It’s lo-fi Attenborough! Why the internet’s going wild for a ‘fish doorbell’

‘Akin to an aquarium in a dentist’s waiting room’ … a pike, one of the species of fish you can see on the fish doorbell’s live stream. Photograph: Ernie Janes/Alamy

Something fishy is happening in the Netherlands and viewers worldwide are hooked. No, this isn’t the latest voyeuristic reality series from the creators of Big Brother and The Traitors. It’s a charmingly innocent live stream which lets you ring a doorbell on behalf of some frisky fish.

For the past three migration seasons, an online feed has broadcast live footage from an underwater camera at a lock to the west of Utrecht. Every spring, thousands of fish swish through the Netherlands’ fourth-largest city, seeking shallow waters in which to lay their eggs. Some swim all the way to Germany, like piscine Adam Peatys. Slight snag: they often have to wait at the Weerdsluis lock, which seldom opens at this time of year.