Salinization alters ecosystem structure in urban stormwater detention ponds

Abstract

Stormwater ponds now comprise a significant portion of standing water in urban areas. These ponds act to sequester excess run-off and pollutants, such as road salt deicers. While these man-made ponds are not intended to serve as freshwater ecosystems, it is becoming clear that they do provide habitat for many organisms, but we know little of their ecosystem structure, function and interactions with pollutants. From April through June 2009, we surveyed 8 stormwater ponds in the Red Run Watershed, Baltimore County, Maryland, USA to describe patterns in aquatic food webs associated with a gradient in road salt inputs. Periphyton, phytoplankton and zooplankton samples were collected from each pond every 4-6 weeks. Specific conductance, a measure of chloride salt loading, among the 8 ponds varied widely throughout the survey, ranging from 99 μS cm −1 to 19,320 μS cm −1 . Low (average=404 +/− 82.6 (SE) μS cm −1 ) and medium (average=1749 +/− 267 (SE) μS cm −1 ) conductance ponds had lower algal biomass and higher densities of zooplankton taxa relative to high (average= 7231 +/− 2143 (SE) μS cm −1 ) conductance ponds, which were largely devoid of all zooplankton through the end of May. The observed decline in zooplankton density along an increasing chloride gradient is consistent with experimental results of road deicer effects, suggesting algal resources are possibly freed from grazing pressure as zooplankton consumers are negatively impacted by road salt exposure. Our results highlight the potential for both direct and indirect effects of road deicers on freshwater communities.

Stability in Planktonic Rotifer Assemblages Found in Four Old Diversified Forest Ponds of Eastern Poland

“…2). A similarly low density of planktonic rotifers was recorded in other reservoirs of this type [14][15][16]. In the majority of other ponds, however, higher or much higher rotifer density was observed by the authors [12,[17][18].…”

Assessing habitat requirements of pond-breeding amphibians in a highly urbanized landscape: implications for management

“…Stormwater ponds in urban areas are built to collect, filter and treat high concentrations of metals, oils, and road salts and these contaminants may have negative impacts on wildlife using the ponds (Gallagher et al 2011(Gallagher et al , 2014Hatch and Blaustein 2003;Van Meter et al 2011;Le Viol et al 2012). While this study did not explore questions related to water chemistry, the urban nature of our sites suggests some level of toxins are likely present.…”

Linking management to biodiversity in built ponds using metacommunity simulations

“…3 and S3, Table 4). These patterns suggest unmanaged ponds drain catchments with greater and more variable impervious surface cover, which creates a less predictable and more stressful local habitat for zooplankton (Kaushal et al, 2005;Van Meter et al, 2011). Therefore, relative to unmanaged ponds, managed ponds represent a more homogenous habitat with the potential for biotic homogenization via nichebased species sorting dynamics.…”