Why aquaculture may not conserve wild fish.

We review literature on the displacement paradox and the Jevons paradox, with consideration of their implications for the potential effects of aquaculture on wild fisheries. The Jevons paradox refers to circumstances where improvements in the efficiency of resource use lead to growth in consumption and therefore undermine conservation. The displacement paradox refers to circumstances where increasing use of a potential substitute for a resource (e.g., farmed fish) does not lead to proportionate reduction in consumption of the other resource (e.g., wild fish). The literature on the displacement paradox and the Jevons paradox suggests that there may be unanticipated consequences from the rise of aquaculture that may be detrimental for fisheries conservation. Here, we present theoretical explanations, drawing on the tragedy of the commodity, for understanding the tendencies for these technological paradoxes to occur and emphasize their relevance for concerns associated with fisheries and aquaculture systems.