Contrary to other regions of the world, freshwater fish farming in in the European Union (EU-27) and Latin America and the Caribbean (LAC) is a marginal sub-segment of the aquaculture sector. This article provides a comparative overview of decadal changes in aquaculture production in these two territories by analyzing freshwater resource endowments and using total renewable water resources (TRWR) as an indicator of water-abundancy.
Since the mid-1990s, nearly all growth in seafood supply has originated from aquaculture. At the global level, the contribution of freshwater fish production to total aquaculture output increased from 55.6% to 61.2% between 1995 and 2019, indicating that the growth rate of freshwater aquaculture outpaces that of mariculture.
In the European Union (EU-27) and Latin America and the Caribbean (LAC), the profile of the aquaculture industry is different from the other regions, since coastal (marine or brackish water) aquaculture dominates the sector in both regions.
In 2019, freshwater aquaculture only contributed 25.0% and 27.4% to total fish production in LAC and EU-27, respectively, and the rate of its growth was lower than that of marine aquaculture in both regions.
Aquaculture Production Trends in the Two Regions
Although at the global level, freshwater aquaculture is expanding rapidly, there is spatial heterogeneity in development patterns both between regions and within each region (Figure 1).
Production in LAC
Figure 2 presents the decadal changes in Latin American freshwater aquaculture production. During this period the output grew by 95% (from 476 to 927 kT), which is considerably higher than the growth rate of the global freshwater aquaculture level (60%).
Brazil is by far the largest producer of LAC; it is the only non-Asian country in the top 10 of the global list of freshwater aquaculture producers (ranking 7th in 2019), and the 2.1-fold growth in Brazilian production over a decade is considerably higher than in other large global producers.
However, in other major producers of LAC (Peru, Mexico, and Colombia) the sector grew at a rate even higher than in Brazil. Altogether the top-4 producers (Brazil, Colombia, Mexico, and Peru) account for 85% of total freshwater aquaculture output in the region, and contributed to 98% of the increment in production volume over a decade.
Production in EU
Contrary to significant development in Latin American and global freshwater aquaculture, output in the EU has not grown for decades. Production has slightly decreased from 284 to 280 kT over the last decade (Figure 3).
Similar to Latin America, big differences exist between the development patterns of individual countries. There are marked west-east and south-north gradients in industry growth rates: aquaculture output in most of the Western and Mediterranean countries fell, on the contrary, Eastern and Northern EU states increased their fish production (Figure 1).
EU aquaculture is heavily concentrated on two species, which altogether account for 83% of production. Rainbow trout, a predatory species predominant in the aquaculture of Northern, Western, and Mediterranean countries, are farmed in cold-water systems.
Diversification and Emerging Species
Species diversification increases the resilience of industry by reducing its vulnerability to market shocks and species-specific disease outbreaks. The diversification index (DIV) calculated for the Latin American freshwater aquaculture was reduced from 0.68 to 0.59 in the last decade, which suggests that concentration of the industry has taken place, and the sector became less diversified at the regional level.
The reduction in the DIV is mainly attributed to the increasing dominance of Nile tilapia in Latin American aquaculture. In Brazil, Mexico, and Peru the diversification of fish production was reduced significantly, corresponding to a development pattern where an already dominant species becomes even more dominant in production (tilapia for Mexico and Brazil, trout for Peru).
This reflects that the aquaculture industry sees the opportunity in concentrating efforts, investments, and infrastructure on the production of these species. In contrast with the Latin American freshwater aquaculture, the species diversity slightly increased in the EU-27 in the last years from 0.54 to 0.56.
This is mainly attributed to the shrinking contribution of trout to total production, but the increasing output of emerging species also contributes to increased diversity in European aquaculture.
Water Use and Resources in LAC and EU Aquaculture
Water Resource Intensity of LAC and EU Aquaculture Production
The intensity of resource use varies widely between culture systems. Pond systems, which are the dominant environment for freshwater fish production both globally and in LAC, are in between RAS/cage and flow-through systems in terms of water use, with footprint values between 3 and 40 m3 / kg, depending on yields, evaporation and seepage conditions at the production site, and water refreshment regime applied.
Generally, it is considered that specific water use has an asymptotic relationship with aquaculture production intensity, since more intensive production systems were found to use water resources more efficiently (per kg of fish produced) than extensive production systems.
Results of studies assessing water use in LAC and EU are summarized in Table 1. Calculated per kg water demands of species farmed in Latin American systems (Table 1) fall in line with finding for other regions of the world.
Although results are not supposed to be directly compared since different studies use different methodologies with different system boundaries, it is important to note that a recent study found that intensive tilapia culture was associated with a higher blue water footprint than extensive farming due to high flow rates of refreshing water in the former technology.
Based on data available it is estimated that 48% of freshwater production originates from flow-through pond/tank/raceway systems, 38% is produced in static-water earthen ponds, while RAS systems and cage/ pen aquaculture account for 10% and 4% of production, respectively.
Under flow-through conditions mainly trout, and to a lesser extent, African catfish, are cultured. Coldwater trout are often reared in surface water diverted from smaller water courses, while warm-water catfish are farmed in subterranean geothermal water. In the pond farming segment, typically a semi-intensive carp-dominant polyculture is practiced with low (<1 t/ha) yields [47–49].
