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

The Tatra Mountains are small range of mountains of alpine character which belong to the Carpathian chain. All components of Tatra nature have a unique character. Tatra lakes are valuable and special environments for hydrobionts. The geological and hydrological attributes as well as water chemistry determining the specificity of those lakes have been described. The uniqueness of life forms present there has been described with regard to epilithic algal, zooplankton, macrozoobenthos and fish communities. The main features determining the structure of Tatra lakes hydrobionts communities are lake altitude, catchment character, water temperature and ice cover period. The influence of anthropogenic activities such as water acidification is also important. Fish introduction to the originally fishless lakes or their natural presence also has significant impact. Vertical distribution of lake organisms is distinctly marked in particular lakes. Based on many parameters, the Tatra lakes can be divided into two groups: of alpine and subalpine character. The water bodies situated on the Polish side of the Tatras are not acidified when compared to those in the Republic of Slovakia. The Tatras and their lakes are the farthest located in Northern Europe centre of endemism and the largest site of high mountain fauna and flora occurrence in Central Europe.

The clearance rates of 14 carbon-labelled Chlamydomonas sp. by the copepodite and adult stages of the 2 dominant species of Copepoda were studied in eutrophic Lake Aydat. They varied from 30 to 3,007 µl ind−1 h−1 for Acanthodiaptomus denticornis (mean = 600 µl ind−1 h−1) and from 20 to 1,133 µl ind−1 h−1 for Cyclops vicinus (mean = 340 µl ind−1 h−1). Their maximum assimilation efficiencies were 58% and 50%, respectively. These populations collectively could consume the available food in 4 days during September (maximum daily grazing rate = 24%). Mean individual clearance rates could be ranked Acanthodiaptomus denticornis > Ceriodaphnia quadrangula > Chydorus sphaericus > Daphnia longispina > Cyclops vicinus vicinus > Bosmina longirostris > K. cochlearis > K. quadrata and Kellicottia longispina. Like cladocerans and rotifers, the copepods living in this eutrophic lake can feed at low oxygen concentrations.

Scientific limnological research in the Tatra Mountains were initiated by Stanislaw Staszic in the early XIX century. After the World War II, the evolution of Tatra lakes was investigated by Kondracki, Klimaszewski, Baumgart-Kotarba and. Extensive paleolimnological investigations in the Tatra Mountains were started by the group of scientists led by K. Starmach in the beginning of the second half of the 20 th century. There has been not much research concerned to the regional distribution of lakes and their properties in the Tatra Mountains (Pociask-Karteczka 2013). Very early division of lakes presented A. Gadomski (1922), which distinguished four types of lakes: a) tarns (cirque lake or corrie loch), b) bedrock-dammed lakes, c) moraine lakes. This division was concerned in subsequent publications (Choinski 2007). M. Luknis (1973, 1985) recognized additional types: kettles and landslide-dammed lakes and M. Klimaszewski (1988) – inter-sheepback lakes. J. Pacl and K. Wit-Joźwik in Klima Tatier (Pacl, Wit-Joźwik 1974) were focused on the temperature of water in lakes in Polish and Slovak parts and M. Borowiak (2000a,b) provided a comprehensive analysis of types, dimensions, temperature and chemical composition of water in lakes in the Tatra Mountains. According to present day state of knowledge, one may distinguish following genetic types of lakes: I) glacial, II) not-glacial. There are four types of the glacial origin lakes in the Tatra Mountains (Fig. 1): a) tarns (cirque lakes or corrie loch), b) bedrock-moraine dammed lakes, c) inter-sheepback lakes, d) moraine lakes, e) kettles. Most of lakes in the Tatra Mountains are tarns and bedrock-moraine dammed lakes, and they are located at the elevation over 1400 m a.s.l. in the Western Tatra Mountains, and over 1600 m a.s.l. in the High Tatra Mountains. Some of them are paternoster lakes – a series of stair-stepped lakes formed in individual rock basins aligned down the course of a glaciated valley. Lakes in the Five Polish Lakes Valley is an example of such type. The inter-sheepback lakes occur at higher elevations (e.g. Wyznie Mnichowe Stawki, Zamrznute oka). There is a little number of moraine lakes in the Tatra Mountains (e.g. Smreczynski, Toporowy Nizni) and kettles (e.g. Strbske Pleso, Kotlinowy Stawek). Some lakes are located among rock debris or rock debris and moraine material (Dwoisty Staw Gąsienicowy, Anitino ocko) – they are of polygenetic origin.

