Sir – I expect that many people watched Springwatch on the BBC recently. In the last episode (June 11) Simon King showed us the remains of balloons which had been found off our shores where the leatherbacked turtles live.

The diet of these turtles (some of whom live for 150 years) is jellyfish. Unfortunately, when they eat a balloon, thinking it is a jellyfish, they die.

A balloon completely blocks their digestive system and this amounts to the murder of these beautiful and ancient species. As Simon King said, do please think of the turtles before releasing balloons into the sky. What goes up must come down.

The Marine Conservation Society, which has found many animals killed by balloons, is worried that the message is not getting through. The number of balloons and balloon pieces found by them on our beaches has trebled in the last ten years.

I am glad to say that Oxford City Council has now banned the mass release of balloons from its property. Also, some major local charities have also banned them.

There are many other ways of fundraising which are more environmentally friendly and kinder to the turtles, dolphins, whales and sea birds than balloons.

All balloons filled with helium, whether called ‘biodegradable’ or not, take a number of months or years to disintegrate. A balloon fllled with air, so that it is not let off into the atmosphere, is the only safe balloon.

Ann Spokes Symonds, Oxford