John Hargreaves, Randall Brummett and Craig S. Tucker
Aquaculture as a farming practice dates back millennia and traditional, small‐scale subsistence aquaculture continues to be an important livelihood activity in rural areas around the world, especially in Asia. Scientific aquaculture did not begin until the 1940s and it really was not until the 1970s that aquaculture became recognised as having the potential to make a significant contribution to global protein supply. During the 1980s, the Blue Revolution of rapid expansion took place and aquaculture began to make a significant contribution to global fish supplies1, just as wild capture fisheries were reaching a production plateau of around 90 million t.
Fish from capture fisheries and aquaculture combined is now the largest source of animal protein in the world. Fish produced in aquaculture make an important contribution to the food security of millions of people, especially in the developing countries of Asia (Béné et al., 2015). Fish provides 4.3 billion people with at least 15% of their consumption of animal protein. Aquaculture production is also the source of livelihoods for 188 million people, 94% of which are in Asia. About 10% of the global population works in fisheries or aquaculture value chains.
Aquaculture is the youngest and fastest‐growing commercial food‐production sector. The activity arose very quickly, in accord with other rapid changes to the planet that have collectively characterised what has come to be called ‘The Great Acceleration’ of the Anthropocene. In 2014, global capture fisheries produced 93.4 million t of fish, with 20.9 million t destined for non‐food uses, leaving 72.5 million t for human food. Aquaculture produced 73.8 million t of fish that year, almost all destined for human food, which accounted for just over 50% of the total human food fish production (146.3 million t).2 In addition to fish production, aquaculture produced more than 27 million t of farmed aquatic plants. The transition from the dominance of capture fisheries to the dominance of aquaculture has occurred within about three decades — an amazingly short time for a change this profound.
The rapid growth of aquaculture raised issues related to environmental degradation, negative impacts on biodiversity and other, mostly local, impacts. Symptomatic of unsustainable growth were much‐publicised issues such as major disease outbreaks in shrimp and salmon, stock crashes in Lake Taal in the Philippines and the loss of mangrove forests in Indonesia and Thailand. In the 1990s, environmental concerns related to the sustainability of aquaculture came to the fore. Food safety, particularly antibiotic and chemical residues, also emerged as a major concern at this time. In response, from the mid‐1990s through the 2000s, commercial aquaculture sectors responded with the development of best management practices to address specific problems and ecolabeling certification systems comprising suites of best management practices to address consumer concerns regarding the environmental performance of aquaculture.
The world needs to produce significantly more fish in the future to provide high‐quality animal protein to a growing and increasingly affluent population (Figure 27.1). Undoubtedly, future supplies of fish will be dominated by aquaculture.3 By 2030, the World Bank (2013) estimates that 62% of fish for human consumption will be produced by aquaculture. Assuming no change in per capita consumption, aquaculture must continue to grow to keep pace with the increased demand for fish associated with a world population expected to exceed 9 billion by 2050.
Figure 27.1 Fresh seafood at a market in Barcelona, Spain. The world’s seafood supply must increase to meet the demands of a growing world population. Most of the future supply will come from aquaculture.
Source: Photograph by Andy Mitchell. Reproduced under the Creative Commons Attribution Share Alike license, CC‐BY‐SA 2.0.
Despite the pressing need to produce more fish, and the market opportunities that this need creates, aquaculture will not be able to grow in the same way as it has over recent decades. New limitations, restrictions and boundaries are emerging to constrain growth. Foremost among these are looming resource limitations (Naylor et al., 2009). The higher value and increasing scarcity of some key resources—trends that will be exacerbated by global climate change—will be major drivers of the new growth trajectory for aquaculture. The annual growth rate of aquaculture in the future is expected to be lower than during the boom years of 1970‐2010 because of the scarcity of fresh water, fewer locations available for optimum production, and the high costs of fishmeal and fish feeds. As competition for these increasingly scarce or limited resources increases, so must the intensity of aquaculture production systems. Another limitation will be imposed by the inability to significantly expand the land area needed to grow the crops used to produce aquaculture feeds.
The challenge for aquaculture is to increase production as a means to improve human health (reduce protein malnutrition and obesity) and contribute to food security while simultaneously minimising environmental damage. In other words, aquaculture must become more sustainable and use resources more efficiently to preserve the natural capital and ecosystem services on which it depends. Combining these key concepts is often referred to as ‘sustainable intensification.’ The goals of the many users of increasingly scarce resources must be balanced against the maintenance of the structural and functional integrity of the ecosystems in which aquaculture and other human activities are embedded. If it can succeed in doing this, aquaculture will undoubtedly play a large role in the future of fish supply and the growing ‘Blue Economy.’ Real prices of farmed fish are likely to rise in coming decades. Whether aquaculture can grow to meet the demand for fish will depend heavily on the extent to which it can internalise the need for sustainable intensification and innovate to increase efficiency. Aquaculture must change to adapt and work within the limitations set by these new constraints and yet expand to meet the demand for fish in the future.
The need for more fish produced in aquaculture is clear. To maintain the current per capita seafood consumption of 18–20 kg, a supply of 160 to 180 million t of fish will be needed by 2050, with at least 100 million t coming from aquaculture (Merino et al., 2012). If predicted increases in the per capita demand for fish in China are realised, 40% of this market will be in China (World Bank, 2013). To keep pace with this growing demand, aquaculture must grow at an annual rate of about 6%, but environmental and social constraints have reduced annual growth in recent years to less than 5%.
A useful approach to considering the future demand and supply of fish from aquaculture is with reference to key global megatrends and drivers. Megatrends are long‐term transformative issues and forces, applicable for at least 20 yr and are relevant globally. Megatrends and drivers are political, social, economic, environmental and technological. They affect the flows of the natural capital and ecosystem services that support aquaculture and so specific geographic context is important. Here we describe some of the main megatrends and drivers of change and look into the future to assess how these will shape the future evolution of aquaculture.
There are four important demographic trends that will affect future demand for fish from aquaculture: global population growth, the rise of the middle class in Asia, urbanisation, and ageing populations. Collectively these present a significant opportunity for future aquaculture through increased market demand for fish. Some demographic megatrends also represent threats to future aquaculture through competition for increasingly scarce resources and from environmental pollution.
The human population is expected to be around 8 billion in 2025, 8.3 billion by 2030 and 9.5 billion by 2050. This population growth will increase the demand for food, water and energy. By 2030, the global population will require 35% more food, 40% more water, and 50% more energy. Without any change in the per capita consumption of fish, aquaculture must grow just to meet the demand for fish by more than 9 billion people.
