Less than half of the European dietary recommendations for fish consumption are satisfied by national seafood supplies

The global fish production industry plays an important role in national economies, supporting an estimated 59.5 million jobs in the primary sector of capture fisheries and aquaculture [1]. Seafood is also the most valuable traded food commodity worldwide, with net exports from developing countries valued at $38 billion in 2018, exceeding that of sugar, tobacco, meat and rice combined [1]. Fish and fisheries products also play a vital role in global food security, particularly in developing countries, providing around 17% of animal protein consumed by the global population in 2017 [1]. In developing countries, fish offers a cheap source of high-quality protein and diversity to a diet dominated by more staple foods such as maize and rice [2]. In these countries, fish is also a valuable contributor to the reference nutrient intakes for a range of micronutrients and, therefore, fish consumption may contribute to alleviating highly prevalent micronutrient deficiencies [3]. A number of studies have highlighted the contribution of fish consumption to adequate intakes of micronutrients on a global scale [4‐6]. A recent modelling approach linking nutrient availability from marine fish to nutrient deficiencies in 43 countries found that nutrients available in marine finfish exceed that of dietary requirements, but only for populations residing within 100 km of the coast [6]. Consumption of seafood is also linked to health benefits, such as a reduction in the risk of mortality of coronary heart disease [7]. Compared with very low fish intake (i.e., < 1 serving/month), low fish intake (1 serving/week) reduces the risk for coronary heart disease and stroke by 16% and 14%, respectively, and moderate fish intake (2–4 servings/week) reduces risk for coronary heart disease and stroke by 21% and 9%, respectively [8, 9].

Given these nutritional and health benefits, many countries have established recommendations for seafood consumption as part of their national dietary recommendations. Some of these recommendations are based on cohort studies that focus on total seafood consumption, while others are based on the content of the main omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) [7, 10]. Moreover, fish are an important source of bioavailable micronutrients, often lacking in plant-based diets [11, 12] and enhance the availability of minerals from cereal-based foods [13]. They also offer an alternative, more-affordable animal-based product [13] with a lower environmental impact [14]. Few countries take the environmental perspective into account in their recommendations for fish consumption [10]. Such an environmental perspective is important due to increasing constraints on the global seafood supply from growing populations, growing disposable incomes, and therefore, increased demand [1]. For example, in a previous study of the UK, fish supply only satisfied 64% of the amount proposed by dietary recommendations [15]. Therefore, national aspirations for increased fish consumption may have wider environmental implications.

Marine capture fisheries represent a large proportion of total fish production, but production from this sector has remained largely stagnant for the past three decades. Broad concern about the overexploitation of wild fish stocks and environmental impacts of aquaculture have been raised over the years. At the start of the twenty-first century, declines in fish stocks were widely reported [16, 17], but stringent management measures have been effective at rebuilding many assessed stocks to above sustainable target levels at European and global levels [18, 19]. However, the majority of global fish stocks are unassessed and, therefore, their status is uncertain [19]. Aquaculture currently provides around half (46%) of global fish production [1], but concerns have been raised about the nutritional quality of farmed fish compared to wild varieties, especially in relation to the former’s lower content of omega-3 fatty acids and some micronutrients [3, 10].

This paper provides an analysis of seafood supplies, defined as the amount of seafood available for human consumption, by examining fish production (accounting for imports and exports) from both wild capture fisheries and aquaculture. Dietary recommendations of European countries were reviewed to determine if they were satisfied by seafood supplies at the national level. Such information is important considering the implications for dietary recommendations and human health, as well as a sustainable supply of seafood products.

We found that national dietary recommendations across Europe varied significantly between countries, ranging from 100 to 482 g/capita/week. Between 2007 and 2017, national dietary recommendations for fish consumption were only satisfied by net seafood supplies in 13 out of 31 European countries. Notably, these countries all have large coastal access or traditional fish-eating cultures. Net seafood supplies were lowest in landlocked countries and those with low production and import rates.

Many European dietary recommendations for fish consumption are underpinned by evidence that fish consumption is associated with a reduced risk of mortality of coronary heart disease [10]. The beneficial effects of fish consumption have historically been attributed to its content of omega-3 fatty acids [7]. A recent systematic assessment of the effects of these fatty acids, mostly provided as fixed-dose supplements, on cardiovascular health outcomes, indicated that increasing consumption had little or no effect on mortality or cardiovascular health [24]. However, the health benefits of fish consumption on cardiovascular health outcomes are well established [8, 9] and may be greater than the sum of its individual constituents such as omega-3 fatty acids [10]. Fish is an important source of protein, long chain n-3 polyunsaturated fatty acids (LC n-3 PUFA), vitamins and minerals [10], and the importance of fish consumption for nutritional status appears to be of high significance, especially in low- and middle-income countries [4, 5, 10]. It has been hypothesised that global net supply of mainly wild catch fish could significantly impact micronutrient deficiencies in the future, especially for coastal regions [5]. However, increasingly, demand for fish is being met by aquaculture production [1] and its nutritional quality has been questioned. The marine finfish aquaculture industry has increasingly sourced fish feed from terrestrial agriculture to become more cost effective. The introduction of vegetable oils and meals to fish feeds has affected the nutritional composition of farmed fish, resulting in lower levels of omega-3 fatty acids and micronutrients over the past decade [10, 25]. Therefore, we may need to eat more fish to provide similar health benefits than those described previously [8, 9]. Existing dietary recommendations for fish intake are based on cohort studies that were performed with mostly capture fish that probably had higher levels of omega-3 fatty acids and micronutrients, and future recommendations will need to take account of how this might change.

