BLUE jellyfish which were washed up in Havelet Bay present no threat to swimmers, according to marine expert Richard Lord.

However, children should be careful not to handle them as they might cause mild irritation to vulnerable skin.

The G-Can member and environmentalist, who studies Guernsey waters, was called to the bay to investigate.

‘The harbour office called me to say there had been reports from worried people that many had been washed up on Havelet, so I went to have a look after work,’ he said.

‘I found about 50 all over the bay, many were washed up in the seaweed.’

The species, known as Cyanea lamarckii – cyan being Greek for blue – would cause an irritation to only the most sensitive skin, according to Mr Lord.

‘I was handling them without protection and I had no reaction at all. If anything it would be milder than a nettle sting. There is no reason not to go swimming or anything like that.’

He had seen the species in Guernsey before, he said.