8. Economic consequences for fisheries and aquaculture

Economic consequences of climate change towards 2100 for fisheries and aquaculture in the Nordic region – outcome of a workshop
Geir Ottersen and meeting participants

Impacts of climate change are becoming evident also in the Nordic region and people in the seafood industries are becoming increasingly worried. According to the Seafood Barometer for Norway (PwC 2023) the biggest concerns for direct climate risks were increased sea temperatures and more frequent extreme weather, while indirect risks such as consumer preferences, change in regulatory climate and environmental requirements and pricing of climate emissions also were reported by many.

To gain new insight into the future economic and societal impacts of climate change on the marine fisheries and aquaculture sectors in the Nordic region, we held a meeting in Bergen, Norway, in May 2024. The workshop brought together a multidisciplinary expert group of resource economists, fisheries oceanographers, and biologists, and one representative from the fishing industry: all researchers working at the interface between natural sciences and societal impacts. The 14 participants represented Norway, Sweden, Finland, The Faeroe Islands and Germany (participants list in Appendix 2). The majority of the participants have their main expertise on fish in the wild and fisheries, leading to somewhat more focus there than on aquaculture.

Through pre-meeting planning and during the first part of the two-day workshop, we identified a broad range of key topics pertaining to climate change impacts on marine fisheries and aquaculture (Table 4). The perspective was high-level, emphasizing how climate change may force general industry changes and associated societal impacts, and more geared towards brainstorming and discussions than in-depth analysis. The intention was not to provide monetary or point estimates, but rather a well-informed evaluation of likely developments ahead. The meeting was conducted partly as a plenary group, partly in smaller groups of 4-5 people split on Day one by sea area, Day two by aquaculture/fisheries (somewhat similar to the World Café method). While the small group conversations revolved around the identified key issues, they were not strictly limited to them but could freely bring up any relevant emerging topics. However, to avoid discussions moving far off-target, the small groups were charged with taking notes and reporting their main findings back to the plenary.

Table 4. Main topics and central subtopics discussed.

From our first discussions, it was clear that the effects of climate change and potential for future development in fisheries and aquaculture will differ significantly between the different Nordic seas. Climate change impacts will vary significantly across the Nordic region because of the differences in physical and biological properties described earlier. Further, the countries differ also by diverse economies and societal structures, including the historical and present socio-economic placement of fisheries and political priorities between aquaculture, fisheries, and other activities.  

The workshop time horizon was to a large degree the same as for the IPCC scenarios, i.e., towards the end of this century. However, as our discussions evolved and it was pointed to that climate change already at present is an important driver, some aspects were focused on the coming two-three decades. Acquiring new fishing vessels typically has a planning horizon of 20 years, while their lifespan is around 30 years, as are the related bank mortgages and ship insurances. Information about climate-driven changes in the fish stocks at such a time scale therefore forms an important basis for investment and risk handling decisions. This is similar for related industries such as land-based fishing and tourist fishing industries. Where relevant we throughout point to which time frame we deal with.

There is inevitably high uncertainty about the future, it be the physical, environmental or socio-economic situation, particularly as far ahead as 2100. It was therefore a priori well understood that tools, knowledge or insight to conduct any meaningful kind of analytical prediction of the situation 75 years ahead do not exist and likely never will. This was not the goal of the workshop. Instead, we build upon climate change scenarios and expected ecosystem impacts at the global (IPCC 2019, 2021) and regional scale (e.g., Meier et al. 2022; Sandø et al. 2024). Further, some socio-economic scenario studies exist for the study region (e.g., Nilsson et al. 2017 for the Barents Sea and Zandersen et al. 2019 for the Baltic). A further challenge with assessing climate change impacts is that it is a globally interlinked problem, making it difficult to isolate the consequences for specific regions. Nevertheless, we expect our report to provide insight and ignite interest in gaining a more robust understanding of the future of the Nordic seas at a regional level.

The ideas and suggestions reported here are not to be taken as consensus opinions of the group as a whole. The participants were invited by virtue of their expertise and expected value to the workshop. They contributed on their own behalf, not as representatives of any country or organization they are employed by or associated to in any other way.

The report is at the highest level structured into a section covering aspects relating to both Fisheries and Aquaculture, followed by sections on each of the two. Within fisheries we further split by geography, considering as separate (although interlinked) regions the Baltic, North Sea, Nordic Seas (Norwegian, Iceland, Greenland seas), and the Barents Sea.

