However, it is problematic that the average rate of growth in global aquaculture production has weakened since the turn of the millennium compared to previous years. This has not occurred everywhere, and not to the same extent everywhere, but the trend is quite clear. In the 1980s and 1990s, the annual rate of growth in the production of aquatic animals, at 10.8 to 9.5 percent, was still unusually large. However, since the beginning of the 2000s, growth has slowed significantly. Purely in terms of numbers and given in average values, the total for 2001 to 2019, at 5.3%, is still positive, however it cannot be denied that global growth in aquaculture is slowing down. In 2017 it was only 4 percent, and in 2019 it was even lower, at 3.7 per- cent. Growth rates have slowed in China in particular. China’s share of global aquaculture declined from 59.9 percent in 1995 to 56.9 percent in 2019. It will probably decline further in the coming years, since Chinese aquaculture only grew by 2.2 percent in 2017 though it increased to 3.4 percent in 2019. What would be welcome growth figures for most other countries in the world is an unusual situation for a global industry leader accustomed to breaking new records each year. However, this shift is an intentional one that has been approved by the state. The lower growth is a result of a change in government policy from 2016 towards more environ- mentally friendly aquaculture practices, higher product quality and more efficient use of resources. China’s share of global aquaculture production will therefore probably continue to decline.
Freshwater species continue to dominate fish production
Since 1991, China has produced more fish, molluscs and crustaceans from aquaculture than the rest of the world put together. Other Asian countries such as Bangladesh, India, Indonesia and Vietnam also have strong aquaculture sectors. In the last 20 years, all Asian countries combined accounted for 89 percent of global aquaculture production. The large production areas have remained nearly constant since the 2000s, although their percentage share of production has shifted slightly. While the production of crustaceans, primarily shrimp, has greatly increased, fish production has declined somewhat relative to other areas. Nevertheless, fish production of both freshwater (‘freshwater aquaculture’) fish at 47 million tonnes, as well as in the marine sector (‘marine and coastal aquaculture’) at 7.3 million tonnes, has reached a new record level. According to FAO experts, the largest reserves of growth are currently in mariculture. Interest in marine fish production is growing significantly, not least because marine fish have a much higher market value than most freshwater fish species. Marine fish made up only 13.4% of fish production in aquaculture, but they contributed a quarter of total value from fish cultivation. Crustaceans have an even greater value potential. They made up 8.2% of the quantity, but 26.3% of the total value of global aquaculture production.
In the fish cultivation sector, freshwater aquaculture continues to play a major role, accounting for 84 percent of total farmed fish production. Crustacean aquaculture in Asia has grown strongly primarily due to shrimp farming. The excellent salt tolerance of whiteleg shrimp (Litopenaeus vannamei) makes it possible to produce this species of shrimp far from the coast in inland areas, even in arid regions with salty alkaline groundwater such as Xinjiang in the Gobi Desert. Coastal farms, which have frequently been located in coastal pools and lagoons, are very important for many developing countries, because they provide local employment and promote economic development in coastal communities. However, not many species are suitable for this type of aquaculture, because the conditions in shallow coastal waters are less stable than in inland water masses or on the open sea due to precipitation and evaporation. Marine and coastal aquaculture produced a total of 30.8 million tonnes of aquatic animals with a total value of USD 106.5 billion. The strongest sector was shellfish and other molluscs at 17.3 million tonnes (corresponding to 56.2% of relevant production), ahead of fish (7.3 million tonnes) and crustaceans (5.7%).
Production share of non-fed species decreasing
In the animal aquaculture production sector, the share of fed species has increased compared to non-fed organisms. At the beginning of the 2000s, 43.9 percent of all aquatic animals produced by aquaculture were still produced without additional feed, but in 2018 this share was only 30.5 percent. This means specifically that 57 million tonnes of marine animals, primarily fish and crustaceans, were provided with various types of feed. This can be compared to 25 million tonnes of non-fed aquatic animals, which do not require additional feeding. These are mostly filter-feeding or grazing species, which get their food naturally from the water, for example, plankton, detritus or algae areas. Almost a third of non- fed species were freshwater fish species, mainly silver and bighead carp, the remaining two-thirds was made up of marine shellfish. The shift from non-fed to fed aquaculture is also an index for the transformation of production methods. Traditional processes such as integrated rice and fish cultivation, which still have great importance in Asia, are increasingly being replaced by more productive processes that use resources more efficiently and allow for better protection of the environment.
The simultaneous cultivation of fed and non-fed species that has been practised in Asia for centuries is now increasingly being applied in multi-species polyculture systems in Central and Eastern Europe and Latin America. In pools such as these, even the smallest remnants of the feed for the main fish species can still be used by filter-feeding species. The supply of nutrients fertilises the water and promotes the development of plankton, which are in turn eaten by filter- feeding fish and shellfish species (extractive species). For this reason, Mississippi paddle fish (Polyodon spathula) and freshwater shellfish for pearl production are currently increasingly being used in Chinese polycultures. Both species feed on plankton and do not require additional feeding.
FAO statistics are only as good as the reported underlying data
In spite of great efforts, the FAO’s statistics cannot fully record and reflect the wide variety of fish, crustacean and mollusc species produced by aquaculture under different climatic and environ- mental conditions. In 2006, the total number of commercially productive species registered by the FAO was 472. In 2018, this number had grown by 31.8 percent to 622. This can be attributed first to improvements in the recording and reporting of data in the producing countries, and second to more precise investigations on the part of the FAO. To be more exact, the 622 figure refers to ‘units’ that are recorded for statistical purposes, it does not refer in each case to a genuinely separate species, but often only to ‘species items’. According to FAO information, this covers 466 separate species, 7 inter-species fish hybrids and 92 species groups at a genus level, 32 species groups at a family level and 25 species groups at an order level or higher. Higher- level groupings such as families and orders cannot adequately reflect the significance of individual species, but can nevertheless allow for certain conclusions to be made.
