Ecological Characteristics of Wetlands Receiving an Industrial Effluent

Abstract

The primary objectives of this study were to evaluate the ecological characteristics of wetland ecosystems that had developed in response to oil sands effluent relative to reference wetland ecosystems and, from such an evaluation, to assess whether these wetlands were viable systems capable of integrating into the northern Canadian landscape. A secondary objective was to evaluate the use of several ecologically relevant endpoints as indicators of an ecosystem response to a known anthropogenic stress, in this case, wetlands receiving oil sands effluent. To achieve this, a suite of endpoints were compared between effluent-impacted wetlands and nonimpacted reference wetlands. Endpoints for comparison included: (1) benthic macroinvertebrate community structure, (2) chironomid density and biomass, (3) the incidence of chironomid mentum deformities, (4) the mutagenetic potential of sediment-dwelling chironomids, (5) growth and photosynthetic rate for the aquatic plant Typha latifolia (cattail), and (6) fish acute lethality and stress response as measured by changes in blood chemistry (percentage hematocrit [%hct], percentage leucocrit [%lct], and differential white blood cell count). Wetlands receiving oil sands effluent supported a low-diversity benthic community, dominated primarily by the Chironomidae and cattail. There was no evidence of mentum deformities or mutagenicity in chironomids sampled from the oil-impacted wetlands. Cattails grown in oil sands effluent and sediment demonstrated increased photosynthetic rates; however, these increased rates did not translate into increased plant growth. In contrast to the benthic community and the cattail, indigenous fish were unable to survive in wetlands containing oil sands effluent. Fish displayed altered blood chemistry (elevated %hct, depressed %lct) and ultimately death when held beyond 14 d in the oil-impacted wetlands. Of the various ecological endpoints measured, the macroinvertebrate community and changes in fish blood chemistry were the most sensitive indicators of an anthropogenic stress, demonstrating distinct differences in response between impacted and reference wetlands. To ensure that these wetlands can safely integrate into the northern Canadian landscape, future studies need to focus on their impacts at higher trophic levels indigenous to the wetland.

Levels of polycyclic aromatic hydrocarbons and dibenzothiophenes in wetland sediments and aquatic insects in the oil sands area of Northeastern Alberta, Canada

“…Consolidated tailings water is tailings water to which calcium sulphate has been added to accelerate flocculation and settling of fine tails (Gurney et al 2005). NW has been described in other studies that have examined the effects of oil sands-process water on biota (Bendell-Young et al 2000;Smits et al 2000;Gurney et al 2005). HP is a small, emergent vegetationdominated wetland with little open water.…”

Nutrient status and retention in pristine and disturbed wetlands in Uganda: management implications

“…Wetlands exhibit different water quality status depending on the geological formation in the catchment and whether the inflow includes wastewater (Bendell-Young et al 2000). The low levels of electrical conductivity and nutrients (N&P) in Nabugabo wetland are indicators of poor or infertile soil in the catchment (Kateyo 2006).…”

Phytotoxicity of oil sands naphthenic acids and dissipation from systems planted with emergent aquatic macrophytes

“…Naphthenic acids are of concern in tailings pond water because they can subsequently migrate into aquatic environments. [3,4] In addition to their water solubility and sorption to soils, NAs are also of toxicological concern in the environment because they have acute aquatic toxicity to a variety of aquatic organisms including fish. [5,6] Investigations of the factors driving the fate and phytotoxicity of NAs in plants have received little attention to date.…”