Climate change, especially if we are not able to implement successful mitigation measures, will in total have strong negative consequences in the seas around the Nordic countries. Regardless, a report financed by the Nordic Council of Ministers on Nordic business leaders' perspectives on climate change shows that 95% view climate change both as a threat and an opportunity (Haga Initiative 2022). There are indeed opportunities for expanding fisheries on species like hake in the North Sea and king and snow crabs in the Barents Sea. Especially in the northern parts of the Nordic region there is also potential for new aquaculture species and expanding on, e.g., kelp or blue mussels.  Despite this, we consider it unlikely that such new activities can replace the diminishing returns from what historically has been important fisheries (like for cod in the North Sea and the Baltic) and aquaculture species (like blue mussels in Danish waters and salmon along the coast of western Norway).  Further, climate change will likely bring severe governance and management challenges. We will need a broad spectre of strategies to meet the issues already arising, and new ones that may arise. While an increasing world population drives towards increased demand for the production from the ocean, there will be restrictions both to natural productivity and willingness to pay related to price/value.

Fishery and aquaculture may have completely different development paths and issues in the future. Fisheries will likely in many areas be challenged by negative impacts of climate change on recruitment, growth reduction, competition from invasive species, acidification (maybe), and other detrimental climate-related impacts. If fisheries are strongly reduced, aquaculture may be subsidised to sustain settlement along the coast, but to thrive the aquaculture industry must be flexible. Technological advancements and economic drivers are crucial for the future. Already now the industries face challenges like high costs (for, e.g., fuel), rising demands for sustainable practices, and competition for land and sea space. While some issues may be solved in the relatively near future (change of fuel), others may intensify. In addition, and especially in Norway, both the fisheries and aquaculture industries must expect debates on the balance between the nation’s future role as a food producer or primarily a technology developer and supplier.

In addition to physical and ecosystem changes, societal developments, climate adaptations and policies will also be very important for shaping the future. Effective future governance and policy decisions depend on political will and capability amidst complex, integrated social-ecological systems. A holistic approach is essential, recognizing the interconnectedness of ocean systems.

Skilful predictions of physical changes are difficult, predictions of ecosystem development more difficult, and predictions about how society is heading towards 2100 even more complex. Societal changes are more uncertain and difficult to predict in the long run while as time progresses, more information narrows the option space and reduces uncertainty. Uncertainty will be further reduced if we pass irreversible thresholds and regime shifts, but this is hardly a positive development. Further, we now have big data, artificial intelligence and generally advanced technology. Unfortunately, there are information gaps, which science alone never will be able to bridge. Political developments and arising issues regarding the compliance with current international agreements are extremely hard to predict. A striking case, especially relevant for fisheries, is the situation with Russia. Russia, which covers almost half of the Arctic and until few years ago was (more or less) part of the open information landscape, is now more closed than for many decades.

Also management and regulations, both at the national and international level, will be challenged by the changing climate. The economic and societal consequences of climate change for fisheries and aquaculture are complex and diverse between countries and regions, as well as among large scale and smaller fisheries and aquaculture operations. The changes are likely to require interim measures for adaptation and permanently more flexible regulations. Ecosystem-based management and multispecies quotas may be feasible options. However, one must be aware of the threat of maladaptation – trying to solve one externality to cope with climate change may increase other problems.

In addition to climate change, the seafood industries are facing increasing demand for eco-friendly products. This implies both focus on fish welfare and the environmental footprint of the activities.

Consumer trends and their stickiness are hard to predict but will play a role in shaping the future of fisheries and aquaculture. Price has been the most important factor in determining consumer choice. In the future, we may face higher food prices in general, caused by a larger population and a globe under tougher climate stress. How this affects seafood prices as compared to other food sources is hard to predict.

Even though there may be opportunities to boost the production of wild fish and other marine organisms in certain areas over both short and long periods, the main driver of overall seafood production growth will have to come through aquaculture. A sustainable increase in seafood production will likely imply both land-based and offshore aquaculture and seafood farming of a wide variety of species. This to meet diverse market demands and reduce the pressure on wild populations and environmental degradation.

