Sea Star Disease a Mystery

A recent influx of disease has taken a destructive toll on sea stars, reducing them from iconic marine echinoderms to blobs of unrecognizable sludge. The Santa Cruz Sentinel reports sea star wasting diseases have been documented before, but this wipeout is unlike any prior. Usually, sea star wasting diseases emerge in warm-water cycles and are confined to smaller regions. In this epidemic, the disease has spread during a cold-water cycle from the coast of Southern California all the way to Alaska. Locally, sea stars are typically found at Natural Bridges, Greyhound Rock and other rocky shorelines.

So far, researchers understand the symptoms once the sea star is infected, but the “how” and “why” are still under investigation. Upon contraction of the disease, sea stars develop cuts in their tissue that inevitably lead to infection and tissue decay. In just a few days, the sea star fragments into pieces, losing its legs. This loss of limbs is known as necrosis, a telltale sign in any sea star wasting disease, and it leaves the legless sea star lacking any star-like qualities—just a shapeless mess of echinoderm goop.

Pete Raimondi, head of UC Santa Cruz's Ecology and Evolutionary Biology lab, is leading the investigation into the roots of the current sea star die-off. The first step is pinpointing the disease’s origin. "If we can find the point of initiation, that will help us find causation," Raimondi told the Sentinel. "It's a classic epidemiological mystery."

With disease-tracking, downloadable documentation available to ordinary tidepoolers, Raimondi and other researchers are hopeful that the tidepooling community will be helpful citizens of science and contribute their knowledge on the spread of the disease. Those interested in contributing to the effort should visit the Pacific Rocky Intertidal Monitoring page for instructions and downloadable spreadsheets.

Photo credit: Aldaron/Creative Commons