The eyewitness, who first heard the animal splashing by the southeastern coast, said she couldn't believe her eyes.
In the frigid waters of the Gulf of Finland, cyanobacteria has been observed for the first time during the winter months.
Sightings of great egrets have been reported for decades, but sightings this summer confirm the first time the species has nested in Finland.
Mild, wet weather has raised water levels in rivers and lakes around the country.