The literature is not very clear on the positioning of seafood within a sustainable diet. Indeed, seafood consumption is commonly presented as a dilemma. The trade-offs between the health benefits of eating seafood, the lower impact of fish consumption on greenhouse gas emissions compared with other animal-based protein such as beef and pork, and concerns of overfishing and ecological impacts are not well defined. Furthermore, farmed and wild‐capture production methods are often not integrated into research on the impacts of diets and future food scenarios [26]. To position seafood within a sustainable diet, it can be argued that greater consideration needs to be given to fish supply when considering dietary recommendations for fish consumption. Our findings for the UK, i.e., that dietary recommendations are not satisfied by net fish supply, agree with those reported by Thurstan and Roberts [15], who concluded that recommended levels of fish consumption were not achievable by net supply in 2012. They found that total supplies of fish in that year only met 64% of recommended fish intake. Our average results from data obtained between 2007 and 2017 were similar: fish supply met 66% of recommended dietary fish intake (185 g of the recommended 280 g was available). A comparison of global fish consumption with regional fish supplies to determine which areas meet demand by production and/or imports using population and catch data for 64 Large Marine Ecosystems (LME’s) found that two-thirds of LME’s reported landings were not sufficient to meet local consumption [27].

Between 2007 and 2017, net seafood supplies were relatively consistent in most European countries. However, there was more variation in net seafood supplies across years in some countries, including those with higher levels of fish production (Faroe Islands, Iceland, Norway, Lithuania, Malta), but also in those with lower levels of fish production (such as Estonia) (Fig. 2). Seafood supply may vary annually due to changes in fish stocks status, consumer demand and socio-economic factors. Thurstan and Roberts [15] also reported annual variability in fish supply in the UK and noted that fish supplies met the recommended level of intake for fish only twice in 124 years.

We appreciate the term “seafood” can be misleading when describing fish supplies in landlocked countries, which have no marine fisheries. Whilst, inland freshwater fisheries contribute little to European fish production, Czech Republic, Hungary and Austria rely on freshwater aquaculture and capture production. Although in this analysis, “seafood” consisted of finfish, shellfish, molluscs and cephalopods from brackish, marine and freshwater systems, we propose that “aquatic protein” or “aquatic food” could be used in the future. “Aquatic food” would also include seaweed, the consumption of which has been postulated to have been significant in the past [28] and may increase in future [29], but is not considered here.

Within the past decade, trade of wild and farmed fishery products has contributed globally to economic growth and food security. Whilst fisheries contribute little to the GDP and food security in developed countries, in Iceland and the Faroe Islands, fish is vital to the national economy [30], with fish exports exceeding 40% of the total value of merchandise traded [1]. In our analysis, we assumed that countries prioritised exporting national fish production over imported fish. Although our results suggest that some imported seafood commodities are re-exported, after accounting for all exports no national dietary recommendations are satisfied by national production alone if exports continued. With limited growth in capture production, the EU is increasingly relying on extra-EU imports to meet demand [1]. Moreover, a recent WWF analysis predicted that many people living in poverty will choose to export fish rather that consume it by 2050 [27]. Therefore, to assure a sustainable supply of fish for current and future generations, greater consistency in national dietary recommendations would aid in the development of more sustainable food systems.

Marine model projections predict climate-induced shifts in fish distributions which will decrease the maximum catch potential by 2050, thereby threatening global supply for human consumption [30]. For example, changes to Atlantic mackerel migration has already led to a breakdown of international management agreements [31]. Additional factors such as habitat degradation and pollution will also affect fish abundance, with a recent report stating a 76% decline in global migratory freshwater fish populations over the last 50 years [32]. There are alternative sources of omega-3 fatty acids supplied into the food system through an expanding aquaculture sector [33], and through the development of new sources of EPA and DHA, such as algal biomass and GM oils, especially for the production of aquafeeds [34]. An alternative plant-based dietary source of omega-3 fatty acids, alpha linolenic acid (ALA), is, however, not found to produce the same health benefits as the marine-derived omega-3 fatty acids EPA and DHA, and the conversion of ALA to EPA and DHA is limited in humans [35].

Strengths of this study include linking dietary recommendations with net seafood supplies with a European perspective, using the most recent food balance sheets from the FAO, providing a comprehensive picture of a country’s food seafood supply and allowing the tracking of fish supply patterns over time. However, care should be taken when comparing production, imports and exports between countries. Calculating fish supplies in g/capita/week may introduce a bias towards those countries with smaller population sizes. For example, over the same 10-year period, Norway, the Netherlands and Spain exported the highest amount of seafood (in grams) in Europe. However, Iceland and Faroe Islands recorded higher exports (g/capita/week) owing to the significantly smaller population sizes of these countries. Also, in our analysis, seafood supplies may be underestimated, especially in southern Europe due to under-reporting of subsistence fisheries. Small-scale fisheries represent 84% of the total fishing fleet by number of vessels in some southern European regions, particularly around the Mediterranean and the Black Sea [36]. On the other hand, supplies are likely to be over-estimated across European countries as food balance sheets do not account for food waste at the retail or household level. Furthermore, it should be noted that the majority of European recommendations for fish consumption are for finfish only and do not include other seafood products such as crustaceans and molluscs; commodities which were included in our calculations of national seafood supply.

In conclusion, our findings emphasise the need to not only consider consumer health outcomes when developing and advocating dietary recommendations, but also seafood supplies and the sustainability of food production systems. As many foods are not necessarily locally sourced, but part of global production and distribution systems, it is important to consider a greater consistency between national dietary recommendations to aid the development of more sustainable marine food systems.