Reservoirs have warmed up to record temperatures – swimmers enjoy, nature suffers

The steady heat warmed up the water in the reservoirs.

In the northern parts of the Gulf of Bothnia, the surface water temperature exceeds the average June temperature for 1990-2019 by seven degrees. In Lake Saimaa, the water temperature on Thursday reached its highest mark in a century of measurements – 26.2 degrees.

According to the hydrologist of the Finnish Environment Center Merja Pulkkanen , in small lakes earlier this year temperatures above 25 degrees have already been recorded.

In the Gulf of Bothnia, heat and calm also provoked a blooming of blue-green algae. In the Baltic Sea region, they are distributed every year, but in the northern parts of the water area such a rapid flowering has not been seen before.

In Lapland, they fear the mass death of fish

According to the Chief Inspector of the Regional Center for Economic Development, Transport and Environment ELY Lapland Jarmo Huhtala, heating lakes and rivers can kill fish. He is particularly concerned about the situation in the Simoyoki River, where salmon have recently been restored. It is salmon that suffers from rising water temperatures.

– Especially here in Lapland, where we pride ourselves on our salmon and whitefish, these species suffer from too warm water. For fish, warmth is a disaster, although people rejoice that they can swim in pleasant warm water.