Fishery management actions focused on the conservation of non-target species may impact the productivity of fisheries in terms of target species. This article studies California’s drift gillnet swordfish (Xiphias gladius) fishery and investigates the impact of a recent regulatory measure aimed to protect leatherback turtles. A parametric approach is used for the primal characterization of the production technology in the California drift gillnet swordfish fishery. The production model is subsequently framed in the context of the difference-in-differences estimator to investigate the effect of the introduction of a regulatory time-area closure on the fishery. The parametric approach also allowing to control for fishing behaviors, equipment characteristics, stock abundance, and climate effects. Estimation results suggest the regulation has a statistically significant negative impact on swordfish productivity.