By 2030, 60% of the world’s population will be middle class, two‐thirds of the middle‐class population will be from China and India, and 80% of the middle class will live in developing countries. Soon, more people will be middle class than poor. By 2030, there will be more than 3 billion people in the middle class in the Asia‐Pacific region, dominated by China and India. Demand for fish will be profoundly influenced by rising affluence and increased purchasing power of the middle class, in part related to increased recognition of fish as part of a healthy diet and an increased environmental awareness of the general population.
Increasing affluence has been accompanied by a dietary shift towards a greater per capita consumption of animal protein, including fish. Rising income is considered to be a more important driver of the demand for fish than population size (Béné et al., 2015). Global consumption of meat has doubled in the last 50 years from around 23 kg to about 42 kg. People in developing countries are, on average, increasing meat consumption at 5% annually, with expectations of future growth ahead. Animal protein production can be resource intensive, placing pressure on commodity grain markets and water resources.
About two‐thirds of the global population will live in cities in 2050 and most of the growth in urban populations will occur in Africa and Asia. Urbanisation has been directly associated with increased consumption of animal protein, including fish. One of the main effects of urbanisation on aquaculture will be associated with increased market demand for seafood from aquaculture. Urbanisation creates some obvious challenges for food production. The economies of countries with a highly urbanised population are less dependent on agriculture as a share of gross domestic product (GDP). However, urbanisation will stimulate agriculture and aquaculture production in urban and peri‐urban areas because marketing and food distribution are facilitated by urbanisation. In many growing cities around the world, especially in Asia, urban land use is encroaching into former peripheral areas used for food production, including shrimp and fish farming (Figure 27.2). Poaching and pollution become more problematic in interface areas, making these sites less suitable for aquaculture.
Figure 27.2 Transformation of mangrove wetlands (foreground) to shrimp ponds (left) and urban land use (right) in Guayaquil, Ecuador. Urban land use is increasingly encroaching on pond aquaculture infrastructure.
Source: Reproduced with permission from John Hargreaves, 2017.
Declining birth rates and reduced mortality rates (especially child mortality) have resulted in increased life expectancy and an increase in the proportion of the elderly in the global population. The fastest‐growing demographic group is people over 65 years of age. In 2011, 11% of the world’s people were over 65 years old and this is forecast to reach 22% by 2050. This means the world will contain more than 1 billion people over 65 by 2030 and 2 billion people over the age of 65 years by 2050. Ageing populations are generally more health‐conscious and, based on a concern with longevity, have begun to shift consumption to more healthful forms of protein, such as fish.
Based on assumptions about population growth, changing diets, and agricultural systems, the FAO estimates that food production needs to increase by 70% by 2050 to meet demand. This includes growth in annual cereal production from 2.1 billion to 5.1 billion t and meat production from 200 million to 470 million t.
Supplies of the natural resource base that supports human life on the planet are limited and some resources are being depleted at an alarming rate. Furthermore, the supplies of key resources, especially fresh water, are not uniformly distributed (Figure 27.3). Some countries have adequate supplies of fresh water and land to support aquaculture development and others do not. As noted in the previous section, population growth, economic development, and middle‐class consumption associated with rising living standards will increase the demand for key resources. Climate change will place additional pressure on resource availability, especially fresh water and food production. The challenge for food production is that productivity gains in agriculture have been declining since 2000.
Figure 27.3 The global distribution of fresh water is uneven. Notice the scarcity of water in countries in Asia that are important global aquaculture producers.
Source: Image from the World Water Development Report courtesy of Wikimedia Commons. Photograph by Axelsaffran. Reproduced under the terms of the Creative Commons Attribution share licence, CC BY‐SA 3.0.
The key natural resources used for aquaculture production are water, land/space, forage fish used for feed, and energy. Use of these resources in production can cause water pollution and impacts on biodiversity. Resource use and the environment are discussed in Chapter 5. Here we highlight aspects related to resource limitation on future aquaculture.
In the context of the global food production system, aquaculture is a small sector and therefore uses much less fresh water, land, and energy than other, larger sectors. The one important exception is the use of marine pelagic forage fish in feeds, for which aquaculture uses most of the resource. In general, aquaculture uses resources efficiently to produce protein and is more efficient than the production of most terrestrial animals (Table 27.1). The relatively small size of the aquaculture sector should not preclude efforts to improve resource use efficiency and lessen environmental impact.
Table 27.1 Some measures of the relative efficiencies of animal protein production.
Source: Data from Hall et al. (2011) and from Boyd and McNevin (2015). Feed conversion ratio = kg feed ÷ kg animal growth; protein conversion efficiency = [(kg animal protein ÷ kg feed protein) × 100].
Commodity | Feed conversion ratio (FCR) | Protein conversion efficiency (%) | N emissions (kg N/t protein) | P emissions (kg P/t protein) |
Beef | 12.7 | 5 | 1200 | 180 |
Pork | 5.9 | 13 | 800 | 120 |
Poultry | 2.3 | 25 | 300 | 40 |
Salmon | 1.0 | 43 | 284 | 71 |
Shrimp | 2.0 | 27 | 309 | 78 |
Tilapia | 1.8 | 24 | 593 | 172 |
Carp | 1.5 | 30 | 471 | 148 |
Global water demand is forecast to increase by 55% between 2000 and 2050, with the largest increases coming from manufacturing, electricity generation, and domestic use. By 2030, the demand for water could be 40% greater than supply, and water shortages could affect 50% of the world’s population. There are 1.2 billion people that live where there is insufficient water to meet human needs and by 2030 nearly half the world’s population will live in areas with severe water stress. Overall, water scarcity represents a serious challenge for food and energy security. Water availability will be a key site‐selection criterion for new aquaculture pond construction.
Agriculture is the largest consumer of fresh water (4000 km3/yr), accounting for some 70% of total withdrawals, mostly from rivers and groundwater aquifers. The total supply of renewable fresh water is about 44 000 km3/yr. Although estimates vary, the current use of fresh water in aquaculture is less than 200 km3/yr, about 5% of agricultural use.
Currently, 35% of the world’s crops are used for animal feed. By 2030, shortages of fresh water could cause a 30% reduction in grain production. Grain production in China and India face significant challenges from environmental stresses relating to water scarcity, soil depletion, climate change and pressures on land availability from urbanisation.
As water becomes very scarce (prolonged and extensive droughts, for example) or altered through climate change, the likelihood of conflicts over water resources increases. Access to transboundary water resources may become a more significant source of contention than energy or minerals in the coming decades. Historically, water tensions have led to more water‐sharing agreements than violent conflicts, but this pattern could change in the face of future risks.
Most aquaculture is conducted in fresh water and competition for this increasingly scarce resource is a much greater problem than the availability of land. Pond aquaculture does not use much water (5–10 m3/kg), but needs good quality water, which may be polluted by other users, even where the absolute amount of water is otherwise sufficient. Water is also needed to produce the feed ingredients required to sustain fish production. On average, feed‐associated water consumption accounts for around 9% of total water use per unit aquatic animal production, the remainder used to fill and maintain water level in ponds. Water limitation will be a key constraint for aquaculture going forward, not only for its obvious need to support increased production but also for the irrigation of crops used to produce future aquafeeds.
