Pacific Sea Star ‘Wasting’ Disease Solved: Bacteria Identified as Culprit in Mass die-Off
MONTEREY, CA – After a decade of devastation, scientists have pinpointed the cause of a mysterious disease that has killed an estimated 5 billion sea stars along the Pacific coast, from Mexico to Alaska. The culprit: a common marine bacteria, Vibrio pectenicida. The breakthrough, announced this week, offers a crucial step toward understanding and potentially reversing the catastrophic decline of these vital ocean creatures.
The epidemic, first observed in 2013, rapidly spread, decimating populations of numerous sea star species. the sunflower star, a keystone predator, suffered a notably dramatic loss, plummeting by approximately 90% within the first five years of the outbreak. Initially, viruses were suspected, but extensive research revealed these were actually naturally occurring densoviruses found even in healthy starfish.
“Tracing the source of such environmental diseases under the sea is incredibly tough,” said Alyssa Gehman of the Hakai Institute. “The detective work done by the investigative team is really smart and critically important.”
The disease manifests as lesions on the sea stars’ bodies, followed by the loss of arms – a process researchers describe as “truly scary.” This widespread mortality has triggered a cascading effect throughout Pacific ecosystems. Sunflower stars are primary predators of sea urchins, and their decline has allowed urchin populations to explode, leading to the destruction of kelp forests. Northern California alone has lost 95% of its kelp forests over the past decade, impacting the fish, otters, and seals that depend on these underwater habitats.
Researchers are now focusing on recovery efforts, including identifying healthy sea stars for repopulation and transplantation, and investigating potential natural immunity within surviving populations. They are also exploring the use of probiotics to bolster the immune systems of vulnerable starfish.
“Such recovery efforts are critical for all Pacific ecosystems, as well as starfish,” emphasized Rebecca Vega Thurber. “Seagrass forests are as vital as the rainforests of the ocean.”
