Aquaculture and Fisheries

13 min read

Introduction

Since 1961, the global consumption of beef has been increasing at an average of 1.1% each year. Consumption of other types of meat has also been increasing at a significant rate. Compared to the average population growth of 1.6% annually during the same period, we can safely assume that population growth has likely been the main instigator of the increased meat production. However, this is not the case in China, India, and the Four Asian Tigers. Here, a more affluent populace has increased the demand for meat and fish, as diets and lifestyles change. Aquaculture and a rapid expansion of fishing fleets has helped satisfy some of the appetite.

The case of fish consumption, however, contradicts the population hypothesis. In the same period, global fish consumption has been increasing at an average rate of 3.1%.[1] This article discusses possible reasons why, as well as issues facing fish production and the future of fish as an integral part of food security and quality.

Fish can be produced through aquaculture, artificial fish farms, or natural fisheries, including oceans, seas, lakes, rivers, and wetlands. In 2018, total global fish production reached 179 million metric tons, with the majority of the fish obtained from aquaculture (52%).[2] In addition, 96.4 million metric tons were obtained through capture fisheries, with 50% of the catch coming from seven countries: China, India, Peru, the US, Russia, Indonesia, and Vietnam. Asian countries are a dominant force in aquaculture, producing 89% of fish over the last two decades.[3]

Graph showing the relationship between GDP and aquaculture and consumption in China, 1950–2015

For context, global per-capita fish consumption in 1961 was only 9kg. In 2015, this had increased to 20.5kg. Presently, fish contribute 17% of all animal protein and 7% of all protein consumed by humans. Farmed species will continue to play an outsized role in fish production, contributing 60% of all seafood produced by 2030.

Despite the seeming status of fish as the new favorite—half the world’s population presently obtains its animal protein needs from fish—some cultures do not eat fish. This aversion is informed by religion or traditions. In India, close to 40% of the population does not eat fish, despite the country having one of the world’s longest coastlines.[4] Similarly, Tibetans do not normally eat fish. The preferences of these two cultures, and a sprinkling of others around the world, are significant given that people who avoid fish usually do not have an alternative source of animal proteins.

Why the increasing consumption?

There are several reasons why fish consumption has been increasing and will further accelerate in the next 30 years. First, urbanization is growing, currently standing at 56.2%, and is expected to reach more than 68% by 2050.[5] A direct correlation exists between increased fish consumption and urbanization. Researchers suggest this correlation is tied to access to fresh fish, as well as a variety of species to choose from.

The Chinese example is perhaps the best case study of how an increasingly affluent populace develops a taste for finer things.[6] In 1980, the per-capita seafood consumption in China was 5kg. At the time, the per-capita annual income was USD 195. Fast forward to 2015, and consumption had jumped to 41kg, fueled by the fact that more people could afford exotic seafood; by then, the per-capita income was approximately USD 10,000. As China’s economy has grown, so too has the deployment of cutting-edge technologies to grow and capture fish.

China has one of the world’s largest and most advanced fishing fleets. The country has been cited as having transformed the world’s seas, contributing not only to increased stress on its fisheries ecosystem but also exploiting fisheries in far-flung areas. For instance, the Chinese fleet has been sighted several times off the Somali coast in East Africa and Fiji in the South Pacific. The Chinese template is replicated in most other developed and newly industrialized countries.[7]

A fleet of shipping boats berthed at Zhoushan, China

The American Heart Association recommends eating fish at least twice a week as part of a healthy diet. Fish is a great source of high-quality proteins, omega-3 and -6 fatty acids, and vitamins D and B2.[8] Consuming fish has been found to lower the risk of heart attack, boost brain health, and prevent depression. Other benefits of fish include better vision, better sleep, and the prevention of autoimmune diseases. These health benefits have been known for some time now. As people become aware of the status of fish as a superior source of animal protein, their consumption has increased tremendously.

How do we obtain fish?

