Acidification and the structure of crustacean zooplankton in mountain lakes: The Tatra Mountains (Slovakia, Poland)

Abstract

Species composition of planktonic Crustacea in 102 lakes in the West and High Tatra Mountains, studied during the peak of anthropogenic acidification (1978)(1979)(1980)(1981)(1982)(1983)(1984)(1985)(1986)(1987)(1988)(1989)(1990)(1991)(1992)(1993)(1994)(1995)(1996), is presented in this work. Zooplankton of the Tatra lakes have been studied since the middle of the 19 th century, which later enabled the recognition of lake acidification and the assessment of its effect on the plankton community of lake ecosystems. In the pre-acidification period, the distribution of zooplankton was determined namely by the lake altitude and orientation (north vs. south) and by the catchment character. Crustacean zooplankton in larger lakes consisted of a limited number of species, with Acanthodiaptomus denticornis and Daphnia longispina dominating lakes in the forest zone, and Arctodiaptomus alpinus, Cyclops abyssorum, Daphnia longispina, Daphnia pulicaria, and Holopedium gibberum dominating lakes in the alpine zone. Ceriodaphnia quadrangula, Daphnia obtusa, Daphnia pulex, and Mixodiaptomus tatricus occurred in lakes with high concentrations of dissolved organic matter and in strongly acidified waters. Anthropogenic acidification has caused drastic changes in both the chemistry and biology of the Tatra lakes. Based on their status during the acidification peak, lakes were divided into three categories: non-acidified (with no change in the species composition of crustacean zooplankton due to the acidification), acidified (planktonic Crustacea disappeared in lakes with meadow-rocky catchments), and strongly acidified lakes where original Crustacea in meadow-rocky catchment lakes disappeared and were replaced by populations of the acid-tolerant littoral speciesAcanthocyclops vernalis, Chydorus sphaericus, and Eucyclops serrulatus. The acidification-induced processes of oligotrophication and toxicity of aluminium played a key role in the extinction of species. Despite the first signs of biological recovery observed in the early 2000s, acidification remains the most important factor governing the structure of plankton in the Tatra lakes.

Long-term change of the littoral Cladocera in the Tatra Mountain lakes through a major acidification event

“…This is in contrast to the pelagic community in non-sensitive lakes, where taxa decreased their numbers but remained present (Hořická et al, 2006). A possible explanation lies in the character of the habitat of those two communities.…”

“…Another key factor, pH, was lowest in lakes with small areas and small catchments. Species inhabiting mountain lakes are typically adapted to low pH values and as shown for pelagic communities, tend to respond to nutrient content, rather than changing pH (Stuchlík et al, 1985;Fott et al, 1994;Hořická et al, 2006). In studied lakes, the least productive are acid sensitive (AS) lakes.…”

Zooplankton community composition of high mountain lakes in the Tatra Mts., the Alps in North Tyrol, and Scotland: relationship to pH, depth, organic carbon, and chlorophyll-a concentration

“…The three fishless lakes had not unique composition of zooplankton. In the Alps and the Tatra Mts., species composition of the fish populations was known at the sampling date (Hořická et al 2006;Tolotti et al 2006). Vulnerability to fish predation is dependent on fish density (Knapp et al 2005), but the density of fish population was not known.…”

Benthic macroinvertebrate fauna of two alpine lakes over the last century: The value of historical data for interpreting environmental changes

“…The biological recovery of communities following the reversal in water chemistry is now one of the main topics of limnological research in the Tatra lake district. Even though this process is delayed by hysteresis in the chemical reversal from acidification , the first indications of recovery for planktonic communities have been observed (Nedbalová et al 2006;Hořická et al 2006;Sacherová et al 2006). Changes in the benthic macroinvertebrate assemblages of the impacted lakes have mostly not been so clear, and need to be interpreted carefully in terms of recovery.…”