Strong and weak sustainability in Nordic aquaculture policies

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.


Introduction
A key challenge for the future development of aquaculture is to increase the production capacity of the industry while minimizing negative environmental impacts (Naylor et al., 2021).Aquatic foods and aquaculture especially, is often referred to as having the potential to increase nutrient availability while generating relatively low environmental impacts (Gephart et al., 2021;Costello et al., 2020).In international strategies and policies on how to make the food producing sector more sustainable, one of the key recommendations is to expand the aquaculture sector, albeit in a sustainable way (EC, 2020, EC, 2021, FAO, 2018a, 2018b).All Nordic countries (Denmark, Faroe Islands, Finland, Iceland, Norway and Sweden) have taken these recommendations to heart and are planning to expand their aquaculture industries (MFNR, 2010;NFD, 2015;NaturErhvervstyrelsen, 2014;MAFF, 2019;Jordbruksverket, 2012a).These countries have been regarded as frontrunners in taking sustainability to national policy level (Sachs et al., 2019), and transforming the food system has been pointed out as a key lever of change to reach sustainability commitments (Wood et al., 2019;Gordon et al., 2017;Willett et al., 2019).Global food systems are heavily interconnected, and international policies, commitments and trade agreements have significant impacts on food production systems (Schipanski et al., 2016).As the Nordic countries are all active participants in international sustainability commitments like the Sustainable Development Goals (SDGs), a global perspective must be considered in domestic strategies and policies.
Formulating policies to enhance sustainable development or sustainability is a challenging feat as the terms involve the wellbeing of environments, societies, and economies (Giddings et al., 2002).Often what is beneficial for one is disadvantageous for the other, a so-called wicked challenge (Christie et al., 2003).What takes precedence in sustainable development policies are usually safeguarding the environment, sometimes referred to as strong sustainability and the economy, weak sustainability (Neumayer, E., 2003;Ekins et al., 2003).
In this paper, we critically analyze how the Nordic countries are planning on achieving environmentally sustainable aquaculture development.We do so by analyzing national strategies and policy documents through the lens of four different environmental discourses, developed from the strong vs weak sustainability dichotomy and John Dryzek's environmental discourse taxonomy (Dryzek, 2013), to identify how ideas of sustainable aquaculture in the different countries are formulated.In doing so, we aim to contribute to the conceptual debate between weak and strong sustainability in general, but in particular in relation to sustainable aquaculture, while also generating empirical insights into key differences between the Nordic countries.We realize that the environment constitutes one of three main pillars in sustainable development and that you cannot have sustainability without addressing the social-economic aspects too (Davies, 2013).However, we agree with the nested sustainability figure outlined by Giddings et al. (2002) that situates the other pillars of sustainability within the limits of the environment (see Fig. 1).We regard this paper as the starting point of a continuous effort to review how sustainability is portrayed and define areas where there is room for improvement.

Aquaculture in Nordic countries
Production quantities and economic significance of the industry vary significantly between the countries.Among the Nordic countries Norway, producing about 1.3 million tons per year, accounts for the lion's share of aquaculture production (SSB, 2020) (Table 1).One commonality though, is that they all produce mainly fed finfish and that salmonids dominate (Table 1).
Environmental conditions vary greatly between the countries.The Faroe Islands, Iceland, and Norway all have coastlines towards the strong currents of the North Sea and the Atlantic Ocean, whereas Denmark, Finland, and Sweden all have longer coastlines towards the brackish Baltic Sea.This creates particular circumstances for aquaculture production and sustainability considerations as the Baltic sea is unfavorable for production due to hypoxia, algae blooms, and low oxygen levels (Nielsen et al., 2014).Denmark and Sweden have coastlines towards the North Sea and Skagerrak, but in comparison to Norway, Iceland, and the Faroe Islands there is limited access to unpopulated coastlines with strong currents, which affects the possibilities of largescale open-water aquaculture.
The direct environmental effects of aquaculture in a region vary depending on type and intensity of farming and the characteristics of the surrounding/impacted environment (Troell et al., 2014).In Norway and Iceland, the environmental concerns related to aquaculture are mainly centered around sea lice, escapes and spreading of pathogens to wild stocks (Olaussen, 2018;Kristmundsson and Freeman, 2014;Finstad et al., 2019).Atlantic salmon does not spawn in the Faroe Islands, so escapes are not a big threat there.Sea lice still pose a threat to the farmed fish though (Gislason, 2018).In Denmark, Sweden and Finland (Baltic sea countries) the emphasis is on emissions of nitrogen and phosphorous and organic wastes (Nielsen, 2011;Soininen et al., 2019).

Problematizing environmentally sustainable aquaculture
Due to its vagueness and width of application, ranging from environmental, social, and economic dimensions, Sustainable Development (SD) can be described as wicked (Christie et al., 2003).Put differently, there are in most cases critical tradeoffs when solving issues and challenges, associated with advancing environmental, social, and economic development simultaneously (Sandersen and Kvalvik, 2015;Osmundsen et al., 2017).Thus, it becomes a matter of substitutability between these three dimensions, usually boiled down to a distinction between the environment and the economy (Gilek and Stalmokaite, 2018).
Relating the argument to aquaculture one could askwhat is the main purpose of production?Is it profitability, environmental sustainability, nutrition, or food security?Are the ambitions compatible or must there be a prioritization?At a global scale, aquaculture is often referred to as having the capacity to provide a growing population and poor regions with nutritious food (FAO, 2018a(FAO, , 2018b;;HLPE, 2017).In wealthier regions it is seen as an opportunity to increase food availability and decrease trade deficits whilst, through strict environmental regulation, limiting environmental footprints (EC, 2021;Lester et al., 2021).However, there are still some significant challenges related to aquaculture (Naylor et al., 2021), e.g. the high reliance on inputs from high-grade food ingredients that could be used directly for human consumption (Troell et al., 2014;Tlusty et al., 2019) and antibiotic treatments (Henriksson et al., 2018).Furthermore, waste outputs would need to be kept at a minimum to avoid harming surrounding environments and ecosystems (Klinger and Naylor, 2012;Eagle et al., 2004;Wiber et al., 2012).
Through effective policies, technological advancements and producing companies/farmers acting more responsibly, the abovementioned challenges have been mitigated (Asche and Smith, 2018), but are not fully addressed.There are still, although less frequently, mass-escapes from farms causing cross-breeding and changes in behavior among wild salmon stocks (Forseth et al., 2017), food-grade fish (and terrestrial food grade resources) is used as feed (Cashion et al., 2017;Naylor, 2005), nutrient waste pollutes the local/regional  O. Luthman et al. environment (Olaussen, 2018) and spreading of pathogens from aquaculture operations to wild stocks can have significant negative impacts (Mordecai et al., 2021).Moreover, the aquaculture sector is one of the fastest growing food production systems in the world and there is an immediate need to ensure reduced environmental impacts to enable expansion within the food planetary boundaries.Even with more technologically advanced aquaculture systems such as closed systems, e.g.Recirculating Aquaculture Systems (RAS) or aquaponics that reduce waste release and risks of negative effects on wild species, there are challenges related to feed resource use, water use and energy consumption (Klinger and Naylor, 2012).Finally, freshwater aquaculture in land-based production systems may create competition for land that can be used for other purposes (Searchinger et al., 2018).One measure towards mitigating some of these challenges is to diversify the sector (Gephart et al., 2021;EC, 2021).