  • Capture fishery – 90 million tons of fish are captured from their natural environments every year. Out of these, oceans contribute 80 million tons, while the balance is obtained from rivers and freshwater lakes. Capture fishery may be commercial, involving massive fleets with advanced technology, or involve subsistence fishing, which is mostly done by communities living near coastal areas, lake basins, and river banks. Due to the magnitude of natural water bodies, and the presence of a natural ecosystem, fish at sea and in lakes thrive better than in closed fish farms, especially when such ecosystems are well managed for sustainability.
A communal fishing party gets underway in Aden, Yemen.
  • Aquaculture – Aquaculture involves the controlled rearing of aquatic organisms for human consumption. Currently, more than half of our fish consumption comes from aquaculture. The number is expected to rise to 60%, with Asian countries particularly keen to enhance production.[9] In recent years, aquaculture has taken on additional modes for synergy and enhanced production. For instance, aquaponics aims to provide the necessary conditions for plants to grow and fish to thrive. Fish waste is purified by the plants, which in turn discharge useful nutrients for fish consumption.

Fish can also be farmed in rice paddies. In countries with refined rice-growing techniques, such as the Philippines, Indonesia, and Japan, paddies have special trenches that are flooded to accommodate fish.[10] The fish eat insects and may act as powerful enemies against weeds. Fish activity stirs up the soil, enabling plants to access useful nutrients, which boosts production. However, agrochemical use must be minimized, since it is detrimental to marine organisms’ survival, as it harms the ecosystem within which they thrive. In an era when these chemicals are seen as essential, fish farming in rice paddies can either be viewed as impractical or as the first real chance of producing organic rice.

Rice-fish polyculture in Indonesia
Illustration of aquaculture in rice paddies

In other cases, farmers may combine poultry farming with fish rearing, especially when the poultry is aquatic (geese and ducks). The birds defecate in the water, encouraging the growth of algae. The fish feed on the algae, while their waste may also be beneficial for the birds. The water is mostly dammed from a water source, particularly a river, ensuring that the ponds have natural conditions as much as possible while allowing for artificial control of the ponds.

Issues affecting aquaculture as a sustainable source of animal protein

Responsible aquaculture has been billed as a great way of not only raising fish but also improving the survival of some species that could otherwise be extinct due to climate change and human activity. Increased aquaculture has fueled technological advances, with numerous benefits for other types of farming, as well as for people’s diets.[11] The practice of aqua ponds, for instance, has helped keep fish in their natural habitat as shown in the image below, protecting them from overfishing while ensuring a stable supply of fish. Human interventions have enhanced fish production, with artificial conditions manipulated to accelerate growth and expand the range of benefits that fish bring to the ecosystem and humans. In some trout farms, fish are assisted to lay eggs, which are then placed in hatcheries and, later on, nurseries. This practice ensures a near-perfect hatch while safeguarding the fish’s health.

Giant roving aqua pond in the Gulf of Mexico, off Texas

A study of the differences between farmed salmon and wild salmon found that, due to the nature of the feed, wild salmon provided less omega-3 and -6 fats but higher levels of other nutrients and minerals, including calcium.[12] One concern related to farmed salmon is that processed fish feed may contain antibiotics to counter the higher susceptibility of farmed fish to diseases. However, wild salmon does not have this problem, because its diet consists mainly of invertebrates in the water.

As farmers seek to accelerate growth, they may resort to methods that might end up producing low-quality fish. The use of fishmeal with unsafe chemicals and hormones is particularly disturbing since it could negate the benefit of turning to fish as a source of healthy meat.

Environmental/sustainability issues for fisheries and aquaculture

As the global appetite for fish grows, there is a renewed focus on the sustainability of the industry.[13] For instance, overfishing, pollution of water bodies, and geopolitical differences all conspire to threaten the sustainability of wild fish as a future reliable source of animal protein. Issues regarding feed, the inability of fish farms to implement permaculture, and a monopoly of fish species farmed also call into question the sustainability of aquaculture.

Overfishing

Fish is a highly lucrative sector, comprising a USD 362 billion industry.[14] As more companies jostle for a piece of the pie, the inadvertent loser is the ocean ecosystem. Poor fishing practices have depleted a significant portion of ocean ecosystems, with some fish species disappearing and others in danger of extinction. Countries that are unable to effectively assert their rights to their waters have been particularly hurt. Unfair practices by international companies in unpoliced ocean waters have also wreaked havoc on the environment.

The Northern Eagle, owned by the American Seafood conglomerate, is a factory trawler with the capacity to carry 1,550 metric tons of frozen fish.

