Effects of zinc on the phosphorus availability to periphyton communities from the river Göta Älv
2002; Elsevier BV; Volume: 56; Issue: 2 Linguagem: Inglês
10.1016/s0166-445x(01)00189-8
ISSN1879-1514
Autores Tópico(s)Aquatic Ecosystems and Phytoplankton Dynamics
ResumoIt has been hypothesised that zinc additions in the phosphorus limited (12-15 microg l(-1)) River Göta Alv leads to an interaction between zinc and phosphate which causes a decreased availability of phosphate and a concomitant decrease in biomass production in the Göta Alv periphyton communities 'Aquat. Tox. 47 (2000) 243'. To test the hypothesis the experiment by Paulsson et al. 'Aquat. Tox. 47 (2000) 243' was repeated, now with focus on phosphorus status of the periphyton. Additional indicators of phosphorus deficiency, e.g. alkaline phosphatase activity (APA), surplus and total phosphorus, intracellular acid phosphatase activity, and nitrogen and carbon were measured in the communities. APA increased and surplus phosphorus decreased at about the same zinc exposure concentration as the dry weight started to decrease (> 0.1 microM), thus supporting the hypothesis of a zinc-induced phosphorus deficiency. Nitrogen and carbon concentrations in the biofilm also decreased with increasing zinc exposure, suggesting an influence on metabolism of these elements as well. It can be concluded that zinc might be an environmental hazard in phosphorus-limited environments at concentrations above 0.1-0.2 microM of total zinc.
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