Aim of study and research questions
The Nordic countries are highly developed states as well as outspoken advocates for sustainability and often viewed as leaders in the path towards sustainability (Sachs, 2019).If aquaculture is to reach its full potential as a sustainable food source, there is a need to better understand what is meant by sustainability in strategies and policies in one of the more environmentally ambitious regions of the world.In this paper, the core focus is on environmental sustainability.By using an interpretive policy analysis and a discourse approach, this paper conceptualizes how sustainability is constructed and expressed in the Nordic aquaculture policies (Yanow and Colebatch, 2004).Furthermore, it aims to contribute to the broader understanding of the content of aquaculture policies as they relate to sustainability.Thus, the paper aims to explore the following questions: -What characterizes different levels of sustainability in aquaculture?-How is 'sustainable aquaculture' framed in Nordic aquaculture policies and strategies?-How do the policies and strategies relate to environmental discourses on weak and strong sustainability?

Material & methods
The analysis for this paper is based on grey literature, peer-reviewed papers, and statistical information available on national statistical authorities in each country (see Appendix I).We use the terms policy and strategy depending on the document.A strategy is regarded as the stated overarching goal set up by the state, a policy is more specific on how to go about in achieving that goal.The documents have been retrieved from government agencies and bodies, ranging from the departments of natural resource management, business and development, fisheries, and coastal departments as well as agricultural departments.There is a large discrepancy in how many relevant policies relating to aquaculture that each country has.Furthermore, some countries update their policies more frequently than others.We used the most recent versions (the oldest from 2009) that had a clear relation to aquaculture.
Environmental sustainability serves as the main focus in the development of the theoretical discourses used in our analysis.We realize that there is a complexity in multi-level goals such as sustainable development, which will affect how policies and strategies are formulated (Abate et al., 2018).There are other goals, policies and norms that are addressed in other documents but not fully addressed in this paper.Furthermore, each Nordic state has related documents, institutions, and agencies that are of relevance for environmental standards and protection in each country.The ambition of this paper is to highlight how environmental sustainability comes across in the policies and strategies related to aquaculture development.

Method: Policy analysis and a discourse approach
Critical policy analysis is a commonly used method for analyzing policies and strategies (Fischer et al., 2015).This paper is based on an interpretive policy analysis that clarifies what assumptions that underpin the challenges or issues that the policies and strategies are addressing (Yanow, 2000;Bacchi, 2009).We use a discourse approach to critically analyze and conceptualize what is being said in the policies and to problematize what the stated ambitions and goals would translate to in real life.To do this, we draw on and modify Dryzek's taxonomy of conflicting mainstream environmental discourses (Yanow, 2000;Dryzek, 2013).This taxonomy differentiates between whether a discourse is based on the political-economic rules set up by industrialism (prosaic vs imaginative) and on whether the suggestions involve a complete overhaul of the industry or if sufficient changes can be made in a moderate fashion (radical vs reformist) (Dryzek, 2013).In this paper we applied kernels of this taxonomy of discourses to the weak and strong sustainability dichotomy and made it case specific for aquaculture.To simplify, we renamed the discourses to very weak (prosaic reformism)-, weak (imaginative reformism)-, strong (prosaic radicalism)-and very strong sustainability (imaginative radicalism).Our discourse definitions are then applied to the national strategies and policies to illustrate how sustainability is characterized and where each state positions themselves on the continuum between very weak to very strong sustainability.
By conducting an interpretive policy analysis and applying it to the theoretical debate between strong and weak sustainability, this study identifies how governments enact certain aspects of sustainability in their aquaculture policies and strategies (Blackmore, 2005).A policy or strategy is not just a string of decisions made by governments, they are a way of thinking and talking about an issue or challenge that justifies the actions suggested in that document (Yanow and Colebatch, 2004).Robert and Zeckhauser (2011) argues that since all policies contain values, the policy analysis must also address these values.In order to address this and understand the steering documents one must also understand the discourses in which they exist (Yanow, 2000).
Interpretive policy analysis needs to be reflexive and acknowledge that most policies are not just advocating for one absolute meaning (Yanow, 2007).Policies and strategies are like everything else related to sustainability, complex.It is not the intention of this paper to give a final verdict on how the policies and strategies are framed.These are ever changing documents that are updated and have more than just one clear agenda.Thus, we do not expect that the policies or strategies will fit perfectly with just one discourse or concept but that there are traces of different discourses and concepts in each policy and strategy.Instead, the aim of this paper is to accentuate the dominating features of either weak or strong sustainability that can be found in the Nordic aquaculture policy context.
Discourses are crucial in framing challenges and solutions, especially when there is one dominating discourse that legitimizes and defines what is right."A discourse is a shared way of apprehending the world […] Discourses construct meanings and relationships, helping define common sense and legitimate knowledge (Dryzek, 2013)."The aquaculture development discourse is centered around the growth prospects of the industry from researchers (Costello et al., 2020), to international steering documents (FAO, 2017;EC, 2017), and national strategies (Jordbruksverket, 2012a, FK, 2009, MFNR, 2010, MFEA, 2019, NaturErhvervstyrelsen, 2014).Therefore, it is important to investigate what the expressed aspirations of growth means for environmental sustainability.

