Field validation of the 'Logie' fish counter at Forge weir on the River Lune, 1992

The stock assessment task group report (1991) mentions that fish counters could play a key role in providing data on the size of the adult stock, and in particular the migratory salmonid stock. This report assesses the performance of the 'logie' fish counter at Forge Weir on the River Lune. Using video surveillance, a total of 1137 hours time lapse and 15 hours real time were used for validation purposes. This report looks at materials and methods, counting accuracy, sizing ability and environmental conditions, performance across the electrode array and salmonid swimming speed.

Biological report - fish mortality, River Conder, 21.7.79

Following a large scale fish mortality caused by a considerable spillage of a pentachlbrophenol-based disinfectant from a mushroom farm, a biological survey of the river Conder was undertaken on 23.7.79. A spillage of this same make of disinfectant from this mushroom farm in February 1976 caused a similar large scale fish mortality. On that occasion, the pollution appeared to have little effect on the benthic invertebrates of the river Conder, with no dead organisms found, although the small beck which received the spillage was quite badly affected. This recent spillage of disinfectant involved a considerably greater volume (approximately 900 gallons) than the 1976 discharge and so this report looks at whether invertebrate fauna of the main river were affected on this occasion. Kick samples were taken at a number of sites in the river Conder from the confluence with the polluted beck to Conder Green. A control sample was also taken upstream of the confluence with the polluted beck. All samples were examined on site and live and dead invertebrates noted and identified as accurately as possible.