A simple, community level, ecotoxicological test system using samples of periphyton

Abstract

The design and performance of a simple, community level ecotoxicological testsystem is reported. Samples of periphyton communities, established on artificial substratum in natural streams were used to study effects on photosynthetic activity in short-term experiments. Photosynthesis was measured as light-dependent oxygen evolution or as 14C02-incorporation. The variability in photosynthetic activity between samples collected at the same time, expressed as coefficient of variation, was ca 20%. The variation in sensitivity of periphyton photosynthesis as dependent on sampling season was less than threefold for the two long-chained aliphatic amines and the textile industry effluent studied. Effects of the amines on periphyton from five different streams were also investigated. The ratio between maximum and minimum values of sensitivity was 5.6. It is concluded that the variation in sensitivity between different periphyton communities is similar to or less than that observed for fresh-water algal species. Some advantages with regard to ecological realism of using periphyton communities as test systems are discussed.

Use of sand-living microalgal communities (epipsammon) in ecotoxicological testing

“…7), the influence of organic matter must be indirect or active only on a longer time scale than hours. The variability within each sampling occasion (0.6 to 0.7 orders of magnitude) was similar to findings of temporal and spatial variability in the sensitivity of periphyton and phytoplankton sensitivity to chemicals (Table 2; Blanck 1985, Kusk & Nyholm 1991. Variability in the estimated toxicity of chemicals is thus not a n exclusive property of the epipsammon test system.…”

“…These doubts have led to the development of more or less complex multispecies test systems, using natural or artificial assemblages of algal species in the laboratory or in the field (see reviews by Cairns & Cherry 1993, Lewis 199513). Both phytoplankton (Lewis & Hamm 1986, Kusk & Nyholm 1991 and periphyton (Blanck 1985) communities have been used in short-term toxicity tests, but the epipsammon seems so far to have been overlooked.…”

Pollution‐induced community tolerance as a measure of species interaction in toxicity assessment

“…Two consecutive long‐term experiments over a period of 11 weeks and 12 weeks were conducted between January to June 2006. Periphyton, obtained from the Mulde river (contributor to the Elbe river, Germany), was grown on 1·5 cm 2 glass discs that were arranged in plexiglass racks according to Blanck (1985). The light regime was a 14 h/10 h light/dark cycle using neon lamps (36 W/21–840; intensities above the water surface 200 µ m photons m −2 s −1 ).…”

Exploring aquatic ecosystem health: a multi-trophic and an ecosystemic approach

“…structure and function) make data interpretation difficult in community-level toxicity tests (Crossey & LaPoint, 1988;Henebry & Ross, 1988). It is therefore important for a communitylevel test to be simple and rapid enough to be used in routine toxicity testing (Blanck, 1985).…”

“…Impacts on competition and resource partitioning may be elucidated, but not processes such as predation, symbiosis, and biomagnification . Structural measures such as periphyton community structure and biomass (Blanck, 1985), plankton size structure Sprules & Munawar, 1986), fish tumours and abnormalities (Smith et al, 1988), and contaminant body burdens (Mac, 1988) have been used to monitor contaminant effects on indigenous communities. In addition, functional measures such as size-fractionated primary productivity (Munawar et al, , 1987c, microbial enzyme activity (Burton & Lanza, 1985), and zooplankton filtration rates (Ross & Munawar, 1987) have been used to examine the relative health of the aquatic ecosystem.…”