The fact that seals move far into the archipelago and close to cities is not so common, according to Linda Törngren, animal manager at Skansen.

- It's not very common. Most often it is younger seals that are seen so far into the archipelago.

Seals have different habits during the year and for long periods they live alone.

- Especially in the autumn, they are more lonely and move over larger distances, says Linda Törngren, animal manager at Skansen.

"Occasional visits to Lake Mälaren"

She says that it has happened in the past that seals swim in Mälaren.

- It's an occasional visit. I think this seal has gone astray. These are not places they usually stay, but as long as they are satisfied, they are right.

Christmas decorations and folk life

Why this seal pulls into Södertälje's water is unclear. Perhaps it could be city life or Christmas decorations that attract - it must be unspoken.

- There is a raft of Christmas ornaments in the middle of Maren and it seems to stick around it, says Fredrik Gustevall.