The years from 2013 through 2015 witnessed the largest non-commercial marine mass mortality event on record (as of 2013) as up to 96% of all Ochre Sea Stars on the coasts of California and Oregon perished. This created a ‘natural experiment’ and an opportunity to study genomic changes in wild populations with unprecedented detail. Rather than observing only the aftermath — usually the case in such catastrophes – a team of researchers from UC Merced is reconstructing the population and genetic consequences of this epidemic outbreak of sea star wasting disease. The team measured the abundance and genetic variation of Pisaster ochraceus (the Ochre Sea Star – a keystone species) in the year preceding mass mortality. They then repeated sampling of adults and juveniles in subsequent years, measuring population dynamics and genomic shifts during and after the disease outbreak. At a time when marine diseases and mass mortalities are on the rise, this study documents the impact of little-known wildlife diseases and potential trajectory of recovery in a keystone marine species.
Learn more and watch: Sea Star Wasting Disease Update 2017