For the first time since 1642, when Queen Christina was the ruler of Sweden, fish can pass freely by Slussen in Stockholm. With the construction of the new lock channel, a passage has been opened for masses of fish.
The passage, which in principle resembles any watercourse, has been functioning since June 15, when the water was released for the first time. Since then, almost 25,000 fish have been recorded by a special fish counter that has been installed.
The pike is probably the most common species, says Stefan Kläppe, representative of Tiva, the company that manufactured the counter.
Other species include pikeperch, perch, asp, eel, and trout. Moving images are possible to see on the Fiskdata website.
Slussen is located between Gamla Stan and Södermalm in central Stockholm. It was when the very first lock was built on the site that the fish migrations were stopped between Lake Mälaren in the west and Saltsjön in the east. It didn't come to a complete stop – some managed to sneak through the locks – but generally, the free contacts ceased. The first lock was named Drottning Kristina's lock to honor the sitting ruler.
Now the water flows in the channel from Lake Mälaren to Saltsjön, but the fish move in both directions. The channel is almost 100 meters long.
It is likely to be used by all species in the area, including beavers, birds, cormorants, and mergansers.
