LAUSR

Significance While there has been much effort to understand how sea otter recovery transforms nearshore ecosystems, the effects on terrestrial systems have remained uninvestigated. We documented a transboundary food web interaction resulting from the recolonization of sea otters in Icy Straight, Alaska, which provided an ample marine subsidy to island wolves, and subsequently caused extirpation of a terrestrial ungulate. This defies former predictions of predator–prey dynamics which do not account for increasingly abundant and predictable subsidies such that occur on the forefront of the sea otter recovery wave. Although disruption of terrestrial consumer-resource dynamics was previously unforeseen, it hints at both the possibility that these interactions occurred historically and could also become more widespread as sea otters continue to rebound.