There is increasing focus on traceability, documented knowledge of where the seafood item origins and how it was produced. This is emerging as a market trend, driven by consumer preferences and enhanced by branding. Traceability has already emerged in (high-end/restaurant) markets in the US, but also in supermarket chains, which with their large market shares may drive such developments further. Traceability has market value, from consumer preferences, branding purpose, and pressure groups. The Marine Stewardship Council (MSC; https://www.msc.org/) is at the forefront of organizations working to ensure that a set of requirements for sustainable fishing are withheld, including a policy for encouraging fisheries to be well managed and better prepared for environmental changes. For farmed seafood, the Aquaculture Stewardship Council (ASC; https://asc-aqua.org/) plays a similar role. We expect MSC and ASC, and similar groups, to increase their importance in the future.

We briefly discussed to what degree aquaculture and fisheries in the Nordic countries are dependent on subsidies or other support schemes. Fisheries may be subsidised through tax exemption, reduced fuel prices or other measures. Municipalities are eager to attract the aquaculture industry and prepare the ground for them in various ways, but mainly by dedicating coastal and offshore locations for aquaculture in their area plans. This may not count as subsidies but work in a similar way. Economists are in general sceptical of subsidies because they disturb incentives but can be argued for if there is some kind of market failure involved.  Market failure is when observable prices such as prices in commercial markets do not reflect the full impacts of the related activity. This relates to the importance economists put on prices as carriers of information and incentive makers.

The Nordic area is a price taker in the global climate development in the sense that the Nordics have limited influence on the global development, in terms of its share of emissions, influence on global decisions and ‘voting power’, and based on its share of the global economy. Still, it may be possible to strengthen our influence within the climate change scenario time frame if we become more of a knowledge and technology provider and set an example of how fisheries and aquaculture can be done sustainably in line with climate action. This potential is heightened by especially Norway being a large actor within fisheries and aquaculture. Further, the Nordic countries can influence their own situation through adaptations. This leads to different possible scenarios for the future.

Our group agreed that the economic and societal consequences of climate change for fisheries in the Nordic region will be diverse and complex, but discussions arose about the degree of impact. Some suggested that fishers will perceive climate impact mainly through alterations in regulation. Fishers may identify climate change impacts as ‘just variation’. Natural variation has always been present, and fishers have always adjusted to these. Others argued that this statement underestimates the impact of climate change, which will go well beyond the natural variations that species and populations are adapted to - at least if we look as far ahead as 2100.

In any case the coming changes will challenge the international legal framework on the management of the seas, which we discussed and here briefly outline. Criteria for distribution of catch shares between countries are laid down in the Convention on the Law of the Sea and the UN Agreement on Fishing on the High Seas (1995), where two central principles of distribution are zone affiliation and historical fishing. Other criteria are dependence on fishing and contribution to research and management. However, how the criteria are to be operationalized has not been determined, nor the weighting between them. The criteria thus do not provide clear guidelines for coastal states and relevant distant fishing states, leaving room for interpretation and negotiation (Henriksen and Hoel 2011). Zonal attachment is an important concept within fisheries regulation. This is the principle that quotas or catch shares should correspond to the share of the fish stock biomass present within a country’s Exclusive Economic Zone. This means that the fraction of the stock residing within a particular country’s economic zone, if necessary weighted by the time it spends in a country’s zone over a year, determines the share that this country gets of the total catch quota for that stock.

There is a contradiction between the zonal affiliation principle and historical fishing. The history surrounding the management and conditions for cooperation on the issue of distribution of quota shares of the pelagic stocks in and around the Nordic seas are examples of this (Bjørndal and Ekerhovd 2014). The zonal attachment concept tends to favour the established coastal states interests over distant fishing states historic fishing rights, but our discussions pointed to its disability to cover changes in fish distribution, specifically more permanent redistributions related to climate change. For example, the established Norwegian-Russian agreement for Barents Sea cod may need to adjust if spawning and feeding distributions shift further east because of warmer conditions. This case demonstrates our group’s concern about national and international regulations having to be flexible enough to tackle impacts of climate change. Fishers will need to adapt to both climate change itself and related changes to regulations.

One aspect of regulations that we discussed is that Norwegian fishing vessels benefit from subsidized fuel, but with an obligation to land catches at local coastal processing facilities. The latter mechanism aims at securing local employment but has often resulted in employing foreign workers. Norway's fishing subsidies and other aspects of the complex quota system highlight the challenges in balancing local job support and market dynamics. With changing fish distribution patterns and new species entering during the coming decades this will be complicated further. By the end of this century, we expect all petroleum-based fuels to be abolished and new and yet unknown technology to have taken over, the accompanying regulatory system we have no foundation to speculate on. 

