Check out our most frequently asked questions. Do you have another question that is not listed here? Please contact us.
When does the Fish Doorbell work?
The Fish Doorbell season starts on March 2, 2026. Around this time, the first fish species, such as pike and ide, begin their migration. You can “ring” the Fish Doorbell from March to May (with a possible extension into June).
How does the Fish Doorbell work?
When the Weerdsluis (in Utrecht, Netherlands) is closed, fish gather in the current in front of the lock. An underwater camera is placed here, streaming live on this website. If you see a fish, press the digital doorbell. At that moment, a photo is taken of the fish. These photos are collected and sent to the lock operator, who then knows when to open the lock.
How often does the lock open?
Early in the season, when only a few fish species are active, the lock is opened a few times per week. As the weather warms and more fish migrate, the lock is opened daily. From April onward, the lock is also opened during the day for boats, allowing some fish to pass through at the same time.
Why doesn’t the lock open immediately when I press the Fish Doorbell?
Opening and closing the lock is done manually and takes about an hour. That’s why the lock does not open “on demand.” The lock operator decides whether it is worthwhile to open the lock.
Why a Fish Doorbell?
Fish are essential for the health of our rivers, canals, and waterways. They help keep the water clean and balanced. By assisting fish in their annual search for spawning grounds, we support aquatic life. Additionally, we want to show people that the Oudegracht is not just a body of water—it’s full of life! The Fish Doorbell helps us learn more about the fish in the Oudegracht.
What fish species swim through Utrecht?
At least 20 fish species can be found in Utrecht’s waters. Common species include roach, bream, blue bream, perch, pike, and rudd. But you can also find rarer species such as ide, bleak, flounder, tench, eel, and even the European catfish.
Are the canals and waterways suitable for fish?
Thousands of fish already swim in Utrecht’s canals and waterways. However, these areas are still quite “empty” with little natural habitat like aquatic plants or hiding spots such as dead wood or reefs. We are exploring ways to improve the canals and waterways for underwater life.
What routes do the fish take?
This depends on the species. Some fish travel only a few dozen or hundred meters, while others migrate as far as Germany! When searching for a spawning ground, some fish settle in a nature-friendly bank within the canal or the Kromme Rijn. Others migrate further, which is important for genetic diversity among different (sub)species.
I’m a journalist and want more information about the Fish Doorbell or footage/images. Who can I contact?
We have created a press kit with useful information and various images of the Fish Doorbell. If you need additional details, please contact us at visdeurbel@utrecht.nl.