Alternatives to Catchment Liming

Direct liming of acid waters to prevent fish mortalities has been practised for several decades in hatcheries and other waters (Jensen and Snekvik, 1972) and is more commonplace than catchment liming. The scientific basis of direct water liming is well established in the literature, whilst relatively little scientific investigation of catchment liming had been reported prior to the start of the Loch Fleet project in 1984. For this reason, a major objective of the Loch Fleet project was to advance the science of catchment liming and only where alternative forms of treatment could complement catchment liming were they considered as part of an integrated strategy. In particular, the possible role of direct lime dosing or in-stream treatment targeted to spawning streams to provide a higher degree of protection for the early life-stages of salmonids was investigated.