Strong and weak sustainability
The plethora of definitions and theories around sustainable development is a result of its multifaceted nature (UNDP, 2015).To help muddle through the waters of these diverse theories and dichotomies and to simplify the differences we (along with others) distinguish between two main camps: weak and strong sustainability (Neumayer, 2003, O. Luthman et al.Dobson, 1998, Dobson, 1996).Other terms, such as soft and hard sustainability have been used to describe the same distinction, which ultimately comes down to perceiving the environment as either a cornucopian system or as ecological limits that frame development possibilities (Gilek, 2018).
Strong sustainability postulates that natural capital or ecosystems are non-substitutable and that healthy ecosystems are crucial for people and societies to flourish.From this standpoint, there are life support functions, so-called critical natural capital, that are seen as impossible to substitute.These system functions include the provisioning of food, water, breathable air and stable climate and should be subjected to the strong sustainability rule (Dietz and Neumayer, 2007;Barbier et al., 1995;Folke et al., 2016).Ecosystem services have intrinsic value and should thus be protected (Barr, 2008).Furthermore, human development cannot be decoupled from the biosphere and technological solutions should not improve the quality of life at the expense of the planet's life-supporting ecosystems (Folke et al., 2016).
Proponents of weak sustainability argue that the natural capital or ecosystem services are substitutable for human-made capital and that the degradation of ecosystems can be compensated for if it increases the total capital,1 thereby ensuring the well-being of people in the present and future (Neumayer, 2003, Ekins et al., 2003).Moreover, they assert that technological innovation will be able to deal with any environmental consequences related to the production of goods and services (inputs) as well as the pollution from it (sinks) (Dryzek, 2013;Qiu and Jones, 2013).This view also implies that human development can be decoupled from environmental degradation (Raudsepp-Hearne et al., 2010).
Intergenerational capital exchange is central for both strong and weak sustainability.What this means is that the capital passed on to the next generation should be growing or be constant, the theories differ in what capital that is prioritized (Barr, 2008;Hediger, 1999).Strong sustainability emphasizes that the natural capital cannot decrease, and that human capital can increase over time, whereas weak sustainability implies natural capital's decline over time while human capital increases (Dasgupta, 2001).This relates to equity and social sustainability as it refers to resource exploitation and accessibility that should be fairly distributed and in a manner that does not create wealth at the expense of the health of another's environment and the well-being or life opportunities of other people or future generations (Lele, 2020).So why has human well-being generally increased in the last decades while the natural environments have been more and more degraded?Raudsepp-Hearne et al., (2010) has put forward the hypothesis of delayed consequences on well-being as an explanation.Advocates of environmental limits would say that degrading the biosphere confines our options and opportunities for future development (Folke et al., 2016).

Applying weak and strong sustainability to aquaculture
This article draws on the strong and weak sustainability literature to add to the theorization of sustainable aquaculture governance.The concepts are reviewed as two fluctuating endpoints on a floating sustainability scale that are applied to characterize the empirical findings from the steering documents.Thus, they can move closer to one another or further apart depending on the content of the policy document.To make this distinction more applicable, we have divided strong and weak sustainability into four different subdivisions, very weak, weak, strong, and very strong sustainability.These divisions are developed from Dryzek's astute definition of environmental discourses (Dryzek, 2013) and modified to deepen the theorization of strong and weak sustainability relating to the aquaculture industry by using key articles regarding sustainability in general (Folke et al., 2016;Lele, 2020) as well as in food (Béné et al., 2019), seafood (Tlusty, 2019) and aquaculture specifically (Naylor et al., 2021).The articles have been chosen based on their relevance to environmental governance theory, applicability to the existing dichotomy between strong and weak sustainability, to food production and aquaculture specifically.A summary of the application of the discourses to the strategies and policies is available in Table 2.

Very weak sustainability (prosaic reformist)
We draw parallels between ecological modernization theory (Mol and Spaargaren, 1993;Blühdorn, 2013) when defining the very weak sustainability discourse as both are based on economic principles and neither questions the status quo practices of the industry or market.Ecological modernization, and very weak sustainability are both based on the idea that technological innovations and market mechanisms can solve most environmental challenges (Blühdorn, 2013).Environmental problems are viewed as external issues that can be resolved by a technological fix or appropriate environmental legislation without questioning, reforming or transforming the core issue related to the problem.Often, this involves solutions to a particular problem that is at the end of the pipeline (Dryzek, 2013).Natural capital (including life support systems) can be substituted and replaced by development in other areas (Neumayer, 2012;Davies, 2013), e.g. if natural capital like fresh water deteriorate during the production process, it can be compensated for by installing water-treatment systems.Local challenges related to output impacts are emphasized rather than a holistic view that emphasizes how inputs and outputs alike impacts all ecosystems in the production line.Sustainability in this sense is obtained by mitigating singular direct challenges rather than aiming for a holistic view of environmental challenges, climate change or being part of a larger system (Tlusty, 2019, Lele, 2020).The emphasis is put on economic growth, intensification, competitiveness, and trade with less attention on the wellbeing of the biosphere (Folke et al., 2016).Efficiency and productivity constitute the core of environmental engagements, decreasing pollution per produced kg opens up for increased production, not necessarily reduced aggregated pollution.There is a strong belief in technological advancements and human ingenuity (Hopwood et al., 2005;Dryzek, 2013).Thus, an assumption is that whatever species and systems that makes most fiscal sense should be advocated for and by increasing technological advancements the related sustainability challenges can be solved.

