Animal welfare

Animals, including fish, are sentient beings and deserve a good quality of life and humane death. Animal welfare is not just about the absence of suffering, but about the provision of ‘what animals want and need’ so that they can lead healthy, happy lives. An animal is considered to have good welfare when he/she is in good physical condition, has a strong mental state (for instance: confident, not fearful or in pain) and is able to express important behaviours (such as foraging, making a nest, or socialising).

Good animal welfare is underpinned by good feeding, housing / environment, health, breeding, and critically good stockmanship / management (animal care).

Introduction to the problem and scale

• Merging all aquaculture production of aquatic animals (e.g. fish, crustaceans, molluscs), global production was over 94 million tonnes in 2022. Most aquatic farming (88%) is focused in Asia, with China being the top producing country worldwide, farming over 52 million aquatic animals in 2022 (56% of the global total)².
• The farming of aquatic animals has increased by 191% from 2000 to 2022, growing on an average 5% each year². Algae farming also more than tripled in the same period².
• In 2022, global farmed fish production was 61.5 million tonnes, accounting for over half (65%) of all aquaculture production. This has been estimated to consist of 86-180 billion fish³.
• Fish farming activities can have negative effects on biodiversity by releasing polluting effluents, consuming wild fish for feed, transmitting disease to wild stocks and releasing invasive escaped fish⁴.
• The majority of fish farming is intensive, with fish kept in barren environments at high stocking densities to maximise profit and farm productivity. They experience a high risk of injuries, diseases, and parasite infections, and are limited in their ability to express natural behaviours. Subsequently, their welfare is often deemed to be poor.
• There is evidence that fish are sentient and feel pain^5,6 and, as such, deserve a good quality of life. As seen below, this is also the shared opinion of the majority of people/consumers in different regions of the world.
  • EU: the majority of citizens agree that fish can feel pain (71%), are sentient (60%), and can feel negative emotions such as fear (60%); 91% think that fish welfare should be protected to at least the same extent as the welfare of other animals we eat⁷.
  • South America: a survey of people with higher education showed that 71.8% of participants in Brazil perceived fish as sentient and 79.7% participants in Colombia⁸.
  • China: 82% of people surveyed in 2024 agreed that fish are sentient. Most people also agreed that fish can feel pain (69%), negative emotions (71%) and positive emotions (60%)⁹. 
• The World Organization for Animal Health (OIE) Aquatic Animal Code, has published recommendations on the welfare of farmed fish during transport, stunning and slaughter¹⁰. In the EU, these guidelines are used as a measure of compliance with EU legislation, but they are rarely followed around the rest of the world. 
  
  • In many countries, fish are not included in animal welfare and humane slaughter legislation.
  • Fish welfare is considered in some certification schemes (e.g. RSPCA and Soil Association), however, many fish-specific schemes focus largely on sustainability issues and omit key welfare issues¹¹.
  • Fish welfare is, however, being increasingly considered by companies throughout the supply chain in their corporate animal welfare policies (as demonstrated in the Business Benchmark for Farm Animal Welfare (BBFAW) (https://www.bbfaw.com/).
  • South America: In the same survey mentioned above, 72% of participants in Brazil and 76% of participants in Colombia believed that fish should be included in humane slaughter regulations⁸.
• Although farmed fish tend to have a low food conversion ratio (FCR) (1-2.4), only 14-28% of the protein and 6-25% of the calories used in fish feed is turned into human edible fish¹². Moreover, it takes 3 - 4 tonnes of raw fish to make one tonne of fishmeal and fish oil for fish feed¹³.

Intensive fish farming

• As of 2022, there were 368 recorded species of farmed finfish². The most commonly farmed are carp species, accounting for 52% of total farmed fish production². Each species of farmed fish has its own characteristics and requirements for maintaining positive welfare.
• In intensive systems, fish are farmed in nets, ponds, or cages, inland or offshore, and are kept at such a high stocking density that they are unable to obtain sufficient feed from their environment. As well as high stocking densities, intensive fish farms are often characterised by barren environments, high levels of disease and parasites, and poor water quality.

What are the welfare issues?

