Future Feeds: Suggested Guidelines for Sustainable Development

Abstract

Whilst the aquaculture sector continues to grow and make an ever increasing contribution to world food supplies, there is a need to ensure that the sector continues to develop in a socially, economically and environmentally sustainable manner, in line with the UN sustainable development goals. The present paper focusses on the major perceived sustainability issues related to feed inputs for finfish and crustacean aquaculture species, including sustainability issues related to feed formulation and ingredient selection, feed manufacture and feed quality, on-farm feed use and impacts, and fish quality and food safety.

Keywords:

• Aquaculture
• sustainable aquafeeds
• fish-in fish-out (IFFO)
• sustainable development
• feed manufacture
• on-farm management

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Introduction

Since the first FAO publication of technical guidelines for aquaculture development (FAO 1997), the FAO has published two feed-related guidelines, the first concerning good aquaculture feed manufacturing practice (FAO 2001) and the second concerning the use of wild fish as feed (FAO 2011). It is hoped that the current paper will provide additional guidance concerning feed ingredient selection and use, and the sustainable development of the aquafeed sector in line with the UN sustainable development goals (the lead author of this paper having been previously involved in preparation of all of the above guidelines).

In particular, considerable controversy has arisen since the use of the term “fish-in fish-out” (FIFO) as a metric for the use of fishmeal and fish oil in compound aquafeeds (Tacon et al. 2006), and the perceived long-term sustainability of the aquaculture sector dependent upon these wild fishery resources (Deutsch et al. 2007; Tacon and Metian 2008a; Naylor et al. 2009; Boyd et al. 2020). In particular, controversy has arisen concerning the methodology used for converting fishmeal and fish oil use back to live fish weight equivalents (Jackson 2009; Kaushik and Troell 2010; Bendiksen et al. 2011; Torrissen et al. 2011; Obach 2012; Sarker et al. 2013; Byelashov and Griffin 2014; Ytrestøyl et al. 2015; Aas et al. 2019; Turchini et al. 2019; Kok et al. 2020).

For example, in the Salmon Aquaculture Dialogue paper of Tacon (2005) and Tacon et al. (2006) live fish weight equivalents were calculated by summing the totals for fishmeal and fish oil use and then multiplying by 4 or 5 (yields of fishmeal and fish oil varying from species to species, season to season, and from country to country; Péron et al. 2010). However, in our later paper (Tacon and Metian 2008a), we followed the methodology used by the Salmon Industry in Chile (SalmonChile; Anon 2006) where transformation yields were also calculated separately for fish oil, resulting in higher FIFO values in the case of salmonids where large quantities of fish oil were consumed.

From the FIFO controversy, a series of derived ratios/indexes have been developed aiming at better assessing the dependency of aquaculture species upon capture fisheries for the supply of their major dietary source of protein and lipids (e.g. forage fish dependency ratio -FFDR-, marine protein dependency ratio -MPDR-, eFIFO). According to Ytrestøyl et al. (2015) most of them are providing a good picture of the pressure on the wild resource while they are failing to really fully cover sustainability aspect.

Nevertheless, existing ratio or indexes are similarly unperfected presenting objectively advantages and disadvantages (see review of Ytrestøyl et al. 2015). The major issue for all of them is that they depend on data subjected to high levels of uncertainty and that are challenging to collect (Merican and Sanchez 2016), probably due to a lack of transparency or to the confidential character of feed formulation. Aside from the debate on the best approach or the limited access to data, their values greatly vary due to a series of other reasons including methods used, data inputs, scale, generalization. For a given method, the best approach is to look at the evolution with time in order to see the improvement with time although this can be challenging too due to previously cited issues of data access.

It is important to note that the FIFO ratio was never intended to be a precise measurement of how much wild fish is required to produce a given amount of farmed fish. The ratio itself was to bring attention to the reliance of the aquaculture feed industry on wild capture fisheries. Further with much of the aquaculture sector seeking to portray farmed seafood as a solution or alternative to wild capture fisheries, the FIFO ratio highlighted the specific dependence aquaculture has on wild capture fisheries. Additionally, some critics of the aquaculture sector have been primarily focused on the wild fish dependency because of a marine conservation focus. The narrow focus of these critics fail to recognize that there are tradeoffs in environmental impact in the substitution of ingredients for wild fish, i.e. soy and deforestation/conversion, manufactured novel ingredients and energy consumption, etc. So while useful as a guidepost and a magnitude snapshot of aquaculture's reliance on wild fisheries, there is a broader lens by which the aquafeed sector should be viewed to account for these tradeoffs and other impacts of ingredient production and feed manufacturing.

