Space for fish
Healthy fish stocks, with many different species, are a feature of clean and healthy water. Healthy fish stocks are achieved when fish are able to migrate freely. We are working hard to achieve this.
Healthy fish stocks
For fish stocks to thrive, fish must be able to swim freely through canals, ditches, ponds, and streams. This is because fish migrate to different habitats during their lifetime. For example, deep water that does not freeze in winter, or shallow ponds that warm up quickly in summer. Some species, for example eels and three-spined sticklebacks, spend part of their lives in the sea and part in freshwater.
Free and safe migration are the most important points
Is the connection between different habitats blocked? If so, many fish species will not be able to survive. This will lead to a decline in water quality. That is why the free migration of fish is an important issue. We have been working to improve fish migration since the late 1980s. We are looking at these two points:
Free migration of fish
Fish can migrate freely from the Wadden Sea to our streams, ditches, and canals because we connect these waters. There are bottlenecks between the different waters, such as pumping stations or weirs. This creates migration routes for fish. This is particularly beneficial for the following fish: ide, dace, minnow, eel, river lamprey, twait shad, smelt, three-spined stickleback, and pike.
Safe fish migration
Some bottlenecks are not located on a migration route. In these places, our goal is to ensure that fish can live there safely. We want to prevent fish from injuring themselves or dying by using fish-friendly solutions. We use the best available methods and technologies. If we are about to renovate or replace a pumping station, lock, culvert, or weir, we assess the use and necessity of fish-friendly solutions. When we build new locks, culverts, pumping stations, or weirs, we make sure they are as fish-friendly as possible.
Solution to bottlenecks for fish
There were 85 bottlenecks for fish in the area. The vast majority have been resolved. We will tackle the last part before 2027. At the beginning of 2021, we still have just under 20 bottlenecks to resolve.
Fish lift in the Otter Valley
The fish lift enables fish migration
Next to the Dijken pumping station at the Matsloot there is the Vislift Up. Sometimes there is an obstacle between two bodies of water. This prevents fish from migrating from one body of water to another. This is the case between the water in the Matsloot and the water in the Otter valey. The fish lift makes fish migration possible.
If you would like to to know more about the fish lift, please visit the fish lift website:
Otter valley pumping station - Fish lift UP!
How does the fish lift work?
In their search for a suitable habitat, fish orient themselves on the direction of the current, for example. Fish are attracted by the current from the pumping station but cannot continue beyond it. The fish passage next to the pumping station attracts the fish with a lure current, which they can swim against. The lure current lures them into a "waiting room" and after a while they are sluiced further into the Otter Valley. Fish can also leave the Otter Valley in a similar way via the fish passage.
Collaboration
Ruim Baan voor Vissen (Make Way for Fish)
The four northern water authorities are working together to promote fish migration, giving fish all the space they need.
More information ruimbaanvoorvissen (make way for fish).nl
Vissen voor Verbinding (Fish for Connection)
Vissen voor Verbinding (Fish for Connection) is a project that aims to create a better connection so migratory fish can migrate between the Wadden Sea, lake Lauwersmeer, and the waters behind it. It is a broad collaboration between managers, governments, and nature conservation organisations.
More information Vissen voor verbinding (Fish for Connection).nl