Water scarcity will force aquaculture to develop and implement technology and practices to become more efficient with the use of water and other inputs. The scope to improve water use efficiency on existing farms through intensification is considerable (Verdegem and Bosma, 2009).
In 2010, global aquaculture occupied nearly 20 million ha of land, including 12.7 million ha of inland (freshwater) lakes and rivers, and 6.0 million ha of coastal, mostly brackish water areas. Aquaculture also indirectly used an additional 26.2 million ha in 2010 to grow the crops used as ingredients in aquaculture diets. More than 50% of land use in carp farming and 40% of land use associated with tilapia and catfish farming is attributable to production of crop‐based aquaculture feedstuffs. Globally the amount of land used for aquaculture is small.
As aquaculture grows, more land will be required to produce fish feeds, but the world is already farming its most productive land. The world loses 12 million ha of productive agricultural land, capable of producing 20 million t of grain, each year to land degradation resulting from poor farming practices and deforestation. Given the limited availability of new agricultural land, improving crop efficiency will be essential to meeting global food needs. Sustainable intensification is the challenge for future agriculture. Intensive irrigated agriculture (including pond aquaculture) will be responsible for most future gains in crop production.
Land and space availability is a key constraint for aquaculture growth. It is important to emphasise that land in this case refers to a specific local place and not land in the abstract of the global aggregate. In developing countries and in agricultural areas, especially in the major aquaculture producing countries of Asia, conflicts over the use of land for fish farming are rare, in part because aquaculture is a traditional activity with a social licence to operate. In contrast, disagreements with property owners, fishing companies, commercial shipping interests, and recreational users are common in more prosperous countries. Often, sites chosen are in or adjacent to land of high ecological value such as coastal and riparian wetlands and flood plains. In the USA and Europe, permits for seaweed, shellfish, and caged finfish aquaculture installations within sight of land are expensive and extremely difficult to obtain. In response, aquaculture has intensified and moved into less expensive areas where competition and conflict over visual footprint is minimal. Unfortunately, in some instances this has translated into destruction of biodiverse wetlands, including mangrove forests.
The spectacular growth of aquaculture over the last few decades is directly attributable to the widespread adoption of manufactured feed as a key production input. For Chinese carps, the species with the greatest global production, the culture system has shifted from inputs of animal manures and agricultural by‐products as organic fertilisers to feeding with pellets. The major source of animal protein in aquaculture feeds is fishmeal derived from the harvest and processing of small pelagic forage fish (e.g., anchovy, menhaden, sardines) from the marine environment (Figure 27.4).
Figure 27.4 Good management of fisheries for small pelagic forage fish will be essential for the future expansion of aquaculture.
Source: Photograph by Etrusko25 (Own work Foto di Alessandro Duci). Reproduced under the terms of the Creative Commons Attribution share licence, CC BY‐SA 3.0.
In 2010, 15 million t of wild fish (or roughly one‐sixth of the marine catch) was converted to fishmeal and fish oil, most of which was consumed by aquaculture. Aquaculture uses about 80% of the global supply of fishmeal and more than 90% of fish oil. Thus, at this time, the dependence of aquaculture on supplies of fishmeal and fish oil is very high, especially in China (Cao et al., 2015). Given the current high rate of use of fishmeal and fish oil by aquaculture, one of the major challenges faced by aquaculture is that current supplies are not sufficient to support the required expansion of aquaculture production (Naylor et al., 2009).
Forage fisheries are generally well managed, but supplies are variable and often influenced by large‐scale climatic phenomena such as the El Niño‐Southern Oscillation (Figure 27.5). In general, similar to other capture fisheries, production from forage fisheries is limited because they are being exploited at approximately their maximum sustainable yield and are not expected to increase. The high dependence of aquaculture on wild fish as feed ingredients can exacerbate negative impacts on marine food chains. Arguably the use of forage fish for feeds is the most important global‐scale environmental impact of aquaculture.
Figure 27.5 Global capture of Peruvian anchoveta, 1950–2010, indicating substantial fluctuation in annual catch.
Source: Photograph by Epipelagic. Reproduced under the terms of the Creative Commons Attribution share licence, CC BY‐SA 3.0.
Prices of fishmeal and fish oil have been increasing, based on the high demand from aquaculture and other uses, especially since 2000. The price of other ingredients is also rising. The price of soybean meal, the main plant protein ingredient in aquaculture feeds, has increased in direct relation to fishmeal. As the price of feed ingredients increases, it is obvious that aquaculture feed prices will correspondingly increase. Feed typically represents 50% or more of production costs and so price increases for fishmeal and feeds can have a profound impact on economic sustainability.
The incorporation rate of fishmeal into feeds varies by species. Herbivorous and omnivorous species like carp, tilapia, and catfish use relatively low levels of dietary fishmeal and fish oil—usually less than 5% fishmeal and 1% fish oil—and research has shown that these fish can be grown on feeds completely devoid of fish products. However, for carnivorous species like salmon, marine finfish, and marine shrimp, much higher levels are used in feeds. It remains to be seen what kinds of species shifts will occur in response to higher fishmeal and fish oil prices. Although incorporation rates are low, most fishmeal is used in diets for omnivorous carps and thus feed prices would not be expected to be very sensitive to changes in the price of fishmeal (Tacon and Metian, 2015). Species with higher dietary incorporation rates of fishmeal tend to be higher‐value marine fish and shrimp and these would be expected to be sensitive to fishmeal price increases because consumers would be less willing to pay the high prices for such fish. On the other hand, rising affluence and shifting consumer preferences suggests that production of high‐value species will continue to expand.
The general trend has been towards reduced incorporation rates of fishmeal and fish oil in aquaculture feeds (Naylor et al., 2009). Fishmeal replacement is an active and on‐going area of research and development and good progress has been made. Finding substitutes for fish oil has proven much more difficult than replacements for fishmeal, suggesting that fish oil might limit the expansion of aquaculture of high‐value species with a high requirement for certain essential fatty acids. Many of the species important for food security in developing countries can be grown on diets with exclusively plant‐based protein sources. Furthermore, improvements in feed formulation and manufacture and especially feeding practices have resulted in a better conversion efficiency of feeds to fish.
There is considerable uncertainty about future energy supplies, but relatively recent use of hydraulic fracturing (‘fracking’) technology has resulted in a glut in supplies of natural gas and oil reserves that were previously unavailable using conventional technology. Aquaculture uses about 1% of the energy in the global food system and most of that energy is currently derived from fossil fuels.