Weak sustainability(imaginative reformist)
Next, we see discourses that acknowledge that there are environmental thresholds but that these are flexible, and that human ingenuity can find solutions to environmental challenges without transforming the current system.This discourse is categorized as weak sustainability.Significant for this discourse is the notion that even if there are environmental challenges, these can always be mitigated by modifying or reforming existing practices to improve the outcome (Dryzek, 2013;Hopwood et al., 2005).Here too there are parallels with ecological modernization as technological advancements, trade, ingenuity, and market mechanisms play a crucial role (Hovardas, 2016).Although local, current, and direct issues and challenges related to outputs are prioritized here too, inputs, e.g.feed, therapeutic treatments, energy, infrastructure, are considered from a global perspective.These challenges could be compensated for through sustainability commitments, such as climate compensation or incorporating challenges in the solutions.E.g. using blue mussels to absorb effluents from a fish farm or that aquaculture feed can be made sustainable by using certified ingredients that ensures that the resources used in the feed are derived from responsible fisheries or production lines.Therapeutic treatments should be managed carefully, however, not to the extent that there are restrictions on the number of treatments.By advocating for these reforms, the discourse legitimizes the sustainability of fed finfish such as salmon.One way to advocate for this is by promoting certifications.

Strong sustainability(prosaic radicalism)
The strong sustainability discourse is based on limits, and that human development is constrained by Earth's carrying capacity (Meadows, 1972;Hopwood et al., 2005).Thus, the outputs from a farm should be within the assimilative capacity of its environment and should not degrade the ecosystem beyond its functions and resilience (Galparsoro et al., 2020).Here there is a recognition that humanity and the biosphere are interdependent and that life-support systems are important for the wellbeing of humanity (Folke et al., 2016).The strong sustainability discourse argues for a transformation of the current system rather than reforming or modifying it.This includes avoiding risk taking that could have dire consequences to ecosystems, thus adhering to the Ecosystem Approach to Aquaculture (EAA) set up by the UN as a guide to increase the sustainability of the aquaculture sector (Soto et al., 2008;FAO, 2010).A more temporal and holistic approach is applied to strong sustainability which includes ecosystems being less degraded and thus better prepared for future challenges and shocks to the system, e.g.climate change.Strong sustainability applies stricter restrictions on resource use, e.g.fish meal and oil should only derive from byproducts/ processing wastes.High grade food like maize and soy may be used as long as use does not push ecological boundaries and products should preferably be eco-certified.Non-renewable resources should only be used if renewable substitutes are developed and that the renewable resources are produced in a pace similar to its use.Efforts to minimize the risk of spreading pathogens and/or other pests to wild stocks must be taken whilst also using veterinarian check-ups to limit therapeutic treatments (Mordecai et al., 2021).Using critical pharmaceuticals for human health is prohibited and therapeutic treatments should be issued in a way that they do not pose threats to the health of people or ecosystems nearby or globally.Technological advancements to reduce negative impacts need to account for energy consumption too, to ensure that the production does not cause environmental harm elsewhere (Badiola et al., 2018).With current fed aquaculture practices this discourse may see a limit to the industry's potential growth.An increasing production of fed species would stress the production of feed, which often uses high grade food ingredients from agricultural and fisheries (Tlusty, 2019, Froehlich et al., 2018, Cottrell et al., 2020).According to the strong sustainability discourse, a larger emphasis should be put on transforming the system rather than on technological innovation (Dryzek, 2013).Suggesting diversification and a move towards less resource intensive species intended for human consumption rather than just for feed.This would also increase efficiency and lead to a net increase of high-grade food.

Very strong sustainability(imaginative radicalism)
Finally, very strong sustainability emphasizes the whole system, inputs, and outputs, equally.This discourse would argue that no lasting or harmful inputs or outputs should be associated with the production of aquaculture.Thus, only natural systems can be reviewed as very strong sustainability, or temporary inputs that do not affect the ecosystem negatively, e.g.lines and buoys for mollusks and seaweed to grow on.The very strong sustainability discourse goes beyond arguments such as needing to produce more food for a growing population and emphasizes how resources are used (Béné et al., 2019).This means that a larger transformation of the food producing system is necessary, one that creates availability of high-grade food for people rather than being used in feed.As in strong sustainability, ecosystems should be given a better chance of surviving future challenges and chocks by not being degraded.Shifting the demand towards more sustainable species is preferable and more efficient to achieve sustainability than applying new technology (Clark and Tilman, 2017).Critical pharmaceutical compounds should not be used at all and treatments should be limited so as to not to expose the wellbeing of local or global ecosystems to risk.Furthermore, protecting wild fish stocks from pathogens and/or other pests is crucial (Mordecai et al., 2021).Even with improved Feed Conversion Ratio (FCR) and with decreasing percentage of fish oil-and meal in the feed, fed aquaculture would, by default, be unsustainable unless the feed only contained byproducts not suitable for human consumption (Naylor et al., 2021).Furthermore, no non-renewable or high-grade food resources should be used, which would remove some environmental injustices as resources would not be exploited at the expense of one ecosystem to improve the wellbeing of another (Lele, 2020).Using crucial life-support systems such as clean water should also be deemed unsustainable under many circumstances as water scarcity is an increasingly pressing issue globally (EC, 2018;Boretti and Rosa, 2019).Extractive species such as algae and filter feeding mussels are perhaps the most viable options to produce seafood at a larger scale whilst being on path to achieve very strong sustainability as they can even have positive reinforcements of ecosystem services (Naylor et al., 2021).Thus, in order for a policy to be advocating for very strong sustainability, it should promote net growth of food without harming the environment or creating unjust nutritional flows.

Results
This section is used as an articulation of how the policies and strategies for aquaculture are formulated in the Nordic countries and provides a summary of what is emphasized and the main goals for the aquaculture industries.To make the concepts more apparent, we have added a checklist at the end of each policy description (see Table 3-8).

