A stressed stream ecosystem: macroinvertebrate community integrity and microbial trophic response

Abstract

A year-long study of a second-order stream in Southwestern Virginia was carried out from 1979-80 . One of the objectives of the study was to evaluate the effects of sewage and electroplating plant effluent stress on the trophic response of aquatic invertebrate assemblages and microbial communities in the stream . Quantitative benthic samples were collected periodically at three reference stations and four stressed stations below the outfalls . Invertebrates were counted, identified taxonomically, and classified into functional groups based on their feeding strategies . Ash-free dry weights were obtained for each functional group by date and station, and the number and density of different taxa were calculated as well . Reference stations had diverse invertebrate assemblages ; scrapers were well represented and all functional groups were present in reasonably equivalent proportions . Stressed stations were dominated by collector gatherers and filterers to the virtual exclusion of scrapers . The trophic status of the microbial community was determined by suspending artificial substrates in the stream for 1-week periods . The community that colonized the substrates was assayed for ATP and chlorophyll a, and an autotrophy index (AI) was calculated using these values . The autotrophic component of the microbial community was greatest at the reference stations, and the community became primarily heterotrophic below the outfalls . The Al correlated well with the proportion of scrapers . Aquatic invertebrate assemblages and microbial communities responded to stress by changing their trophic structure to fit best the available energy sources . Where heterotrophic microbes dominated, gathering and filtering invertebrates utilized the abundant organic matter . In areas where a mainly autotrophic microbial community existed, scrapers, gatherers, and filterers were all present in balanced proportions .

Studies on the Evaluation of Biocenosis in Sewage Oxidation Ponds for Fish Culture

“…According to Wallace and Merritt (1980) some species of benthos were found in high number when algal productivity was maximum. The present findings are in conformity with the studies of Olive andDambach (1973), Brightman andFox (1976) and Kondratieff et al (1984) that benthic invertebrates were concentrated in areas in the streams and wetlands receiving organic waste. Dehghani et al (2007) also observed that sewage maturation ponds are appropriate for the growth and development of aquatic insects especially species of Diptera and Hemiptera.…”

The Role of Disturbance in Stream Ecology

“…These diverse demands on water resources, combined with forest management practices, place severe stresses on these streams. Major anthropogenic disturbances include: sewage and industrial effluents (e.g., Kondratieff et al 1984, Kondratieff and Simmons 1982, Tarter 1976; clearcut logging (Silsbee and Larson 1983, Tebo 1955, Webster et al 1983) and associated road-building (Lenat et al 1981); mining practices (Tarter 1976), which often result in acid drainage problems (Samuel et al 1978); dam construction; and potential susceptibility to acidic precipitation (Lynch and Dise 1985). In the southeastern Piedmont, major anthropogenic disturbances include: urbanization (Benke et al 1981); channelization; agriculture and grazing; logging, including associated road construction (Lenat et al 1975); and dam construction for hydroelectric generation, recreational use, and water storage.…”

Effects of sewage waste stabilization lagoon effluent on stream invertebrates

“…The magnitude and nature of the impact are expected to vary with distance from the discharge (Hynes, 1960;Kondratieff et al, 1984). For example, DO depletion effects will be greatest some distance downstream, whereas ammonia toxicity and particulate matter smothering effects will be maximal near the discharge.…”