Nearly all fisheries management is based on assessing one species at a time, ignoring any interactions with other species. Many have claimed that including these interactions will improve management and lead to greater fisheries profits. A new paper tests whether precise information on species interactions improves economic performance in fisheries. Somewhat reassuringly, economic value was not markedly lower if managers assumed that an incorrect type of interaction was true. But, risk of economic losses were uneven, with the fishery targeting the predator much more negatively affected than the fishery targeting the prey species, particularly when predators are at low abundance. The results show a path forward for managing fisheries using an ecosystem approach instead of a single-species approach: adopt strategies that maintain predator and prey stocks at levels where management decisions are robust to uncertainty about the true state of species interactions. The paper was authored by SAFS professor Tim Essington and appears in the journal Proceedings of the National Academy of Sciences with a commentary by the author here and a UW press release here.