Denmark
The Danish aquaculture development strategy has two clear goals, to increase production of fish and shellfish by 2020 and for a substantial part of production to be organic (NaturErhvervstyrelsen, 2014).
These goals have been successfully accomplished (MFD (2018).The Danish aquaculture directive previously focused on regulating inputs to O. Luthman et al. farms, i.e. the amount of feed used and therapeutic treatments, but since 2010 the release of wastes have received more attention in policies (Andersen et al., 2010;Nielsen et al., 2020).Even with the increasing potential of marine aquaculture, the Danish government decided to put a halt on marine aquaculture expansion as a result of environmental concerns regarding the pollution aquaculture farms may have in marine environments (Andersen, 2019).
Technological advancements are emphasized and usage of Best Available Practice (BAP) and Best Available Technology (BAT) is suggested as measures to increase sustainability.According to the strategy, two of the larger aquaculture related exports are fish feed and technology for recirculating systems (NaturErhvervstyrelsen, 2014).By advocating for BAP and BAT the strategy emphasizes technocentric solutions that are not really questioning the sustainability of a species on a global or holistic perspective but rather on solutions to mitigate the negative impacts on a local level.
The decision to stop expansion of farmed marine fed fish is in line with strong sustainability.Furthermore, the new strategy emphasizes the importance of blue mussel farming as a possible source of protein for pig feed as well as a compensatory measure for fed fish farming to absorb nutrient outflows (MFD, 2018).Blue mussels and algae are also mentioned as a possible substitute to terrestrial ingredients in fish feed (NaturErhvervstyrelsen, 2014).However, increasing land-based activities such as RAS systems or pond is stressed as the main way forward for sustainable aquaculture.This does not really address the possible sustainability issues associated with fed aquaculture.Even with the high percentage of green electricity in Denmark (IEA, 2020), there are challenges associated with energy consumption, biodiversity loss from land use and freshwater consumption that is not completely accounted for.The policies recognize the fact that the aquaculture industry primarily is focused on rainbow trout but argue that through production in ponds and RAS they should be able to diversify the sector.
There is a strong emphasis on organic aquaculture, which fits with both strong and weak sustainability.The emphasis on blue mussel production to mitigate nutrient outflows is an end of pipeline solution.The suggestion to use algae and blue mussels in feed has elements of strong and weak sustainability, strong if replacing wild caught seafood.The main ambition of blue mussel and algae production seems to be as feed ingredients rather than as human food.Arguably this could be categorized as very weak or weak, however, as it is used in the strategy it fits more with weak as it is a rather imaginative solution to an existing sustainability challenge.

Faroe Islands
The Faroe Islands claim to have the most comprehensive aquaculture policy and regulation to increase the sustainability of the industry (MFNR, 2020).However, the documents are rather one-sided, with a strong emphasis on salmon production.Most marine resources in the feed used for aquaculture are produced domestically, however some is imported, mostly from Norway (MFNR, 2010).The industry is completely free from antibiotic usage (SeafoodWatch, 2018).According to the Faroese house of industry, almost all suitable locations for aquaculture sites are being used.There is a clear emphasis on the importance of the aquaculture industry and that the salmon industry have stringent regulations on veterinary visits, controls of inputs and outputs and that each site must have a fallow period for the sediment to recover from the production cycle (MFNR, 2010).Furthermore, the Environmental Agency is in charge of pushing the industry to use the best available technology on all sites as a measure to increase the sustainability of the industry.
The most pronounced aquaculture development plan is to diversify

Table 3
Summary of Danish strategy.

Technocentric (Very weak)
The strategy is emphasizing technological advancements as the key component for sustainability Market solutions (Weak) One of the main goals was for a larger part of the industry to become certified Not risking marine environments (Strong) The government decided to stop marine expansion due to pollution Using food in feed (Weak) The strategy is advocating for using aquaculture produce as feed to other animals.

Table 4
Summary of Faroese strategy.
Reforming the system (Weak) The Faroese strategy argues that the salmon farming industry has managed to improve on several environmental challenges and as a result have become a sustainable commodity on international markets Using food in feed (Weak) The strategy stresses how local the whole aquaculture industry is, and that feed ingredients derive from wellmanaged fisheries Technocentric (Very weak) The strategy argues for a high-tech industry that guarantees that the BAT is used to safeguard the environment

Table 5
Summary of finnish strategy.

Technocentric (Very weak)
The strategy is centered around increasing productivity and improving environmental performances through technological development Using food in feed (Weak) The strategy advocates for using more local resources (Baltic herring and Blue mussels) in feed for fed aquaculture Reforming the system (Weak) The Finnish strategy emphasizes how increased production of aquaculture and BAT could be a competitive advantage

Table 6
Summary of Icelandic strategies and policies.
Treading on unknown territory (Very weak) The Icelandic strategy calls for an opening of previously protected waters to increase production Technocentric (Very weak) The strategy sees opportunities to expand using technology to maximize beneficial geological conditions

Table 7
Summary of the Norwegian strategies and policies.
Treading on unknown territory (Very weak) The Norwegian strategies and policies argue for a five-folded increase of aquaculture production, admittedly with some environmental consequences unaccounted for Technocentric (Very weak) The strategies suggest that technological advancements will remove several of the issues related to salmon farming, e.g.pollution and escapes Reforming the system (Weak) The Norwegian strategies argue that moving the industry further out at sea or up on land will increase the sustainability of the industry.

Managing resources (Strong)
The Norwegian ambition is to increase efficiency of feed ingredients to decrease waste of high-grade food and to use alternative, renewable resources

Table 8
Summary of the Swedish strategy and policies.

Technocentric (Very weak)
The strategy is emphasizing technological advancements as the key component for sustainability Using food in feed (Weak) The strategy is advocating for using aquaculture produce as feed to other animals.Market solutions (Weak) Certifications are seen as a measure to increase environmental performances O. Luthman et al. the aquaculture industry, e.g. through increasing cod farming (MFNR, 2010).However, in the past ten years there has been no advancements in cod aquaculture production.The minimization of waste and pharmaceutical compound use is considered key for sustainable aquaculture (MFNR, 2010;Landsstýri, 2019).The plans are however not addressing sustainability issues related to producing fed fish and the use of marineor other high-grade ingredients in feed.Fed fish is still advocated for and while there are strict regulations on inputs and outputs the use of marine-or high-grade feed ingredients is unquestioned, and no suggested transformation of the production system is presented.

