Arrow Lakes Nutrient Restoration

To address the nutrient losses in Arrow Lakes Reservoir as a result of the construction of the Hugh Keenleyside, Mica and Revelstoke dams, a bottom-up approach was taken with the addition of nutrients (nitrogen and phosphorus in the form of liquid agricultural grade fertilizer). These additions increase phytoplankton populations that are suitable for the production of Daphnia, a main food source for Kokanee. Nutrients have been added to Upper Arrow Lake since 1999 and this year, will be dispensed from the Shelter Bay-Galena Bay Ferry (operated by Waterbridge Ferries) from the end of April through mid-September.

Arrow Lakes Power Corporation contributes 25 per cent of the costs to this project to compensate for fish entrainment through Arrow Lakes Generating Station. The program replaces nutrients lost as a result of upstream impoundments. The target is to maintain sufficient abundance of Kokanee as forage fish to meet targets for large piscivores through the continued application of appropriate quantities of nutrients. Output targets for Kokanee are between the lower acceptable threshold for spawners of 13/ha or 371,000 total, to the upper threshold of 20/ha or 584,000 in total. The average size of Kokanee spawners is targeted as 24 centimetres.