Meeting Abstract
Sea star wasting disease (SSWD) is impacting ecological communities along the Pacific coast. Multiple environmental stressors such as changes in temperature, salinity, or pH might increase susceptibility to SSWD. Surveys of changes in sea star abundance are an important tool for understanding the spread and impact of the disease on marine communities. Many survey efforts focus on the larger stars including the keystone predator Pisaster ochraceous that suffered initial drastic population declines from SSWD but has recently shown some localized signs of recovery. In contrast to P. ochraceous and other stars that disperse via larvae and can re-colonize large areas decimated by SSWD, the small cryptic six-armed sea star Leptasterias spp. brood its young. Brooding stars tend to have minimal gene flow between populations, which leads to the potential of both reproductive isolation among relatively close sites and greater fluctuation in population density over time. An analysis of abundance surveys conducted in central and northern California during the period 2010 to 2016 shows differential but sometimes-drastic declines in Leptasterias abundance. The onset of decline in Leptasterias abundance appears to be later than in larger-bodied sea stars. In central California multiple local populations appear to have been extirpated. Populations in northern California presently show levels of abundance similar to what was previously found in central California despite the fact that symptomatic stars are found in these locations. Given the life history of Leptasterias spp. recovery from SSWD in severely impacted populations in central California may be unattainable over a short time frame.
