Crustaceans show responses consistent with signs of pain and distress. [1-6] They also have the cognitive capacity to remember, and learn to avoid unpleasant stimuli. [7-9] As a result, RSPCA Australia considers that crustaceans should be captured, handled, transported, stored and killed humanely. This is true for all crustaceans, like crayfish, lobsters, crabs, Moreton Bay bugs, and yabbies, whether they are cooked or eaten raw (sashimi).
Killing involves loss of sensibility (ability to feel pain), followed by death. For killing to be humane, either:
A variety of methods are used to capture, hold, kill and process crustaceans. How it is done depends on the species, whether it is a commercial or noncommercial operation, and what the end product is. In each case, crustaceans should be killed by the most humane method.
The legal status of crustaceans in Australia varies between different states and territories. Crustaceans are protected by animal welfare laws in New South Wales, Victoria, the Northern Territory, and the Australian Capital Territory. In some states, this only applies to crustaceans that are meant to be eaten by people. Penalties may apply if crustaceans are not treated humanely.
People love shrimp; every year, Americans eat almost 1 billion pounds of them. But not many people know about the controversial ways shrimp that are going to be eaten are killed. This article will talk about how shrimp are killed, the arguments about how to make the process more humane, and whether better ways of doing things may come up.
Overview of Shrimp Slaughter Methods
Wild-caught shrimp are often harvested through trawling nets then sorted while still alive. Farmed shrimp meet their demise through two main methods
Asphyxiation – Placing shrimp in containers without oxygen until they suffocate. Takes 1-2 hours.
Freezing – Quickly freezing shrimp to death More humane but still causes pain
Boiling Alive – Dropping live shrimp into boiling water. Traditionally used but considered highly inhumane.
Chemical Use – Intensive shrimp farms utilize antibiotics, pesticides and disinfectants that raise environmental and health concerns.
Ikejime Spiking – Inserting a spike to instantly kill shrimp. Considered most humane but rarely implemented.
Let’s analyze each technique and the welfare issues surrounding them.
Asphyxiation – A Slow and Stressful Death
Asphyxiation by oxygen deprivation is a common slaughter method in industrial shrimp farming. The process involves placing shrimp in containers filled with ice or seawater, then sealing the container to cut off oxygen supply.
Without oxygen, the shrimp become motionless as they slowly suffocate over the course of 1-2 hours. They may thrash around initially as they struggle for oxygen.
While cost-effective for processors, many criticize asphyxiation as an extremely inhumane method. Shrimp experience significant stress and panic as they gradually suffocate.
Some places, like New Zealand and parts of Canada, have banned asphyxiation as a cruel way to kill animals. But it remains common practice across much of the industry.
Freezing – Rapid but Still Painful
An alternative to asphyxiation is to kill shrimp through rapid freezing. This involves placing shrimp in large freezers or blast freezers set to -31°F or below. At these ultra-low temperatures, the shrimp freeze to death relatively quickly.
Freezing is considered more humane than asphyxiation since death occurs faster, usually within minutes. However, research still indicates shrimp experience pain and distress as ice crystals form in their tissues and organs.
Stunning shrimp before freezing could improve welfare, but most processors forego this added step to cut costs.
Boiling Alive – A Controversial Cooking Practice
A traditional method of cooking shrimp is to boil them alive. This involves simply dropping live shrimp into a pot of boiling water and cooking until pink and opaque.
But boiling shrimp alive is hugely controversial. Many argue that plunging conscious shrimp into boiling water essentially scalds them to death. The sudden heat shock paired with being cooked alive is believed to cause extreme pain and suffering.
The practice remains common in Asian cuisine but faces growing backlash. More chefs are shifting to killing or stunning shrimp first before cooking. But boiling alive persists among purists who argue it better seals in flavor. The welfare cost remains high though.
Chemical Use in Shrimp Farms
Intensive shrimp farming relies heavily on chemicals like antibiotics, disinfectants and pesticides. Their improper use has raised concerns about environmental impact, residues in shrimp and other health risks.
Antibiotics are overused to control diseases from crowded shrimp ponds. Heavy use of antibiotics leads to resistance, prompting even stronger drugs.
Pesticides and herbicides applied to ponds also leach into surrounding waterways, damaging ecosystems. And chemical residues may endanger consumers.
Governments have begun restricting certain chemicals. But weak regulations in major exporting countries enable ongoing chemical reliance and abuse.
Ikejime – A Rapid and Humane Method
Ikejime is a traditional Japanese slaughter technique considered highly humane. It involves instantly killing the shrimp by piercing its nerve center with a sharp spike.
Properly performed, the shrimp is killed within seconds without experiencing pain, stress or distress. The technique also helps preserve meat quality.
