I am writing to appeal to readers not to visit dolphinariums when on holiday abroad.

In some parts of the world dolphins and whales are brutally snatched from their families and natural environment and transported long distances to be kept in small, bare concrete enclosures and made to perform tricks for a reward of dead fish.

They suffer extreme mental and physical stress and there is a lower life expectancy and a higher infant mortality rate than in the wild.

They frequently suffer injuries through rubbing themselves against the side of the tank. They may have to tolerate members of the public wanting to stroke them and swim with them in so-called petting pools.

They are surrounded by crowds of people stroking and patting them often near sensitive areas such as their blowholes and they become obese through uncontrolled feeding.

It would be much better to go on a whale or dolphin-watching holiday and see them in their natural surroundings.

The Whale and Dolphin Conservation Society has information on well-organised and responsible trips on its website www.wdcs.org/outoftheblue P E Stevens Eversley Avenue Bexleyheath