Relationships among ciliated protozoa and water chemistry in small peat-bog reservoirs (Łęczna-Włodawa Lakeland, Eastern Poland)

The aims of this study were to identify the taxonomic and trophic diversity of planktonic ciliate communities occurring in small peat-bog reservoirs of various acidities (from about 3 to 6), and to assess the effects of chemical factors on them. Generally the highest numbers of ciliate taxa were recorded in high pH (>6) reservoirs, and the lowest in low pH (3.28-4.6) reservoirs. The mean numbers of planktonic ciliates in the high pH reservoirs were about three times higher than in the low pH reservoirs. However, the greatest biomass of ciliates occurred in low pH reservoirs.

The results suggest that pH, conductivity and total organic carbon (TOC) are more important than total phosphorus (P_tot) in the distribution of planktonic ciliates in peat-bog reservoirs. In the low pH peat-bog reservoirs, the biggest factor affecting ciliate distribution is the pH of the water, whilst in the higher pH reservoirs the role of organic matter becomes increasingly important with increasing pH.