Need for a more holistic “feed-in fish-out” approach

Notwithstanding the above, it is clear that the FIFO metric, like other ratio/index, is not an indicator of sustainability per se unless it is linked with the sustainability or not of the specific fishery and/or processing waste targeted for fishmeal and fish oil production (FAO 2011; Ytrestøyl et al. 2015). Moreover, apart from the current dependence of high trophic level aquaculture species upon fishmeal and fish oil use (Naylor et al. 2009; Olsen 2011; Tacon et al. 2011; Auchterlonie 2016), there is a need for a more holistic approach and to consider other feed-related factors to ensure the long-term sustainable development¹ of the aquaculture sector.

In the view of the authors, the major perceived sustainability issues facing the commercial aquafeed sector can be viewed at four levels, namely:

Sustainability issues related to feed formulation and ingredient selection

Required

• Need to prohibit the use of non-sustainble marine feed ingredient sources, including meals, oils and silages/hydrolysates derived from over exploited and/or non-sustainably managed wild-caught marine fish, crustaceans, mollusks, and aquatic plant species (Hasan and Halwart 2009; Tacon and Metian 2009; FAO 2011);

• Need to prohibit the use of non-sustainble and/or adulterated terrestrial feed ingredient sources, including meals derived from endangered and/or protected wild animal species, the use of non deforestation/conversion-free feed ingredients, the use of highly subsidized imported feed ingredient sources, and the use of spoiled, adulterated and/or contaminated feed ingredients (FAO 2001, 2019; Berntssen et al. 2010, 2021; Siegel et al. 2016; Gonçalves et al. 2018; MOWI 2020);

• Need to prohibit the use of non-approved terrestrial feed ingredient sources (depending upon the producing/importing country) for perceived religious and/or food safety concerns, including feeds containing terrestrial animal byproduct meals, genetically modified plant feed ingredients, and animal manures (Schofield 2002; Boyd et al. 2020);

• Need to prohibit the re-feeding of feed ingredients derived from the same species for biosecurity concerns, including fishmeals produced from salmonid, pangasius, tilapia and/or shrimp aquaculture processing wastes (FAO 2001; Tacon 2017; GAA 2020);

• Need to prohibit the use of non-approved chemicals, medicants & feed additives (depending upon the producing/importing country), including antibiotics, hormones, antioxidants, binders, medicants, pigments, and non-protein nitrogen compounds (FAO 1997, 2019);

Recommended

• Need to reduce the carbon footprint of aquafeeds through the reduced use of imported feed ingredient sources and the increased use and recycling of locally available agricultural and fishery resources derived from sustainably managed and operated agricultural and fishery operations (FAO 1997; Tacon et al. 2012; Boyd et al. 2020; Ghamkhar and Hicks 2020; Jones et al. 2020);

• Need to limit the selection and use of potentially food-grade feed ingredient sources, including fisheries bycatch, small pelagic fish species, and food-grade cereal grains, starches, pulses, and oilseeds (FAO 2011; Tacon et al. 2012);

Sustainability issues related to feed manufacture and feed quality

Required

• Need to ensure that the feed manufacturing plant is run and operated following all national laws and local environmental/social standards, and according to standards, guidelines and criteria concerning the manufacture of compound aquafeeds developed by FAO (Technical Guidelines on Good Aquaculture Feed Manufacturing Practice; FAO 2001; FAO/IFIF 2010), the Global Partnership for Good Agricultural Practice (GLOBALG.A.P; Compound Feed Manufacturing), the Global Aquaculture Alliance (GAA; Feed Mills BAP Standards and Guidelines), and/or the Aquaculture Stewardship Council (ASC; Responsible Feed Standard);

• Need to ensure oversight in feed ingredient supply chains to demonstrate to buyers and authorities that ingredients are not produced with forced or child labor;

• Need to ensure that feeds produced by the feed plant are formulated so as to meet the dietary nutrient requirements of the target species for optimum growth and health (NRC 2011), and for the intended farming system and stocking density (FAO 2001);

• Need for the feed plant to have a dedicated laboratory for feed quality control, including the use of both Near Infra Red (NIR – for rapid analysis) and wet chemical analytical techniques (for certified anlaysis) for the routine analysis of feeds and feed ingredients, including proximate analysis, specific nutrient analysis (if so required), and screening for mycotoxins and possible adulterants/contaminants (De Jonge and Jackson 2013; Tangendjaja 2015);

• Need for transparency concerning feed ingredient use and the open-declaration of all major feed ingredients and feed additives used on feed bags and/or labels (listed from highest to lowest), as well as key essential dietary nutrient levels (FAO 2001; Schofield 2002);

Encouraged

• Need to minimize the use of feed mill sweepings and processing wastes (includes floor sweepings and rejected processed feeds due to quality concerns) within finished feeds;

• Need for the feed mill to establish a dedicated research and development (R & D) program and facility for the routine in-house testing of novel feed additives, feed ingredients, and feed formulations, including for determining the apparent nutrient digestibility of the feed ingredients used by the feed plant;

