The culprit? Bacteria that has also infected shellfish, according to a study published Monday in the journal Nature Ecology and Evolution.

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Now that scientists know the cause, they have a better shot at intervening to help sea stars.

It’s a wasting-disease bacteria. Here’s the link to the study, as found in the article I clicked so you don’t have to:

https://www.nature.com/articles/s41559-025-02797-2