Norfolk sightseers told to stay away from seals
A group that protects grey seals said it was "really stupid" that people were still getting close to a colony despite signs and warnings against it.
Sally Butler, from Friends of Horsey Seals, on the Norfolk coast, said people needed to remain at least "10m (33ft) back" from the animals.
She was worried that too many people had scared the pregnant females and it could cause them to miscarry.
"It's just common sense - stay as far back as possible," she said.
"We've got signs up everywhere, but the message doesn't seem to be getting through to people."
She said she even saw a photographer chased by a seal after they got close to take a picture.
"The adult females are now quite heavily pregnant and they will start to give birth," she said.
"Also the males are getting quite testosterone-filled and you can see them fighting at the water's edge, so it is really stupid to get anywhere near them.
"For people to put their children in that situation is just unbelievable."
The Friends group was supporting a petition to introduce laws that would protect seals against dog attacks and from human contact.
It has attracted about 18,000 signatures.
"For the seals to be scared and going in and out of the water all the time - they're using up their vital resources and the females can abort their pups if they get too scared," said Ms Butler.
She added that dogs should be kept on leads as they could be deadly.
In March, a seal known as Freddie Mercury had to be put down when it was attacked by a dog on the Thames in London.
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