Starfish Die-Off: Scientists Uncover Cause of Decade-Long Epidemic

The sunflower sea star (Pycnopodia Helianthoides) is among the largest sea stars in the world and has a maximum arm span of one meter.Universal History Archive/Universal Images Group via Getty Images

The bacterial culprit behind a devastating sea star epidemic has finally been identified.

A decade-long mystery involving the mass death of sea stars along the Pacific coast has been solved.

• Scientists have identified bacteria as the cause of a sea star wasting disease.
• The epidemic, starting in 2013, has killed over 5 billion sea stars from Mexico to Alaska.
• The sunflower sea star species lost 90% of its population in the first five years of the outbreak.
• Understanding the cause could lead to conservation efforts for the critically endangered sunflower sea star.

Scientists have pinpointed bacteria as the cause of a devastating sea star wasting disease that has wiped out billions along the Pacific coast. Starting in 2013, this mysterious ailment swept from Mexico to Alaska, impacting over 20 species and continuing to this day.

The sunflower sea star was hit notably hard, with about 90% of its population perishing in the first five years of the epidemic.Marine disease ecologist Alyssa Gehman from the Hakai Institute in British Columbia, Canada, described the effects as “gruesome,” noting that healthy sea stars with “puffy arms sticking straight out” develop lesions,