In aquaculture, the main direct uses of energy are for water pumping and aeration. Overall, the biggest energy demand in aquaculture is for capture of wild fish and reduction into fishmeal and fish oil for feeds (Hall et al., 2011). Considerable embodied energy is contained in aquaculture feeds, including the energy used to produce the crops used as feed ingredients. The intensification of aquaculture will require more direct energy, especially for aeration, and indirect energy in the form of feeds. The energy efficiency of farmed fish production, measured as industrial energy input per protein energy output, is better than that of most terrestrial livestock production.
It is unlikely that energy will be a resource that will limit aquaculture in the future, but the desirability of continuing to use non‐renewable energy sources in light of attempts to curb greenhouse gas emissions will be a big question going forward. The broader goal of reducing greenhouse gas emissions to limit global climate change conflicts with the necessity of using more energy to drive the intensification of aquaculture. Access to energy supplies in the form of local electricity infrastructure is more important than any large‐scale energy resource availability.
There are inevitable trade‐offs between land, water, energy, and feeds. For example, freshwater pond production systems use energy and feeds efficiently, but can consume more than 10 m3 of water per kg of fish produced when ponds are drained and refilled and to replace water lost through seepage and evaporation. Closed, recirculating systems use little land and water (<2 m3/kg) but require large amounts of energy. Marine finfish farming directly uses practically no land or freshwater but is going to have to innovate to replace increasingly scarce and expensive fishmeal in diets. Trade‐offs will be decided on the basis of the availability and price of the most limiting resource in a particular setting.
There are growing pressures and demands on ecosystems caused by population growth, human activities, and the shifting consumption patterns that result in increased per capita resource use. Collectively these are causing ecosystem degradation, biodiversity loss, and an erosion of life‐supporting ecosystem services. These also have impacts on agriculture and fisheries production. The main environmental pollutants are greenhouse gases, fertiliser nutrients, and chemicals from industrial facilities, especially persistent bioaccumulative toxins. Effluents from agriculture and wastewater treatment are projected to increase, leading to detrimental effects such as eutrophication and acidification. For example, by 2050, the number of lakes with hypoxia is expected to increase by 20%, most in Asia, Africa, and Brazil.
Biodiversity loss is being caused by habitat fragmentation, resource overexploitation, environmental pollution, invasive species, and climate change. The rate of biodiversity loss shows no sign of slowing. Despite an increased number of protected areas, deforestation of tropical forests and conversion of wetlands and rangelands to cropland or urban areas represent irreversible loss of habitat and associated biodiversity. Reduced catches of wild fish have increased the demand for farmed fish, putting additional pressure on terrestrial ecosystems associated with the need for crop‐based feed ingredients. The trends of ecosystem degradation and biodiversity loss will be exacerbated by climate change. In addition, the rapid expansion in crops used for biofuels production has put additional pressure on terrestrial ecosystems and water resources.
Ecosystem degradation and biodiversity loss are leading to a loss of provisioning, regulating, and cultural ecosystem services. Non‐market ecosystem goods and services provide a majority of the total income of the rural poor in many developing countries. Thus, the effects of losses of ecosystem services will disproportionately affect vulnerable poor people in developing countries.
Agriculture accounts for 35% of greenhouse gas emissions, and about 18% of emissions come from meat production. In 2010, aquaculture production contributed about 330 million t of CO2 in greenhouse gas emissions, equal to about 5% of emissions from agricultural production and less than 1% of total global anthropogenic emissions. The accumulation of greenhouse gases from anthropogenic emissions has led to climate change, challenging the resilience of natural ecosystems and human‐built infrastructure. Throughout this century, climate change is projected to slow the rate of economic development, erode food security, and increase income inequality to cause the displacement and migration of people.
Average global air temperature is predicted to increase by 0.5–1.5°C by 2030 and impacts are expected to accelerate beyond a global temperature increase of 1–2°C. Global ocean temperature in the upper 100 m is projected to increase by 0.6–2.0°C by 2100. Thermal expansion of warming ocean water and melting of ice sheets and glaciers are very likely to cause an increase in global mean sea level of 10–35 cm by 2050. Climate change has also resulted in the increased frequency of extreme weather events, such as storms and droughts. By 2050, the costs of extreme weather could reach 1% of global GDP per year. About 20–35% of CO2 emissions are taken up by oceans, leading to ocean acidification.
Climate change threatens unique and vulnerable ecosystems like coral reefs. In terrestrial and freshwater ecosystems, climate change causes biodiversity losses and increased colonisation by invasive species. The combined effects of sea‐level rise, coastal erosion, pollution, and ocean acidification threaten coastal ecosystems. With respect to agriculture, increased temperature and decreased rainfall are expected to reduce yields of wheat, rice, and corn.
The effects of climate change will disproportionately affect disadvantaged people in developing countries. Climate change is already accelerating instability in vulnerable areas of the world and the associated arising resource scarcities are contributing to conflicts.
The implications of climate change for aquaculture in the future are profound. As climate change results in increased frequency of droughts and extreme weather, disruptions to pond‐based production can be expected. Furthermore, reduced crop yields and increased demand associated with population growth and economic growth will create scarcity and increase prices of commodity crops used to produce aquaculture feeds. Sea level rise and extreme weather will increase the vulnerability of aquaculture in the coastal zone, including coastal shrimp and fish ponds, shellfish rafts, and fish cages, especially in Asia where there is abundant aquaculture infrastructure (Figure 27.6). Ocean acidification will challenge the sustainability of coastal bivalve shellfish aquaculture. It is likely that global climate change will exacerbate the susceptibility of aquaculture to disease events.
Figure 27.6 Coastal aquaculture ponds, like these on the Bohai Sea, China, are vulnerable to the effects of climate change.
Source: Photograph by Planet Labs inc. Reproduced under the terms of the Creative Commons Attribution share licence, CC BY‐SA 4.0.
The costs of climate change mitigation and adaptation will be enormous. Human communities can be buffered against adverse impacts of climate change through ‘adaptation services’ from coastal wetlands serving as buffers against storm surge, for example. For the existing coastal pond infrastructure, it is prudent to begin coastline fortification soon, followed by a gradual retreat from the coast to more inland areas by the next century. The reality of climate change will require advance planning to implement measures to adapt or mitigate climate change impacts, especially for millions of highly vulnerable small‐scale fish farmers. Of necessity, developing resiliency will be a part of sustainable development strategies.