• Need for the feed mill to dedicate sufficient funds and resources (incuding personnel) for farm data collection and technical support to farmers concerning the storage and management (feeding) of their feeds, including training for both large-scale and small-scale farmers (Bondad-Reantaso and Subasinghe 2013; Robb and Crampton 2013);

Sustainablity issues related to on-farm feed use and impacts

Required

• Need for farmers to monitor and record feed consumption, fish/shrimp biomass, survival and apparent biological and economic feed efficiency on a regular basis (based on the frequency of sample weighings for each individual production unit), and in particular at the end of each farm production cycle (Hasan and New 2013);

• Need for farmers to store their feeds under protected, cool and well-ventilated conditions so as to maintain feed quality and nutrient stability, and to use feeds on a first-in first-out basis (FAO 2001; Hasan and New 2013; O’Keefe and Campabadal 2015);

• Need to prohibit farmers from top-dressing their feeds with non-approved feed ingredients and feed additives, including antibiotics, growth promoters and un-processed marine feed ingredients that may pose a biosecurity or health risk to the cultured species (Tacon 2017);

• Need for the farmer to optimize feed intake and feed efficiency of the cultured species to farm and water quality conditions, including water temperature, dissolved oxygen levels, feeding frequency, feeding method etc following internationally recognized good or best on-farm feed management practices (Boyd 2009; Molina 2009; Hasan and New 2013);

• Need for the farmer to monitor the environmental impact of their feeds by monoitoring waste nutrients levels (including P, N, suspended solids, biological oxygen demand) over the culture cycle, and by minimizing their potential negative environmental impacts through water-recirculation and/or effluent treatment/IMTA prior to discharge (Bartley et al. 2007; Boyd 2009; Hasan and New 2013; Ghamkhar and Hicks 2020);

Encouraged

• Need to encourage farmers to establish a dedicated research and development (R & D) program and facility on-farm for the in-house testing of different feeds and feeding regimes so as reduce feed costs and optimize their feeds and feeding systems;

• Need to increase communication and information between farmers, feed manufacturers, policy makers, consumers, and researchers so as optimize on-farm feed use, farm management, profitability, and the long-term sustainability of the aquaculture sector (Robb and Crampton 2013);

Sustainability issues related to fish quality and food safety

Required

• Need to ensure that feeds used by farmers have no negative effect on the nutritional quaity and safety of aquaculture products (Tacon and Metian 2008b);

• Need to monitor the nutritional composition, quality and safety of aquaculture products destined for direct human consumption, including whole fish/shrimp, gutted fish, shrimp tails, fish fillets, fish balls, fish sausages, fish burgers, nuggets etc depending upon the species and country of origin (Lie 2008; Tacon et al. 2020);

Encouraged

• Need to maximize the use of aquaculture derived trimmings and fish/shrimp off-cuts for direct human consumption when ever possible, including the production of lower-cost (in marketing terms) fast-food and/or ready-made meals for mass consumption (Nikolik 2015; Stevens et al. 2018);

• Need to encourage the nutritional enhancement and potential health attributes of aquaculture products through dietary fortification with limiting key essential nutrients (Tacon et al. 2020);

• Need to promote public awareness and understanding concerning the nutritional and health benefits of farmed aquatic food products and by so doing encouraging increased consumption of aquaculture products (Tacon et al. 2020); and

• Need to promote public awareness and understanding concerning resource-use efficiency, nutrient retention efficiency, and environment/climate change impacts of different cultured fed-fish and shrimp species production compared to other terrestrial animal food production systems from feed to consumed product (Boyd and McNevin 2015; Fry et al. 2018; Ghamkhar and Hicks 2020; MOWI 2020).

Concluding remarks

With the total global production of major fed-aquacuture species reaching a new high of 45.41 million tonnes in 2018 and compound feed consumption estimated at 52.74 million tonnes (Figure 1, Table 1), fed-species aquaculture production is expected to grow 58.96 million tonnes by 2025 (Tacon 2020). However, to achieve this growth the aquafeed industry has to grow at an average rate of 7.7% per year (Figure 2), including the supply of feed ingredient inputs.

Figure 1. Global production of major fed-aquaculture species: 2000 to 2018. Growth expressed as % APR from 2000 to 2018 for total fed-species production was 6.8%/year (13.94 to 45.41 million tonnes), and individually by major species as follows: Chinese-fed carp 3.8%, Tilapia 9.4%, Shrimp 9.6%, Catfishes 14.2%, Marine fishes 6.4%, Freshwater crustaceans 11.4%, Salmon 5.4%, Other miscellaneous freshwater & diadromous fishes 12.4%, Milkfish 5.9%, Trout 3.0% and River eels 1.3%; data calculated from FAO, 2020a).

