Urban stormwater ponds are designed to reduce localized flooding and erosion, but there is a growing interest in their potential additional benefits for biodiversity. Similar to aquatic ecosystems outside the urban setting, water chemistry of stormwater ponds is strongly influenced by factors surrounding the catchment basin. However certain chemicals, such as chloride, have a more prominent effect on these water bodies, due to city maintenance activities such as salting roads during the winter. As a result, research is needed to better understand biodiversity responses to water chemistry in city environments. In this project, I will determine whether certain chemicals, specifically chloride, will affect the abundance of aquatic invertebrates in stormwater ponds. 

Water samples were collected from 35 stormwater ponds in the Edmonton area, and at 5 of those ponds a dip-net sample was collected to obtain aquatic invertebrate data. Each dip-net sample was then sorted, identified to the order level, and enumerated.

Upon analysis I found that water quality guidelines for chloride could not be used to determine the overall invertebrate abundance of each pond, as there was no significant relationship between chloride levels and overall number of individuals, as the p-values were greater than an alpha level of 0.05. While there seemed to be a visual relationship between chloride levels and the abundance of individual invertebrates, with some having a negative relationship with chloride levels and others having a positive relationship, p-values for each invertebrate order were all greater than an alpha level of 0.05. This is likely due to the low number of ponds sampled for invertebrates. Overall further sampling effort and research is needed to determine whether or not water chemistry has a significant effect on the abundance distribution of observed orders of aquatic invertebrates in urban stormwater ponds, and whether these results can be applied to current Canadian Environmental Quality Guidlines to determine if certain aquatic invertebrate Orders could be indicators for these water quality thresholds.