When overfishing is the sustainable option: controlling a range-extender

Abstract

Climate change is driving species to colonise new ranges, sometimes causing uncontrollable damage. We present a remarkable scenario where government-supported incentives have driven the establishment of a commercial fishery targeting a destructive urchin, intentionally encouraging overfishing to protect kelp ecosystems. This ecosystem management strategy is paradoxical in the objective to overfish sustainably. Due to consistent and increasing larval influx, eradication of urchins in their extended range is implausible. Management therefore focuses on maintaining urchin density below a critical threshold while ensuring a viable commercial fishery for long-term species control. Our bio-economic model dissects the fishery’s impact, offering practical strategies for controlling a destructive range-extender given economic and spatial dynamics. Beyond the implications of subsidising a commercial fishery to counteract the impacts of climate change, our study explores the conflict between exploitation and conservation, challenging traditional views and presenting practical pathways to sustainability.