Figure 2. Total estimated commercial feed usage by major fed-aquaculture species: 2000 to 2018 and estimates for 2020 and 2025.

Table 1. Estimated major fed-aquaculture species production and compound feed usage in 2018 (values given in thousand tonnes; after FAO, 2020a & Tacon 2020).

Top fed species	Tonnes	% on feeds	eFCR	Feed use Tt
Chinese fed carp	14,141	58%	1.7	13,943
Tilapia	6,031	93%	1.7	9,535
Shirmp	6,004	86%	1.6	8,261
Catfishes	5,781	81%	1.3	6,87
Marine fish	3,006	83%	1.6	3,992
Freshwater crustaceans	2,961	58%	1.8	3,112
Salmon	2,637	100%	1.3	3,428
Other freshwater & diadromous fish	2,358	44%	1.6	1,660
Milkfish	1,327	53%	1.7	1,196
Trout	871	100%	1.3	1,132
Eel	269	98%	1.5	395
Total fed species production Mt	45,406			52,741

¹ Growth expressed as % APR from 2000 to 2018 for total major fed-species production and estimated compound aquafeed usage was 6.8%/year (13.94 to 45.41 million tonnes) and 7.7%/year (13.83 to 52.74 million tonnes), respectively.

However, in the case of fishmeal and fish oil, the aquafeed industry has successfully learnt how to reduce its reliance upon these two limited natural commodities. For example, according to the latest data from MOWI (2020), the average fishmeal and fish oil content of Norwegian salmon feeds has fallen over a 30-year period from a high of 65% and 24% in 1990 to a low of 13% and 11% in 2019, respectively. The decreased dependency of the aquafeed manufacturing sector in Norway upon fishmeal and fish oil has been due to the increased use of terrestrial vegetable and animal protein and lipid sources, and dietary supplementation with limiting essential amino acids, fatty acids, and trace minerals (Bandara 2018; Turchini et al. 2019; Aas et al. 2019; Hua et al. 2019; Boyd et al. 2020; MOWI 2020).

Notwithstanding the dependency upon marine feed resources (and in particular fish oil), the salmonid aquaculture sector has received considerable negative media attention in several European and North/South American countries, primarily due to its perceived negative environmental impacts; ranging from visual pollution/site objections, potential nutrient discharge and benthos impacts, to issues related to chemical use, fish welfare, fish escapes, to potenital genetic impacts and disease risks to wild fish populations (Whitmarsh and Wattage 2006; Bartley et al. 2007; Torrissen et al. 2011; Boyd et al. 2020; MOWI 2020). In marked contrast, in the Asian region, where the bulk of aquaculture production is currently realized (105.05 million tonnes in 2018 or 91.76% of total global aquaculture production; FAO 2020a), aquaculture is viewed in a much more positive light, not only as a much needed supplier and provider of high quality affordable aquatic food products (aquaculture production in the region being larger than total capture fisheries production; FAO 2020a; Subasinghe et al. 2010; Tacon et al. 2020), but also in terms of employment opportunities, and increased income, health and well-being of rural inland and coastal communities (Gephart et al. 2020; FAO 2020b). Clearly, aquaculture needs to be viewed holistically, and that the social and economic impacts and benfits of the aquaculture sector also be considered in the overall assessement of the long-term sustainability of the sector for future generations (FAO 2014, 2018); everyday aquaculture produces 313,647 tonnes (live weight) of food, including 148,710 tonnes of farmed fish, 88,729 tonnes of farmed aquatic plants, 47,975 tonnes of farmed mollusks, and 25,716 tonnes of farmed crustaceans, valued at over US $0.72 billion per day, and employing over 20.5 million people (FAO 2020b). Careful management of this sector is a key feature of a sustainable future.

In conclusion, a sustainable food system (SFS) is a food system that delivers food security and nutrition for all in such a way that the economic, social and environmental bases to generate food supply and nutrition for future generations are not compromised, and that it is profitable throughout (economic sustainability), has broad-based benefits for society (social sustainability), and also has a positive or neutral impact on the natural environment (environmental sustainability; FAO 2014, 2018). Moreover, in view of the complexity of food production systems (including aquaculture food production systems) it is clear that a more holistic and coordinated response is required, and that these systems generate positive value along the three dimensions of economic impacts, social impacts, and environmental impacts, simultaeneously (Figure 3; FAO 2018).

Figure 3. Sustainability in food systems (Adapted from FAO 2018).

Notes

1 Sustainable development is the management and conservation of the natural resource base and the orientation of technological and institutional change in such a manner as to ensure the attainment and continued satisfaction of human needs for present and future generations. Such sustainable development (in the agriculture, forestry and fisheries sectors) conserves land, water, plant and animal genetic resources, is environmentally non-degrading, technically appropriate, economically viable and socially acceptable (FAO 1997).