Static management presents a simple solution to a dynamic fishery and conservation challenge

Abstract

Dynamic ocean management, which leverages near real-time data to adaptively shift management in response to changing ocean conditions, is gaining attention as an alternative to static approaches for managing dynamic fisheries challenges. While promising, dynamic management can be data-intensive, costly, and difficult to implement, and its value relative to simpler static approaches should be evaluated before being applied, especially when endangered species and economically crucial fisheries are at risk. Here, we use management strategy evaluation to compare static and dynamic management strategies for reducing humpback whale (Megaptera novaeangliae) entanglement risk in the highly lucrative California Dungeness crab (Metacarcinus magister) trap fishery. We find that simple gear reductions outperform dynamic management strategies across several measures of performance. Gear reductions maintain uninterrupted fishing seasons and high fisheries catch and effectively prevent whale entanglement risk by directly reducing the number of vertical trap lines. Furthermore, gear reductions are robust to delayed openings resulting from biotoxin contamination and low meat quality, do not depend on the availability or accuracy of entanglement risk indicators, add no new management costs or enforcement challenges, and avoid biases in geographical equity. Dynamic management strategies, which proactively or reactively respond to indicators of entanglement risk, struggle to achieve their intended benefits because they are implemented after long logistical delays and because they redistribute rather than reduce entanglement risk. Bycatch threatens protected species and valuable fisheries around the world and models like the one developed here present valuable tools for weighing solutions to complex fisheries and conservation challenges.