to save Pycnopodia — whether that's in the form of funding, policy changes, or conservation programs,' Gehman said. The federal ministry of the environment and climate change will examine the committee's report in the fall to consider protecting the sunflower sea star under Canada's Species at Risk Act (SARA). It's illegal to kill, harm or capture wildlife listed under the act. Identifying critical habitat and devising a recovery strategy, complete with timelines and outcomes, is also required for a protected species. 'I hope it's a speedy process because there's real urgency,' Gehman said. 'From a conservation perspective, even though we have these really amazing refuge populations that give us a lot of hope, they're not stable … So, the more we can learn about what is happening with them, the more that can help us to try and conserve the species.' The sunflower sea stars are carnivores that play an important role in ocean health, said Gehman. Their primary prey is sea urchins which, if left unchecked by predators, can mow down kelp forests that offer food and shelter for lots of different marine life. Gehman and other researchers are monitoring between six and 12 fjords to pinpoint the conditions that offer sunflower sea stars the most protection against the disease. Water chilled and churned up by Arctic winter winds channelled into the inlets seems to buffer the impacts, she said. In warmer weather, glacial melt creates a freshwater surface layer in the fjords. Since Pycnopodia don't like fresh water, the sea stars move deeper into saltier, colder water layers, which appears to slow but not completely prevent outbreaks, Gehman said. Typically, sunflower stars in other areas of the coast prefer water temperatures around 16 C. But now it appears that water temperatures must be less than 12 C to limit the spread of the pathogen. 'The disease is actually changing what temperature would be best for them,' Gehman said. The sea stars haven't adapted quickly enough to the disease to consistently avoid warmer waters, which makes understanding the factors at play in their cold-water hideouts critical for their survival, she said. Research is taking place south of the border to breed sunflower sea stars that are more resistant to the wasting disease, so they can potentially be released into the wild to repopulate marine areas. In future, Gehman wants to study other kinds of sea stars — like the purple or orange ochre sea stars on the West Coast— that have better withstood the withering disease in a bid for clues scientists could use to help out their much larger cousins. Identifying and protecting coastal fjords that offer the best conditions for sunflower sea stars is also an important step. Although the Pycnopodia situation is grave, Gehman says she recently experienced a rare and magical moment when the research team witnessed a massive spawning event involving 20 to 30 sea stars, while surveying one of the fjords. 'It's absolutely wild,' Gehman said, The sunflower sea stars have pores that circle the centre of their body. The marine creatures stretch upward on extended arms and arch their bodies, with females releasing masses of pinkish eggs while males emit white clouds of sperm. 'Only the tips of their arms are on the bottom with their middle body tented up into the water column,' she said. 'There were some absolutely giant animals. It kind of looks like there's a halo of pores on them, and everything is pouring out into the water — it's really surreal.' The spawning event is a hopeful sign these cold-water strongholds can offer the endangered species some measure of resiliency from climate change and disease, she said. But the situation remains tenuous and variable, said Gehman, noting on the same trip researchers found sunflower sea stars had been wiped out in one inlet but had bounced back in another. 'So, scientifically, we're learning a lot while also being sad,' she said. Rochelle Baker/Local Journalism Initiative/Canada's National Observer Error! Sorry, there was an error processing your request. There was a problem with the recaptcha. Please try again. You may unsubscribe at any time. By signing up, you agree to our terms of use and privacy policy . This site is protected by reCAPTCHA and the Google privacy policy and terms of service apply. Want more of the latest from us? Sign up for more at our newsletter page .