Although fishers have learned to live with and adapt to variability enforced through regulations, climate change may have consequences beyond what they can adapt to. Climate-resilient fisheries must either be robust enough to withstand substantial changes or flexible enough to be able to adapt and transform to the new state.

We expect pronounced differences in risks, possible opportunities and the ability to adapt between geographic areas and fleet types. We anticipate that over the coming decades the need for change/diversification in the Nordic and Barents Seas fisheries is less than in the Baltic, which already for some time has been challenged by a mixture of pressures. Also, the larger ocean-going vessels are more flexible to new distribution patterns and even new species than coastal fleets. There is a worry that coastal fleets may disappear from some areas. This points to a (potential) underlying conflict between locally owned and operated (smaller) vessels and larger ones (trawlers, purse-seiners) that may operate more freely in different areas. 

There were worries in our group about the future of commercial fisheries in especially the Baltic where the main commercial fisheries, and fish stocks, of cod and herring are already struggling. The same worry to a certain degree also applies to the North Sea when climate change strikes for full on top of all the other pressures. One scenario is a shift to the situation we have had on land most places in the world for a very long time, with food production totally dominated by agriculture and hunting more of a recreational activity. Tourist fishers may create more value than standard fisheries, at least if one takes the full cascading effects into account, including hotels, renting of boats and fishing gear. While the total worth is hard to estimate even for today, especially in northern Norway many different varieties of tourist fishing – including offshore for cod from the large skrei stock – has increased manifold over recent years. If regulations are followed and fishing is directed towards large healthy populations or cautious catch-release practices, this fishery may remain sustainable also under (moderate) climate change.

We may also see a development were there still is professional fishery but geared more towards high-end and lower volume. This is not totally new, we already have consumer acceptance for a price premium for high quality products, also related to specific gear (cod caught by line rather than trawl, for instance). If these developments are wanted or accepted as inevitable, infrastructure should be more geared towards high quality rather than large quantity. However, such changes and/or reductions will have large broader consequences, especially in smaller communities built upon fisheries. This opens for more general decisions relating to societal and cultural priorities. In Iceland, the Faeroe Islands, and (parts of) Norway, fisheries are deeply rooted in the culture, and we expect a willingness to support it even if the economic value decreases. Fisheries likely have lower priority in Sweden and Finland where their contribution to total economy is very small. Still, also in Finland and Sweden fish is an essential part of local traditional cuisine and culture (albeit in Finland mainly lake fishing), and the role of domestic fish as a healthy and environmentally friendly choice of protein is already being promoted. Also in Germany where fisheries has low economic value compared to the overall, there is a big public interest in fisheries and also environmental NGOs want to keep it. Thus, Germany maintains fisheries mainly for cultural and touristic reasons. While low volume high quality fisheries a priory should decrease the complexity of management and support sustainable practices, in practice future fisheries management will need to balance economic, socio-cultural, and environmental considerations.

This section relates to the coming decades; we have little foundation for saying anything sensible about the technology at the end of the century. Climate change, in interaction with other pressures, will drive development of new technology. The urge for a green transition also puts new demands to the fisheries sector, mainly through requirements related to engines and fuel. New types of fishing boats are developed for use in some Nordic areas, naturally where there is expected returns from such investments. In the Baltic this is not the case, people cannot risk such investments, so the fishing fleet is becoming old. New boat technology must be safe, energy efficient and not too expensive. Electrically powered boats are presently not safe enough nor able to undertake long trips, but hybrid alternatives are being developed. The introduction of CO₂ taxes encourages development of greener fuel. In Norway fishers are subject to such a tax on fuel, although it is partly refunded. For large vessels and/or long trips ammonium should be considered as an alternative fuel. Unfortunately, green fuel adoption is hindered by cost and space requirements for hybrid two engine systems.

The conditions in the Baltic Sea, with low salinity and oxygen levels, have always been challenging for marine species like cod and herring, although the stocks in long periods have thrived. The recent development with eutrophication, a strong temperature rise, and increased frequency and longevity of marine heatwaves has worsened the situation for established commercially harvested species, and there are low prospects of new species taking their place due to the unique characteristics of the sea (e.g., brackish water). Sprat are doing quite well but is used nearly only as fish feed and as such has also low value in the market and cannot replace cod or herring. Looking ahead towards the end of the century, even an intermediate IPCC scenario is bad news for the Baltic. 

