Local authorities in Japan have drawn a line in the sand amid anger over a rise in graffiti by foreign tourists disfiguring its pristine coastal dunes.

Tottori, a prefecture (county) on the Japan Sea coast, banned the defacement of its sand dunes – a major tourists attraction – a decade ago, but the local government said there had been a dramatic rise in “sand graffiti” in recent years as the area attracts more visitors from overseas.

The prefectural government said it would erect more foreign-language signs urging visitors looking for the perfect Instagram memento not to vandalise the dunes, which cover a 16km stretch along the coast.

More than 3,300 incidents of “sand graffiti” have occurred in the last decade – including more than 200 last year – according to the Mainichi Shimbun. In January, a couple from overseas were ordered to erase a 25-metre-long message that read “Happy Birthday Natalie”. Other graffiti have been erased by local officials and volunteers, the newspaper added.

The offending ‘happy birthday’ message from January. Photograph: courtesy Tottori prefecture

The undulating dunes, which constantly change shape and reach heights of up to 50m, were formed over thousands of years by sand from a nearby river that was washed out into the sea and then deposited back along the coastline by ocean currents, according to japan-guide.com.

In 2008, a spate of graffiti prompted the local government to pass an ordinance banning people from carving large letters into the sand, with offenders facing fines of up to 50,000 yen (£356). But the measure appears to have had little effect.

The Mainichi said local officials would increase the number of warning signs in English, Chinese and Korean.

Irritation over the dunes’ defacement has added to the list of complaints directed at foreign visitors as Japan struggles to adapt to record numbers of tourists.

Last year the number of visitors exceeded 30 million for the first time, with the government targeting 40 million in 2020, when Tokyo hosts the summer Olympics, and 60 million a decade later.

Shop owners in Kyoto’s Nishiki Market have started displaying multilingual signs asking people not to eat while walking – often viewed as impolite in Japan – amid complaints about littering and, less plausibly, concern over injuries caused by wooden skewers.

In the ancient capital of Kamakura, authorities have declared eating on the hoof a “public nuisance” following complaints from businesses along Komachi-dori street, which attracts as many as 60,000 visitors a day, Jiji Press reported.