Exploring marine conservation futures to inform systematic conservation planning

Marine conservation must advance towards global biodiversity targets despite significant climatic and geopolitical uncertainties. We present an expert-informed scenario framework to support systematic conservation planning in marine environments in the face of such unpredictable conditions. Through a six-step process involving an expert workshop and a survey of 85 respondents, climate change and international politics, governance and legislation were identified as the most relevant and uncertain drivers of marine conservation futures amongst the fourteen drivers considered. Their contrasting states were combined into four qualitative scenarios, ranging from effective climate mitigation and international cooperation to inadequate climate action and geopolitical conflict. We propose ways to translate these scenario narratives into conservation planning options by linking them to spatial decision-support tools and analytical workflows, considering biodiversity distributions, ecological connections amongst areas, climate risks, socio-economic costs and other effective area-based conservation measures. Two proposed analytical approaches illustrate how these considerations could be combined under different scenarios about the future. The resulting conservation priorities would provide information for ecosystem-based marine spatial planning by identifying biodiversity objectives and spatial requirements for consideration alongside other marine uses. The proposed framework provides a basis for exploring the way in which conservation strategies may perform under contrasting futures and adapting planning choices as ecological and governance conditions change. Expert-informed scenarios explore alternative futures for marine conservation. Climate action and geopolitics frame four contrasting conservation scenarios. Proposed planning approaches link these scenarios to systematic conservation planning. Comparing priorities across scenarios could support adaptive decisions. Conservation priorities can provide information for wider marine spatial planning processes.