Five lessons for avoiding failure when scaling in conservation.

Many attempts to scale conservation actions have failed to deliver their intended benefits, caused unintended harm or later been abandoned, hampering efforts to bend the curve on biodiversity loss. Here we encourage those calling for scaling to pause and reflect on past scaling efforts, which offer valuable lessons: the total impact of an action depends on both its effectiveness and scalability; effectiveness can change depending on scale for multiple reasons; feedback processes can change socio-ecological conditions influencing future adoption; and the drive to scale can incentivize bad practices that undermine long-term outcomes. Cutting across these themes is the recognition that monitoring scaling can enhance evidence-informed adaptive management, reporting and research. We draw on evidence and concepts from disparate fields, explore new linkages between often isolated concepts and suggest strategies for practitioners, policymakers and researchers. Reflecting on these five lessons may help in the scaling of effective conservation actions in responsible ways to meet the triple goals of reversing biodiversity loss, combating climate change and supporting human wellbeing.

Expanding ocean food production under climate change.

As the human population and demand for food grow1, the ocean will be called on to provide increasing amounts of seafood. Although fisheries reforms and advances in offshore aquaculture (hereafter 'mariculture') could increase production2, the true future of seafood depends on human responses to climate change3. Here we investigated whether coordinated reforms in fisheries and mariculture could increase seafood production per capita under climate change. We find that climate-adaptive fisheries reforms will be necessary but insufficient to maintain global seafood production per capita, even with aggressive reductions in greenhouse-gas emissions. However, the potential for sustainable mariculture to increase seafood per capita is vast and could increase seafood production per capita under all but the most severe emissions scenario. These increases are contingent on fisheries reforms, continued advances in feed technology and the establishment of effective mariculture governance and best practices. Furthermore, dramatically curbing emissions is essential for reducing inequities, increasing reform efficacy and mitigating risks unaccounted for in our analysis. Although climate change will challenge the ocean's ability to meet growing food demands, the ocean could produce more food than it does currently through swift and ambitious action to reduce emissions, reform capture fisheries and expand sustainable mariculture operations.