Catching a seal

Scientists often work with wildlife vets when they catch seals.

Cows and juvenile seals are small enough to be restrained in a purpose-built catch-net. The scientists have to creep up on the seals as they can run very fast and will escape into the water if they know the scientists are near them. When the scientists are close enough, they jump up, run after the seal and drop the net over it. A portable gas-anaesthetic machine is then brought over. A gas mask is placed over the seals’ nose and an anaesthetising gas is provided for the seal to breath in. This is the same way that humans and pets can be anaesthetised when they need operations.

To catch a bull is trickier because they are too big and strong to be restrained in the catch net. Scientists creep up and fire a dart into the bull's back. The dart contains a tranquilliser which makes the bull groggy. A tranquilliser takes about 10 minutes to start working. When influenced by the tranquilliser, the bull can still move around slowly, but it's reactions are slow enough for it to be restrained in the catch net. The gas-mask is then used to anaesthetise the bull.