Increasing the resource use efficiency of any food production activity is inherently desirable, resulting in beneficial (or less damaging) environmental effects and improved economic performance. However, resource use efficiency in aquaculture should be considered in the broader comparative context of resource use in animal agriculture. Fish in aquaculture can convert the protein and grains in feed to fish protein more efficiently than most terrestrial livestock. Culture of extractive species, such as molluscan shellfish, are among the most efficient animal protein production systems of all. Seaweeds actually make a net positive contribution to water quality by capturing nutrients emitted from agriculture or fed aquaculture. Among fed species, culture of relatively low trophic level, omnivorous fish are among the more efficient, with efficiency greater than many terrestrial animal protein production systems (Hall et al., 2011). The resource use efficiency of higher trophic level species such as salmon and marine finfish approximates that of poultry and has much more scope for improvement. Thus, aquaculture can play a role in improving the overall environmental efficiency of animal protein production in the broadest sense. Aquaculture can add resilience to the food system if the culture of lower trophic level species is emphasised (Troell et al., 2014). The relative efficiency of certain kinds of aquaculture can be a stimulus or incentive for more aquaculture, increasing production efficiency, and shifting production to more efficient species.
Scarcity of water, land, feeds and energy has increased their prices, driving aquaculture producers to increase the efficiency of farming operations out of self‐interest. These trends of increased resource scarcity driving efficiency and intensification are likely to continue. Resource scarcity has also driven private sector investment in research and innovation, resulting in further efficiency improvements. For example:
Although the efficiency of resource use is better in animal agriculture than in natural food webs, it is inherently inefficient. Each time a unit of food is consumed, more energy and nutrients are lost than are recovered in the animal consuming the food. Efficient resource use is therefore inextricably tied to the concept of making better use of feed. This can be accomplished in two ways:
At the farm level, the best way to improve overall resource use efficiency is to improve feed conversion ratio (Boyd and McNevin, 2015). Feed typically represents 40–60% of total costs and so there is a strong economic incentive to improve feed conversion. There is considerable embodied energy (and other resources) in feed, representing about 50% of the carbon footprint of pond aquaculture and about 80% of cage aquaculture. Thus, improving feed conversion improves the efficiency of the use of all the resources used to grow crops, catch fish, produce feed ingredients and feeds, and all associated transport. These resources include the supplies of renewable fresh water for irrigation, energy, fertiliser nutrients, and stocks of forage fish. In addition to being cost‐effective and resource efficient, improving feed conversion also reduces emissions from aquaculture.
Resource efficiency can also be enhanced by resource capture and recycling. Although this is an intuitively appealing approach, the practical realities of aquaculture production indicate that effective resource recycling is difficult. For example, 70–80% of feed nutrients are lost as metabolic waste, yet efforts are seldom made to recover and recycle those nutrients in the world’s major aquaculture production systems. Waste nutrients have a low economic value, are difficult to recover as a practical matter, and traditionally have been treated internally or discharged to the environment at no direct cost to the producer.
In some traditional integrated agriculture‐aquaculture farming systems, the fish component was used to recover nutrients from feeding ducks, chickens, or pigs. The dike‐pond system of southern China had an elaborate system of nutrient flows between components. These systems have largely been replaced by a simplified fed carp polyculture with 80% fed carps and 20% sanitary species (Edwards, 2016).
Despite the practical difficulties with nutrient recovery, systems have been developed to recycle nutrients into higher value products. Integrated multi‐trophic aquaculture (IMTA) systems, especially in the marine environment, have been designed to capture nutrients released from fed fish in cages. Shellfish and seaweed rafts are placed near fish cages to grow secondary products. Vast areas of coastal southern China have been developed with this system, even before fish cages were added. Although development of the seascape at sufficient scale in this way can provide valuable ecological services, the recovery of feed nutrients by extractive species is low. There are also difficulties with synchronising production cycles of the many species that are part of the system.
Aquaponics is a form of recirculating aquaculture system that uses waste nutrients derived from feeding fish to produce a vegetable crop. With respect to nutrient uptake, very large plant growing areas are needed to ‘balance’ nutrient production from a relatively low biomass of fish. Aquaponics can be locally important by supplying fish and vegetables to niche markets but it is unlikely that aquaponics will make significant contributions to the global food supply (Edwards, 2016).
Fresh water in pond aquaculture can be conserved and reused but in most areas there is little incentive to do so. Pollution of source water and biosecurity concerns have led some fish farmers to recirculate water through storage and treatment reservoirs, but these remove land from fish production and require large inputs of energy for pumping.
Resource‐use efficiency can be improved at the farm level through implementation of best management practices (BMPs). Efficient production in pond aquaculture can be achieved by using good‐quality feed, careful feeding practices, and aeration to manage water quality. A commitment to continuous improvement is a core element of BMPs, although it is seldom emphasised in BMP programs, including ecolabeling certification systems. Producers can use a set of standard efficiency indicators to benchmark their farm operation and then track the indicators over time to demonstrate improvement in resource use efficiency.
It is clear from the preceding discussion that producing more fish from aquaculture is a necessity that will be constrained by resource availability and other environmental and social challenges. A range of approaches to increasing the food supply have been proposed (Table 27.2) some of these with relevance to aquaculture are discussed here.
Table 27.2 Perspectives on how to feed 9 billion people.
Godfray et al. (2010)
Foley (2011)
Clay (2011)
Forum for the Future – The Protein Challenge 2040 (www.forumforthefuture.org/sites/default/files/The_Protein_Challenge_2040_Summary_Report.pdf)
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Culture system intensity is a useful framework to understand and manage environmental impacts, but here we consider how production intensification will be the main approach to providing more fish in the future. Simply put, intensification means producing more fish with the same land and water. In the inverse, the land area and water volume needed to produce a ton of fish will be less as systems intensify. Compared to increasing aquaculture production by expanding area, it is likely that most future gains in aquaculture production will be derived from intensification on the existing land area.
A large part of the gains in aquaculture production since the 1980s has been from intensification. These gains are mainly attributable to two technological advances. Firstly, the development and adoption of high‐quality feeds that fully meet the nutritional requirements of fish allowed development of efficient production systems as measured by the conversion of inputs to fish. Secondly, the increasingly widespread adoption of aeration permitted higher‐density culture through oxygen provision for life support. The increased profit per hectare is justified by the higher production costs associated with intensification. With high‐quality feeds and aeration to maintain water quality, the full growth potential of cultured fish, especially genetically improved strains, can be realised.
The scope for increasing yields from the existing infrastructure of ponds is tremendous. While the average fish pond in the world produces only 2–3 t/ha, aerated and fed ponds can produce 5–6 t/ha, and intensively‐managed fish and shrimp ponds can produce 15–20 t/ha. Ponds used to grow air‐breathing fish like pangasius catfish can produce 400–500 t/ha (Figure 27.7). The experience in China with the transition from traditional carp polyculture to a feed‐based system over the span of three decades is an example that has the potential to be repeated elsewhere (Edwards, 2016). Less than half of the total fish pond area in the world is fed, indicating that significant production gains can be made by expanding the area of fed aquaculture.
