In this paper, we critically analyze how sustainability is considered in aquaculture policies and strategies using the Nordic countries as a case. The strong versus weak sustainability concepts are used to define and clarify what sustainability aspects are central to each state. To illustrate these concepts further, we draw on and modify four mainstream environmental discourses defined by John Dryzek and apply them to the strong and weak sustainability dichotomy to help categorize how environmental sustainability is portrayed in Nordic aquaculture policies and strategies. Subsequently we apply the characteristics of the concepts to aquaculture and sustainability in the Nordic countries. This allows us to identify each state's depiction of sustainable aquaculture, compare these to one another and assess where the Nordic states position themselves regarding sustainability and aquaculture. Our findings show that the policies emphasize technological advancements, intensification, and economic growth, which correlates with weak sustainability. Environmental sustainability receives a significant role in the documents too but does not seem to trump increased intensification or profitability. All policies are heavily focused on fed aquaculture and in order to reduce negative impacts from aquaculture there is a need to incorporate key elements of strong sustainability in policies, including measures to reduce impacts from pollution and the spread of pathogens, use of high-grade food resources and energy consumption. This to transform the industry to sustainability rather than just making it less unsustainable.

Farmed salmon has become an important export commodity for many countries and regions. The expanding salmon aquaculture industry has, due to its rapid increase, resulted in environmental concerns, most notably relating to the interaction with wildlife, effects of effluents and discharges in local ecosystems, in some regions overuse of antibiotics and development of Antimicrobial Resistance (AMR) and high dependence on fish resources in feeds. As a response to these concerns, the industry has strengthened their efforts to improve practices and private led sustainability initiatives, including certification and eco-labelling, has become increasingly important. This study examines the differences between salmon farming governance policies in the four largest salmon producing regions; Norway, Chile, Scotland (UK) and British Columbia (Canada) and the Aquaculture Stewardship Council's (ASC) salmon standard. The purpose of the study is to clarify how the standard from a well-established eco-certification program compares to national or regional conventional standards, using additionality as measuring method. The paper concludes that at present the ASC standard has mainly three strong advantages over existing regional/national standards and these relate to; escape numbers allowed, antibiotic usage and fish resources in feed. Changing these three main divergences in the national/regional regulations would significantly improve some of the main sustainability issues with uncertified salmon farming. The study also finds that the potential additionality of the ASC standard can differ between regions, with the highest difference in Chile and lowest in Norway.