In early spring, dead frogs are often found floating in ponds because they were trapped under ice. If there is freezing weather for three continuous nights and the ice is more than an inch thick, oxygen can't get in and vrious toxic gases like carbon monoxide and sulphur dioxide can't get out. Frogs and fishes suffocate. Buy a device to float on the pond, which allows gases to escape when the pond is iced over.
But there is also a new infectious virus which is killing our frogs. The frogs turn red on their legs, chests, or bellies. Froglife (www.froglife.org ) are studying this disease, and would like to hear from you, with photos and descriptions. But please don't send them corpses however well packaged!
There is now another threat to UK amphibians from 'chytrid fungus', a fungal infection that is thought to be related to the enormous decline of amphibians worldwide - 1/3 of all amphibians are faced with extinction. It was discovered in a non-native bullfrog colony in the UK in October 2005 - the most significant symptom is large-scale mortality of juveniles on emergence from the pond. It is thought this disease is of most threat to common toads - Froglife urgently want people to get in touch if they think they have seen signs of this in their pond or ponds at nearby nature reserves.