Figure 27.7 Feeding pangasid catfish on a farm along the Mekong River in Vietnam. Aquaculture of air‐breathing fish permits high pond carrying capacity, in this case around 500 t/ha.
Source: Reproduced with permission from John Hargreaves, 2017.
Significant attention has been given to aquaculture in recirculating systems as an intensive approach with potential to make a significant contribution to future fish supplies (Klinger and Naylor, 2012). Although such systems are attractive on the basis of the high degree of control over production and the high efficiency of land and water use, the degree of technical sophistication for proper operation, the capital intensity of the infrastructure, and the high risk of business failure suggests that there are limits to the value of recirculating systems to produce more fish.
In agriculture, about 90% of production growth in recent decades has come from the intensification of land use and only 10% from expanding into new areas. In aquaculture, the potential for finding and developing new, good production sites is better in Africa and Latin America than it is in Asia because those areas are simply less developed. In Asia, conversion of rice fields to fishponds represents perhaps the greatest opportunity to increase aquaculture production through expanding area (Edwards, 2016). Even converting 1% of the more than 230 million ha of rice fields in Asia (Figure 27.8) would result in an enormous expansion of productive capacity. There is considerable potential for aquaculture to occupy lands that are not suitable for crop production or as range land, such as sites with saline soils, but are acceptable for fish or shrimp farming. Area expansion requires a land use change that, depending on specific location and type of prior land use, could negatively impact ecosystem function and biodiversity.
Figure 27.8 Conversion of a small proportion of rice fields, like these in Tamil Nadu, India, to aquaculture ponds represents one of the greatest opportunities to expand global aquaculture production.
Source: Photograph by Thamizhpparithi Maari. Reproduced under the terms of the Creative Commons Attribution share licence, CC BY‐SA 4.0.
In recent years, the case has been made that we live on a ‘water planet’ and that land and freshwater availability will limit aquaculture (and agriculture in general). According to this line of thought, the future of aquaculture should be to move more production to the sea and in particular from nearshore to offshore. Although this is an appealing idea, the extreme environment of the high seas and the large capital investment necessary are major risk factors in developing a marine aquaculture sector that can make a meaningful contribution to global fish supplies. Although use of the coastal environment is much more competitive, the example of the development of the coastal zone in China indicates considerable scope for similar development elsewhere in Asia, where aquaculture is culturally accepted.
Professional breeding programmes for salmonids, carps, channel catfish, and tilapia have more than doubled growth rates and will continue to be one of the main drivers of the increase in global aquaculture production, especially among the more widely cultured species. Production gains of 10–15% per generation have been demonstrated in several commercially‐important species. One of the best documented examples is the Genetically Improved Farmed Tilapia (GIFT) program in the Philippines, which contributed to increased consumption. The average consumption rate of tilapia in that country increased by 144% over the 8 years following its introduction and, along with a number of other breeding programs continues to improve growth of Nile tilapia by nearly 7–8% per year. Genetic improvement programs are discussed in more detail in other chapters. With the culture of about 300 species, the scope for gains from genetic improvement through standard selective breeding techniques is enormous. Selective breeding in aquaculture is still in the early phase, compared to the thousands of years of selection in terrestrial livestock. Currently, only about 10% of the fish grown in aquaculture are derived from genetically improved strains.
The importance of biotechnology will likely increase, especially given its role in the security of food, water, and energy. Development of genetically modified crops, including fish and other culture species, will be aided by new biomolecular tools. New precision gene‐editing tools, genotype‐sequencing technologies, and marker‐assisted selection will be applied to conventional breeding and genetically‐modified crops for growth rate, feed conversion, carcass traits, and disease resistance.
As public perceptions of other methods of genetic enhancement become more sophisticated, gene transfer, and the introduction of novel genes will further improve productivity. At the current time, the cultural acceptance of GMO crops—especially animals—is low. This is especially true in developed countries. Although there is less resistance to GMO crops in developing countries, the technology has not yet been applied to aquaculture species that currently make the largest contributions to global fish supplies.
A key megatrend is the acceleration of technological change, especially biotechnology, nanotechnology, and information and computer technology. Research and development of science and technology around the world is accelerating, driven by economic growth and public investment. China and India will become the largest investors in technological innovation and development of a skilled workforce and China is expected to overtake the USA as the largest global spender on research and development in the next decade. Knowledge industries will become more important as a proportion of overall economy. These will support increased resource efficiency and the shift to a low‐carbon energy economy. The threats of climate change and environmental pollution will stimulate innovation in more efficient, less polluting technologies.
Technology will evolve to allow improved yields. Precision farming and automation are influential trends in agriculture. Sensors, software, and wireless connectivity allow collection and analysis of data in real time. Linked to output devices, these allow timely responses to data inputs. For example, video monitoring of salmon feeding allows efficient feeding with better feed conversion, less wasted feed, and less pollution. Oxygen sensors in ponds linked to analysis and control software can activate aerators to control pond oxygen concentration. The ‘Internet of Things’ will be supported by the development of sensors, automation, autonomous machines, drones, and submersibles. Digital and robotic technologies will increasingly augment or replace workers.
Technology is central to improving the productivity and environmental performance of aquaculture. Key areas for innovation are in feeds, genetic improvement, disease control, seed production, and grow‐out production systems. Overall, increasing productivity through:
will continue to be major drivers of sustainable growth.
Aquaculture will only grow to meet its maximum potential if it can adapt to local conditions and adopt new technology to minimise waste, while optimising the amount of fish produced relative to the amount of land, water, feed, and energy used. Fortunately, technological change in aquaculture is in its early stages and there is tremendous scope for increasing technological efficiency.
Use of increasingly more efficient technology is likely to have negative consequences for the many small‐scale farms that currently produce an estimated 80% of aquaculture products. Increasing capital costs for new technology and the adoption of BMPs will undoubtedly drive consolidation. Although small‐scale farmers will always be a part of aquaculture, in the future it is likely that there will be fewer, larger, and more sophisticated farms. The consolidation of the salmon industry in Norway is perhaps illustrative of the future of commercial aquaculture elsewhere.
Although feeds have improved significantly since the early days of aquaculture, diets for most fed species remain somewhat generic with major gains yet to be made. Specific nutrient requirements have been defined for only about 20 species of fish. Since the beginning of fed aquaculture, the main impetus for feed research has been to reduce and replace the most limiting and expensive ingredients: fishmeal and fish oil. Even while aquaculture has been expanding, the shares of fishmeal and fish oil in farmed fish diets have fallen significantly since 1995 and are projected to further decline by 2020 (Tacon and Metian, 2015). In recent years, the ratio of the amount of forage fish in feeds to farmed fish output (fish in‐fish out ratio; see section 5.6) for global aquaculture has declined from 0.6 in 2000 to 0.3 in 2010, while aquaculture production nearly doubled. Fish oil is more likely to limit the expansion of aquaculture, especially marine aquaculture, than fishmeal.
