Microbial respiration in the asteroid diffusive boundary layer influenced sea star wasting disease during the 2013-2014 northeast Pacific Ocean mass mortality event

Abstract

Sea star wasting disease (SSWD) describes a suite of abnormal signs in affected Asteroidea (Echinodermata). The disease gained prominence in 2013-2014 after it was linked to mass mortality in the northeast Pacific Ocean. Recent work highlighted the key role of heterotrophic microorganisms inhabiting the diffusive boundary layer around sea stars in generating disease signs via oxygen depletion. However, it is unclear whether this phenomenon occurred during the 2013-2014 mass mortality or how surviving populations may have adapted to low oxygen conditions. In this opinion piece, I outline evidence for this phenomenon in both oceanographic conditions experienced by asteroids in 2013-2014 and from population genetic studies of surviving asteroids.