BackgroundMultiple transitions to obligate parthenogenesis have occurred in the Daphnia pulex complex in North America. These newly formed asexual lineages are differentially distributed being found predominantly at high latitudes. This conforms to the rule of geographical parthenogenesis postulating prevalence of asexuals at high latitudes and altitudes. While the reproductive mode of high-latitude populations is relatively well studied, little is known about the reproduction mode in high altitudes. This study aimed to assess the reproductive mode of Daphnia pulicaria, a species of the D. pulex complex, from high altitude lakes in Europe.Methodology/Principal FindingsVariation at eight microsatellite loci revealed that D. pulicaria from the High Tatra Mountains (HTM) had low genotype richness and showed excess of heterozygotes and significant deviations from Hardy-Weinberg expectations, and was thus congruent with reproduction by obligate parthenogenesis. By contrast, populations from the Pyrenees (Pyr) were generally in Hardy-Weinberg equilibrium and had higher genotypic richness, suggesting that they are cyclic parthenogens. Four lakes from lowland areas (LLaP) had populations with an uncertain or mixed breeding mode. All D. pulicaria had mtDNA ND5 haplotypes of the European D. pulicaria lineage. Pyr were distinct from LLaP and HTM at the ND5 gene. By contrast, HTM shared two haplotypes with LLaP and one with Pyr. Principal Coordinate Analysis of the microsatellite data revealed clear genetic differentiation into three groups. HTM isolates were intermediate to Pyr and LLaP, congruent with a hybrid origin.Conclusion/SignificanceInferred transitions to obligate parthenogenesis have occurred only in HTM, most likely as a result of hybridizations. In contrast to North American populations, these transitions do not appear to involve meiosis suppressor genes and have not been accompanied by polyploidy. The absence of obligate parthenogenesis in Pyr, an environment highly similar to the HTM, may be due to the lack of opportunities for hybridization.

At 1197 m in the French Massif Central, lake Pavin has a volcanic origin. It is a meromictic lake of 44 ha area and 98 meters depth. Zooplancton samples (250 liters) were collected bimonthly with a water pump from May 1973 to April 1974 at six depths from surface to 20 meters. Countings were made to study the dynamics of two Cladocera: (Daphnia longispina and Ceriodaphnia quadrangula), two copepode populations, the calanoide Acanthodiaptomus denticornis and the cyclopoide Cyclops abyssorum. For the last two species, males, females, ovigerous females, Nauplius larvae and each of the five copepodite stages were differentiated. If Cladocera have a period of development limited from June to September for Ceriodaphnia and from June to December for Daphnia, copepods are presents all around the year with two principals periods of reproduction. The first during spring (March–April), the second during fall (October–November). If this second generation presents an important development for Cyclops abyssorum, that is not the same for Acanthodiaptomus denticornis, in which species nauplius larvae died in winter. The synthetical mathematical model realized by Principal Components Analysis illustrates the relationships between phyto-and zooplancton and bio-physico-chemicals parameters and specially the fact that, in this lake, the highest values of phytoplanctonic primary production and activity coefficient (Production/Standing crop) are found when herbivorous zooplancton presents the more important development and nutrients their lowest concentrations.