• Confinement: The high stocking densities of fish within a net, pond or cage results in physical injuries such as fin damage from aggressive conspecifics and poor body condition resulting from food competition and stress. High stocking densities can also cause poor water quality and increased risk of disease and parasite infections¹⁶. Fish should be provided with the opportunity to express natural behaviours and access favourable environmental conditions, which is not possible at high stocking densities.
• Disease and parasites: Diseases and parasites can spread through the water from one farm to another because of the close proximity between them in many areas¹⁷,  and they can also spread to wild fish¹⁸.
  • In farmed salmon, sea lice are a widespread problem. Sea lice cause open wounds and injuries to the gills and mouth, and they can result in the infected fish dying. Most sea lice treatments can also cause injury and death for the fish. As the salmon farming industry expands, the number of salmon infected with sea lice is likely to increase.
• Transport: Fish are transported as juveniles to on-growing facilities (e.g. to sea cages) or from rearing pens to slaughter facilities. Common methods include transport via well boat (boats with a well in which to keep fish alive), by towing of cages with tugs (where the fish must swim to keep up with the speed of the boat), or by road^{19, 20}. Capture, loading, transport, and unloading of the fish for transport, as well as high stocking densities and poor water quality during transport, can cause exhaustion, physical injury, and severe physiological stress²¹. There are currently no maximum transport times written into legislation for fish and transport is not considered by most certification schemes.
• Inhumane slaughter: Fish are slaughtered without stunning in many areas. This causes prolonged suffering as death can be slow to occur depending on the killing methods used. This means that millions of fish suffer unnecessarily every year²¹. Inhumane slaughter methods (without stunning) involve cutting the gills to sever the blood vessels so that fish remain conscious while they bleed out. Carbon dioxide is also still used to slaughter fish in some countries, a process during which the fish exhibits head shaking and vigorous tail shaking for up to two minutes before losing consciousness²². Exposure to air results in fish taking over an hour to lose consciousness, depending on the species²³. Live chilling in ice slurry without an effective stun, traditionally used for bass and bream, can result in the fish struggling for up to 40 minutes²⁴ and it can take over 3 hours for the fish to die²³. This means that fish slaughtered using air or live chilling may be gutted alive.
• Fasting: Prior to transport or slaughter, fish are fasted to reduce oxygen demand and physical activity and to empty the digestive system to reduce water fouling. In salmonids, for example, 2-3 days is a sufficient fasting period to reduce metabolic rate¹⁰. Some certification schemes, even allow farms to withhold food for up to two weeks²⁵.
• Crowding: In addition to fasting, fish are crowded prior to slaughter at extremely high stocking densities while they wait to be pumped or netted out to be killed. This is a stressful procedure that can lead to reduced water quality and physical injuries from the net or other fish. Fish will often be seen gasping for air, attempting to escape (jumping), and burrowing into the net.
• Physical health: In fish farming, mortality rates during rearing that are considered acceptable by the industry can be high (up to 20% in pangasius²⁶). In addition, culls to prevent the spreading of disease²⁷ or mass mortality events²⁸ occur during which tens of thousands of fish die. High stocking densities during rearing and crowding events also cause physical injuries such as fin damage, skeletal deformities, snout, and eye damage, and skin/scale damage. Physical health is also impaired as a result of disease and parasites.

What are the environmental and sustainability issues?

• Damage to the natural environment:
  • By weight, almost a fifth of the world’s total catch of wild fish is processed into Fishmeal and Fish Oil (FMFO), of which 69% of fishmeal and 75% of fish-oil production are used to feed farmed fish²⁹. This accounts to 0.5-1 trillion fish being processed into fish feed every year³⁰.
  • Aquaculture can cause environmental pollution and habitat/wildlife destruction because of an excess of nutrients (faeces and uneaten food) and chemical runoff from treatments entering the surrounding area^{31, 31}.
  • Approximately 63% of global aquaculture took place inland (freshwater) during 2022²which can put a strain on limited water resources¹⁸.
• Damage to wild animals:
  • Escaped farmed fish can be a threat to wild fish populations. Fish farmed in the proximity of wild populations can sully the genetic diversity of wild fish populations and transfer pathogens from farmed fish to wild populations¹⁷. Escaped fish farmed in non-native areas can replace endemic species¹⁷.

Link to the relevant Sustainable Development Goal (SDG)

• SDG 14: Life below water. Conserve and sustainably use the oceans, seas, and marine resources for sustainable development³⁴