Mystery of Sea Star Deaths Resolved
WASHINGTON – Researchers have uncovered the cause of a devastating epidemic that wiped out over five billion sea stars along the Pacific Coast of North America. This issue began around 2013, with a mysterious disease leading to widespread mortality from Mexico to Alaska.
Sea stars, commonly known as starfish, vary in species and can feature anywhere from five to twenty-four arms, showcasing colors ranging from orange to shades of purple and green. The “wasting disease” notably decimated the population of the sunflower sea star, resulting in a staggering 90% loss within the first five years of the outbreak.
The culprit behind this massive die-off has been identified as a type of bacteria that has also impacted shellfish, as revealed in a recent study in the journal Nature Ecology and Evolution. Marine ecologist Alyssa Gehman highlighted the gruesome effects of the disease, explaining that healthy sea stars normally have robust arms, but those afflicted develop lesions, resulting in their arms falling off.
This breakthrough in understanding the disease comes after more than a decade of research filled with misleading leads. Initially, scientists suspected a virus was to blame; however, it turned out that the virus thought responsible was merely a bystander in healthy sea stars rather than a disease-causing agent. Studies focused on tissue samples from deceased sea stars actually overlooked the key evidence found in their coelomic fluid, where the harmful bacteria, Vibrio pectenicida, was ultimately discovered.
Experts believe that knowing the root cause opens up avenues for possible interventions. Scientists are now considering breeding healthy sea stars in controlled environments and possibly relocating or transplanting them to affected areas. There’s also interest in exploring whether certain populations possess natural immunity or if treatments, such as probiotics, could boost their defenses against the disease.
The recovery of sea star populations is critical, not just for their species, but for the entire Pacific ecosystem. As voracious consumers of sea urchins, healthy sea stars play a vital role in maintaining balance within marine habitats. With their decline, sea urchin populations have surged, which has led to the rapid degradation of kelp forests—a crucial environment providing food and shelter for various marine life. Researchers are hopeful that restoring sea stars could help rejuvenate these vital underwater forests, likening them to the “rainforests of the ocean.”
This discovery not only addresses a long-standing ecological puzzle but also emphasizes the importance of responsible environmental stewardship. Protecting our oceans and understanding the delicate interdependencies amongst marine species are essential for the health of our planet.
