Kent and Sussex beachgoers have been warned by animal welfare experts to not approach seals on the beach and in water.
Wildlife organisations have expressed concerns that curious seaside visitors may disturb seals by encroaching on their space or trying to take selfies with them.
Repeated disturbances can cause fatal injuries to seals.
Paddleboarders also pose a risk as they can get up close to a seal in the sea very quietly.
“Seals can be curious animals, but are also easily frightened,” said Nina Jones, a protected area warden for Kent Wildlife Trust.
The mammals haul themselves onto rocks or beaches to rest and digest their food, or to look after pups.
This means seals are at their most vulnerable when on land.
“It is important not to disturb them so that they can get the rest they need without being stressed by people or dogs, which could be perceived as a threat,” said Charlotte Owens from Sussex Wildlife Trust.
Experts say if a seal resting on the beach feels threatened, it may get back into the sea, potentially cause it injuries such as gashes on its belly from sharp rocks.
“Paddlers can help seals by paddling slowly and steadily, not stopping at a seal site, or getting too close,” said Ms Jones.
She advised never to feed or follow them, or to take a selfie with a seal.
Follow BBC South East on Facebook, on Twitter, and on Instagram. Send your story ideas to [email protected].