Evaluating the lake management approach, applied biomanipulation techniques and progress in restoring ecological function of littoral macrophytes in Grenadier Pond, Canada

Grenadier Pond, Canada, is a shallow, eutrophied, urban pond system. Pond managers employed biomanipulation techniques in an attempt to alleviate symptoms of eutrophication. Alternate stable state theory may provide an additional or alternate approach to nutrient reduction/abatement strategies. Biomanipulation techniques apply alternate stable state theory through: macrophyte-phytoplankton competition, piscivore/grazer predation pressures and mitigation of physical disturbances. Long-term success of biomanipulation in shallow systems has been linked to intermediate nutrient levels and well-established and relatively abundant macrophyte communities. An evaluation of the aquatic macrophyte regeneration project in Grenadier Pond did not yield the expected ecological functional relationships between sediment characteristics (total phosphorus, organic content, water content) and rooted-macrophyte density. Wave-wind action may be a main mechanism of nutrient redistribution in the littoral zone in Grenadier Pond. Newly planted macrophytes seem to provide some macrobenthic invertebrate habitat. Sediment chloride may be influencing macrophyte diversity in Grenadier Pond.