UTILIZATION AND PROCESSING OF FISHERIES AND AQUACULTURE PRODUCTION15
Fisheries and aquaculture harvests are transformed into a wide range of products with different characteristics and flavour depending on the species, preservation method and product form. Major improvements in processing, refrigeration, ice production and use, freezing, storage and transportation have enabled extended shelf-life, distribution over long distances and across borders, and an increasing variety of products.
The proportion of fisheries and aquaculture production of aquatic animals used for direct human consumption has increased significantly from 67 percent in the 1960s to about 89 percent in 2020 (that is over 157 million tonnes of the 178 million tonnes of total fisheries and aquaculture production, excluding algae15) (Figure 35). The remaining 11 percent (over 20 million tonnes) was used for non-food purposes; of this, 81 percent (over 16 million tonnes) was reduced to fishmeal and fish oil, while the rest (about 4 million tonnes) was largely utilized as ornamental fish, for culture (e.g. fry, fingerlings or small adults for ongrowing), as bait, in pharmaceutical uses, for pet food, or as raw material for direct feeding in aquaculture and for the raising of livestock and fur animals.
FIGURE 35UTILIZATION OF WORLD FISHERIES AND AQUACULTURE PRODUCTION, 1961–2020
In 2020, live, fresh or chilled aquatic food15 continued to account for the largest share of fisheries and aquaculture production utilized for direct human consumption (44 percent), and it often represents the most preferred and highly priced form of fisheries and aquaculture products.15 It was followed by frozen (35 percent), prepared and preserved (11 percent) and cured16 (10 percent) products. Freezing represents the main method of preserving fisheries and aquaculture products for food purposes, accounting for 63 percent of all processed aquatic animal production for human consumption (i.e. excluding live, fresh or chilled).
These general data mask major differences. Utilization and processing methods differ significantly across continents, regions, countries and even within countries. In Asia and Africa, the share of aquatic food production preserved by salting, smoking, fermentation or drying is higher than the world average. Approximately two-thirds of the fisheries and aquaculture production used for human consumption is in frozen, prepared and preserved forms in Europe and North America. The share of fisheries and aquaculture production utilized for reduction into fishmeal and fish oil is highest in Latin America, followed by Asia and Europe.
Overall, in more developed economies, processing of aquatic food has diversified particularly into high-value-added products, such as ready-to-eat meals. In 2020, over 50 percent of the aquatic animal food production destined for human consumption in high-income countries17 was in frozen form, followed by about 26 percent in prepared and preserved form, and 13 percent in cured form. In many developing countries, processing of aquatic products18 has been evolving from traditional methods to more advanced value-adding processes, depending on the commodity and market value. However, there are significant differences depending on countries’ infrastructure and cultural preferences. In 2020, about 20 percent of the aquatic food production of upper-middle-income countries was utilized in frozen form, 11 percent in canned form, and over 60 percent in live, fresh or chilled form. In contrast, for low-income countries, only 7 percent was in frozen form, more than 20 percent in cured form and about 70 percent in live, fresh or chilled form.
Aquatic products commercialized in live form are principally appreciated in East and Southeast Asia and in niche markets in other countries, mainly among immigrant Asian communities. In China and some Southeast Asian countries, live aquatic animals have been traded and handled for more than 3 000 years, and in many cases practices for their commercialization continue to be based on tradition and are not formally regulated. Commercialization of live aquatic animals has continued to grow in recent years also thanks to improved logistics and technological developments. Yet, marketing and transportation can be challenging, as they are often subject to stringent health regulations, quality standards and animal welfare requirements (notably in Europe and North America).
Overall, the ongoing expansion in consumption and commercialization of fisheries and aquaculture products (see the sections Consumption of aquatic foods, and Trade of fisheries and aquaculture products) has been accompanied by a significant development in food quality and safety standards. In recent decades, the fisheries and aquaculture sectors have become more complex and dynamic, with developments driven by high demand from the retail industry, species diversification, outsourcing of processing, and stronger supply linkages between producers, processors and retailers. Expansion of supermarket chains and large retailers worldwide has increased their role as key players in influencing market access requirements and standards. To meet these food safety and quality standards and ensure consumer protection, increasingly stringent hygiene and handling measures have been adopted at the national, regional and international levels, based on the Codex Code of Practice for Fish and Fishery Products (FAO and WHO, 2020) and its guidance to countries on practical aspects of implementing good hygiene practices and the Hazard Analysis Critical Control Point (HACCP)-based food safety management system.