However, ikejime requires specialized skills and tools. The spike must precisely target the nerve center behind the eyes to induce immediate death. Done incorrectly, it can maim but not kill the shrimp. As a result, only a handful of specialty processors have adopted ikejime.
The Debate Around Crustacean Welfare
The ethics of how shrimp are slaughtered ties into a larger debate around whether crustaceans like shrimp even feel pain. Researchers remain divided.
Some studies suggest shrimp do experience pain and should therefore be killed humanely without suffering. But others argue they lack the mental capacity for suffering.
Most governments currently exclude crustaceans from animal welfare laws. But nations like New Zealand now require humane killing of shrimp, suggesting perspectives are shifting.
More research is still needed to definitively determine if shrimp feel pain. But either way, there are compelling reasons to avoid gratuitously inflicting harm.
Potential for More Humane Practices
Could the shrimp industry adopt more humane slaughter methods? Experts believe it is possible but will require consumer pressure and regulations forcing change.
-
Electrical stunning appears effective for shrimp but optimal voltage levels require calibration.
-
Spike severing the nerve cord after ikejime could prevent revived reflex movements.
-
Mechanical crusher instantly killing shrimp shows promise in research trials.
-
Tannic acid baths sedate and immobilize shrimp before killing.
-
Low atmospheric pressure stunning (LAPS) uses gradual pressure reduction and avoids pain.
The challenges are developing efficient technology and gaining industry buy-in. But enhanced welfare could become a market advantage as consumers demand more ethical seafood.
How shrimp are slaughtered and cooked remains a largely hidden ethical dilemma. From freezing to asphyxiation and boiling alive, many common practices prioritize efficiency over welfare. But growing awareness and pressure could drive adoption of more humane methods. While challenges exist in overhauling practices at scale, even incremental steps could significantly reduce the suffering of these delicate creatures.
Skills and experience required
The RSPCA Australia does not think that live crustaceans that can be eaten by humans should be sold to the public. Instead, they should be humanely killed by trained and competent personnel before purchase.
Training should include how to:
- Handle and care for live crustaceans in the right way to keep them from suffering and stress.
- induce insensibility
- recognise signs of insensibility
- recognise signs of stress
- apply the method of killing
- operate and maintain any equipment involved in the killing process.
Signs of insensibility vary from species to species but generally include: [10]
- no resistance to handling—for example, the abdomen or tail can be easily stretched out or moved, and the outside parts of the mouth can be moved without any trouble.
- no control of limb movement
- no eye reactions when the shell is tapped
- no reaction when touched around the mouthparts.
Signs of stress include:
- thrashing
- autotomy (casting off of body parts, such as limbs).
Procedure: chilling in an ice slurry
- First, put crushed ice in a insulated container like an esky. Then, add water. For marine species, add salt water that is the same salinity (salt concentration) as sea water.
- For marine species, make sure that the ratio of ice to water (salt water) is 3:1. This will give the mixture the consistency of wet cement and a temperature of about -1°C. Make sure that there is enough ice to keep the right temperature throughout the chilling process.
- Place the crustaceans in the ice slurry. Check them often for signs of not being sensitive (see “Signs of insensibility” for more information). How long it takes to make an animal insensible will depend on its species, its size, and its metabolic state. For many species, at least 20 minutes is required.
- Once the crustaceans start to lose their senses, kill them mechanically right away to make sure they don’t come back.
Large crustaceans that are adapted to very cold temperatures may be stunned by chilling in air. Because heat moves more slowly through air than through water, cooling in air takes longer than cooling in ice slurry. [3, 14, 17].
What Fish Feel When They Are Killed for Food | NowThis
What do shrimp eat?
They’re just as likely to feast on the rotting corpse of a fish as they are to make a meal of plankton. As a result, the diet of shrimps is wholly dependent on their environment — and the fact that they typically occupy the sea, lake, or river floor means that their diets consist of what all the other animals have left behind.
What animals eat shrimp?
Cod, herring, and catfish have all been seen consuming shrimp, and they’re also preyed upon by larger marine mammals like whales and dolphins. Shrimp spend most of their lives at the lowest depths of their habitats, but there are other predators in their deepwater environments.
How do brine shrimp eat?
The actual methods that shrimp use to forage for food can vary from species to species. Brine shrimp are filter feeders, which means that they strain potential food matter from water while swimming through it.
What do shrimp eat in a tank?
Roughly a quarter of shrimp species occupy freshwater environments. Shrimp is what is known as opportunistic omnivores, and will eat anything from algae to plankton. What Do Shrimp Eat in a Tank vs in the Wild? Brine shrimp, ghost shrimp, and cherry shrimp are some of the most popular types of shrimp to put in a tank.