Finland
Use of marine net pens are still regarded as Best Available Technology (BAT) (Soininen et al., 2019) even with international commitments such as WFSD, WFD and the HELCOM 2 Baltic Sea Action Plan, which states that a decrease in emitted nutrients in the Baltic Sea is a must to achieve "natural levels" of eutrophication (HELCOM, 2007).
The Finnish aquaculture strategy has three overarching goals: competitiveness, innovation, and sustainability (FCM, 2014).It acknowledges the difficulties of increasing production, whilst decreasing the nutrient effluents in the Baltic sea.A suggested strategy for increasing aquaculture production without increasing nutrient effluents (or its effect) is to move the industry offshore or up on land in RAS systems (FCM, 2014).This relates back to the ambition of having advanced technology and lessen the environmental effects of the industry.Some of the suggested species for production are rainbow trout, zander, common whitefish, sturgeon, and brown trout (MAFF, 2019).All of these species are fed and (when in the wild) high trophic finfish.To mitigate the negative environmental effects of producing predatory species and increase the degree of self-sufficiency, the strategy suggests increasing production of mussels in the Baltic sea to be used as feed or use the Baltic sea herring as feed.Furthermore, algae farming is identified to be an important future industry, both for minimizing the use of fish oil in feed as well as for energy production.Another ambition is to increase the use of voluntary eco-certifications.
The suggested solutions to keep nutrient levels in the Baltic at natural levels can be considered rather technocentric and there is no suggestion to transform the industry or move away from fed aquaculture.However, algae production is advocated as a source of energy and feed.While using Baltic ingredients in the feed would increase the degree of selfsufficiency, it still advocates using high-grade food such as Baltic herring.Another issue is the high dioxin levels in Baltic sea fish that could pose risks for human health (Miller et al., 2013).Furthermore, the quotas of these species are already pushing the boundary of Maximum Sustainable Yield (MSY) and increasing the use of Baltic herring for fish meal and oil could have a negative impact on the species and ecosystem (ICES, 2019c;ICES, 2019b;ICES, 2019a;Karlson et al., 2020).

Iceland
Salmon farming has increased rapidly during the last decades, predominantly in marine net pens in the West fjords and East fjords (MII, 2019).However, the technology for land-based aquaculture has continued to develop and by using geothermal water, tropical species such as Senegalese sole and tilapia have been farmed in controlled landbased environments.However, only at a small scale so far (MII, 2019).Furthermore, geothermal heating is used for smolt production of both salmonids and trout (Orkustofnun, 2021).By injecting the water in landbased pools with pure oxygen, the industry is trying to reduce its usage of fresh and seawater as a means to reduce water changes (Orkustofnun, 2021).
The Ministry of Finance and Economic Affairs issued a statement that aquaculture production is expected to double from 2019 to 2021 and that the export value of the industry is to grow to potentially 3% of annual exports (MFEA, 2019).The progression is predicted to continue past 2021 as well based on license applications the state receives.As a measure to increase salmon aquaculture in marine environments the Icelandic government decided to implement a risk assessment law in 2019 (MBI, 2019;Jóhannsson et al., 2017).This law requires a risk assessment on impacts on wild salmon stocks in fjords where previously aquaculture sites were banished.The idea is to allow salmon farming in previously protected areas, which will put them closer to where wild salmon spawn (MBI, 2019).This will allow for the industry to increase.According to a risk assessment model, the Icelandic salmon industry could increase to about 71.000 tons without risking that escapes would severely affect the wild populations (Jóhannsson et al., 2017).According to the model, this significant production increase is within a safe operating space from changing the genome of the wild stocks if a mass escape were to happen.However, there are other risks associated with increasing production, i.e. sea lice and pollution having ecological consequences.The suggested solutions portray the environmental challenges as external factors that should/could be dealt with.

Norway
Environmental aspects have been increasingly prioritized in national aquaculture strategies (NFD, 2015).In 2009, the minister of fisheries and coastal affairs stated that aquaculture development should not only be limited by the markets but also by what is locally environmentally sustainable (FK, 2009).The policy stated that the state should define what are acceptable environmental effects from farms and that legislation should be in place for counties and/or related government bodies to act when there have been transgressions (FK, 2009).The rhetoric has continued with environmental considerations being emphasized in policies and strategies when deciding whether or not operations can expand (NFD, 2015).In 2015 the policies tried to incorporate stricter pollution management but argued that measuring the effects of pollutants from aquaculture operations is too difficult but that it should be addressed and become a factor in the future (NFD, 2015). 3This eventually resulted in a policy change and a "traffic light system" for salmon aquaculture development plans as well as a new strategy to minimize risks of mass escapes.The traffic light system divides the Norwegian coast into 13 different regions and each region will be assigned either a red, yellow, or green light.The colors refer to the environmental status of the region and whether or not production must decrease (red), remain (yellow), or increase by maximum 6% (green) (Havsforskningsinstituttet, 2020).The environmental indicator used for the traffic light system is mortality rates of wild stocks related to sea lice (Lovdata, 2017).The Ministry of Trade, Industry and Fisheries will review the environmental performances continuously and decide on the traffic light every other year (Lovdata, 2017).The escape mitigation strategy does not vary much from previously existing regulations, i.e. that escapes should be reported, that production sites must have mitigation and recatch plans, that moorings should be controlled regularly and that new, safe technology should be implemented (NFD, 2017;Fiskeridirektoratet, 2006).
Even if salmon is the most advocated for species and marine net pens dominate, the strategies also regard macroalgae as a promising future industry that hopefully could replace some of the marine ingredients in O. Luthman et al. the salmon feed (Regjering, 2017).Norway imports about 200.000 tons of fish meal from mainly Peru, Denmark and Iceland and ca.170.000 tons of fish oil, while producing ca.55.000 tons domestically (FK, 2009).The amount of marine ingredients has decreased over time while landbased ingredients such as soy has increased (Aas et al., 2019).There is a common understanding that marine products need to be replaced if the industry is to increase further and one way to do that is to increase the use of marine byproducts/fish processing wastes, which has increased over time (FK, 2009;Aas et al., 2019).Furthermore, there is an increasing production of macroalgae that is used in salmon feed but only to a very limited extent (Regjering, 2016).
The strategies also advocate for closed land based aquaculture (RAS), stating that development will happen with or without the involvement of the Norwegian state and that they thus should facilitate development of land based salmon aquaculture so as to not lose opportunity for continued growth (NFD, 2015).There is a belief that even though there are several environmental concerns remaining and that the wild Atlantic salmon population is diminishing and that a third of that population spawn in Norwegian fjords and rivers, there is still room to increase production even in coastal waters (NFD, 2015).Offshore farming is also suggested as a viable option for aquaculture expansion (OED, 2017).Through measurements and assessments, the Norwegian state aims at mitigating the industry's negative environmental effects.However, in a rather conflicting way to that ambition they still push for a five-folded expansion, even when the environmental outcomes are unknown.

