A fish doorbell (Dutch: ''visdeurbel'') is a system that allows fish to pass through a closed
sluice gate through
crowdsourced input when fish are present. The
Utrecht Visdeurbel uses a
livestreamed underwater camera that allows users to press a
doorbell button to notify the
lock operator that there are fish swimming in the
gracht
''Gracht'' (; plural: ''grachten'') is a Dutch word for a canal within a city.
''Grachten'' often have a round shape, and form a circle around the city cores in the Netherlands, Belgium, and northern Germany. Outside the Netherlands, the word '' ...
, and that the lock should be opened. It is designed to aid in seasonal fish migration, as an alternative to a physical
fish ladder.
Usage
It was deployed for the first time in
Utrecht in March 2021, at the ''Weerdsluis'' on the
Oudegracht. In the first two weeks, it was used 23,000 times. It was disabled in June,
but has since been reinstated a
visdeurbel.nl
References
{{Reflist
External links
Visdeurbel
Ecological connectivity