Utrecht's Fish Doorbell System Helps Thousands Migrate Through Historic Lock

The innovative five-year-old system combines technology and public participation to enable fish migration during the spring season.

The 400-year-old Weerdsluis lock in Utrecht obstructs the migration of thousands of fish each spring as they travel to spawn in warmer waters.
The fish doorbell system, operational since 2020, uses an underwater camera and livestream to let viewers signal when the lock should be opened.
Ecologists review viewer-submitted alerts before manually instructing the lock operator to open the gate, ensuring efficient fish passage.
Last year, nearly three million people globally participated in monitoring fish activity, highlighting the system's success and international attention.
The system not only aids fish migration but also raises awareness about urban wildlife challenges and fosters community-driven conservation efforts.