Realistic fisheries management reforms could mitigate the impacts of climate change in most countries

today with such reforms. However, the ability for management reform to mitigate the impacts of climate change is dependent on swift efforts to reduce greenhouse gas emissions. Even per- fect climate-adaptive management (“full adaptation”) is unable to maintain current catch and profits under high-end greenhouse gas emissions (RCP 8.5). Furthermore, although perfect adaptation could maintain global catch and profits under partial emission reductions (RCP 6.0), tropical and temperate regions would still incur dramatic losses in fisheries benefits. This underscores the fact that emission reductions consistent with the Paris Agreement could have significant impacts on the ability for fisheries to feed and employ people into the future [38,39]. The development and implementation of stock assessment methods and management strat- egies necessary to achieve benefits in the face of climate change is nascent but rapidly develop- ing. For example, Skern-Mauritzen et al. [40] reviewed 1,250 stock assessments from around the world and found that only 2% incorporated ecosystem information into either the final stock assessment model or the recommended harvest control rule. In the United States, Mar- shall et al. [21] found greater, though still limited, incorporation of ecosystem information into stock assessments: 24% of 206 evaluated assessment reports included ecosystem informa- tion in either the exploratory or final stock assessment models. The effective incorporation of environmental information into management strategies is similarly challenging but is also

increasing in frequency and effectiveness. Punt et al. [37] reviewed management strategy eval- uation (MSE) studies that test procedures for setting environmentally-linked harvest control rules and found that, in general, these procedures were only effective when the environmental drivers were well understood. This emphasizes the need for increasing monitoring and pro- cess-oriented lab and field studies in conjunction with the development and testing of more sophisticated analytical techniques [41]. Furthermore, achieving the benefits of climate-adaptive fisheries reform will require account- ing for shifting productivity and distributions along a gradient of scientific, management, and enforcement capacities. Many countries lack the monitoring programs required to detect and describe shifts in distribution and productivity, the scientific capacity for conducting either cli- mate-agnostic or climate-adaptive stock assessments, and the management capacity for setting and enforcing fisheries regulations [25,42,43]. This is frequently the case for the tropical develop- ing countries that are forecast to experience the greatest losses in fisheries catch and profits under climate change and exhibit the greatest vulnerability to these reductions in food and income [44]. The tools for enacting climate-adaptive fisheries reforms and achieving biological and socioeconomic resilience to climate change will have to span this gradient of capacity. Fortunately, a growing body of literature provides guidance on accounting for shifting dis-

tributions and productivity in fisheries assessment and management [14,17,45,46] and for fos- tering socioeconomic resilience to climate change [47–49] in diverse fisheries systems. In the remainder of this paper, we provide a brief overview of this literature and recommend general principles as well as specific strategies for achieving the benefits of climate-adaptive manage- ment reforms. We offer recommendations for higher and lower capacity fisheries systems as well as recommendations for countries where even the best management reforms will be unable to offset the negative impacts of climate change. Guiding principles for climate-adaptive fisheries management Principle #1: Implement best practices in fisheries management. Historically, well- managed fisheries have been among the most resilient to climate change [4], and our results predict that well-intended, albeit imperfect, management will continue to confer climate resil- ience. Together, these results indicate that the wider implementation of best practices in fisher- ies management will mitigate many of the negative impacts of climate change. In higher PLOS ONE Realistic fisheries management reforms could mitigate the impacts of climate change in most countries PLOS ONE | https://doi.org/10.1371/journal.pone.0224347 March 5, 2020 13 / 21