The Blue Mud Shrimp, Upogebia pugettensis , is an ecosystem engineer of western North American estuaries and strongly influences estuarine biogeochemical cycling, surface area, biodiversity, and trophic dynamics. In recent decades, U. pugettensis populations have declined or been extirpated over the species’ range due to infestations by the introduced Asian isopod parasite Orthione griffenis . These widespread losses highlight...