Sweden
The Swedish strategy for aquaculture development strongly emphasizes the correlations between markets, green consumerism, and a strong environmental profile (Jordbruksverket, 2012b).The strategy contains thirteen goals.These involve and emphasize intensification, competitiveness, low environmental impacts, and positive contributions to all three pillars of sustainability.Technological advancements are seen as a measure to cover many issues related to the sustainability of aquaculture.Municipalities and politicians at different levels are to increase awareness and sight availability to allow for the industry to grow.
Mussels are seen as alternatives to fish meal and oil in feed to decrease the dependency on forage fish in feed and increase food security by using local resources (Jordbruksverket, 2012b).In 2020 the first large-scale RAS production site was approved in Sweden, which is expected to produce 80,000 tons of Atlantic salmon per year (Varas, 2020), which would be an eight-fold increase of the current total national aquaculture production.
The goals of the strategy are ambitious and full of belief in the prospects of aquaculture.However, it is quite vague with no real action plan included.The inland lakes in the north are regarded as ideal for finfish production and the Swedish west coast for mussel production.The latter comes with environmental benefits, if managed properly, through the mussels cleaning capacities (Jordbruksverket, 2012b).The Swedish Government stresses the importance of having a competitive food producing industry where economic growth plays a crucial role (Näringsdepartmentet, 2017b).In the food strategy from 2017, the government also advocates for a market sensitive industry that produces after demand but also strives towards increasing organic production (Näringsdepartmentet, 2017b;Näringsdepartmentet, 2017a).
The Swedish government decided in 2020 that a rather modest sum of approximately 7 million SEK would be invested annually in domestic aquaculture projects to increase production and a sustainable food supplying resource (Näringsdepartmentet, 2020).
One of the larger concerns regarding sustainability of producing higher trophic species would be mitigated through an increased use of domestic blue mussels in fish feed.Farming of seaweed and blue mussels are regarded as sustainable food/feed alternatives and also beneficial for the environment through nutrient uptake (Jordbruksverket, 2012b).There is a strong emphasis on collaboration and using the knowledge and expertise of people in different sectors of society, research, private, civil, and public.The growth of the Swedish aquaculture industry will depend on technological advancementsincluding further development of RAS systems.The ambition also includes expanding fed-fish production in the Northern lakes and expansion of blue mussel and algae in marine coastal waters.Blue mussels and algae will mainly be farmed for feed ingredients, but also for human consumption.

Summary
Nordic aquaculture policies and strategies advocate for intensification and generally a focus on high-value, fed-fish like salmon or trout.Technological advancements and improving environmental performances as a means to increase their international competitiveness are also seen as measures to increase the sustainability of the industry (see Table 9).

Discussion
As mentioned in the introduction, a policy or strategy is rarely focused on only one aspect of sustainability, they are emphasizing all three pillars of sustainability and this paper focuses solely on the environmental aspects.However, some discourses stand out more than others and very strong sustainability is non-existent.Very strong sustainability would mean a complete overhaul of the industry and a shift away from resource intensive species and towards an industry that does not cause environmental harm anywhere along the value chain.Furthermore, very strong sustainability would decrease dependencies of high-grade food for aquaculture feed, which may result in a more equitable distribution of highly nutritious aquatic foods (Schipanski et al., 2016).Most policies and strategies can be classified as advocates for weak sustainability discourse with kernels of very weak and strong sustainability, most notably relating to resource use in feed.They are geared towards promoting technological advancements and opportunity seeking businesses, such as advancing land-based salmon farms.Furthermore, some of them argue for using more locally sourced products in fish feed, i.e. bivalves and trimmings.Rather than advocating for the direct consumption of mussels and algae by humans, the strategies primarily emphasize their importance in reducing some of the negative effects associated with producing fed fish.Instead of transforming the industry towards producing less environmentally harmful species, the priority seems to be to minimize the effects of each kilo produced, whilst increasing production significantly.In most cases, economic growth, trade, and competition is regarded as the first and foremost ambition and goal of the policies and strategies.Norway is the exception here stating that the environment takes precedence.However, this is not reflected in the policies/strategies as expansion of salmon farming is a dominating policy ambition.Technological advancements and BAT are referred to as solutions to sustainability issues in all strategies and policies.However, environmental aspects are not overlooked, and they are connected to the economic goals.The proposed solutions range from the traffic light system in Norway to increasing food availability by producing ingredients for feed from local mussel-and algae farms.

