What’s Melting Starfish?

By Cassie Martin
BU News Service

Starfish along the shore in Olympic Coast National Marine Sanctuary in Washington State. Photo Courtesy of NOAA.
Starfish along the shore in Olympic Coast National Marine Sanctuary in Washington State. Photo Courtesy of NOAA.

If starfish could talk, we’d probably hear them screaming “I’m melting…melting!” Along the west coast of the U.S. and Canada, starfish are dying off in massive numbers, succumbing to sea star wasting syndrome—a mysterious illness that turns them into what scientists are calling piles of white goop.

In July, marine researchers from the University of California in Santa Cruz (UCSC) were doing fieldwork off the coast of Alaska when they noticed something strange: scores of starfish were losing their arms and developing white lesions on their bodies. The syndrome, which affects at least 10 different species, is swift. The time from infection to goop can be as short as a few days. In some regions, 95 percent of starfish populations have been wiped out.

Starfish are keystone species in many tidal ecosystems, responsible for maintaining biodiversity. A significant decrease in their populations could tip the scales, allowing other organisms such as mollusks to dominate and throw the whole system out of whack.

The culprit behind the outbreak continues to elude researchers, but suspects include viruses, bacteria, and/or environmental factors. In the past, scientists attributed starfish die-offs to warming water temperatures, which leave the multi-armed creatures vulnerable to disease-causing bacteria. But that’s not the case here. Water temperatures along the west coast are currently experiencing a cold period.

While research to identify the cause of sea star wasting syndrome continues, the good news is that starfish are resilient creatures. Although their populations are in shambles, they regenerate quickly according to UCSC experts. To learn more about current efforts to stem the disease, check out this interactive map from the UCSC Pacific Rocky Intertidal Monitoring Program.