People meeting up for “dogging” are preventing children from visiting a nature spot, it has been claimed.
They are gathering in sand dunes at Seacroft Marsh in Skegness and surprising visitors, according to Lincolnshire Wildlife Trust.
Dave Miller, a coastal ranger for the trust, said he is loath to take children to the Site of Special Scientific Interest (SSSI).
He wants help from the public to monitor the extent of the problem.
A public meeting is being held at Gibraltar Point Visitor Centre at 19:00 GMT on Tuesday.
Mr Miller said: “In some areas it happens at night-time and out of the way and it’s not a problem but this is happening during the daytime.
“People do bump into people doing unsavoury things.
“If there’s a lady walking there with a couple of dogs, it’s not very nice.”
Seacroft Marsh is an extension of Gibraltar Point, which is designated as a National Nature Reserve.
Mr Miller said there had been problems for a number of years.
“It’s a fantastic area and I would like to use it more for education purposes and recreation, but at the moment you would be scared to do that because of the issues there.
“There are people around leaving not very nice litter. It’s not nice when a young child sees any of this stuff.”
Mr Miller wants people to report any unsavoury activity to the trust so he can build up a database of incidents and pass the information to the police.
“We may find it happens at certain times of the day,” he said.
“I’m hearing all these things anecdotally as I’m working but the police can’t do much about it unless they catch someone in the act.”