Sustainable seafood and sustainable seas? Global trajectories and patterns of mariculture, fisheries, and marine protected areas

Society faces an urgent challenge to chart a sustainable path for the planet and humankind, including conserving degraded ecosystems while supporting a population that is forecast to increase more than 25% by 2050. Scholarship and policy engaging with this challenge often focus on land, overlooking the oceans, including threats to marine ecosystems and the important role seafood could play in future food systems. Conservation of marine ecosystems is gaining more prominence, as evidenced by initiatives to protect large portions of the ocean in marine protected areas (MPAs), although these efforts can be at odds with societal needs for food and other resources. Thus there is a growing body of research examining the conflicts, tradeoffs, and synergies between MPAs and wild fisheries. However, there has been far less attention on how marine conservation might interact with farming in the ocean (i.e., mariculture), despite mariculture having orders of magnitude higher production potential than wild fisheries. Here, we examine whether and how seafood production from mariculture might conflict or be compatible with marine conservation goals. Specifically, we show how country-level trajectories of mariculture development are related to patterns of wild seafood harvest and MPA creation worldwide. We document the degree to which countries that have experienced more mariculture development show less progress in achieving marine conservation objectives and conversely, where a focus on marine conservation seems to have stifled mariculture development. We also explore the inter-relationships between mariculture development, fisheries harvest and sustainability, marine conservation, and ecosystem health. This research helps to reveal whether there are fundamental conflicts between mariculture, fisheries, and conservation or if some countries can achieve all three, with important consequences for how society can balance and co-manage these priorities.