IMPACT OF WATERSHED URBANIZATION ON STREAM INSECT COMMUNITIES¹

Abstract

The impact of urbanization on stream insect communities was determined by sampling 22 sites in northern Virginia representing a range of human population densities. Watershed development had little effect on the total insect numbers (no./m2), but shifted the taxonomic composition markedly. Relative abundance of Diptera (mainly chironomids) increased at more highly urbanized sites, while most other insect orders including Ephemeroptera (mayflies), Coleoptera (bettles), Megaloptera (dobsonflies), and Plecoptera (stone‐flies) decreased. Trichoptera (caddisfiles) exhibited a variable response. Genus diversity and richness (number of genera) were significantly higher in less urbanized streams. Two genera of chironomids were positively correlated with increased urbanization, while 14 other genera (scattered through several orders) were negatively related to human population density. Principal components analysis demonstrated a gradient from more urbanized to less urbanized stations based on generic and order level biological data. Results of this study indicate that watershed urbanization has a major impact on benthic insect communities even in the absence of point source discharges.

Effects of urbanization on stream quality at selected sites in the seacoast region in New Hampshire, 2001-03

“…These correlations indicate that the macroinvertebrate community may be affected by the percent and type of vegetation near the sampling site and that these data appear to discriminate urbanization effects on stream quality at sampled sites in this study. These results are in agreement with those of previous studies (Coles and others, 2004;Jones and Clark, 1987;Lenat and Crawford, 1994).…”

“…Although the exact point at which stream quality and macroinvertebrate communities shift from good to poor is not known with precision, increased urbanization within a watershed does result in degraded water quality and a less diverse macroinvertebrate community (Schueler, 1994;Jones and Clark, 1987).…”

Diet and trophic guilds of fish assemblages in two streams with different anthropic impacts in the northwest of Paraná, Brazil

“…Impacted streams present fewer trophic guilds, with species being more opportunistic and generalist and more flexible in their foraging (POFF & ALLAN 1995, ROY et al 2006. This was mainly caused by a decrease in the abundance of invertebrates due to the instability of urban aquatic environments (JONES & CLARK 1987). Some studies addressing urban streams have detected the presence of trophic groups such as omnivores and detritivores , ALEXANDRE et al 2010.…”

Evaluation of spatial-temporal variations and trends in surface water quality across a rural-suburban-urban interface

“…Water pollution occurs worldwide as a result of anthropogenic activities, including unprecedented population growth, urbanization, industrialization, and agricultural practices (Jones and Clark 1987;Baker 2003;Claessens et al 2006;Li et al 2009b). Human disturbance on water quality occurs at the watershed scale due to changes in land use/land cover, which impact the physical, chemical, and ecological characteristics of aquatic environments (Donohue et al 2006;Chang 2007).…”