This design is intended to create replicated systems to test the effectiveness of the designed measures against the invasion and establishment of the red crayfish (Procambarus clarkii). One of the pond systems is surrounded by a mesh with 4 cm of mesh-size, while the other has not a barrier around it. Our hypothesis is that the mesh is permeable for amphibians but the red crayfish will not be able to pass through it.

Once the amphibians are inside the fenced system, two ramps that overpass the mesh facilitates the access to the “outside world” if they have grown far too much to walt out through the fence.