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Humanely killing crustaceans

We are often asked by the public and by chefs what our advice is on how to most humanely kill crustaceans before cooking them.
Crustaceans are often stored, transported and sold live. It is vital to ensure that they are handled carefully and treated humanely at all times to minimise unnecessary suffering.
Many people have heard that boiling crustaceans alive is a painful and inhumane way to kill a crab or lobster and this is backed up by many convincing studies as well as physical evidence such as animals dropping their limbs and writhing around before dying.
Shellfish such as crab and lobster are among the most sustainable of our Cornish seafood so we felt it was important to give some clear advice to the public to ensure that people know how to humanely kill them.
Working with experienced shell fisherman and marine biologist Phil Lockley, and taking advice from the RSPCA, we have created a quick guide which helps you make sure you kill your lobster or crab quickly and humanely.
Step 1 
Before killing the animal should be stunned
This can be achieved in two ways 
1.By using electric shock – a specialised piece of equipment called a crustastun is available (but many people won’t have access to this).
2. By cooling the animal down to a temperature within its natural range (i.e. down to 2 or 3 degrees)– this can be done by wrapping the animal in a wet cloth or seaweed and then cooling it by putting it in a freezer or by packing crushed ice around it.  
Step 2 
Once the animal is in a sleep state (torpor) it can be humanely killed by physically severing the main nervous system and then draining the animal of blood.
Killing a Crab
For a brown crab Cancer pagurus, this is achieved by spiking the animal on the underside of the crab and thus destroying the main nerve centre see diagram, the procedure takes only a few seconds.  The Crab should be turned over and the fluid allwed to drain from the animal.
Killing a lobster
By cutting the underside of the lobster along the centre line from the head to the tail the animal can be quickly and humanely killed. There is no need to cut right through the shell as the nerve centres of the animal are close to the underside.
The crab or lobster should then be cooked as soon as possible  
Phil Lockley – pers comm

Cornwall Good Seafood Guide is underpinned by the Marine Conservation Society (MCS) Good Fish Guide. The first UK consumer guide to sustainable seafood. For more information visit

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