THE FISH COMMUNITY OF LOCH-LOMOND, SCOTLAND - ITS HISTORY AND RAPIDLY CHANGING STATUS

The fish community of Loch Lomond is of national importance. Its diversity of species and rare populations of powan (Coregonus lavaretus) and freshwater feeding river lampreys (Lampetra fluviatilis) warrant high conservation status. It is also of value for its sport fisheries for sea-trout (Salmo trutta), salmon (Salmo salar) and pike (Esox lucius). Historical records demonstrate that the species composition of the fish community has remained stable over a very long period until recently when a series of introductions of fish species new to the catchment has resulted in successful colonisation by a number of species. These have resulted in fundamental changes in the ecosystem. Here using historical records the long-term stability of the fish community is examined, recent rapid changes in the fish community are documented and some of the resultant effects of changes in the fish community are demonstrated.