Researchers urge swimmers to avoid Estonia’s bog pools

Estonian bog pools are sensitive to heavy visitor pressure, and frequent swimming is changing their ecosystems, ERR’s Aktuaalne kaamera reported. Researchers recommend using other bodies of water to help preserve biodiversity.

Nature tourism hike organiser Imre Arro said swimming has caused the water in the main swimming pool to mix evenly, leaving the surface and deeper bottom layers at practically the same temperature.

Changes have also been observed in vegetation along the edges of the pools. Herbaceous plants have become more abundant, while shrub plants have receded, Arro said.

Sunscreen and other cosmetics entering the water are another concern.

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

The extent of the changes depends partly on how often and in what way people use the same bog area. Research shows that heavy foot traffic causes small local changes. When many such changes occur in one place, including popular bogs such as Viru, Kakerdaja and Kõnnu, the ecosystems may be significantly affected, Kose said.

Researchers recommend limiting the time spent in bog pools or choosing another place to swim.

Kose said people should not necessarily be prohibited from touching the water, but should consider whether swimming there is essential. She suggested taking a brief swim and leaving without creating additional traces or pressure.

“Perhaps a larger lake with swimming infrastructure would be more suitable, or lakes, rivers and beaches that are actually intended for swimming,” she said.