Aquarium Staff Work On Sea Star Wasting Disease Treatment
In 2013 and 2014 a mass die off occurred along the Pacific coast: near-unidentifiable gelatinous bulks–pools of decaying tissue–littered the seafloor. They were the remnants of sea stars, having fallen to sea star wasting (SSW). Sea star populations in Washington and California were devastated. Sea star wasting’s arrival to Oregon’s coast was not a matter of if, but when. Oregon Coast Aquarium’s scientific dive team and research partners regularly surveyed coastal waters, identifying the variety and frequency of the offshore sea stars they encountered. It was about a year and a half after initial reports of the disease that divers identified SSW in Yaquina Bay.
The stars dissolved at a rapid pace, catalyzing research efforts surrounding their disappearance. Some stars proved more susceptible to the syndrome than others. Ochre star populations saw dramatic declines, and sunflower sea stars were decimated–they’re now categorized as a critically endangered species. The loss of sea stars is felt across ecosystems. Ochre stars and sunflower stars are both considered keystone species due to their essential role in holding together complex food webs.
As a primary predator of purple sea urchins, the absence of the sunflower star allows urchins to proliferate, in turn negatively impacting the health of the kelp forests they consume. Kelp forests provide vital habitat in which species can reside and reproduce–without them, the foundation of marine food webs are threatened. Since 2014, reports of SSW have become less frequent–there are even signs of population recovery in ochre stars and other species. While mortality events of the same nature have happened in the past, none were of such magnitude, and research efforts continue today.
There is no cure for sea star wasting syndrome, and treatments for its symptoms have not yielded an optimistic prognosis. Until now. Aquarist Tiffany Rudek works behind-the-scenes, caring for the animals in the Aquarium’s quarantine area. Here, she examines the sea stars with a practiced eye. She’s spent the last three years at Oregon Coast Aquarium observing and caring for ill sea stars, both those with and without the wasting syndrome.
Over the last two years, Tiffany has put countless hours into developing a method of treating ill, injured, or stressed sea stars. And it’s working. For many of the stars under her care, the treatment was the difference between life and death. Rudek has carried out this work alongside fellow OCAq staff, partnering closely with supervisor and Sea Jelly Specialist/Assistant Curator of Fish and Invertebrates Evonne Mochon Collura to refine the method and develop the comprehensive treatment documentation and formal submission.
The experimental treatment used for the sunflower stars and others diverges from past methods. While the sea stars may be afflicted by an infection, the method does not include antibiotics. The method involves getting the star to a state of equilibrium, in which its immune system is supported and allows the star to heal, as opposed to treating myriad bacterial factors that may or may not be the root cause of the issue. This also provides the added benefit of being applicable to physical injuries caused by another animal, as well as sick sea stars who are actively exhibiting melting tissue.
As this method does not use antibiotics, it may still allow the stars to meet the complex criteria for release. This means that those who are authorized may be able to collect sickly stars during a wasting event, treat them, and then release them, as is commonly done with other marine wildlife, such as sea turtles. Currently, the Oregon Coast Aquarium only treats the sea stars in its collection. So far this method has proven successful with 17 sea stars of varying species.