Utrecht’s visdeurbel (fish doorbell) has returned for its sixth consecutive season, and the world wasted no time: the site was so swamped at launch that it briefly stopped working altogether.
The underwater camera at the Weerdsluis lock in Utrecht’s city centre went live at 9 AM on March 2. Within minutes, demand had overwhelmed the stream.
But it’s no surprise that the doorbell is so busy.
A global phenomenon with Utrecht roots
Last year, 2.3 million people tuned in from around the world, and the platform racked up 30 million visits. In fact, the site went down entirely one morning under the weight of traffic.
John Oliver’s Last Week Tonight even dedicated a full segment to it, commissioning R&B singer Mario to perform an original song in its honour.
It’s quite a trajectory for something invented in 2021 by Utrecht ecologist Mark van Heukelum.
Why do fish even need a doorbell?
Van Heukelum created the doorbell to solve a fairly niche springtime problem.
Every spring, fish in Utrecht’s canals migrate toward shallower water to breed. Early in the season, lock gates stay shut due to low boat traffic, leaving fish stranded and unable to continue their journey to the Kromme Rijn.
The fish doorbell fixes this with a simple idea: an underwater camera streams live footage of the Weerdsluis, and anyone watching at visdeurbel.nl can hit a virtual button when they spot fish on screen.
This alerts the keeper, who opens the gate and lets them through.
And it’s already a busy season
Van Heukelum thinks the bell will be ringing early and often this year.
“Fish follow temperature,” he tells NOS. “It’s been a mild winter, so there’s a good chance they’re already active and wanting to swim upstream.”
He’s relaxed about the sheer volume of incoming alerts, too.
“Keep pressing. No problem, we can handle it,” he says, noting the team can quickly scroll through photos to see whether a crowd of fish is waiting or whether it’s the same one photobombing repeatedly.
If you’ve never pressed the fish doorbell before, now is as good a time as any. It’s oddly satisfying, and you get to help actual fish, which is more than most of us can say about our Monday mornings.
Have you ever pressed the visdeurbel? Let us know in the comments below!