As aquatic products are highly perishable, particular care is required at harvesting and all along the supply chain. If not correctly treated after harvesting, they can soon become unfit to eat and possibly dangerous to health as a result of microbial growth, chemical change, breakdown by endogenous enzymes and cross-contamination leading to food safety risks. Proper handling, processing, preservation, packaging and storage measures are essential to extend shelf-life, ensure food safety, maintain quality and nutritional attributes and avoid loss and waste. Furthermore, improved utilization can help reduce the pressure on aquatic resources and foster sustainability of the sector.
Preservation and processing techniques are also essential to allow aquatic products to be distributed and marketed domestically and internationally. These techniques are based on temperature reduction (chilling and freezing), heat treatment (canning, boiling and smoking), reduction of available water (drying, salting and smoking) and changing of the storage environment (vacuum packaging, modified atmosphere packaging and refrigeration).
Nutritional attributes of aquatic food can vary according to the way in which it is processed and prepared. Heating (by sterilization, pasteurization, hot smoking or cooking) reduces the amount of thermolabile nutrients, including many vitamins. However, the concentration of some nutrients can increase with heating, which removes water.
Significant technological development in food processing and packaging is ongoing in many countries, with increases in efficient, effective and lucrative utilization of raw materials, and innovation in product diversification for human consumption as well as for production of fishmeal and fish oil and other purposes.
Products: fishmeal and fish oil
A significant but declining proportion of world fisheries production is processed into fishmeal and fish oil. Fishmeal is a protein-rich flour made by milling and drying fish or fish parts, while fish oil is obtained by pressing cooked fish and centrifuging the liquid extracted. Fishmeal and fish oil can be produced from whole fish, fish trimmings or other fish processing by-products. A number of different species are used as whole fish – mainly small pelagic fish, such as Peruvian anchoveta (accounting for the greatest proportion), menhaden, blue whiting, capelin, sardine, mackerel and herring.
Fishmeal and fish oil production fluctuates according to changes in the catches of those species, in particular anchoveta, dominated by the El Niño–Southern Oscillation, which affects stock abundance. Over time, the adoption of good management practices and certification schemes has decreased the volumes of unsustainable catches of species targeted for reduction to fishmeal. The amount utilized for reduction to fishmeal and fish oil peaked in 1994 at over 30 million tonnes and then declined to less than 14 million tonnes in 2014. In 2018, it rose to about 18 million tonnes due to increased catches of Peruvian anchoveta (see the section Capture fisheries production) before declining in the subsequent two years to reach over 16 million tonnes in 2020. This corresponds to about 20 percent of capture fisheries in marine waters.
This progressive reduction in supply has been coupled with a surging demand driven by a fast-growing aquaculture industry, as well as by pig and poultry farming, and the pet-food and pharmaceutical industries. According to the estimates of the Marine Ingredients Organisation (IFFO), in 2020 about 86 percent of fishmeal was used in aquaculture, while 9 percent was destined for pig farming, 4 percent for other uses (mainly pet food) and 1 percent for poultry. In the same year, about 73 percent of fish oil was destined for aquaculture, 16 percent for human consumption and 11 percent for other uses (including pet food and biofuel) (Figure 36). The increasing demand for fishmeal and fish oil led to an increase in their prices. The fact that supply is lower than demand and the sector is a profitable one has led to pressure to find additional or alternative sources. While the majority of whole fish used in the production of fishmeal and fish oil originates from well-managed resources, the sustainability of some fisheries remains of great concern in some countries where fishmeal production is on the rise. This is the case in some countries in West Africa, where an increasing amount of catches are reduced into fishmeal for export purposes, rather than used for human consumption. In Senegal, for instance, whole fish used for decades for direct human consumption are now being redirected into production of marine ingredients. This not only increases the pressure on fishery resources, but it impacts food security and livelihoods. In these areas, it is essential to improve governance and fisheries management, while prioritizing the utilization of fish for human consumption (Thiao and Bunting, 2022).
FIGURE 36UTILIZATION OF FISHMEAL AND FISH OIL
A growing share of fishmeal and fish oil is being produced using fish by-products from capture and aquaculture processing with a positive impact on waste reduction. With no major increases in raw material expected to come from whole wild fish (in particular, small pelagics), any increase in fishmeal production will need to come from fish by-products and other sources such as krill. Fishmeal from by-products has a different nutritional value, being lower in protein but richer in minerals in comparison with fishmeal obtained from whole fish. According to IFFO, in 2020, 27 percent of the global production of fishmeal and 48 percent of the total production of fish oil were obtained from by-products (IFFO, 2021; Figure 37).
