Seven years ago, a wasting disease began killing sea stars all along the West Coast. The largest and hardest-hit species, the sunflower sea star ( Pycnopodia helianthoides), is now critically endangered, reduced in numbers by some 90 percent. Scientists with the International Union for Conservation of Nature (IUCN) put it on their “red list” last week. But researchers at Friday Harbor Labs on San Juan Island say there’s reason for hope.