Utrecht’s Fish Doorbell Returns March 2, Helping Fish Navigate Canals

Utrecht, Netherlands – The world’s first Fish Doorbell, an innovative system designed to help fish migrate through the city’s canals, will reactivate on March 2, 2026. The project allows citizens worldwide to assist fish in their spring journey by remotely operating a lock.

How the Fish Doorbell Works

Every spring, thousands of fish swim through Utrecht’s Oudegracht, seeking suitable locations to lay their eggs. However, the Weerdsluis lock is often closed, obstructing their passage. The Fish Doorbell addresses this issue with an underwater camera and livestream accessible at visdeurbel.nl. Viewers can press an online doorbell when they spot fish waiting at the lock, alerting the lock keeper to open the gates and allow them to continue their migration.

A Growing Phenomenon

The Fish Doorbell has gained significant popularity since its installation in 2021. In 2024, the website saw 2.7 million visitors from around the globe, including the United States and Brazil. The project even went viral after being featured on John Oliver’s HBO demonstrate, Last Week Tonight, causing a surge in daily visitors to approximately 700,000, a substantial increase from the usual 200,000. In 2025, the site recorded an impressive 30 million visits from 2.3 million unique users, with over 200,000 doorbell rings.

Species Supported and Data Collection

The Fish Doorbell assists a variety of fish species, including bleak, catfish, perch, pike, bream, and eel. Observing rare species like eel and bleak is considered an indicator of excellent water quality. Data collected in 2025 revealed that fish are most active in the early morning, at dusk, and after dark.

The Weerdsluis Lock

The Weerdsluis lock itself is a 200-year-old monument capable of releasing approximately 1.5 million liters of water with each opening, managing water levels in Utrecht with precision.

Looking Ahead

The Fish Doorbell typically operates until the end of May, providing crucial assistance to migrating fish during their spawning season. The continued success of this unique initiative highlights the growing global interest in urban wildlife conservation and the power of citizen science.