Salmon in 9th place in the production rankings
Fish production, the most varied aquaculture sub-sector, includes over 364 species and species groups as well as five hybrids (e.g. Morone, Clarias and Oreochromis crosses), of which the ten most important make up almost two-thirds of total global production at 54.3 million tonnes. This does not include the Nile tilapia, which has risen to third place in the species rankings in the last few years (if cichlid species of the genera Sarotherodon and Tilapia are included as well as Oreochromis species, tilapias actually make second place). As ever, fish production is dominated by Chinese (grass carp, silver and bighead carp) and Indian carp species (catla, rohu, mrigal), which are however almost entirely locally consumed and do not play any role in supplying the global market. Atlantic salmon, which has enormous economic significance for Western markets, but increasingly also in Asia and South America, appears at 9th place in the global production statistics, followed by ‘pangasius’. It is also noteworthy that nine of the ten most important fish species by quantity are produced in fresh water (salmon should be partially counted as one of them, since it breeds in fresh water until its offspring are smolts).
Vannamei shrimp are strongest growth dynamic in global aquaculture, particularly shrimp farming. The production of marine shrimp, which is typically done in coastal areas, has become an important source of income for numerous developing countries in Asia and Latin America. The farming of vannamei shrimp, which replaced monodon shrimp as the dominant species in aquaculture in 2003, is particularly strong. The five most important crustacean species by quantity account for more than 92 percent of relevant global aquaculture production.
The growth in production of red swamp crawfish which increased almost 2.5 times from 895,000 tonnes in 2016 to 2.16m tonnes in 2019, is also impressive. Chinese river crab, which is known as a nuisance in European waters, is popular in China and other Asian countries and fetches attractive prices. Breeding in farms is particularly profitable because the preferred sizes and qualities of the crabs can be achieved more easily in aquaculture under controlled conditions.
China produces three quarters of aquaculture shellfish
China is also the world’s largest producer of molluscs, contributing more than three quarters (76.3%) of global shellfish production at 13.36 million tonnes. This is made up almost exclusively of marine species, which are mainly cultivated in coastal areas. All other shellfish-producing countries are significantly behind this enormous quantity, although the percentage share of molluscs in total aquaculture cultivation is often even higher. From a global perspective, shellfish production is concentrated primarily on five species or species groups, which taken together account for more than 77 percent of the total quantity produced. The largest proportion is contributed by rock oysters, followed by Japanese carpet shell and various species of scallops and other pectinidae.
Global algae production has declined slightly
In contrast to the other large sec- tors in aquaculture, the production of algae and water plants has grown more slowly in recent years and actually declined by 0.7 per- cent in 2018. This was not due to the loss of cultivation areas, but somewhat slower algae growth for climate reasons. The decline in the production of tropical algae species in South-East Asia was the strongest indication of this, while the production of algae in temperate and cold waters increased. Algae and water plants were mostly produced in aquaculture by countries in East and South-East Asia. The production of marine microalgae (seaweed) has tripled since the turn of the millennium from 10.6 million tonnes to 32.4 million tonnes in 2018. The expansion of cultivation of the Kappaphycus alvarezii and Euchema spp. species of algae in Indonesia is responsible for this. It is used as raw material for carrageenan production. Indonesia has increased its algae production in the last decade from less than 4 million tonnes to over 11 million tonnes. Although the value of algae production remains significantly behind the other sectors in aquaculture, it is currently gaining in importance. On the one hand, it can provide a regular, albeit modest, income with a limited amount of investment for a large number of people, who are disproportionately women. On the other hand, algae farming is particularly environmentally friendly. In addition, demand for algae products such as carrageenan and agar-agar as well as algae products for direct human consumption (e.g. Undaria pinnatifida, Porphyra spp. and Caulerpa spp.) is increasing. Algae are becoming increasingly important, including as a feed for abalone cultures.
The cultivation of microalgae such as Spirulina spp., Chlorella spp., Haematococcus pluvialis and Nannochloropsis spp. currently remains a black box in the FAO statistics, for which the quantities produced are not yet fully recorded and regularly reported. For 2018, the FAO cites a statistic of only 87,000 tonnes from 11 countries, of which China alone accounts for 86,000 tonnes. The actual quantity may be much higher as the demand (e.g. for use as a food supplement) is steadily increasing and microalgae production is being expanded globally.
Developing countries are exploiting the opportunities offered by aquaculture
Although aquaculture is growing and gaining in importance globally, it still remains the case that production is very unequally distributed across the globe. This has not changed in recent years. As ever, aquaculture production is dominated by Asian countries, which have produced 89 percent of the total volume almost continuously over the last two decades. Africa has slightly increased its share, but at only approximately 2.7 percent of global aquaculture production this is still limited. Europe’s share has actually slightly declined. Particularly large efforts have been made to develop aquaculture in countries such as Egypt, India, Indonesia, Vietnam and Bangladesh, which need to feed rapidly growing populations. The political will and readiness to expand aquaculture through private and public investment is correspondingly great in these countries, where the focus is increasingly on more sustainable production.
All data from FAO statistics, FIGIS