Quirky livestream that lets viewers help fish is a hit with millions

UTRECHT, Netherlands (AP) — The central Dutch city of Utrecht has installed a “ fish doorbell ” on a river lock that lets viewers of an online livestream alert authorities to fish being held up as they make their springtime migration to shallow spawning grounds.

The idea is simple: An underwater camera at Utrecht’s Weerdsluis lock sends live footage to a website. When somebody watching the site sees a fish, they can click a button that sends a screenshot to organizers. When they see enough fish, they alert a water worker who opens the lock to let the fish swim through.

Now in its fifth year, the site has attracted millions of viewers from around the world with its quirky mix of slow TV and ecological activism.

Much of the time, the screen is just a murky green with occasional bubbles, but sometimes a fish swims past. As the water warms up, more fish show up.