Collaborative Research: RAPID: Sea Star Wasting Disease in the High Antarctic: Deciphering the Role of Shifting Carbon and Climate Cycles on a Keystone Predator

This RAPID project aims to study a sporadic occurrence of sea star wasting syndrome (SSWS) in McMurdo sound by leveraging diving resources of a CAREER grant to Thurber. The disease was first noted in 2019, with a second occurrence documented by the group at their study site near a methane seep at Cinder Cone in McMurdo Sound in 2022. Sea stars are key species in many benthic ecosystems, including the Antarctic, and this disease has caused significant losses in populations worldwide. In the Southern Ocean, the sea star Odontaster validus preys upon Acodontaster conspicuous, a predator of Antarctic giant sponges. In 2022, about 30% of the O. validus at the methane seep were affected. The conditions associated with the disease in other areas are environmental hypoxia, warm temperatures, and organic enrichment. This recent outbreak provides the opportunity to study how the disease may progress in the Southern Ocean, and test the hypothesis that oxygen dynamics play a key role in the development of SSWS. The investigators aim to measure oxygen concentrations on and off the Cinder Cone seep and at the surface of affected and unaffected sea stars and identify whether the disease causes and microbiome characteristics of SSWS are similar between Antarctic and non-Antarctic outbreaks. These findings can be used to understand the potential effects of future climate conditions on disease outbreaks of Southern Ocean marine organisms critical to ecosystem function and health. In addition to disease dynamics, the study will also help to understand how methane seepage impacts benthic oxygen dynamics. Other broader impacts include communicating the research through a student led YouTube documentary and facilitating the transition of an early career URM researcher from NSF postdoc to a faculty position (lead on viral component of the project). This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.