The RSPCA has urged the public to stay away from seals after incidents of people taking selfies with the mammals.
The charity's East Winch Wildlife Centre in Norfolk said there were "tragic consequences" when people or their dogs disturbed and interfered with seals along the coastline.
Its manager said people were taking pictures with or feeding the mammals.
Alison Charles said walkers and beach-goers should "learn to respect nature and enjoy from a distance".
Ms Charles said she was "really concerned" that people had been "pushing seals back into the water".
"I cannot emphasise enough how dangerous this is for the seals," she said.
"They are not whales and haven't been beached. It is perfectly normal behaviour for seals to spend much of their time out of water."
Ms Charles said people were putting the seals and themselves at risk by trying to move the mammals.
Each time a young grey seal was disturbed their feeding would be interrupted and they would start to lose weight, meaning many would not survive, she said.
There have also been reports of seals being bitten by dogs that were not on leads, the charity said.
The RSPCA has asked for people to stay away from seals "no matter where you find them or whether or not they look healthy".
It advised anyone with concerns about a seal that looked sick or injured to contact the RSPCA's emergency line.