FIGURE 37SHARE OF RAW MATERIAL UTILIZED FOR REDUCTION INTO FISHMEAL AND FISH OIL, 2020
Nevertheless, fishmeal and fish oil are still considered the most nutritious and most digestible ingredients for farmed fish, as well as the major source of omega-3 fatty acids (eicosapentaenoic acid [EPA] and docosahexaenoic acid [DHA]) in animal diets. However, their inclusion rates in compound feeds for aquaculture have shown a clear downward trend, largely as a result of supply and price variation coupled with continuously increasing demand from the aquafeed industry. Fishmeal and fish oil are increasingly used selectively at specific stages of production, such as for hatchery, broodstock and finishing diets, and their incorporation in grower diets is decreasing. For example, their share in grower diets for farmed Atlantic salmon is now often less than 10 percent and there has been a continued reduction across all categories of species. With regard to direct human consumption, fish oil is a major natural source of the omega-3 long-chain polyunsaturated fatty acids (EPA and DHA), which perform a wide range of critical functions for human health.
Because of the fluctuations in fishmeal and fish oil production and associated price variations, many researchers are seeking alternative sources of polyunsaturated fatty acids (PUFAs). These include stocks of large marine zooplankton, such as Antarctic krill (Euphausia superba) and the copepod Calanus finmarchicus, although concerns remain over the impacts on marine food webs. Krill oil in particular is marketed as a human nutrient supplement, while krill meal is finding a niche in the production of certain aquafeeds. However, processing entails practical challenges – the fluoride content of the raw material needs to be reduced and the high cost of zooplankton products means that they cannot be included as a general oil or protein ingredient in fish feed. In addition to fish by-products, insect meals offer good potential as a protein feed input to aquafeeds (Hua et al., 2019).
Fish silage, a rich protein hydrolysate that contains high amounts of essential amino acids, is a less expensive alternative to fishmeal and fish oil, and it is increasingly used as a feed additive, for example, in aquaculture and the pet-food industry. By using a technology such as fish silage, fish and parts of the fish not used as human food could easily be preserved and transformed into a valuable feed input for aquaculture (Toppe et al., 2018).
The expansion of processing of fisheries and aquaculture production has resulted in increasing quantities of by-products, which may represent up to 70 percent of processed fish, depending on the size, species and type of processing. The by-products are usually composed of heads (accounting for 9–12 percent of total fish weight), viscera (12–18 percent), skin (1–3 percent), bones (9–15 percent) and scales (about 5 percent). Historically, fish by-products were often diverted to the production of fishmeal or discarded as waste, resulting in economic losses and environmental problems. The processing of by-products often involves significant environmental and technical challenges due to the high microbial and enzyme load of the raw material and its susceptibility to rapid degradation unless processed or stored properly. Thus, timely collection and treatment of by-products is crucial for their further processing. The development of new ingredients or new products in various forms based on fish by-products provides a potentially valid alternative to increase the value added of products, avoid economic loss, reduce environmental impact, and supply consumers with nutritious, low-cost, and convenient food with a more stable shelf-life.
The fillets are the most valuable in terms of protein, but heads, frames, fillet cut-offs, belly flaps and parts of the viscera such as liver and roe are particularly good sources of nutrients such as long-chain omega-3 fatty acids, vitamins A, D and B12, as well as minerals such as iron, zinc, calcium, phosphorus and selenium. By applying processing technologies to parts of the fish traditionally not eaten, they can be converted into highly nutritious products at a low cost such as fish sausages, pâté, cakes, snacks, soups, sauces and other products for human consumption. If these products are tasty and locally acceptable, this could be an excellent opportunity to increase the nutritional impact from fisheries and aquaculture resources as well as reduce fish loss and waste.
Small fish bones with a minimum amount of meat are consumed as snacks in some countries. Furthermore, these by-products can be converted into flour and used as a flour substitute in breads, pastries, cakes and noodles to add nutrients such as protein and calcium. Gelatine made from skin and bones can be further processed into edible films and edible coatings for food applications. Fish gelatine is an alternative to bovine and porcine gelatine and can stabilize emulsions. Fish bones, in addition to providing collagen and gelatine, are also an excellent source of calcium and other minerals such as phosphorus, which can be used as feed or food supplements. Using simple low-cost technologies, fish by-products can also be converted into the above-mentioned fish silage.
