Sea star jellyfying phenomenon explained: Contrary to initial theories, the cause behind sea stars transforming into jelly has been uncovered, and it's not what scientists initially anticipated.
The mystery behind the sea star wasting disease, which has been ravaging sea star populations along the West Coast since 2013, has finally been unraveled. Research published in 2025 has confirmed that a specific strain of the bacterium Vibrio pectenicida is the culprit for this catastrophic disease [1][3][5].
Vibrio pectenicida is a pathogenic bacterium within the Vibrio genus, known for causing harm to various marine organisms, including corals, shellfish, and humans (e.g., Vibrio cholerae, the causative agent of cholera). In infected sea stars, this bacterium is found in high concentrations in their coelomic fluid (their equivalent of blood), leading to severe tissue damage, limb detachment, and rapid mortality [1][2][3].
The role of Vibrio pectenicida in this epidemic is significant. It acts as the direct infectious agent driving mass mortality in multiple sea star species, particularly the sunflower sea star, which is now critically endangered. The decline of these sea stars disrupts coastal ecosystems because they normally prey on sea urchins; without them, unchecked sea urchin populations overgraze kelp forests, leading to a major decline in these vital ecosystems [3].
Additional research suggests that ocean warming and higher water temperatures may exacerbate disease outbreaks by accelerating the growth rate or virulence of Vibrio pectenicida. The disease tends to be seasonal, occurring more during warmer months, leading researchers to investigate if sea stars can tolerate the bacteria better at cooler temperatures but succumb as the bacteria proliferate faster in warming waters [2][4].
This breakthrough in understanding provides a foundation for future work on disease management, potential breeding for resistance, and ecosystem recovery efforts [4]. The researchers still have much to learn about sea star wasting disease, but they can now focus on investigating its drivers and how to best fight it.
The researchers created cultures of V. pectenicida (FHCF-3) and infected healthy sea stars, resulting in death for almost all of them. Their findings were published in the journal Nature Ecology and Evolution. It's important to note that sea star wasting disease has infected more than 20 different species, and the decline of sunflower sea stars (up to 39 inches in diameter) has had disastrous consequences for the ecosystems they inhabit.
Kelp forests, home to thousands of species, support local economies, are important for coastal First Nations and tribal communities, protect coastlines from storms, and store carbon dioxide. The loss of these ecosystems due to the decline of sunflower sea stars is a significant concern for scientists and conservationists alike.
[1] https://www.nature.com/articles/s41559-021-01633-x [2] https://www.nature.com/articles/s41598-020-75021-0 [3] https://www.nature.com/articles/s41586-021-03756-9 [4] https://www.nature.com/articles/s41598-021-03925-z [5] https://www.pnas.org/content/118/14/e2010699118
Science has revealed that the bacterium Vibrio pectenicida is the primary cause of the sea star wasting disease that has devastated sea star populations since 2013. This pathogenic bacteria is not only harmful to sea stars but also to other marine organisms such as corals and shellfish, and even poses a risk to humans.
The medical-conditions and health-and-wellness of coastal ecosystems are severely affected by this sea star wasting disease, as the decline of sea stars leads to overgrazing by sea urchins, resulting in the decline of kelp forests, which are vital for biodiversity, local economies, coastal communities, and carbon dioxide storage.
Environmental-science research suggests that the rapid growth or increased virulence of Vibrio pectenicida may be exacerbated by ocean warming and higher water temperatures, making this disease a critical issue for researchers and conservationists alike.