Policy implications
Most strategies and policies are advocating for the increased production of high trophic species that, even when using BAT, can cause environmental harm.Furthermore, promoting fed aquaculture still creates a net loss of resources unless the feed contains only resources that would have been lost otherwise.A very strong sustainability approach would necessitate countries to adopt a global resource management perspective, including more emphasis on species that contribute to net gains in food rather than (as is the current practice) on relatively resource intensive species.A push for strong sustainability would be to further emphasize aquaculture development for species with lower environmental impacts, like bivalves, algae and even some carp species (Gephart et al., 2021).
The suggested strategies to mitigate some of the environmental effects, e.g.overfishing and nutrient rich effluents, are scattered between the very weak, weak, and strong sustainability discourses.Using algae and mussels as a source of omega-3 acids instead of fish oil in the feed could be regarded as advocating for strong sustainability.It could also be seen as weak sustainability as it does not optimize overall resource use.Using land-based tanks with better water treatment systems can minimize the outflow of nutrients but can still imply high freshwater and energy consumption and maintain dependence on high-grade food.However, one could close the loop by using the nutrient effluents to feed the mussels or algae which then could be used in the feed again.This would incorporate the environmental challenges and make them part of the solution and thus potentially more sustainable and promote strong sustainability.However, technological challenges still remain for such systems (Naylor et al., 2021).
Technological advancements and collaborations between the public and private sectors have been successful in reducing nutrient effluents from salmon farms (70% reduction since the 1990's).Fishmeal and fish oil in fish feeds has also been significantly reduced and today more of the marine ingredients derived from fish trimmings from the processing industry (Naylor et al., 2021).If the strategies or policies would advocate more for this kind of feed development, i.e. feed from processing wastes not suitable for human consumption becoming the norm, the strategies would promote strong sustainability.Thus, the industry is already applying some solutions to environmental concerns that pushes them towards strong sustainability.National strategies and policies could follow suit.However, in other instances, less environmental impact would result in advanced technological solutions that need more energy, which in turn must be derived from clean energy in order for it to not offset another ecological system.Unless the state advocates for producing less resource intensive species that would increase sustainability even without more advanced technology.
In all countries, economic growth fueled through a competitive market condition is regarded as one of the main ambitions and goals of the policies and strategies.However, environmental aspects are not overlooked, and they are connected to the economic goals.The solutions proposed are mostly a mix between the very weak and weak sustainability, where the emphasis is on growing the industry even if there are unknown risks for the ecosystems associated with them.This is a contradiction to the precautionary principle, which is a staple in FAO recommendations for sustainable aquaculture development (Garcia, 2005).However, there is a presence of the strong sustainability discourse in most strategies as well, acknowledging that there are environmental thresholds and that a move to RAS systems or offshore could mitigate some of the current pollution issues.
The biophysical environment varies significantly between the countries; thus, the stringency of policies and strategies will differ and have more or less effect on the environment and the industry as a whole.Some aspects of sustainability related to feed can be considered to be more generic as its effects are less dependent on the local environment.Policies promoting production of filter feeders like blue mussels and seaweed are in line with strong sustainability.However, in order for it to make sense fiscally and have a real environmental impact there is a need to change dietary preferences away from more impactful aquatic foods which, in turn, could be impacted by policy formulations (Schipanski et al., 2016;Hilborn et al., 2018).
As was noted earlier, sustainable development plans usually include multi-level goals and ambitions.The ambition to intensify the industry could have positive environmental impacts if the seafood produced replaced some of the more impactful animal proteins, e.g.beef which generally have a larger environmental footprint (Hilborn et al., 2018;Gephart et al., 2021).However, if the ambition is for the industry to be sustainable in the long term, it might be more strategic to emphasize other species (primarily non-fed) and diversify the industry.Earlier calls for enhancing the role of fish in food policies and strategies (Bennett et al., 2021; Blue food assessment), a larger emphasis on mussels, algae and other unfed species may have greater potential to increase food and nutritional security in a more sustainable way.

Conclusion
In this paper we analyzed how environmental sustainability is portrayed in Nordic aquaculture policies and strategies.The reason why we emphasized the environment is because we agree with Giddings et al.'s nested sustainable development figure which argues that the economy and society is dependent on the wellbeing of their biophysical surroundings (Giddings et al., 2002).Thus, we must start at that end and work ourselves out to social and economic sustainability.However, the other aspects must also be properly considered.We are not arguing for a transition to very strong sustainability without thoroughly analyzing its effect on the other aspects of society.However, we do argue that the policies and strategies could be more ambitious in their endeavor to promote environmentally sustainable aquaculture.
The main emphasis of the Nordic aquaculture strategies and policies is growth, both in terms of production volumes and economic gains.Local environments have an integral part in the policies and strategies as the countries want to promote and safeguard natural environments.The emphasis is on increasing production of high-value species like salmon and trout whilst limiting outputs from the production.A more global perspective especially related to feed resources would increase the sustainability aspects in the policies.The environmental aspects in the policies does not trump intensification but rather sets standards that increase the environmental performance of the industry, which seems to result in less unsustainable practices rather than sustainable, at least initially.Business promotion, intensification and technocentric solutions are at the forefront.Based on the discourse definitions, we found that the most salient discourses were weak, very weak, and strong sustainability.
All states mention that other types of aquaculture could complement fed fin-fish production, either as filterers of emissions or as ingredients O. Luthman et al. in feed or a source of renewable energy, or for human consumption or all of the above.However, in order for the policies and strategies to move closer to strong and very strong sustainability they would need to emphasize these species further.If the industry is to live up to its potential as a sustainable food producing industry and increase food accessibility globally, net production of edible foods should be prioritized and not at the expense of local or distant ecosystems.Currently the strategies advocate for some reforms of the industry that leads to less unsustainable practices.Furthermore, there is an important aspect of how to make policies and strategies impactful that has not been considered in this paper.A strategy or policy should be based on attainable goals, but they should also set ambitions that are not yet achieved.We argue that the policies and strategies could be more ambitious and advocate for a more diverse and environmentally sustainable industry.

Declaration of Competing Interest
None.

Fig. 1 .
Fig. 1.Nested sustainable development, where the economy is dependent on society and society on the environment (from Giddings et al., 2002).

Table 1
Main production of aquaculture species and their value by country (2018).

Table 2
Summary of key components of the discourses.

Table 9
Summarizes three key findings per country and dominating discourses.