When overfishing occurs, the World Wildlife Fund says, fish and fisheries are impacted in profound ways. The size of fish, how they reproduce, and the speed at which they mature change. This is caused by bycatch–capturing of unwanted or unneeded fish, and imbalance in the food chain, which may the capacity of the ecosystem to support other organisms, even when they are not targeted or caught. This is coupled with an imbalance that can disrupt the food web, threatening the existence of important organisms that are not usually on the dinner plate, such as turtles.

Algae are important food for fish and other marine animals, and predators are essential to the environmental sustainability of the oceans. When some of the animals that feed on algae are excessively captured, and predators such as whales and sharks are eliminated, an imbalance occurs that could practically lead to the collapse of an important ecosystem.

Overfishing can be limited by a more robust system of government oversight and by industry self-regulation, and the limitation of government subsidies. Currently, 20% of the fishing industry’s revenues come from subsidies. These subsidies encourage fishing companies to catch fish in poorly policed oceans, resulting in almost irreversible damage to the marine ecosystem… In addition, extensive mapping of seas to understand which species inhabit which regions would significantly reduce overfishing and protect vulnerable species.

Pollution

The runoff from farms that use excessive agrochemicals encourages the growth of algae in the ocean, which can become dangerous to fish. The algae could be poisonous, discouraging fish from swimming in some areas and thus threatening fish stocks. Some areas could become either too polluted to host any fish or could poison the fish without necessarily killing them, resulting in poor-quality fish being consumed by people.

Plastic pollution is an even bigger threat. Fish can be injured by debris or mistake garbage for prey. Once their stomachs become full of plastic, they starve to death. Fish are also hurt by microplastics and nanoplastics.[15] When people consume contaminated fish, they expose themselves to health issues that, ironically, they may have been trying to avoid by eating fish.

A blue-striped grunt fish constrained by a plastic band in the Caribbean Sea.

Advantages of fish as a source of food

  • Health and safety – Perhaps the biggest advantage of eating fish over other protein sources is the nutritional value of fish. Besides the high concentration of omega-3 oils, which are essential in maintaining a healthy brain and heart, fish contains proteins that are easier to absorb. Fish has qualities found to prevent an array of diseases, including heart disease and diabetes.[16] Developing evidence suggests that when eaten as part of a healthy diet, fish significantly reduces the risk of cancer. Inconclusive evidence links reduced dementia risk with regular fish consumption; it is not clear whether omega-3 oils or other qualities in fish are responsible for this.

In recent years, there have been reports of animal products being unsafe for human consumption. The warnings are based on concerns regarding how animals are raised, such as the use of growth hormones to accelerate beef and poultry production and the quality of animal feed. Fish products do not have the same problem, being seen, especially when captured from the wild, as safer and healthier sources of meat.

  • Cost – In many regions, especially close to the coasts of large water bodies, fish is considerably cheaper than other meats.[17] Demand for more food to support a growing population is pushing fish consumption since available resources can be better utilized by turning to fish. In such areas, however, this is not always the case; but even then, health benefits should inspire regular fish consumption.

Disadvantages

  • Health issues – Ironically, some seafood can have dangerous side effects if not consumed properly. Whale meat contains mercury levels that are sometimes as high as 900 times beyond government recommendations. Some fish may be farmed or caught in contaminated waters, and the chemicals they absorb could negatively impact human health.

Conclusion

Fish presents the best opportunity for the world to match the growing demand for sustainable, high-quality food. The health benefits, ease of aquaculture, and support from governments and private entities mean that fish production will only accelerate. Serious issues regarding the environmental impact of large-scale open-sea fishing and safety concerns regarding fish farms threaten this industry’s future. Compared to other meat sources, however, the risk is minimal and is increasingly being managed with robust mitigation interventions.

