William Smith, the television mathematician, has sold his Featherbed nature reserve on Knysna's undeveloped western head to a property developer and mining magnate.

The pristine 150-hectare reserve, accessible only by ferry, is home to the Knysna Loerie, the Blue Duiker, and the rare Black African Oyster Catchers.

The controversial sale has got Garden Route residents and environmentalists jittery about potential developments on the reserve which currently attracts 200 000 visitors a year.

Smith said that he could not guarantee Featherbed's future but had taken what he believed was the best offer for the land, which he inherited from his father JLB Smith, the renowned ichthyologist.

The deal included the company's ferries and restaurant.

Smith said he decided on Eastern Cape-based businessman Kobus Smit because he was "into nature conservation and tourism".

He said he and his wife were getting old and after running the business for 25 years, seven days a week, they wanted to retire.

"With land like that you don't own it, it owns you. You're just a custodian for a short time."

Many Knysna residents assumed that one of Smith's three daughters would carry on the operation, but he told one newspaper that he had decided to sell because there was no succession to a son, and that it was impossible to rule "something like this from the grave".

Smith then said this week that his daughters had been given the option to buy, but had felt it was too much of a responsibility.

The Saturday Star was unable to contact Smit, a major shareholder in mining company Umcebo with mining interests in Namibia.

Marylou Newdigate, a member of the environmental group Guardians of the Garden Route, said Smit would have a monumental battle on his hands if he tried to develop the area.

"The eastern Head is full of revolting empty Tuscan villas."