Currently available alternatives to fishmeal include by‐products of terrestrial animal agriculture and fish processing wastes and by‐catch. Animal by‐products include meat and bone meal from swine and cattle, poultry by‐product meal, and feather meal. Some of these products have favourable amino acid profiles compared with plant protein feedstuffs and are used in feeds for many fish species. High‐quality meals and oil derived from fish‐processing waste and from the by‐catch of wild fisheries can partially replace feedstuffs obtained from pelagic fisheries. Major obstacles to greater use of fish‐processing waste include certain nutritional deficiencies and possible bioaccumulation of contaminants in the recycled feedstuffs.
Early gains were made through research into better balanced diets (e.g., protein to energy ratio) and the use of meals produced from animal and fish processing by‐products. Synthetic amino acids, especially taurine, have been used to complement plant protein quality to make it more suitable for fish diets, and new work will likely further improve these diets.
Recently, investigations using proteins derived from insects as a substitute for fishmeal have shown promising results (Figure 27.9). Meal derived from insect larvae grown for this purpose has been analysed for nutritional composition and trials have been started with different farmed animals. Several insect species (black soldier fly, housefly, mealworm and crickets, among others) are being tested as substitute protein sources in the diet of farmed fish. Key constraints to future use of insect meals include the cost, especially transport costs, producing sufficiently large quantities needed by an expanding aquafeed sector, availability of by‐products to serve as a food source for insect larvae, and consumer acceptance of fish produced with insect larvae meal. Single‐cell proteins and microalgae produced in intensive fermentation systems have shown promise as sources for more sustainable protein and oils for aquaculture, but still require large amounts of energy and/or land to produce the sugars needed to drive growth.
Figure 27.9 Larvae of the black solider fly Hermetia illucens are being considered as a replacement for fishmeal in aquaculture feeds, although the challenge of scaling to an appropriate level remains.
Source: Photograph by MD‐Terraristik – Laut [1] ist Dennis Kress Mitinhaber des Unternehmens (www.MD‐Terraristik.de) [Public domain], via Wikimedia Commons.
Ultimately, reducing the energy demand of aquaculture and the indirect use of land and water in feeds will require fishmeal and fish oil replacements that can be produced in the oceans and the most likely source of these materials will be seaweeds. The dry‐matter composition of seaweeds ranges from 10–30% protein and 1–5% lipid. Assuming an average composition of 19% protein and 3% lipid, 500 million dry t of seaweed would produce about 150 million t of protein and 15 million t of oil. Based on the amino acid profile and some issues with anti‐nutritional factors in seaweed and soybean meal, algae protein can be thought of as roughly similar in value to soy protein. Algae oils, however, can contain long chain omega‐3 fatty acids, which make them more comparable to fish oils in nutritional value. Currently, about 1 million t of fish oil and 250 million t of soybean meal are produced annually. The 500 million t of seaweed would represent about 20% of current soy‐protein production and algae oils could represent a 750% increase over current fish oil production. Given the importance of oils containing long chain omega‐3 fatty acids, this could provide a significant boost to human health, while eliminating the need for fish oil in aquaculture and animal feeds.
Improvements in production systems technology and management are leading to greater efficiency in the use of water, land, energy resources, and reduction in the unit emissions of waste in aquaculture. While global freshwater finfish production grew from 1.2 million t in 1970 to 32.1 million t in 2010 (a 27‐fold increase), the release of nitrogen from aquaculture systems into the freshwater aquatic environment grew from 0.06 million t to 1.2 million t (only a 20‐fold increase) and phosphorus release grew from 0.01 to 0.1 million t (only a 10‐fold increase) during that period. Results were similar for marine finfish production. Although it is difficult to disaggregate these gains from those engendered through improved feeds and breeds, the importance of improved culture practices, such as aeration, fish health management, feeding practices, and stock management, cannot be overstated.
The overwhelming majority of aquaculture production (aside from seaweeds) occurs in conventional, shallow aquaculture ponds. In recent years, as pond aquaculture has intensified, new models of production systems have been developed, and some of these new systems have been adopted on a limited commercial scale. One example is the use of partitioned ponds, where the fish containment and waste treatment functions of the pond are physically separated but linked by pumped water that is circulated between the two basins. These systems have been adopted by several ictalurid catfish farmers in the USA, with annual fish production rates increasing from about 5 t/ha in traditional ponds to 15–20 t/ha in the partitioned systems (section 19.3.2.5). Another example is biofloc production systems that use vigorous aeration to maintain a suspension of organic particles that serve to maintain water quality and provide supplemental food to culture animals, such as shrimp or tilapia that can harvest the floc. In Thailand and Vietnam, some intensive shrimp farms have been reconfigured with smaller ponds that have central drains to capture waste solids. China has been undertaking a major program of pond renovation and modification, where pond size was reduced and aeration was added. Such large‐scale modifications to existing pond infrastructure may be necessary periodically to implement new production systems technology as it develops.
Moving aquaculture production into the oceans would generally reduce land and freshwater demand from aquaculture but is itself constrained by conflicts with other users of crowded coastal zones. More efficient work boats and deep anchoring technology will create opportunities over the horizon, while new submersible cage‐based systems might be deployed nearshore in some locations.
New approaches have reduced disease incidence and reliance on antibiotics and chemical therapeutants. In Norway, development of vaccines and improved biosecurity (control and containment of diseases) has greatly reduced the need for antibiotics in salmon production. Required investments in biosecurity to minimise the risk of disease outbreaks will vary by place and scale, but the need for improved diagnostic and surveillance capacity of national veterinary services is one common element. Although aquaculture will continue to be challenged by new diseases, new health management technologies will be developed to meet these challenges. The cost of genome sequencing is falling exponentially. This will allow the development of diagnostic testing methods and drugs and other therapies customised for specific pathogen strains, in a form of customised disease treatment.
There are several key structural and behavioural attributes of aquaculture sectors that make it vulnerable to disease losses and negative environmental impacts that constrain growth. First and foremost, effective disease and water quality management transcend the boundaries of individual farms. Area management systems are essential and these will require governments and industry to revise their approach to regulation.
To live within the boundaries set by nature, estimation of the carrying capacity of the watershed or water body in which aquaculture is being conducted requires spatial mapping of production systems and their related hydrology. A major constraint to effective disease management in many forms of aquaculture is the lack of co‐operation among producers. Encouraging management planning at the ecosystem level rather than farm level serves not only to define the space over which biosecurity rules should be implemented but creates a context in which farmers may be better able to understand the need for collective action. Only through an ecosystem approach can the industry reduce volatility, improve profitability, and approach greater sustainability.
