TAIPEI • The Taiwanese authorities are confiscating pebbles collected as mementos by tourists and returning the stones to the island's picturesque beaches, as they step up moves to preserve the scenic east coast.

In the latest geological repatriation, a cache of stones taken from outbound visitors by airport immigration was sent back to Taitung county last week, where rugged seascapes attract tourists, particularly from China.

The haul of pebbles, collected over two months at Taipei's main airport, weighed 100kg, according to the East Coast National Scenic Area Administration.

Fears that tourists taking stones will erode the island's beaches have prompted the authorities to put up signs at the most popular sites and at airports in recent years.

Tourists want to keep the patterned volcanic rocks as souvenirs, the administration said.

"Taking one or two doesn't seem like a lot, but our scenery will slowly disappear the more it happens," said Ms Lin Wei-ling, deputy director of the administration.

Taiwan's tourism bureau has introduced a fine as high as NT$500,000 (S$21,000) for those caught, but Ms Lin says no one has been slapped with penalties yet.

"We mostly rely on persuasion. After all, the fine seems disproportionately harsh for just taking a few stones," she said.

She added that educating the public has been effective, as some visitors have sent back rocks they have taken after realising it is illegal when they return home.

The stones returned were from Taitung's Sanxiantai - a group of offshore islands and coral reefs - and Baxian Cave, where natural sea caves are carved into cliff faces.

The two areas are also well known as settings for Chinese Taoist legends about "baxian" or the Eight Immortals. Myths tell the tale of how three of the saints landed in Sanxiantai, and the immortals were said to have resided in Baxian Cave.

AGENCE FRANCE-PRESSE