Managing populations after a disease outbreak: exploration of epidemiological consequences of managed host reintroduction following disease-driven host decline

Disease outbreaks in wild populations around the globe can lead to widespread mortality within populations, where recovery of individuals can be rare. An example of this population is the sunflower sea star Pyc-nopodia helianthioides in the Northeastern Pacific coast. The populations of this species, as well as many other sea star populations, have experienced massive mortality events due to an unidentified disease called Sea Star Wasting Disease (SSWD). Pycnopodia play a key role in providing top-down control of kelp grazers in rocky reefs across the Northeastern Pacific coast. This, combined with the massive declines in kelp coverage observed during the 2015-2016 marine heat wave observed in the Northeastern Pacific, has sparked an interest in reintroducing Pycnopodia individuals in the coast to potentially assist in recovery of the populations. However, the epidemiological implications of reintroducing healthy sea stars into the wild populations is an under-explored question. This work explores this question using a dynamical population model of Pycnopodia. We use this model to estimate the impacts of reintroducing healthy individuals into a wild sea star population. This analysis will provide valuable information for managers interested in restoring Pycnopodia populations.