Phytoplankton of artificial ecosystems – an attempt to assess water quality
ABSTRACT. Phytoplankton changes in canals were described in light of communities in chosen lakes of the Konin lakes system, and links were identified between these changes and water quality assessments based on different biological indexes. Seasonal phytoplankton studies were performed in the Warta-Gopło (WG) and Konin Power Plant (EK) canals. 258 and 223 taxa from six divisions were identified that comprised a maximum biomass of 13.4 mg dm-3 in the EK canal and 9.3 mg dm-3 in the WG canal. The communities in the canals were co-dominated by diatoms, cryptomonads, and chlorophytes. Blooms of the cyanobacteria Microcystis aeruginosa and Aphanizomenon flos-aquae were only noted in the WG canal. The phytoplankton in the EK canal and Lake Ślesińskie were closely similar. Consistent water quality assessments were obtained with the saprobic system (moderately polluted and good quality), while the results of the algal genus pollution index indicated there was a high degree of pollution. Classifications using the Shannon-Weaver and indexes (IT) indicated the water quality in the EK canal was good, while in the WG canal the water had low levels of pollution and was at a poor ecological potential. Classification modifications based on the Shannon-Weaver index permit assessing canal water quality analogously to the saprobity index. Using these indexes is proposed as a phytoplankton-based alternative to multi-metric assessments of ecological status or potential in small rivers, streams, and canals. The possibility of performing comprehensive, five-degree classifications was confirmed, thus, permitting the recommendation of this method for water quality assessments.
Keywords: biomass, phytoplankton indexes, biological water quality, WFD, saprobity, the Konin lakes system