Pond owners are being urged to help prevent a conservation catastrophe.
Northumberland Wildlife Trust says people may think they are doing a good turn moving frogspawn from their own pond into other ponds.
But this can lead to severe contamination and pose a threat to the frogs, toads and newts living in the area.
Frogs are at risk from two deadly diseases.
The first one, chytrid fungus, clogs their pores and, as they breathe through their skin, causes them to choke.
This fungus has already been responsible for amphibian extinction in various parts of the world.
The second disease, which is commonly referred to as red legs, causes the skin to drop off frogs’ legs, subjecting them to a very slow and painful death.
This condition is incurable and is on the increase in various parts of the UK.
Mike Pratt, Northumberland Wildlife Trust chief executive, is calling on people to leave frogs where they belong.
He said: “Frogs are great to watch, but people need to remember they are wild creatures and should be left in their native environment as moving them causes distress. Likewise, when it comes to excessive frog spawn in ponds, our message is clear – leave it where it is and let nature sort it out.”
The wildlife charity has had a number of reports of children removing frogs and frogspawn from the ponds at its St Nicholas Park reserves in Gosforth and throwing them at each other.