People often go swimming in Estonia's many pristine bogs, but this has caused some problems.

"As a result of swimming, the water in the main swimming pool has become thoroughly mixed. This means that both the surface layer and the deeper bottom layers are practically the same temperature. We also studied the vegetation along the edges and at pools used for swimming there was clearly an abundance of grasses, while dwarf shrubs had receded," said Imre Arro, a nature tourism guide and tour organizer.

Sunscreen and other cosmetics entering the water have also been a concern.

"It is certain that they remain in the water and you can also see a layer of them there, but their impact definitely needs to be measured," said Marika Kose, senior lecturer in nature tourism at the Estonian University of Life Sciences.

The extent of the changes depends, among other things, on how often and in what ways people use the same bog area.

"Our research shows that when a lot of people walk in one place, small local changes do occur. If there are a great many of these small changes in one place — for example, in very popular wetlands such as Viru Bog, Kakerdaja Bog or Kõnnu Wetland where many people walk both on and off the trails — then perhaps these wetlands are no longer doing so well," Kose said.

To preserve biodiversity in bog pools, scientists recommend keeping visits brief or going elsewhere instead.

"We certainly can't say that people can't or mustn't touch the water there. But it may be worth considering whether you really need to go swimming there. Perhaps you can go in, have your swim, experience the water and what it feels like and then get back out without leaving additional traces or putting additional pressure on the area, so to speak. A larger lake with infrastructure for swimming may be more suitable, as may lakes, rivers and beaches that are actually intended for swimming," Kose said.

--

Follow ERR News on Facebook and X and never miss an update!