Effects of ammonia on periphytic communities.
Environ Pollut
; 66(3): 207-21, 1990.
Article
em En
| MEDLINE
| ID: mdl-15092235
ABSTRACT
Laboratory tests were conducted to evaluate the chronic effects of ammonia on periphytic communities. Species richness of the protozoan component of these communities was affected at un-ionized ammonia concentrations of = 0.01 mg NH3 litre(-1). A biologically important concentration was defined as the concentration of ammonia affecting 20% of species and was estimated from a concentration-response regression as 0.011 mg litre(-1). A comparable value based on literature reports of chronic toxicity to fish and invertebrates was 0.0126 mg litre(-1). Other non-taxonomic responses were equally sensitive to ammonia. Biomass (ash-free dry weight) and algal biomass (in vivo fluorescence) were significantly reduced even at the lowest tested ammonia treatment, 0.01 mg litre(-1), but the abundance of bacteria was reduced only in the highest treatment group, 0.43 mg litre(-1). Net community metabolism was reduced in all ammonia treatments. Periphyton communities were affected at levels below the USEPA chronic criterion of 0.027 mg litre(-1) (temperature = 8.8 degrees C and pH = 8.1). Successional maturity or age of the periphytic community affected the amount of biomass and algal biomass, but did not modify sensitivity to ammonia.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Ano de publicação:
1990
Tipo de documento:
Article