Comparative sensitivity of Scenedesmus acutus and Chlorella pyrenoidosa as sentinel organisms for aquatic ecotoxicity assessment: Studies on a highly polluted urban river

Abstract

ABSTRACT:The effects of spatial and temporal differences on the water quality of the urban contami-( ) nated Reconquista River Argentina were evaluated by means of bioassays based on the growth of two ( ) algal populations Chlorella pyrenoidosa and Scenedesmus acutus . The effects produced by the addition of cadmium and/ or nutrient salts to the samples were also assayed. Noticeable differences in algal biomass were detected among samples from different sites, the highest values corresponding to the most polluted zones. The toxic effect of cadmium was more pronounced in S. acutus than in C. pyrenoidosa, particularly in the least polluted waters. The addition of nutrient salts to the culture medium attenuated heavy metal toxicity, mainly to C. pyrenoidosa, and also revealed nutrient limitation to algal growth in certain sites and dates. Site classifications based both on algal bioassays and on physical and chemical variables showed good agreement. ᮊ

Vegetated roofs for stormwater management at multiple spatial scales

“…These effects are a function of increased stormwater runoff volumes across a watershed due to the efficient routing of stormwater off impervious surfaces and into a storm sewer system that ultimately discharges into a receiving water body. These elevated volumes impact stream ecosystems through amplified flow rates which increase bed and bank erosion (Wolman, 1967), increased frequency of disturbance (Booth and Jackson, 1997), rapid and efficient pollutant transport (Olguin et al, 2000;Sutherland et al, 2002) and an increase in nuisance flooding in urban watersheds (Niezgoda and Johnson, 2005). Cumulatively, the effects of impervious surfaces found in urban areas have recently been called the "urban stream syndrome" (Walsh et al, 2005b).…”

Assessing and Restoring the Health of Urban Streams in the Puget Sound Basin

“…By 1972 over 200,000 miles of streams and rivers in the United States had been channelized ( Riley 1998), and in many cities most streams are now in culverts ( Finkenbine et al 2000). Urbanization alters stream biotas in numerous ways: local extinction of anadromous fishes ( Limburg & Schmidt 1990), increased dominance by pollution‐tolerant invertebrates ( Rossano 1996), and frequent algal blooms (Olguin et al 2000).…”

National-level integrative ecological health assessments based on the index of biological integrity, water quality, and qualitative habitat evaluation index, in Korean rivers

“…Lotic ecosystems have been subject to both chemical and habitat degradation (Lee, 2001;Kwon and An, 2006;Lee and An, 2007;Lee and An, 2010). Across the world similar environmental degradation has been associated with reduced species diversity of phytoplankton, zooplankton, macroinvertebrates, and fishes (Karr et al, 1985a(Karr et al, , 1985b, increased dominance of pollution-tolerant fish, frequent algal blooms (Olguin et al, 2000), extinction of sensitive species and endemic species (Karr et al, 1985a, Limburg andSchmidt, 1990), and overall decreased ecological health of the aquatic ecosystems (Karr et al, 1985a(Karr et al, , 1985bMorley and Karr, 2002).…”