Spawning Enhancement

Fishtrack are experienced in fish spawning habitat assessment, habitat creation and mitigation. We have assessed cyprinids and esocids in various locations within the UK, such as northern pike spawning habitat assessment for Natural England and creating mathematical models for cyprinid habitat suitability indices for the Broads Authority for use in the Broads National Park.

The paucity of spawning habitats is an issue for species that have very specific spawning habitat requirements, and where sub-optimal habitat leads to increased egg and fry mortality, or failure of spawning success. Lack of habitat can be addressed by the use of artificial substrates and creation of new habitats, and also facilitated by enhancement of natural spawning substrates. Compaction of gravels that lead to loss of oxygen flow through the gravel substrate, which adversely affects the invertebrate communities and impacts on fish spawning opportunities and egg survival, can be rectified using various methods, including gravel jetting.

Diffuse pollution (below left) chokes gravels and spoils spawning substrate for many rheophilic species, such as chub, dace, barbel as well as salmonids. Cleaning gravels using specialist equipment restores these spawning areas to enable fish to successfully spawn once more on them (below right)

Spawning pike, a female with two males in attendance. The end result of searching for spawning locations through suitable habitat assessment and deployment of our Pike Spawning Habitat Suitability Index, a mathematical model predicting suitable habitat which is based upon various ecological and environmental criteria. Output is via GIS map based systems as above (top)