AQUENS offers a complete service to survey impacted rivers and to advise and supervise procedures to restore environmental conditions in order to optimise fish life and amenity value following activities such as mining and arterial drainage.
Three distinct sectors are recognised in rivers – riffles, glides and pools, each of which is characterised by water velocity and depth. Riffles are shallow and the presence of rocks and boulders breaking the surface waters gives a well aerated environment with optimal habitats to support invertebrate life – food for fish. Riffles are attractive habitats for fish less than one year old and as such may be nursery areas. Glides are generally knee deep and often support aquatic plants such as Ranunculus and associated macroinvertebtrates. Pools may be up to 10.0M in depth and more often provide refugia for adult fish.
Damage to riffle and glide ecosystems may occur through siltation from natural flood events or by human influence from urban, industrial or agricultural activities. AQUENS applies scientific principles to restore damaged river habitats. A range of bioengineering strategies may be used to strategically increase water flow to form riffle regions or increase the erosional resistance of river banks and prevent siltation by judicious placement of boulders and gabions. Such environmentally sensitive approaches ensures restoration of riffle-glide-pool sectors and enhances habitat availability for fish production and ecosystem sustainability. AQUENS has wide experience in fish habitat rehabilitation.