Fish
Chalk rivers in Hampshire support a variety of fish species including brown trout, Atlantic salmon, grayling, bullhead and lamprey.
Much of today's fly-fishing on chalk rivers is dependent on stocked trout. In the River Itchen, sea trout is supported by the chalk river system, and populations are found predominantly downstream of Bishopstoke. Brown trout are actively fished by game fishermen on the Rivers Test and Itchen and the reaches where this occurs are often managed by fishing clubs. They are often heavily stocked with this species to meet the demand of this type of angling. Stocking too many trout in a river may affect populations of wild trout and alter the balance of the fish community.
Atlantic salmon is widely distributed in the EU, and the UK salmon population comprises a significant proportion of the total European stock. Numbers of salmon in southern chalk rivers declined in the late 1980s and since then, stocks have remained stable, but still below their conservation target. From November to December they can be found spawning in the River Itchen just below Winchester and along some sections of the Lower Test.
Bullhead is a species of national and international importance. They are a good indicator to the health of a river as they will not occur in badly polluted watercourses. Bullhead is found in high densities in the Itchen catchment, throughout many of the channels and along most of their lengths.
