FACTORS INFLUENCING THE DOWNSTREAM TRANSPORT OF SEDIMENT IN THE LOUGH FEEAGH CATCHMENT, BURRISHOOLE, CO. MAYO, IRELAND

A fundamental requirement of salmonid fish is an abundant supply of cool, clear and well-oxygenated water. High levels of suspended silt in streams have a negative impact on salmonids at all stages of their lifecyle. Silt deposits in spawning beds have a negative impact by reducing the flow of water, and therefore of oxygen also, around incubating eggs (Bruton 1985). The fry and adult stages are impacted by the clogging of gills and lower light penetration which affects food production and also reduces the ability of fish to forage for food (Alabaster 1972). An understanding of the factors that give rise to high silt loads in salmonid-bearing waters is therefore of fundamental importance.