National Observer
10-06-2025
- Science
- National Observer
BC's sunflower sea stars are now endangered, but rays of hope remain
Sunflower sea stars clinging to life in BC's cold-water fjords are officially on the edge of extinction, a scientific advisory panel is warning. A once-abundant predator of the sea floor along the Pacific coast, stretching from Alaska to Baja California, Pycnopodia helianthoides, has been assessed as endangered by the federal Committee on the Status of Endangered Wildlife in Canada (COSEWIC). While disheartening, the decision isn't unexpected and could offer a margin of hope for the survival of the massive, vibrant sea star, said Alyssa Gehman, marine ecologist with the Hakai Institute. The only type of its genus, an adult sunflower star Pycnopodia (which comes in a variety of purple, orange or pinks) is one of the largest, fastest sea stars in the ocean, often reaching a metre wide with 16 to 24 arms. It has 15,000 tube feet that suspend it off the seafloor and allow it to move more than a metre per minute when on the prowl for prey, Gehman said. 'They kind of look like a hovercraft moving towards their food.' The species has suffered catastrophic population declines of 80 to 90 per cent in the last decade due to a marine epidemic known as sea star wasting disease that causes white lesions on the many-armed creatures before rapidly reducing them to mush. Sunflower sea stars clinging to life in BC's cold-water fjords are officially on the edge of extinction, a Canadian scientific advisory panel warns. The wasting syndrome surfaced in 2013 along with spiking ocean temperatures caused by climate change, Gehman said. The disease attacks other types of sea stars as well, but it's decimated the sunflower variety, pushing them into virtual extinction in California and Mexican waters. Pockets of sunflower sea stars have found some refuge from the disease tucked away in the deep, cold inlets of the BC central coast, Gehman said. However, those remaining populations aren't immune to outbreaks and their chances of survival remain fragile. 'While [being endangered] is clearly bad news, the silver lining is that COSEWIC's acknowledgment might finally generate momentum to save Pycnopodia — whether that's in the form of funding, policy changes, or conservation programs,' Gehman said. The federal ministry of the environment and climate change will examine the committee's report in the fall to consider protecting the sunflower sea star under Canada's Species at Risk Act (SARA). It's illegal to kill, harm or capture wildlife listed under the act. Identifying critical habitat and devising a recovery strategy, complete with timelines and outcomes, is also required for a protected species. 'I hope it's a speedy process because there's real urgency,' Gehman said. 'From a conservation perspective, even though we have these really amazing refuge populations that give us a lot of hope, they're not stable … So, the more we can learn about what is happening with them, the more that can help us to try and conserve the species.' The sunflower sea stars are carnivores that play an important role in ocean health, said Gehman. Their primary prey is sea urchins which, if left unchecked by predators, can mow down kelp forests that offer food and shelter for lots of different marine life. Gehman and other researchers are monitoring between six and 12 fjords to pinpoint the conditions that offer sunflower sea stars the most protection against the disease. Water chilled and churned up by Arctic winter winds channelled into the inlets seems to buffer the impacts, she said. In warmer weather, glacial melt creates a freshwater surface layer in the fjords. Since Pycnopodia don't like fresh water, the sea stars move deeper into saltier, colder water layers, which appears to slow but not completely prevent outbreaks, Gehman said. Typically, sunflower stars in other areas of the coast prefer water temperatures around 16 C. But now it appears that water temperatures must be less than 12 C to limit the spread of the pathogen. 'The disease is actually changing what temperature would be best for them,' Gehman said. The sea stars haven't adapted quickly enough to the disease to consistently avoid warmer waters, which makes understanding the factors at play in their cold-water hideouts critical for their survival, she said. Research is taking place south of the border to breed sunflower sea stars that are more resistant to the wasting disease, so they can potentially be released into the wild to repopulate marine areas. In future, Gehman wants to study other kinds of sea stars — like the purple or orange ochre sea stars on the West Coast— that have better withstood the withering disease in a bid for clues scientists could use to help out their much larger cousins. Identifying and protecting coastal fjords that offer the best conditions for sunflower sea stars is also an important step. Although the Pycnopodia situation is grave, Gehman says she recently experienced a rare and magical moment when the research team witnessed a massive spawning event involving 20 to 30 sea stars, while surveying one of the fjords. 'It's absolutely wild,' Gehman said, The sunflower sea stars have pores that circle the centre of their body. The marine creatures stretch upward on extended arms and arch their bodies, with females releasing masses of pinkish eggs while males emit white clouds of sperm. 'Only the tips of their arms are on the bottom with their middle body tented up into the water column,' she said. 'There were some absolutely giant animals. It kind of looks like there's a halo of pores on them, and everything is pouring out into the water — it's really surreal.' The spawning event is a hopeful sign these cold-water strongholds can offer the endangered species some measure of resiliency from climate change and disease, she said. But the situation remains tenuous and variable, said Gehman, noting on the same trip researchers found sunflower sea stars had been wiped out in one inlet but had bounced back in another. 'So, scientifically, we're learning a lot while also being sad,' she said.
