Sunflower sea stars (Pycnopodia helianthoides) are one of the biggest sea stars in the world, with 24 limbs that could be as long as one meter. They are usually found on the Pacific coasts and in North America. Unfortunately, they are now listed as critically endangered species under the International Union for Conservation of Nature's (IUCN) Red List of Threatened Species.
Marine biologist and senior research scientist Jason Hodin, together with colleagues from the University of Washington's Friday Harbor Laboratories, have spent the last two years trying to figure out how to raise the 24-armed sea creature. The group hopes to reintroduced lab-grown species to the ocean to prevent them from going extinct.
Critically Endangered Sunflower Sea Stars
Sunflower sea stars were commonly seen in the coasts of Alaska to Baja California ten years ago, according to Forbes. Still, they slowly died off due to rising water temperatures and pathogens that caused the sea star wasting disease. Scientists recorded 5.75 billion sunflower sea stars that have died from the disease, 90% of their global population.
IUCN wrote that these 24-armed sea creatures are opportunistic hunters of different marine vertebrates and serve as important predators in some areas to help keep the ecosystem healthy.
The cause of the sea star wasting syndrome in 2013 was unknown, although it is mostly associated with the warming sea temperatures. But after many years, scientists did not see any improvement in their numbers. The IUCN classified them as critically endangered species, which calls for conservation measures.
Some scientists have started captive rearing methods while exploring the possibility of reintroduction to the wild. But until the cause of the sea star wasting is not identified and resolved, sunflower sea stars will still be threatened.
Rearing Sunflow Sea Stars in the Lab
According to NPR, the Nature Conservancy approached Hodin in 2019 for the possibility of setting up a program that will breed sunflower sea stars. Since he has been interested in these 24-armed sea creatures, he agreed to raise large numbers of sunflower sea stars to adulthood.
He had a lot to learn in raising them, like what they ate when they were young and how fast they could grow. Raising sunflower sea stars had not been done before, so the mission was a bit of a challenge for Hodin and his colleagues.
He named the sunflower sea stars based on their colors and characteristics, like Prince for its purple tips and Deep Blue. He also described some shy ones who only come to life when they clutch a mussel.
Over time, the team learned to extract sperm and eggs from the wild-caught adults and grow them in the lab. So far, the oldest lab-grown sunflower sea star is now one and a half years old and measures about 3 inches. The lab produced dozens of more young sea stars, which to Hodin and his team seems lucky because the pandemic had restricted them from going into their lab.
They aim to produce 1,000 more young stars after their success of raising sunflower sea stars in just two years. Hodin said these lab-grown creatures could be reintroduced to local waters where the parents came from to test how well they would fare in the wild, despite the possible danger of the sea star wasting disease.
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