“Contrary to Latin America, European RAS systems are constructed primarily to farm freshwater species, mainly trout, catfishes, and sturgeons.”
There are farms also that rear Atlantic salmon and eel in a freshwater RAS environment. Unlike many regions of the world, where cage farming is an important segment of both freshwater and marine aquaculture, in the EU cage systems are not typical in freshwater environments, only some facilities exist to farm carp and sturgeon in reservoirs and on cooling water of thermal power plants.
To minimize the discharge of trout farms and comply with strict environmental regulations, partial recirculation of water was a tendency in Denmark, one of the largest producers in the EU. The water demand of the flowthrough trout farming segment is high (50–100 m3 /kg), and this can be reduced by up to two orders of magnitude (to 0.1–2.0 m3 /kg) if systems are converted to RAS.
Carp produced in semi-intensive pond production in an Eastern European climate have a water demand of around 20 m3 /kg (Table 1).
Role of Water Resources in Aquaculture Development
The aquaculture production growth requires some 5–50 m3 of water per kg of additional capacity, depending on the species and production system. Tilapia and carp aquacultures in most typical semi-intensive systems demand 10–30 m3 /kg, while trout produced in conventional flow-through require more than 50 m3 /kg.
It was examined two regions: LAC, which are abundant in water resources with a TRWR value of 21,476 m3 /capita/year, and the EU-27, which have a TRWR less by an order of magnitude (3,041 m3 / capita/year).
Growth in annual freshwater aquaculture production over the last ten years was −0.01 kg/cap (the EU) and 0.70 kg/cap (LAC). Figure 4 plots the per-capita availability of annually renewed freshwater resources against per-capita growth in the aquaculture sector in the last decade for the top 12 producing countries in each region.
Per-capita growth if aquaculture was calculated as the difference between per-capita production in 2017–2019 and in 2007–2009. Therefore, countries with increasing populations and slightly increasing production may have negative values for per-capita change in fish production (e.g., Denmark).
The calculated Pearson-r correlation between the two variables is 0.53 (p = 0.08) for Latin American countries, while for European countries it is 0.75 (p < 0.01) if outlier data for Bulgaria was excluded. These values suggest a positive relationship between per capita freshwater aquaculture development and per capita freshwater availability.
In Latin America, Peru, Colombia, and Brazil are the most water-abundant countries, and these countries are ranked 2nd, 1st, and 4th in terms of per capita aquaculture growth, respectively. On the other hand, Cuba is characterized by the lowest water resource availability in LAC, and this corresponds to the biggest reduction in aquaculture production.
“Among the major freshwater fish producer countries in the EU, Sweden, Hungary, and Romania have the largest volume of water resources, corresponding to positive growth rates of aquaculture on a per-capita basis in these countries.”
Sweden has the highest water abundance among the major producers in the EU and this enables the high growth rate of trout production in flow-through systems, which have the highest water demand among European systems. In water-poor regions, one strategy to maximize production value per m3 of water used is to farm high-value species in recirculation aquaculture systems (RAS), which minimize water footprint.
RAS aquaculture (farming sturgeons, eel, catfish, trout) has developed rapidly, especially in the European countries where per capita water renewable resources are below 4,000 m3 . Denmark, France, Germany, Poland, and Spain altogether account for 75% of RAS production in the EU.
Emission of Aquaculture Production
Aquaculture generates emissions either to the air or to the aquatic space. The most pronounced environmental concerns are over:
(i) the release of nitrogenous or phosphorus, which may stimulate eutrophication processes in the receiving water body, and
(ii) greenhouse gas (GHG) emission.
Unlike water footprint, which is mainly generated during on-farm activities, the majority of aquaculture related GHGs are emitted during feed production, thus carbon footprint is largely determined by the feed conversion rates and the ingredients used in aquafeeds.
This implies that the nutritional habit of the cultured species and the regional availability of ingredients matching these nutritional requirements have a major influence on climate change mitigation.
Conclusions and Perspectives
There are several factors that play a significant role in aquaculture development, including market demand, environmental concerns, licensing regulations, and institutional capacity. The LAC, accounting for one-third of the world’s total runoff, is wellendowed with currently underutilized renewable water resources and still has a huge scope for expansion.
In the European context, it is often cited that bureaucracy and restricting environmental regulations are barriers to growth, but it needs to be further understood whether regions poor in natural resources tend to have stricter environmental rules to ensure the conservation of biodiversity and ecosystem functioning and whether socio-economic and institutional influences are themselves consequences of resource scarcity.
In fact, many of the European producers see the future potential of the industry rely on subsidies, rather than expansion of physical output.
This is a summarized version developed by the editorial team of Aquaculture Magazine based on the review article titled “FRESHWATER AQUACULTURE DEVELOPMENT IN EU AND LATIN-AMERICA: INSIGHT ON PRODUCTION TRENDS AND RESOURCE ENDOWMENTS” developed by: GERG ˝O GYALOG; JULIETH PAOLA CUBILLOS TOVAR; EMESE BÉKEFI – Hungarian University of Agriculture and Life Sciences. The original article was published on MAY, 2022, through SUSTAINABILITY.
The full version, including tables and figures, can be accessed online through this link: https://doi.org/10.3390/su14116443