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

necessary to establish data sharing and collaborative management will require overcoming prevailing management mentalities that one party “wins” while the other “loses” when stocks shift across boundaries. This could involve broadening negotiations to allow for alternative avenues of compensation or “side payments” [74]. In cases where establishing international cooperation proves difficult, marine protected areas (MPAs) placed along country borders could buy time for negotiations by protecting stocks as they shift across borders. A more pre- cautionary approach would be to put new fishing areas on hold until adaptive management can be put in place, as illustrated by the Central Arctic Ocean Fisheries Agreement (e.g., the CAOF Agreement, [75]). Principle #4: Build socioeconomic resilience. The impact of climate change on fishing communities can be reduced through measures that increase socioeconomic resilience and adaptive capacity to environmental variability and changing fisheries [49,76,77]. Across low to high capacity systems, these measures include (1) policies that facilitate flexibility, such as diversification of access to fisheries and alternative livelihoods, (2) policies that provide better assets, such as the enhancement of fisheries technology and capacity, (3) policies that provide better organization in the system, including multi-level governance, community-based manage- ment, and other governance structures [14,48], and (4) policies that promote agency and learn-

ing [49]. For example, policies that promote access to multiple fisheries provide fishers with a portfolio of fishing opportunities that can buffer against variability [78,79] while policies that promote diverse livelihoods reduce reliance on fisheries [80,81]. Increased mobility through technological enhancements can increase social resilience by allowing fishers to follow shifting stocks [49], but can also result in the migration of fishers. Multi-level governance promotes flex- ibility in resource governance by matching biological and management across scales [82]. Com- munity-based management can increase adaptive capacity by incorporating local knowledge and can improve sustainability by fostering a sense of stewardship [83]. Spatial-rights based approaches such as TURFs may confer social resilience insofar as they are often community- managed and allow fishers to generate revenues through other compatible activities such as tourism, recreation, and aquaculture [84]. On the other hand, ITQs may confer a different kind of resilience because rights are defined over fish catch rather than spatial areas. Therefore, they may be more resilient to range shifts arising from climate change assuming that the quota right remains usable in the new range of the species. Furthermore, all of these measures can be designed to reduce fishing pressure, and promote ecological resilience to climate change. Aquaculture could help compensate for losses in capture fisheries Even the best climate-adaptive management will be unable to maintain current catch and prof-

its in most tropical developing countries. Although these countries should still pursue climate- adaptive reforms to maximize catch and profits from capture fisheries, they will also need to develop, expand, and reform other sectors to compensate for capture fishery losses and meet growing production demands [85]. Marine aquaculture (hereafter called mariculture), the cul- tivation of marine animals and plants, presents a particularly promising substitute for capture fisheries. The biological potential for mariculture is enormous [86] and exceeds both current production and projected demand even after accounting for economic feasibility and the avail- ability of feed for fed-finfish mariculture [87]. This potential is expected to decrease under cli- mate change [88] but breeding a larger proportion of stocks for fast growth could more than offset these negative impacts [89]. Expanding mariculture under climate change will require (1) streamlining permitting for sustainable mariculture in highly regulated countries where mariculture growth has often been slow [90–93]; (2) promoting better practices in weakly reg- ulated countries where mariculture growth has often been rapid and less sustainable [92,93]; 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 15 / 21