20Although climate change is altering the productivity and distribution of marine fisheries, 21climate-adaptive fisheries management could mitigate many of the negative impacts on human 22society. We forecast global fisheries biomass, catch, and profits to 2100 under three climate 23 scenarios (RCPs 4.5, 6.0, 8.5) and five levels of management reform to (1) determine the impact 24 of climate change on national fisheries and (2) quantify the national-scale benefits of 25implementing climate-adaptive fisheries reforms. Management reforms accounting for shifting 26 productivity and shifting distributions would yield higher catch and profits in the future relative 27to today for 60-65% of countries under the two least severe climate scenarios but for only 35% 28of countries under the most severe scenario. Furthermore, these management reforms would 29 yield higher cumulative catch and profits than business-as-usual management for nearly all 30 countries under the two least severe climate scenarios but would yield lower cumulative catch 31for 40% of countries under the most severe scenario. Fortunately, perfect fisheries 32 management is not necessary to achieve these benefits: transboundary cooperation with 5-33year intervals between adaptive interventions would result in comparable outcomes. However, 34the ability for realistic management reforms to offset the negative impacts of climate change is 35bounded by changes in underlying biological productivity. Although realistic reforms could 36 generate higher catch and profits for 23-50% of countries experiencing reductions in 37 productivity, the remaining countries would need to develop, expand, and reform aquaculture 38and other food production sectors to offset losses in capture fisheries. Still, climate-adaptive 39 management is more profitable than business-as-usual management in all countries and we 40provide guidance on implementing -and achieving the benefits of -climate-adaptive fisheries 41reform along a gradient of scientific, management, and enforcement capacities. 42 43 44Marine fisheries provide a vital source of food for over half the world's population and 45 support the livelihoods of over 56 million people globally [1].