Holes are being made in the dike in more and more places. The stark separation between inland and outside water and between salt and fresh water has not done nature any good. Even the Hoogheemraadschap Hollands Noorder Kwartier, which monitors our water safety in most of North Holland, leaves the locks ajar here and there. Like recently in the Wieringen Fish Cycle.
Sandra Roodzand is looking for fish. With a large landing net she goes along the banks of the fishing cycle. Unfortunately, every time she pulls in the fishing net, she is disappointed: “Nothing again!” And that’s not so crazy. “Actually, this is only the first year that the fish cycle has been completed. Before that, this was a pasture.” Now there are revolving ditches in a fan pattern, freshly dug into the ground.
You can see that nature still has to get up to speed here. “Look, flap is growing everywhere, from that slimy weed. Reeds are already growing here and there, but few aquatic plants are growing. That means that the oxygen balance in the water is not yet is optimal. We have to wait a few more years before it is really full of fish here.”
Fish cycle in Wieringermeer – NH Nieuws
Nevertheless, fish already know how to find the cycle. Fish swim into the area from the foreboezem, the adjacent canal that surrounds the south side of Wieringen. And out. “We know that because there are cameras in the large tube that connects the two waters. We see large common carp swimming. Roaches too, but especially the target species: stickleback and eel.”
Living between sea and ditches
The stickleback is born in the ditch and finds its way to the sea to continue living there. The eel swims in the opposite direction: “It is born at sea and, like glass eels, seeks the shelter of North Holland ditches. Once it is an adult, the eel wants to go back to the sea to reproduce. That the eel is doing so badly This is partly because there are very few places left where fish can swim from salt to freshwater and back again.
The Wieringen fish cycle promises to be a beautiful nature reserve. Nice for us, but vital for various types of fish.