Commercial fisheries, which has been highly important, seems to be losing in competition with other interests. Following the decline of fish resources, the number of fishing vessels is going down. Also, for example in Germany the mean age of fishers has increased a lot, now 57 years with hardly any young people entering. Further, fishing now has relatively low monetary value. For instance, in some harbours fishing vessels have had to move out of the best and most central locations as there is more money in marinas for recreational boats. Still, the social-cultural value of fisheries is significant in some countries bordering the Baltic Sea, especially at the local level there is support.

Fishing is in intense competition for space in the Baltic, not least with the shipping and energy sectors. This is a source of conflict that perhaps could be weakened by good spatial planning, but at least in Germany fishing is not included in the main processes. Fishing also has conflicts with marine conservation, which has high priority. While successful environmental conservation and restoration may be benefactory to fisheries, fisheries are by many considered as one of the main threats to the ecosystem. Based on current evidence, our group considers it highly unlikely that the fish stocks and fisheries will return to the high levels of the past. With increasing effects of climate change, future fishing may be restricted to low volume high-end. This will likely be geared towards tourists who are willing and able to pay a price premium and more for the experience than the food. This form of fishing, especially if catch-release is practiced, may also be marketed as eco-friendly.

North Sea fish and fisheries are already under strong pressure from climate change, especially rising temperatures. The most prominent case is that of cod, which in the North Sea live towards the southern boundary of the species’ preferred temperature. The once large stock (300,000 tonnes in the 1970s), has dwindled, in the southern North Sea there are few cod left. There is little doubt that this is related to intense fisheries. However, there is also considerable evidence for high temperatures being a substantial cause, especially through negatively affecting the main zooplankton prey of the young fish. With continued temperature rise, the future for cod fisheries in the North Sea is bleak.  

Sand eel (also called sand lance) is another commercially important fish that is under pressure. Warmer seas, especially during winter, may cause problems, resulting in a decrease in overwinter survival and delayed maturation. However, the most immediate threat is likely through habitat disturbance. The North Sea has been heavily industrialised for decades. Until recently the main offshore installations were related to petroleum, but now there is also the development of wind farms. This industrial growth poses unknown consequences, potentially displacing traditional fisheries. Danish fishers are particularly concerned about the full development of Dogger Bank, a crucial habitat for sand eels. The combined effects of an increasing number of offshore structures, often in areas of importance for fish and fisheries, and changing climate is highly troublesome.

With increasing temperatures, warm water affiliated species can move in from the south, this is a distinct difference between the North Sea and the Baltic. Hake, a sought-after food fish further south in Europe, have already established themselves in the North Sea and are expected to respond positively to further warming towards 2050. They are presently fished in the North Sea, but the fisheries here are relatively small. Bluefin tuna are also expanding their habitat northwards and are again found in the Skagerrak. There is now a fleet of around 10 vessels fishing Bluefin in Norwegian waters, and in addition a commercial rod and reel fishery targeting recreational fishers. Some flatfish species are also doing well, like plaice, which is especially popular in Denmark and now has an advised quota by ICES of 150 thousand tonnes.

Norway, Iceland, Faroe Islands, UK, Greenland, and Russia as well as various members of the EU participate in harvest and share the three large pelagic stocks of herring, mackerel, and blue whiting. The fisheries are of considerable commercial importance, and the stocks straddle the Northeast Atlantic, various EEZs and the high seas. These pelagic stocks are currently per definition overfished (in the sense that total TACs are higher than the ICES-based advice) and management in a state of conflict. Still, and although the total biomass is a lot lower than the peak values, none of the three stocks are in serious trouble.

The stocks’ distribution patterns are highly variable, to a large degree influenced by stock size and sea temperatures. Higher temperatures in the future may open for new distribution patterns. We consider temperature unlikely to be much of a problem (as direct impact) in the foreseeable future, but if primary production is hit, it will cascade to the pelagic fish. Acidification may become a threat by affecting fish eggs and larvae or through phytoplankton, but too little is yet known to draw any conclusions.

The Norwegian spring-spawning herring stock mainly inhabits Norwegian waters throughout their life cycle but can migrate into Russian waters during the juvenile phase and into Faroese, Icelandic and international waters as adults during the summer feeding period. However, the feeding migration pattern, especially for large herring, has changed several times over the last 60 years (Utne et al. 2012), varying with the size of spawning stock biomass and ocean conditions.  The mackerel spend most of the year in EU an UK waters, but a large part of the stock migrates into the eastern part of the Norwegian Sea and the North Sea from June to October. From around 2007 onwards Icelandic waters have also been inhabited by mackerel, linked to both to the stock being large and high-water temperatures. 

