Every spring fish swim through the heart of Utrecht, Netherlands looking for a place to spawn and reproduce. Some swim all the way to Germany. There are complications, though, as the fish often have to wait a long time at the Weerdsluis lock on the west side of the city, since the lock rarely opens in spring. A creative solution was found to alleviate the problem: an underwater camera at the locks, live-streamed, allows anyone watching to press the ‘digital doorbell’ if a fish is there.

Many fish species—including bleak, catfish, eels and pike—traverse the Netherlands’ numerous waterways in the spring to reach their spawning grounds upstream. Even as aquatic creatures are starting to fill the canals, however, ships are still sparse in the early spring, and the locks that allow movement through the water are often closed. This creates an obstacle for migrating fish, most of which start their journeys around this time of year, when the water is first starting to warm.

“The fish doorbell allows us to work together to ensure that fish do not have to wait as long. This is good news, because it means they are less likely to be eaten by other animals, such as grebes and cormorants.”

Dinging the doorbell notifies the lock operator that there are fish, so they can decide to open the locks and let them pass. Click HERE befriend the fish.