WASHINGTON (AP) — Scientists have finally unraveled the mystery behind the mass death of over 5 billion sea stars along the Pacific coast of North America. This epidemic, known as sea star wasting disease, has impacted these beautiful creatures since 2013.
Sea stars, often called starfish, come in many colors and can have five to 24 arms. The outbreak, which stretched from Mexico to Alaska, has devastated more than 20 species. The sunflower sea star was hit hardest, losing about 90% of its population in just the first five years.
Alyssa Gehman, a marine disease ecologist, described the situation as “gruesome.” Healthy sea stars are robust with arms that stick out. Unfortunately, the disease causes lesions and leads to their arms falling off.
The culprit? A bacteria called Vibrio pectenicida. This finding, published in the journal Nature Ecology and Evolution, finally answers a long-standing question about a serious ocean disease, according to marine microbiologist Rebecca Vega Thurber from UC Santa Barbara.
Identifying the disease’s cause took years of research. Earlier studies misidentified it as a virus, focusing on densovirus, which later turned out to be harmless. Research challenges arose because studies often looked at dead sea stars lacking critical bodily fluids. The new study successfully analyzed coelomic fluid, where the harmful bacteria was identified.
Blake Ushijima, a microbiologist from the University of North Carolina, Wilmington, highlighted the difficulty of tracking environmental diseases, especially underwater. He praised the research team’s methodical approach.
Now that scientists have pinpointed the cause, there’s a chance to help sea star populations recover. Options include testing remaining healthy sea stars for natural immunity and possibly breeding them for reintroduction into the wild.
The recovery of sea stars is crucial for Pacific ecosystems. These starfish play a vital role in controlling sea urchin populations. With fewer sea stars, sea urchins have exploded, leading to the destruction of nearly 95% of kelp forests in Northern California. Kelp forests are vital for marine life, providing food and habitat for numerous species, including fish and sea otters.
Researchers are hopeful that with these new insights, they can restore sea star numbers and revitalize the kelp forests, often called the “rainforests of the ocean.”
For more information on the impact of sea star wasting disease and marine ecosystems, you can read about it on Nature’s website here.
The efforts to understand and combat this disease highlight the importance of marine health and the interconnectedness of ocean life.