Changes in stock size and distribution have led to disagreements about the distribution of quota shares and renegotiations of concluded agreements (Baudron et al. 2020). When the negotiations on quota allocation have not progressed, the states have set their own quotas, which has resulted in fishing far more than scientific quota recommendations. Persistent overfishing can lead to overexploitation and greatly reduced stocks. Nevertheless, the states have not been able to agree on joint management and fishing pressure that is not assessed as sustainable continues.

With the sharing of catch quotas based on the zonal affiliation of fish stocks, it is not surprising that changes in distribution and migration patterns lead to a breakdown in existing agreements. It also shows the contradiction between the zonal attachment principle and historical fishing and that a cooperation agreement is not necessarily consistent over longer time horizons (Kvamsdal et al. 2022).

We discussed several possible developments in the region. We did not operate with any precise time horizon, but more towards 2050 than further ahead. This brief exercise was partly inspired by an earlier Barents Sea 2050 scenario workshop were several of us also took part. That workshop, reported in Planque et al. (2019), built their analyses upon the four perspectives “fisheries management,” “ecosystem,” “ocean climate,” and “global context and governance”. Here we were less systematic, but three scenarios were described: 1. An industrialized Arctic. With retreating ice cover and higher temperatures in the region there will be a struggle between nations to utilize the more accessible resources. We can imagine an industrialized Arctic with much increased activity in the established shipping, oil industry and tourism industries, and maybe also renewable energy (e.g., wind, wave), and deep-sea mining. Fisheries will then be less important than what they are today, but there could potentially be aquaculture on the coast of Svalbard. In this scenario, the region may become more like the present North Sea in many aspects. In a transition to an industrialized Arctic security and geopolitics will be important. The competition for resources could, as often before, escalate to 2. A conflicted Arctic with high military presence from different nations and less opportunities for developing industries. The world’s two superpowers, USA and China, both have military and commercial interests in the region, and Russia has an extensive Arctic coastline. A more optimistic development could be towards 3. An environmentally protected Arctic. This would be an expansion of the present cautious fishery management of the international waters of the Central Arctic Ocean to include limited or no oil and gas exploration, restricted and eco-friendly tourism, no-go marine protected areas, and a focus on preserving healthy fish stocks and nature more generally. This latter scenario would obviously be best for the climate, but it demands high levels of cooperation that seem unlikely today. One can hope that climate awareness at the governmental level increases when the impacts of climate change become severe enough. 

From a more strictly fisheries point of view, future management should balance economic, cultural, and environmental considerations, considering public interest and the potential for increased competition from other industries. The Norwegian-Russian cooperation on managing the fish resources of the Barents Sea has for decades been more resilient than most other places, but now faces challenges.

The group had broad discussions on the future of aquaculture in the Nordic areas in light of climate change and societal developments. Topics included the pronounced difference between the countries and seas regarding present aquaculture and future potential, a shift from wild fisheries to aquaculture, expansion of aquaculture northwards, offshore, on land and into new species, technology, co-existence with other industries, feed for the fish, and food for humans; all with the backdrop of changes in climate and the consequential impact on the environment. A complicating factor is that climate change will affect aquaculture through a range of different pressures and there are large knowledge gaps when it comes to the combined effect of multiple stressors. It should be noted that another workshop, focusing specifically on climate change and aquaculture, was held shortly prior to ours, more information at https://nofima.com/press-release/climate-change-adaptation-for-aquaculture-discussed/

Among the Nordic countries, Norway and the Faeroes are in the lead in marine fish farming, although also Denmark has had a significant fish sea cage industry for decades and an increasing focus on blue mussels. We consider that Iceland has a potential for increasing production. Finland and Sweden have numerous fish farms in lakes and rivers, but our focus was marine and that was not further discussed. We will see distinct differences in how climate will affect ecosystems and sea farming industries between the Nordic countries. There has been and is little aquaculture in the Baltic proper due mainly to pollution, eutrophication and low oxygen levels. While the group saw the potential becoming further reduced with climate change it should be noted that except in the worst climate scenario combined with very large inputs of nutrients, oxygen levels in the Baltic Sea are expected to be higher/better by the end of the century than today. Still, rising temperature is a challenge, and the Baltic ecosystems are in need of severe restoration, especially dealing with the large amounts of nutrients that have accumulated in the system during the last century, before substantial aquaculture can be established.

