SVT's reporter Bodil Appelquist had been to a seminar on zoo animals in the Riksdag and crossed the bridge towards Drottninggatan.

"Then I see people standing and looking down from the bridge. Then I see something big in the water and realize it's a seal – I thought the poor guy had swum wrong. It felt strange, they are not supposed to be here at all.

May show up in town

According to Didrik Vanhoenacker, biologist on duty at the Swedish Museum of Natural History, it is relatively rare to see a seal in fresh water. But on the side of town where there is salt water, there is a greater chance of seeing a seal.

"It's not uncommon for them to be seen in the city. At Skeppsbron in the Old Town you can usually see them sometimes. They don't live in the city, but they can swim around the whole archipelago," he says.