CBC
03-04-2025
- Science
- CBC
These sea stars were nearly wiped out — but B.C. researchers say fiords provided refuge
Social Sharing B.C. researchers have found that the fiords of the Central Coast may be providing refuge for the critically endangered sunflower sea star, a discovery that could have implications for wider ecosystems at risk due to warming seas. Nine out of 10 sea stars have been wiped out since 2013 due to sea star wasting disease, which has led to a mass death of the animals along North America's West Coast, from Alaska to Mexico. The sunflower sea star is listed as critically endangered by the International Union for Conservation of Nature. While the exact cause of the disease is unknown, scientists say it's had major ripple effects, as sunflower sea stars eat sea urchins and perform an important role in keeping those populations in check. Without them, urchins have flourished and been able to eat kelp forests, which further destabilizes marine ecosystems. Now, after years of diving along B.C.'s Central Coast, researchers have found many healthy adult colonies of sunflower sea stars in the fiords there. Alyssa Gehman, a scientist with the Hakai Institute and an adjunct professor at the University of B.C., co-authored a paper on the findings. What they found, she said, is that while sea star wasting disease has been found in fiords and sea stars have died there, the mortality rate is far lower than elsewhere in the ocean. Researchers suspect the difference has something to do with water temperature. In fiords — long, narrow, and deep inlets often found between high cliffs along the central and north coasts — the ocean tends to be cooler than elsewhere. Gehman said the research team was first alerted to the large number of sunflower sea stars in fiords by Central Coast Indigenous Resource Alliance divers who were looking for rockfish — and the two groups ended up collaborating on the final research paper. "When we looked at the oceanography ... we found that where the sea stars are, it's colder," Gehman told Darius Mahdavi, CBC's science specialist. "That's our next thing, is trying to figure out exactly what that temperature relationship is, and how that's working." Changes in seasons Jeff Sha, an aquarium biologist at the Vancouver Aquarium who wasn't involved in the study, said scientists have evidence that sea star wasting disease thrives in warmer water. "The higher the temperature, the more likely the onset of the disease, and the harder it is for an infected sea star to come back from that," he said. "As temperatures are rising along our coastlines ... we've had a couple of heat domes in the last decade, each of those events basically was another round of devastation for the population." Gehman said in the fiords, Arctic outflow conditions create cold winds in the winters, cooling the water and making the environment higher in oxygen, which is good for sea stars. "In the summer, when it's hot, there's glacial runoff that comes through," she said. "And it's so fascinating, but it creates essentially a little freshwater river on the surface of the fiord." Sha said sea stars don't like fresh water, which means they'll go deeper and into the colder water. "The researchers are hypothesizing that that's kind of what's giving them a little bit of a refuge away from the warmer temperature zone, and keeping them healthy from the wasting disease," he said. Implications for recovery efforts Sha said sunflower sea stars, in particular, are a ferocious predator for sea urchins — and without them, there's been devastating effects for other species. "Sea urchin populations have boomed on our coast, causing a decline in our algae and our kelp forest, which then removes habitats for rockfish and all these beautiful animals that we have," the biologist said. WATCH | Some sea stars released into the wild: Sunflower sea stars released into the wild after disease stunted population 7 months ago Duration 4:13 Over the past decade, disease has killed off around five billion sunflower sea stars, disrupting underwater ecosystems from Alaska to California. Now, the starfish are being released back into the wild around the San Juan Islands in Washington State. They're the first of their kind to have been bred in captivity by researchers at the University of Washington. Jason Hosin, a University of Washington marine biologist, shares more about his research. Gehman said some kelp forests along B.C.'s coast have been reduced to "urchin barrens," where all of the leafy portions of the kelp have been consumed by sea urchins. The scientist said that, as researchers look to raise sunflower sea stars in the laboratory and put them back in the ocean, their work in the fiords could be important — though she acknowledged that climate change will continue to affect whether fiords can remain a "refuge habitat" for the species. "There's hope that we could potentially raise stars that would be resistant to the disease," she said. "And this suggests that we need to pay attention to temperature when we're doing that work as well."