Although both The Faeroes and Norway have their aquaculture dominated by Atlantic salmon and are technologically advanced, there are significant differences. This relates to environmental conditions, with temperatures being more stable in Faeroese water, but with the farms there being closer to the open ocean and more vulnerable to large waves and ocean swells. This will likely cause different impacts from climate change with a general transformation towards both higher temperatures and stronger winds. The combination of this and little remaining place in the fjords will likely hamper further expansion of Faeroese aquaculture.

A major difference between the Faeroese and Norwegian salmon farming is the fish feed. The Faroe farms mainly use marine-based feed, typically blue whiting, while Norway relies heavily on plant-based feed, mostly soya from Brazil. Unfortunately, neither of these practices are sustainable, especially if the industries are to scale up. Faeroese salmon are considered to have the highest quality (also because they are slaughtered at a larger size) and get a price premium, the highest price in the world market. However, the practice of using small pelagic fish as salmon feed puts pressure on the world’s fish stocks and their ecosystems. Still, using blue whiting as feed is less unsustainable than sardines or anchovies, which to much larger degree are directly eaten by humans. Plant-based feed ingredients may to certain degree replace fishmeal and fish oil, but demand land and water resources. Relying on soya from Brazil is especially troublesome, as the soybean production has led to clearing of large areas in the Amazon rainforest. Both this and the long-distance transportation to the salmon farms cause substantial greenhouse gas emissions accelerating climate change – the opposite of climate change mitigation. 

As for fish caught in the wild, there is a rising demand for sustainable practices in the aquaculture industry. The debate on the demand side, including the carbon footprint of farmed salmon and ecological farming certifications, reflects changing consumer preferences. Traceability, documented greener production lines including knowledge of where the seafood item origins and how it was produced, may secure a price premium. Finding ways to feed the fish in a sustainable way is perhaps the factor most strongly restricting substantial expansion of the aquaculture industry. A number of innovative and more sustainable feed solutions have been suggested and studied, including algae, insect meal, by-products from production of other food (such as using dairy waste for shrimp farming), and laboratory produced single-cell proteins. So far, price and the need for scale-up possibilities has been too challenging to make any of these into real-world solutions. 

Although climate change will affect fisheries very differently across the Nordic sea areas, we expect an overall decline. An expansion in fisheries is unlikely, that must come in aquaculture. Such a shift is influenced not only by decreasing limits to productivity (carrying capacity) in the wild fish stocks, but also by consumer trends and technological advancements within aquaculture, suggesting a future where farmed fish plays a dominant role. We expect geographical shifts (northwards) to lower temperatures, new species, new technology, and/or offshore and/or on land. Geographical moves and expansion of cod and kelp farming present opportunities, but also challenges. Temperatures will likely become too high at some existing salmon farms in south-western Norway within ten years, already the expansion is into more northerly and cooler areas. Moving the core of Norwegian salmon aquaculture northwards may reduce conflicts along the wild versus farmed salmon axis, but introduce new lines of conflict between aquaculture, fisheries for e.g. cod, and other industries. Management should be flexible enough to respond adequately to changes driven by climate and/or market demand. For example, in Norway, new regulations are opening opportunities for diverse species like lobster and halibut. 

The vast majority of fish farms in the Nordic region are of the sea cage type, also known as net pen or semi-closed farming systems. According to the industry, this conventional technology will be the main production method for many years to come (PWC 2023). However, looking “some decades” ahead, the industry believes that an increased focus on new technologies, such as offshore and land-based production and closed marine cages, will create a shift away from the conventional technology that is totally dominating today (PWC 2023). Although still in its infancy, offshore aquaculture farms are operative in Norwegian waters and others are planned. The are several reasons for this development. There is limited space close to the coast, the best locations are taken. Offshore there is room for larger installations. Offshore locations reduce the threat from and spread of diseases and parasites, like sea lice, that challenge coastal fish farms. Advances in automation and smart technology now make it more feasible to operate fish farms further from the coast. 

