Development of aquatic communities in aggregate ponds in southern Ontario
Extraction of aggregates (sand and gravel, limestone) below the water table results in the creation of pit and quarry ponds. Under the Aggregate Resources Act of Ontario (ARA), rehabilitation plans are required to obtain an aggregate extraction license. During this study I surveyed 12 pits and 3 quarries, ranging from 0-25 years old, for morphometric, chemical, physical and biological features to determine the effect of pond age and pond volume on succession of aquatic communities, and the potential of aggregate ponds for use as fish habitat. The results show that of the parameters studied, organic periphyton biomass and macrophyte biomass and species richness are significantly correlated to pond age. Macrophyte biomass was the only parameter significantly correlated to pond volume. The data indicate that colonization by benthic macroinvertebrates and zooplankton occurs quickly after extraction ceases. Abundance, species richness, and diversity of benthic macroinvertebrates, macrophytes and zooplankton in young ponds (<1 year old) was similar to that of older ponds (10 to 25 years old). Results show that aggregate ponds do provide a productive biological environment, which could be exploited for a variety of active or passive after-use activities, such as sport fisheries or conservation related activities that fit into the surrounding land use.