Periphyton communities in a pristine mountain stream above and below heavy metal mining operations

Abstract

1. Changes in species composition of the periphyton on introduced substrates were determined in an oiigotrophic mountain stream subject to long-term heavy metal contamination.2. At the upstream control site, the numerically most abundant taxa were Bacillariophyta {Achnanthes minutissima, Achnanthes microcephala and Achnanthes linearis) as well as, in summer, the Chlorophyta (Mougeotia spp. and Ulothrix subtilissima).3. At the downstream contaminated site the periphyton community was totally dominated by Bacillariophyta throughout the sampling period. A. minutissima and A. microcephala were co-dominants during spring. Seasonal succession patterns did not parallel those at the upstream site. Chlorophyta were virtually absent and A. minutissima comprised 94% of the community during summer.4. Species diversity, species evenness and dissimilarity index were utilized to delect differences in species composition, abundance and number. Slight differences were found in spring samples while summer samples indicated major differences between sampling sites.

Diatoms in river water-monitoring studies

“…(1) Direct sampling of one of the above communities, the favourite being the epilithon (Sherman & Phinney, 1971;Lange-Bertalot, 1978;Descy, 1979;Rushforth et al, 1986;Leclercq & Manquet, 1987;Sabater & Sabater, 1988;Watanabe et al, 1988. (2) Sampling of artificial substrata placed in the water, the favourite being glass slides (Geitler, 1927;Butcher, 1932;Cattaneo et al, 1975;Deniseger et al, 1986;Patrick, 1949), but plastic (Besch et al, 1972;Antoine & Benson-Evans, 1985;Engelberg, 1987), wood, stones, slices of rock (Antoine & Benson-Evans, 1984;Lay & Ward, 1987) have been used to a lesser degree. For some purposes counting has been abandoned and chlorophyll a has been used to assess biomass; also a few studies have used uptake of 1 4 C (Keithan & Lowe, 1985).…”

Induced Metal Tolerance in Microbenthic Communities from Three Lowland Rivers with Different Metal Loads

“…Genter et al (1987) and Colwell et al (1989) applied artificial streams to demonstrate that long-term zinc treatments as low as 0.76 µM changed the structure of microbenthic algal communities. Furthermore, field surveys proved the shift of algal assemblages provoked by metal pollution in rivers (Foster 1982a;Deniseger et al 1986). None of these changes toward metal-adapted organisms could be detected by measuring algal photosynthesis in the present short-term test.…”

Seasonal changes in species composition and production of periphyton in an urban river running through an abandoned copper mining region.

“…The influence of a metal on epilithic algal communities in natural streams has been investigated mainly in mountain oligotrophic ones (WEHER and MCFARLAND, 1981 ;FOSTER, 1982 ;LELAND andCARTER, 1984, 1985 ;DENISEGER et al, 1986 ;YASUNO and FUKUSHIMA, 1987). However, there are few studies in urban rivers where nutrient concentrations are high.…”