Inappropriate spatial arrangement and the management of aquaculture have more than once undermined sustainable development and expansion of aquaculture. Repeated disease and water quality catastrophes in Chilean salmon and shrimp in Southeast Asia are but two examples of how overcrowding and short‐sighted planning have led to massive losses of fish and revenues. Because disease and negative environmental impacts are the major exogenous risk factors in aquaculture and are determined primarily by water management, production intensity, and the proximity of fish farms to one another, there are clear incentives for responsible farmers to support zoning and ecosystem monitoring to ensure sustainability and protect their investments.
Risks of adverse consequences from poor spatial management affect not only existing aquaculture facilities, but also affect the potential of new facilities to meet future demands for farmed seafood. New investments of at least USD100 billion are needed to meet anticipated demand. The generally small scale and organic growth of aquaculture has made it difficult to regulate and contributes to the high levels of risk perceived by potential new investors. Clearly, a new approach to managing growth is needed to improve the economic climate for aquaculture investment so that it can sustainably meet food security and economic development targets without causing environmental degradation.
One of the major challenges for sustainable aquaculture development is the sharing of water, land, and other resources with alternative uses, such as fisheries, agriculture and tourism. Spatial planning for aquaculture—including zoning, site selection, and the design of aquaculture management areas—should consider the balance between the social, economic, environmental and governance objectives of local communities and sustainable development (Figure 27.10). It is now widely recognised that further aquaculture development should be planned and designed in a more responsible manner so as to minimise negative social and environmental impacts as much as possible. Although many of the social and environmental concerns surrounding impacts associated with aquaculture may be addressed at the individual farm level, most are cumulative and insignificant when an individual farm is considered, but potentially large and highly significant when the entire sector is considered. The process and steps through which aquaculture is spatially planned and managed, integrated into the local economy and ecological context is termed the ecosystem approach to aquaculture. Three principles govern the implementation of the ecosystems approach:
Figure 27.10 Rafts for the cultivation of Pacific oysters in Bizen, Okayama, Japan. Extractive species will play an important role in future aquaculture by providing ecological services of food provision and water quality regulation. Aquaculture planning/zoning.
Source: Photograph by 松岡明芳 (Own work). Reproduced under the terms of the Creative Commons Attribution share licence, CC BY‐SA 4.0.
The ecosystem approach provides a planning and management framework to effectively integrate aquaculture into local planning. It affords clear mechanisms for engaging with producers and government for the effective sustainable management of aquaculture operations by taking into account local and national environmental matters addressing the social, economic, and governance objectives.
Knowing and growing with the carrying capacity of the environment is the key to success. A variety of carrying capacity models have been developed and used in Norway, Ireland, the UK, New Zealand, Australia, Mexico, Brazil, Indonesia, and other leading aquaculture countries. Systems to ensure ecosystem‐level sustainability of aquaculture should aim to sustain the abundance and diversity of wildlife at desirable levels and will require: 1) spatially explicit regulatory/zoning instruments to define the boundaries over which aquaculture sustainability should be assessed and 2) sustainability indicators and monitoring systems in respect to the local ecological carrying capacities of these zones. Institutional arrangements that assure compliance and transparency will be needed to operationalise the system.
Planning at ecosystem level will simplify permitting and ensure that farms occupy less environmentally sensitive areas. Within zones, collective action among farms and with veterinary services to control diseases would be made easier. Once established, zoned aquaculture areas could be certified collectively so that all farms have access to markets. Norway and Scotland (salmon) and Ireland (bivalves) have pioneered user‐friendly approaches to ecosystem‐level management based on extensive, heuristic carrying capacity datasets that could inform initiatives elsewhere. Australia and New Zealand are exploring aquaculture park leasing arrangements for salmon and shellfish.
With shifting economics and continued scrutiny from governments and consumers, investments in aquaculture must be thoughtfully undertaken with consideration of the entire value chain of the seafood industry and its interaction with natural ecosystems and other sectors of the economy. Policies should provide an enabling business environment that fosters efficiency and technological innovation in aquaculture feeds, genetics and breeding, disease management, product processing, and marketing and distribution.
Changes in public policy played a role in improving productivity and performance. Policy changes have helped to correct market failures and stimulate technology innovation and adoption, curb pollution, direct aquaculture development onto appropriate sites, ensure food safety, and ensure the economic viability of the aquaculture sector. For example:
Aquaculture industry associations have encouraged increases in environmental performance through the development of standards, certification programs, and codes of conduct in response to economic and reputational risks and to open up market opportunities (especially for exports to industrialised countries). Other companies, non‐governmental organisations, and universities have helped the industry improve farm management, productivity, and performance through research (e.g., in support of IMTA in Canada), advocacy, and service delivery.
One important political megatrend is the development of new models and approaches to environmental regulation and governance, including multilateral agreements and public‐private partnerships. New models are needed because 1) market prices do not internalise the full cost of resource use and pollution, 2) there are weak incentives for sustainable management of common property resources, such as the oceans, global atmosphere, and transboundary water resources, 3) there is social and environmental harm associated with current global value chains and 4) citizens are increasingly demanding transparency and accountability from governments and businesses.
Traditionally environmental governance was controlled by hierarchical state institutions, but increasingly that role has been assumed by businesses (such as international food corporations) and civil society groups working to defend the global environmental commons. The authority of state institutions is limited by national borders, but that of market actors is limited only by global trade agreements. These actors and their associated governance approaches operate across national borders, often bypassing government, and undermining its authority. In general, there is a trend towards fragmentation and layering of governance, ranging across high‐level multilateral agreements among nations, hierarchical state laws and regulations, and mixed governance approaches that include non‐state actors such as environmental non‐government organisations (eNGOs) and businesses that establish standards, norms, and consumer labels.
The development of corporate social responsibility (CSR) and business ethics is an important political megatrend (see sections 5.9 and 5.10). In aquaculture and other productive activities, certification and labelling schemes have been developed and will be likely to continue as a way for farms to comply with sets of voluntary standards of good practice that simultaneously support environmental protection goals of the state. It is not clear if the proliferation of these standards will continue or if there will be coalescence around standards that claim greater market share. Meaningful incorporation of small‐scale producers in certification systems will continue to be a challenge.
To date, environmental certification systems in aquaculture have focused on the most widely traded species (e.g., shrimp and salmon) and have essentially ignored species such as carps that are less involved in international trade but are far more critical for food security. Such certification systems have arisen in response to consumer demand and concern about the environmental impacts of aquaculture. A more meaningful system for certification of aquaculture products would consider the extent to which a product provides nutrition and food security as well as its environmental performance. At this time, there are no incentives in the global seafood market to create such a system.