The normative implications of sustainable development mean that different understandings of how sustainability should be achieved will either facilitate or put at risk different values associated with economic, environmental and social aspects of sustainability. By a qualitative analysis of Swedish fishery legislation documents, we analyse and outline the consequences of two different and competing sustainability epistemologies: a top-down system understanding and a bottom-up experiential understanding. To define these two epistemologies, the case study adopts discourse analysis on one fishery law and one fishery regulation proposal, and the remittance answers to these documents. We demonstrate how a top-down system approach shapes social reality according to its own logic of efficiency, and that pre-defined principles of economic optimization prevail over social experience and continuity. We conclude that qualitative analysis holds promise to expand the understanding of the premises and consequences of alternative environmental governance trajectories due to its ability to uncover social constructions of meaning.