Our actions to protect aquatic environments
Why Restore Nature
In this section, discover how the Maison wallonne de la pêche works to protect aquatic ecosystems in Wallonia. Faced with threats such as river alterations and habitat loss, we design tailor-made projects to recreate environments where fish can thrive.
With over 20 years of expertise, we have already carried out numerous projects that benefit aquatic biodiversity. Each initiative is carefully planned to provide solutions tailored to the specific needs of each site.
Habitat restoration
Vegetated Baskets
Description
Vegetated baskets consist of metal cages attached to the riverbank, filled with biodegradable coir fiber bundles that have been pre-planted with semi-aquatic vegetation. These baskets are submerged by about 15 centimeters to allow for optimal plant growth.
Purpose of the Installation
The aim of the vegetated baskets is to recreate a natural habitat for aquatic wildlife. Through their root systems, they provide spawning substrates as well as shelter and feeding areas for juvenile fish.
Vegetated Floating Islands
Description
Vegetated floating islands are buoyant structures designed to hold semi-aquatic plants. The entire assembly is anchored to the bottom using concrete ballast.
Purpose of the Installation
Similar to vegetated baskets, these floating islands aim to recreate a natural habitat for aquatic wildlife. Their root systems provide spawning supports, as well as shelter and feeding areas for juvenile fish.
Fixed or Floating Artificial Spawning Grounds
Description
Artificial spawning grounds consist of stainless steel frames fitted with slats that hold bundles of synthetic fibers. These structures can be installed vertically along the shoreline or positioned horizontally using buoys.
Purpose of the Installation
The primary purpose of artificial spawning grounds is to provide a substrate for egg-laying, serving as a substitute for aquatic vegetation.
Vegetated Berms
Description
These consist of coir or xylit fascines secured to riverbanks using specially designed metal stakes. The fascines are pre-planted with semi-aquatic vegetation. In some cases, flat rock armoring (riprap) is placed beneath the berm for additional support.
Purpose of the Installation
Primarily installed in river environments, this structure aims to compensate for habitat deficiencies in certain river sections. It can also serve as a spawning substrate for aquatic species.
Refuge Cages
Description
Refuge cages are structures made of welded mesh, typically square or rectangular in shape. The mesh openings measure 50 x 100 mm. A tarpaulin partially covers the top of the cage, creating a shaded area that attracts fish.
Purpose of the Installation
The purpose of these installations is to protect fish species from predation by piscivorous birds, particularly the Great Cormorant. They also serve as a refuge area for juvenile fish.
Vegetation of Shallow Water Zones
Description
Shallow water zones are areas of low depth where reed-like plants are established. These zones may be protected by a rock barrier to shield the vegetation from wave action caused by boat traffic.
Purpose of the Insallation
This development helps recreate a true aquatic ecosystem similar to a reed bed. The plants in these shallow areas provide spawning grounds as well as shelter and feeding zones for juvenile fish.
River Restoration
Reconnection of River Side Channels
Description
Over time, connections between the main river and its side channels tend to degrade and become blocked. This natural process is primarily caused by sediment deposits during flood events. The disappearance of these connections directly impacts the ability of spawning fish to access their breeding grounds, and also affects the ecological exchanges between the side channels and the main river.
Purpose of the Installation
Restoring these connections will improve access for spawning fish during reproduction periods and facilitate the downstream movement of juvenile fish. The new reconnections are designed to eliminate recurring blockage issues and ensure long-term functionality.
Creation of Fish Passes
Description
A fish pass is a structure installed in a watercourse that allows fish to bypass or ascend otherwise impassable obstacles such as dams. These structures can take various forms, including fish ladders, fish lifts, rough ramps, bypass channels, vertical slot passes, and more.
Purpose of the Installation
The goal is to enable fish to overcome barriers like dams, allowing them to move freely and maintain genetic and demographic diversity. This type of infrastructure also contributes to the overall ecological health of rivers.
Bank-Embedded Fish Shelters
Description
To create these shelters, logs are laid longitudinally into recesses carved into the riverbanks. The logs are secured in place using stakes. The entire structure is then covered with a geotextile mat, followed by a layer of soil that supports the growth of herbaceous plants or small shrubs.
Purpose of the Installation
The goal is to support the development and sustainability of local fish populations across all age classes by offering protection from predators (such as piscivorous birds). These shelters also provide refuge during floods and serve as ideal resting areas for fish.
Grain Size Replenishment
Description
This operation involves replenishing the riverbed with aggregates (boulders, stones, and gravel) of various sizes to restore its natural quality. It is typically applied to small watercourses. The aggregates used must be carefully selected: they should match the local geology and contribute to the river's natural dynamism.
Purpose of the Installation
This addition of natural substrate creates favorable conditions for the reproduction of salmonids and other fish species inhabiting our rivers. Grain size replenishment also significantly enhances the quality of in-stream habitats, particularly by diversifying flow patterns.
Alevibox
Description
The Alevibox is a device designed to incubate trout or salmon eggs directly within the riverbed. It consists of a structure that houses an incubation chamber, where fertilized eggs complete their development until hatching, and a growth chamber, where sac-fry continue to develop until the yolk sac is fully absorbed. At that stage, they are released into the natural environment. The system can incubate approximately 5,000 eggs.
Purpose of the Installation
The Alevibox system supports the development of brown trout populations by introducing young fry into the natural environment at an early stage. Exposed from the start to natural selective pressures, only the individuals best adapted to their environment will survive to adulthood.
Last update: September 11, 2025
