Not all the fishermen who frequent Amsterdam’s canals are trying to catch dinner. In addition to fish, the waterways are filled with bicycles—and to clean the channels, skippers use giant, claw-shaped machines to yank the vehicles from their watery resting place and onto dry land. In just one year, a skipper may pull anywhere from 15,000 to 20,000 bikes from the city’s 165 canals.

In the video below, Great Big Story introduces us to two “bike fishermen” named Jan de Jonge and Swavek Vervoort. They explain how two-wheelers end up in the canal, where they go once they’re “fished” out, and why it's bad to simply leave them in the water.

[h/t Great Big Story]