The shocking practice that shows prawn farming is as cruel as factory farming.

Have you ever heard of 'eyestalk ablation'?

Animals Australia

Animals Australia team

Last updated August 28, 2017

Female prawns in prawn farms have their eyes cut off.

You may have heard about the horrors inflicted on pigs and chickens inside factory farms but it might come as a surprise to learn of the cruel procedure that is happening in almost all prawn farms around the world.

It’s called ‘eyestalk ablation’ and this is the definition from the Australian Prawn Farming Manual:

eyestalk ablation: a hatchery technique of macerating or destroying the eyestalk gland in female broodstock prawns to encourage spawning

In short, female prawns have their eye sliced open or cut off — usually without pain relief — to make them reproduce faster. This illustration shows one method of the gruesome procedure:

This image contains content which some may find confronting

Illustrations of the cruel 'eyestalk ablation' practiced on prawn farms.
Image credit: Food and Agriculture Organisation of the United Nations | Shrimp Hatchery Manual

Along with cutting and squeezing the prawn’s eye, other methods include cauterisation (cutting the eyestalk with a heated blade or forceps) and ligation (tying a thread or wire around the eyestalk causing it to fall off after a few days).

Female prawns have a gland behind their eyes that tells their ovaries when to mature. In the wild, this could be influenced by things like breeding season or environmental factors, but prawn farmers have found that the stressful and crowded conditions on farms can make prawns reluctant to reproduce. By destroying this gland, farmers rapidly force ovary growth, denying female prawns the natural instinct to only reproduce when the conditions are right.

Research has found that, given the right environment, female prawns in farms will breed without having their eye cut off. One of Latin America’s largest group of prawn farms, SeaJoy, has already phased out this gruesome procedure.

Does it hurt?

Prawns have been recognised as sentient in the UK – meaning their capacity to experience feelings and sensations has been acknowledged by law. This recognition was the key recommendation of a recent report commissioned by the UK Government:

We recommend that all cephalopod molluscs (such as octopus and squid) and decapod crustaceans (such as crabs, lobsters & shrimps) be regarded as sentient.
Review of the Evidence of Sentience in Cephalopod Molluscs and Decapod Crustaceans, London School of Economics and Political Science (UK)

The ability of prawns to feel has been known, but largely ignored, for a long time. A 2012 study into the pain experienced by prawns whose eye was sliced open and crushed or ligated found that both procedures caused prawns to become disoriented, flick their tail (an escape reflex) and rub the traumatised area – all behaviours associated with pain. The ‘ablated’ prawns were also less likely to seek shelter following the procedure, which researchers believe to indicate a degree of stress amongst these animals. The study concluded that:

These procedures are traumatic not only because of the surgical treatment or ligation but also due to the subsequent discomfort and hormonal changes.”

Scientist Dr Robert Elwood has also studied the way prawns react to negative stimuli and concluded that their behaviour was “consistent with the interpretation of pain experience.”

What’s more, studies have found that prawns and other crustaceans are able to see polarized light, which humans can’t. This superior vision helps them with navigating through water, seeing transparent or silvery prey, and avoiding predators. Destroying a prawn’s eye not only destroys the hormonal gland moderating their reproduction, but impacts their vision as well. In a crowded farm environment, impaired vision is likely to increase the stress on these animals.

This image contains content which some may find confronting

A closeup of black tiger prawn sitting on the bottom of sea.

Prawn farming: A cause for concern?

Cutting off and crushing prawn’s eyes is not the only reason to be concerned about prawn farms. In January 2017, the ABC reported that an outbreak of disease saw millions of Australian prawns suffocate to death as lethal chlorine was pumped into their water. Prawns could be seen leaping out of the water, desperately trying to escape.

Their gills are getting torn apart by the chlorine, it is a pretty horrible death.
Nick, prawn farmer

Sadly, just like factory farms on land, the overcrowding on factory farms for marine animals can quickly spread diseases. And it’s the animals who suffer the most gruesome consequences.

There are also environmental and human rights concerns with prawn farming. A Daily Mail reporter declared he would never eat a king prawn again after seeing inside the Thai prawn trade. Thailand is the world’s leading exporter of farmed prawns and journalist Jim Wickens described every aspect of the trade as ‘stomach-churning’. Not only are working conditions appalling and illegal slave labour rife, trawler men responsible for gathering ‘trash fish’ for prawn feed are using one of the most environmentally destructive forms of fishing found anywhere in the world — bottom trawling.


Bottom trawling for prawn feed destroys habitats and kills indiscriminately. Animation: Greenpeace.

Animals pulled onto ship decks are killed unscrupulously, with sea snakes, octopus, sea horses, puffer fish, crabs and starfish being thrown into the ‘trash fish’ hold to rot.

Weighted nets dredge up marine life from the sea bed, destroying habitats and breeding populations – effectively destroying the future of entire ecosystems. Animals pulled onto ship decks are killed unscrupulously, with sea snakes, octopus, sea horses, puffer fish, crabs and starfish being thrown into the ‘trash fish’ hold to rot. Back on shore, this will be processed into pellets to feed prawns in Thailand’s industrial prawn farms, which now occupy many kilometres of what used to be mangrove forest. When it’s time for these prawns to be killed for food to meet the largely international demand, the water – filthy with excrement and food waste – is often washed straight out to sea.

What about prawn fishing?

Whilst bottom trawling is especially destructive, all trawling involves the loss of lives as by-catch – including sea turtles, sharks, dolphins and seals. Due to the type of nets used, trawling for prawns is considered the worst culprit for by-catch, with between 80-90% of sea animals caught tossed back, usually dead or dying. It’s estimated that thousands of turtles alone die every year as a result of prawn trawling.

This image contains content which some may find confronting

A beautiful photo of a turtle swimming gracefully through water and rays of sun falling on him.

What’s more, prawns are vital to a healthy ocean ecosystem, and scientists predict that at the current rates at which we are pulling animals out of the sea, our oceans could completely collapse by 2050.

The solution:

The good news is that there are two simple ways you can help prawns. Firstly, join others in urging the Australian prawn farming industry to stop cutting eyes off prawns. Prawns shouldn’t have to suffer this brutal procedure to force them to breed more quickly.


Secondly, the choices you make can have a huge impact on prawns in Australia and around the world. Industrial prawn farms and commercial prawn fishing, which exploit humans, animals and the environment, exist only to meet demand for prawn cocktails, cutlets, sushi and more. Similarly, demand for animal products has seen fish suffering depression in overcrowded farms, chickens being bred to grow so fast that their legs can’t support their weight, and piglets having their tails and testicles cut off without any pain relief. But there is a very easy way to reduce the demand that fuels cruel and unsustainable farming practices – and many Australians are already doing it.

More and more people are cutting back on animal products and opting for healthy, plant-based meals to help create a kinder world for animals, humans and the environment. And with mouthwatering animal-friendly recipes for all your favourite dishes, it’s never been easier.

This image contains content which some may find confronting

A plate of mouthwatering plant-based shrimp - crumbed and fried beside dipping sauce and a lemon wedge.

Head to Veg Kit for healthy tips, shopping guides, and hundreds of animal-friendly recipes. You can also order your free Veg Starter Kit here.


The future of food?

Innovative food companies around the world are investing in sustainable foods that don’t use animals and US-based New Wave Foods is leading the way when it comes to plant-based seafood. Its animal-friendly shrimp debuted in Google’s cafeteria in 2016 and could start popping up on supermarket shelves soon. For now, head to our top picks for ‘seafood’ alternatives that are already available in Australian stores.

Could this spell the end of the cruelty and environmental destruction caused by prawn farms?