Contamination and wildlife communities in stormwater detention ponds in Guelph and the Greater Toronto area, Ontario, 1997 and 1998. Part I - Wildlife communities

There is very little information about the wildlife utilization of stormwater detention ponds although such ponds often self-seed into wetland habitats. To inventory wildlife utilizing stormwater ponds, a study was performed in 1997 and 1998 of 15 stormwater ponds and one natural wetland varying in age from 3 to 22 years in the Guelph and the Greater Toronto Area (GTA) in Ontario, Canada. Seven of the stormwater ponds were primarily open water with the aquatic vegetation accounting for less than 50% of the surface area. However, 90% of the surface area of four ponds was covered in aquatic vegetation. The surface area of those ponds covered with vegetation was positively correlated with total organic carbon and copper concentrations in sediment Invertebrate populations in the stormwater ponds were often dominated by a single taxon. The most abundant benthic animals were tubificid worms or chironomidae. The number of taxa in sweep-net samples ranged from 4 to 25 and correlated positively with the age of the pond and total organic carbon in sediment The number of taxa in the benthos correlated negatively with oil and grease concentrations in sediment. The range in number of amphibian species was one to seven in Guelph and zero to four in the GTA. In total, 40 species of birds were observed in the GTA ponds and 71 species were observed in the Guelph ponds during April to November 1997. A mean of 1.6 to 1.7 bird species was observed per survey at stormwater ponds in Guelph and the GTA. The number of species of amphibians and birds did not correlate with water quality, sedimentology, contaminant concentration, percentage of surface area of the pond covered with plants, or any benthic community parameter measured. Four species of reptiles and eight species of mammals were noted at or adjacent to the stormwater ponds and six species of fish were found in the ponds. We concluded that wildlife made use of the ponds, but species richness at almost all sites was low to moderate, indicating that the ponds did not provide high quality habitat for wildlife.