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c0lo [soylentnews.org] writes:

The 2024 Fish Doorbell season is over [visdeurbel.nl]

It’s over again, the 2024 Fish Doorbell season. And what a special season it was! Thanks to the efforts of you and many thousands of other people from all over the world, thousands of fish have passed the boat lock....

We will be back on the 3rd of March, 2025. And we hope to see you next year again!

What's all about?

Fish Doorbell: The viral livestream that’s saving fish in the Netherlands [discoverwildlife.com]

As I type, there are 1,032 people around the world staring at a murky, snot-coloured screen, waiting. For now, it’s quiet but they might need to spring into action at any moment and ring the Fish Doorbell.

These citizen scientists have gone online to watch underwater footage of the Weerdsluis lock in the small Dutch city of Utrecht, which has been causing problems for fish that migrate upstream each spring.

Three years ago, two ecologists – Anne Nijs and Mark van Heukelum – were standing beside the lock looking at some artwork when they noticed lots of fish in the water. Lots of big perches were waiting for the lock to open.

“In the early spring, when the water gets warmer, some fish species migrate to shallower water and they swim right through the centre of Utrecht looking for a place to spawn and reproduce,” says Anne. But at this time of year “there are no boats sailing through Utrecht so the lock rarely opens.”

While they’re stuck waiting around for the lock to open, the fish are left vulnerable – if predators realise they’re loitering, they could come to snap them up. The lock should open more often in spring to let the fish go on their way, they thought, but how would the lock operator know if fish were waiting to go through?

Mark came up with the idea of the Fish Doorbell. A live stream in the water lets members of the public keep an eye out for fish gathering by the gates. When they see them waiting, they ring the digital doorbell to alert the lock keeper that fish are waiting. When there are enough fish in the 'queue', the keeper opens the wooden gates so the fish can continue their journey more quickly and with less chance of being eaten.

...

As well as freshwater bream, common roach, crabs and walleye, they’ve spotted some unusual species, such as eels – which travel in the opposite direction, says Anne: “The only place the eel reproduces is in the Sargasso Sea, 5,000 km away from the Netherlands” – catfish – which they didn’t know were living in the canal – and even a koi carp which may have been released from a pond.

The response from the public has been huge with people logging on from all over the world, including England, America, Australia and New Zealand.

Original Submission