  1. More people are eating more seafood, according to the UN. Besides farmed and wild fish, the world consumed 32.4 million tons of algae in 2018 alone. The figure is expected to rise alongside the consumption of regular seafood.
  2. Also in 2018, capture fisheries yielded 7.9 million tons of tuna fish. Two-thirds of the species were harvested at biologically sustainable levels. This was enabled by better technology and knowledge of the seas.
  3. As the accompanying graph shows, China’s aquacultural production has surpassed the rest of the world since at least 1960. A big percentage of what is farmed is in the form of algae and mollusks, with marine finfish making up a tiny but growing percentage.
  4. 81% of Indians, who are mostly Hindu with a sizeable Muslim minority, limit meat in their diet. 39% do not eat meat, according to Pew Research. This includes fish, other types of meat, and animal products. At 7,000km, India’s coastline is the 18th longest in the world. It also has numerous inland lakes and rivers, which, if unpolluted, would host massive reserves of fish and other seafood.
  5. Asia, home to more than half of the world’s population, has been urbanizing at an accelerated rate. China, which only recently passed the 50% mark in urbanization, still has more than 500 million people living in rural areas. As they go to cities, they will have to abandon their subsistence forms of survival, seek gainful employment, and buy food.
  6. In less than 30 years, China’s GDP per capita has jumped from less than USD 1,000 to more than 10,000. Between 2000 and 2020, Vietnam managed to triple its GDP per capita from USD 1,100 to 3,300. Both countries are major fishing nations and also have advanced aquaculture industries. Other countries in the region, including Indonesia and Malaysia, seem to be following a similar trend.
  7. For instance, Japanese vessels have been impounded in South Africa and Russia, accused of illegal fishing activities. Japan has set up a base in Mauritius, from where it directs a massive fishing enterprise around the African Coast and Southern Indian Ocean.
  8. Omega 3 fatty acids are important in preventing several types of cancer, hypertension, and diabetes. Vitamin B2 helps in red-blood-cell production, body growth, and the breaking down of proteins, fats, and carbohydrates to produce energy.
  9. While this is the case in Asia, the pattern is not necessarily replicated elsewhere. Much of the fish captured or farmed in Africa is either for subsistence or small-scale enterprises. The per capita consumption in Africa is currently 10kg. The consumption will fall more in the coming years since rapid population growth is not being matched with increased production or supply of seafood. Overall, however, aquaculture is improving on the content.
  10. Rice-fish systems are the oldest forms of permaculture/polyculture, in which farmers try to mimic the natural environment as much as possible in producing food. Rice-fish systems have a rich history in Indonesia, where they have been practiced since the 9th Century AD. Presently, this farming method is practiced in 17 of Indonesia’s 27 provinces. Combining rice farming with fish provides animal protein for people who are cut off from fish-containing water bodies. It also forces farmers to use fertilizer responsibly, since overuse could harm the fish. Besides fish, ducks are also integrated into the system, using a rotational farming technique that ensures the land and water retain optimal characteristics for the thriving of all crops and animals farmed in the paddy.
  11. To escape the many challenges posed by farming on open seas, technology has evolved to produce robotic, roving aqua ponds.

    The ponds give the fish adequate protection from predators while exposing them to their natural environment. Additionally, the ponds can easily move with changes in wind and still be steered safely when need be.

  12. Farmed salmon has higher amounts of fat, due to the feed it is given on the farm, with a higher calorie concentration, more cholesterol, and almost twice the amount of omega fats. On the other hand, wild salmon has higher amounts of vitamins, selenium, and protein.
  13. In SDG 14.4, the U.N. set a target of 2020 for global overfishing to be contained. There has been very little movement towards achieving this goal due to the difficulties of policing the sea and agreeing to more responsible fishing. Places, where poverty and conflict exist, are in particular trouble, which is perhaps why the Somali and Libyan coasts, as well as the South Pacific, have seen such a rapid deterioration in their marine ecosystems.
  14. According to FAO, 85% of marine species are overfished or fully exploited. A large number of other animals are victims of bycatch, getting accidentally captured by industrial fishing operations that can’t rescue such species. The population of large marine fish has fallen to just 10% of preindustrial levels, due to minimal regulation.
  15. Though the research has been termed as inconclusive, preliminary evidence suggests that the ingestion of micro and nano plastics may, in sufficient quantities, damage human organs. Many variables are involved, including the chemical composition of the plastic, the organism that ingests the compound, and the level of exposure.
  16. Evidence strongly suggests that oily fish, white fish, and shellfish can prevent cancer and diabetes if eaten regularly enough. Omega-3 oils are thought to help in controlling heart disease, among an array of other diseases.
  17. This is especially so in areas where it is possible to practice subsistence fishing. On the Kenyan coast, for instance, a kg of fish costs less than two dollars.
Author
Mbau Tim