Native trout are threatened worldwide by introductions of non-native trout that in many cases are themselves threatened within their native range and historical habitats. This chapter focuses on this paradox and addresses how information gained to protect and restore a species in its native range can be used to suppress the same species outside its native range, where it may be invasive. We describe examples of three trout species, Lake Trout, Brown Trout, and Brook Trout, which are managed for the opposing goals of restoration versus suppression, in relation to their opposing roles as both native and non-native species in aquatic communities. We also attempt to develop insights into how this information might be used to accomplish both seemingly incompatible ends.