However, there are also factors that challenge offshore fish farming. Firstly, it is very expensive, establishing a new offshore farm costs a lot more than a coastal one, despite new technology also routine operation and maintenance at sea is costly. Related to this is technological and logistic challenges. Offshore farms must endure tough environmental conditions, including strong and variable currents, strong and high waves, and exposure to storms. This requires robust and often expensive infrastructure. Increased windiness and waviness is expected, further stressing the infrastructure. Wind and waves may also stress the salmon, fish welfare must be taken into consideration. The Norwegian Ministry of Trade, Industry, and Fisheries recent strategy document “Business plan for the Norwegian sea areas” (NFD 2024) states that the government is working on developing a separate licensing regime for offshore aquaculture with strict requirements for sustainability and coexistence between different marine industries.

Although uncommon in the Nordic area, Recirculating Aquaculture Systems (RAS), have also been introduced. Such systems are enclosed, sealed off from the environment and replace the natural flow of water in the sea with a water filtration and recirculation system. As a result, they can be and most often are placed on land. Recent technological advances and growing regulatory support (e.g., Norway is incorporating land-based farms into their aquaculture strategies) are making it feasible to farm fish and other aquatic species in controlled, land-based environments. There are environmental-based arguments both in favour and against a switch towards more land-based aquaculture. Closed land-based systems will diminish the impact on marine ecosystems by reducing pollution, issues with wild (e.g., salmon) populations, and the salmon lice infestation. On the other hand, RAS consumes large amounts of fresh water, requires much more energy than the natural flow of water utilised by cage systems, and will have to compete with other activities for space on land. RAS plants can in principle be placed close to the cities where the markets are, but scarcity of land in such areas drives the costs up. Also, countries like Norway, have, with a long coastline and proximity to open sea areas, a natural advantage for coastal and offshore aquaculture. This may not be the case for land-based operations, thus there may be little motivation at the national level for shifts in that direction.

Climate change may encourage and enforce different industries to work together. Our discussions touched upon co-existence of wind plants and kelp aquaculture and even potential multi-use wind farms and aquaculture infrastructure. Several possibilities are being explored in the EU funded project “Offshore Low-Trophic Aquaculture in Multi-use Scenario Realisation in North and Baltic Seas” (OLAMUR; olamur.eu; coordinated from IMR). This includes demonstration cases where kelp and blue mussels are grown within windfarms and near a trout farm. This includes work lead from Aarhus University that demonstrates the potential of multi-use in offshore areas, highlighting both sustainable energy, nutritious seafood, and restorative ecosystem services through nutrients and carbon capture and utilization (Maar et al. 2023b). They more particularly examined co-locating wind farm with blue mussels and sugar kelp aquaculture in the North Sea - Baltic Sea transition zone.

There is a broad range of solutions available and also ideas in the pipeline. These span from genetically adjusted fish to new nets that can be pulled down to adjust temperature and avoid surface marine heat waves. However, there are also downsides, genetic modification is debated and complicated. Fish that are modified to cope with higher temperatures may as a side effect become more vulnerable to low oxygen content.

In addition to being a large fish producer, Norway is a leader in providing technology and knowledge, for instance in rearing new species (like cod) and applying genetic tools to enhance specific targeted fish properties. With Norway’s high costs and a location far from large markets, our discussions suggested that the country could move more towards becoming a supplier of technology more than actual fish. However, awareness of impacts of climate change is still often low and adaptation measures not prioritized. This is problematic, as climate change, especially through rising sea temperatures, is expected to have increased negative impacts on the aquaculture industries, already in the near future. Challenges include intensified marine heat waves and algal blooms, more jellyfish invasions, parasites and diseases. Sea lice is a severe problem both economically and for fish welfare. Also, the treatments to get rid of sea lice are problematic from a fish health and –welfare perspective. In addition to gill problems, skin health is currently the main factor leading to loss, and this is mostly related to injuries caused by treatment. Further, increased temperature has shown to worsen the effect from production related stress.

Higher temperatures also tend to spread and increase the lice problem. Unfortunately, this is already happening - unusually warm water during the summer of 2024 caused severe lice issues much further north than earlier. The knowledge level of impacts of MHWs like this is low, but we expect them to be quite different in, e.g., northern Norway than in the Danish straits.

Technology should also be applied towards climate change mitigation, that is reducing the GHC emissions from the industry. Pressure towards sustainability on the demand side, including reducing the carbon footprint of farmed fish and ecological farming certifications, reflects changing consumer preferences. This may help drive development of more green technology. Ideally, as pointed to in the aforementioned strategy document (NFD 2024), the cultivation and farming of seaweed and kelp can also be a means for nature-based carbon sequestration.