In addition to their various uses in food, fish by-products are increasingly gaining attention in biotechnological and pharmaceutical applications as they offer a significant and sustainable source of high-value bio-compounds, due to the high content of collagen, enzymes, peptides, PUFAs and minerals (Coppola et al., 2021). Fish collagen is considered to be an alternative to collagen from bovines and pigs and has recently been recognized as a promising biomaterial with great potential in pharmaceutical and biomedical applications (Wijaya and Junianto, 2021). Enzymes and bioactive peptides can be isolated from fish viscera and can be used in a range of applications in leather, detergent, food and pharmaceutical industries, and in bioremediation processes. Fish oil contains a large quantity of long-chain PUFAs, which cannot be synthesized by the human body and provide a wide range of critical functions for human health.
By-products of crustaceans and bivalves can be used in many ways to increase their value while also addressing waste disposal issues. Chitin, a polysaccharide extracted from crustacean shell waste, is a potential source of antimicrobial substances. Its derivative, chitosan, has a wide range of applications, notably in the fields of wastewater treatment, cosmetics, toiletries, food, beverages, agrochemicals and pharmaceuticals. The shells of bivalves, such as mussels and oysters, can be turned into calcium carbonate or calcium oxide, two highly versatile chemical compounds with wide industrial applications. Shells can also be used in cosmetics and traditional medicines (pearl powder), as a calcium supplement in animal feed (shell powder), and for handicrafts and jewellery.
In addition, seaweeds are processed into food additives or food supplements and are a good source of iodine, fucoidan, fucoxanthin and phlorotannins (Cai et al). Seaweeds and microalgae generate socio-economic benefits for tens of thousands of households, primarily in coastal communities, making a contribution to human health, environmental benefits and ecosystem services. Generally rich in dietary fibre, micronutrients and bioactive compounds and with some species having high protein content, seaweeds are often viewed as a healthy, low-calorie food.
Aquatic food loss and waste
Despite major progress in processing, refrigeration and transportation, every year millions of tonnes of aquatic products are lost or nutritionally compromised. This does not only occur in the fisheries and aquaculture sectors, as global food loss and waste is a major issue and is the focus of Sustainable Development Goal (SDG) Target 12.3, which aims at halving wastage by 2030. In fisheries and aquaculture, it is estimated that up to 35 percent of the global fisheries and aquaculture production is either lost or wasted every year. In most regions of the world, total fish loss and waste is estimated to lie between 30 percent and 35 percent (FAO, 2011b). Wastage rates have been estimated to be highest in North America and Oceania, where about half of all aquatic animals caught are wasted at the consumption stage. In Africa and Latin America, fisheries production is mainly lost because of inadequate preservation infrastructure and expertise. Nevertheless, Latin America is the least wasteful region (under 30 percent of total production lost).
Fish losses, in quantity and quality, are driven by inefficiencies in value chains. Many developing countries – especially the least developed economies – still lack adequate infrastructure, services and know-how for adequate onboard and onshore handling and preservation. Inability to access electricity, potable water, roads, ice, cold storage and refrigerated transport represents a major handicap. Effective fish loss and waste reduction requires the application of a multidimensional and multi-stakeholder approach. Such a broad approach considers the factors affecting national capacities in loss prevention such as supportive policies and legislation as well as skills, knowledge, services, infrastructure and technology. Understanding how these different factors interact in a given context, influenced by factors related to location, species, climate and culture, is important in order to be able to design effective and sustainable solutions. This approach is promoted by the FAO Voluntary Code of Conduct for Food Loss and Waste Reduction (FAO, 2021a). It should be emphasized that reducing fish loss and waste can lead to a reduction in pressure on fishery stocks and contribute to improving resource sustainability as well as food and nutrition security.19
- 15For algae, aquatic food, fisheries and aquaculture production, and fisheries and aquaculture products, see Glossary, including Context of SOFIA 2022.
- 16Cured means dried, salted, in brine, fermented, smoked, etc.
- 17The World Bank assigns the world’s economies to four income groups: low, lower-middle, upper-middle, and high. More information is available at https://datatopics.worldbank.org/world-development-indicators/the-world-by-income-and-region.html
- 18For aquatic products, see Glossary, including Context of SOFIA 2022.
- 19Food loss and waste (FLW) refers to the decrease in the quantity or quality of food. A reduction in quality usually leads to a reduction in nutritional value, economic value, or food safety issues (FAO, 2017a). Food waste is part of food loss. It occurs along the entire food supply chain and is the result of decisions and actions by primary producers, retailers, food service providers and consumers. An example of “waste” in fisheries is “discards”, whereby captured aquatic species are thrown away at sea. Information on the food loss and waste in value chains of aquatic products can be found on an FAO web page devoted to this topic (FAO, 2020b).