The Cladocera, Cyclopoida and Calanoida species diversity of the mountain part of the Stryi river basin is described. The objects of research were found in 48 lenthic water bodies (Zhuravlyne lake, Yavirske reservoir, numerous ponds, puddles, swamps, springs, and wells) and on 7 sections of the Stryi and Yablunka rivers. 24 species of Cladocera, 23 Cyclopoida, and 1 Calanoida are found. The most diverse is the fauna of Lake Zhuravlyne, which is located in the Skole Beskydy National Nature Park. 56% of the species diversity of the mentioned groups is noted in ponds, 42% in puddles and swamps, 8% in springs and wells, 15% in rivers, 10% in Yavirske reservoir, 44% in Zhuravlyne. The fauna of the mountain part of the Stryi river basin includes 44% of the Cladocera, Cyclopoida and Calanoida species diversity of the territory of the Ukrainian Carpathians. Only Eudiaptomus transylvanicus is noted within Calanoida. Alona protzi, Eurycercus lamellatus, Simocephalus expinosus are found only in the study area within the Ukrainian Carpathians. The most common species in this area are Chydorus sphaericus (36% frequency of occurrence in the investigated lenthic water bodies) and Eucyclops serrulatus (55%). These species are the most common in the Ukrainian Carpathians as well. The highest total density of Cladocera and Cyclopoida was 253,5 thous.ind./m3. Daphnia obtusa, Alona protzi, Eucyclops subterraneus, Paracyclops poppei та Grateriella unisetigera are rare species for Lviv region. Eurycercus lamellatus, Simocephalus expinosus, Chydorus latus together with the previous species are rare for the Ukrainian Carpathians in total. 47% of the investigated lenthic water bodies are in oligosaprobic zone. The most valuable communities of the Cladocera, Cyclopoida and Calanoida exist in the Zhuravlyne lake, springs and wells near village Verkhnia Rozhanka, pools of the Vododilnyi masiff, riverbed of Stryi and the along-river reservoirs between the villages Zavadavivka and Yavora, and ponds near the village Dovge.

We used a natural experiment to test whether wildfire smoke induced changes in the vertical distribution of zooplankton in Lake Tahoe by decreasing incident ultraviolet radiation (UV). Fires have a variety of effects on aquatic ecosystems, but these impacts are poorly understood and have rarely been observed directly. UV is an important driver of zooplankton vertical migration, and wildfires may alter it over large spatial scales. We measured UV irradiance and the distribution of zooplankton on two successive days. On one day, smoke haze from a nearby wildfire reduced incident UV radiation by up to 9%, but not irradiance in the visible spectrum. Zooplankton responded by positioning themselves, on average, 4.1 m shallower in the lake. While a limited data set such as this requires cautious interpretation, our results suggest that smoke from wildfires can change the UV environment and distribution of zooplankton. This process may be important in drought‐prone regions with increasingly frequent wildfires, and globally due to widespread biomass burning.

The present study was conducted to determine zooplankton fauna of Kiğı Dam Lake during September 2012 and August 2013 seasonally. The zooplankton samples were collected by using plankton net with the mesh size of 55µm horizontally and preserved in 4% formaldehyde. Total 22 taxa (16 Rotifera, 4 Cladocera, and 2 Copepoda) were identified in Kiğı Dam Lake. Ascomorpha saltans, Asplanchna priodonta, Brachionus angularis, Cephalodella gibba, Euchlanis dilatata, Kellicottia longispina, Keratella cochlearis, Keratella quadrata, Lecane luna, Lecane lunaris, Notholca squamula, Polyarthra dolichoptera, Rotaria rotatoria, Synchaeta pectinata, Synchaeta oblonga, Trichocerca capucina from Rotifera species; Bosmina longirostris, Chydorus sphaericus, Daphnia cucullata, Daphnia longispina from Cladocera species; Acanthodiaptomus denticornis, Cyclops vicinus from Copepoda species are new records for this dam lake. Zooplankton samples were consisted of 72.7% Rotifera, 18.2% Cladocera, and 9.1% Copepoda.

Preface. Diatoms, lake acidification and the Surface Water Acidification Programme (SWAP): a review R.W. Battarbee. Lipid storage in Diaptomus kenayi (Copepoda Calanoida): Effects of inter and intraspecific variation in food quality N.M. Butler. Nitrogen in Pyrenean lakes (Spain) J. Catalan, L. Camarero, E. Garcia, E. Ballesteros, M. Felip. Plankton dynamics in a high mountain lake (Las Yeguas, Sierra Nevada, Spain) L. Cruz-Pizarro, I. Reche, P. Carillo. Acidification of lakes in Sumava (Bohemia) and in the High Tatra Mountains (Slovakia) J. Fott, M. Prazakova, E. Stuchlik, Z. Stuchlikova. Chemical characteristics of lakes in the High Tatra Mountains J. Kopacek, E. Stuchlik. Paleolimnological records of carotenoids and carbonaceous particles in sediments of some lakes in the Southern Alps A. Lami, A. Marchetto, P. Gullizzoni, A. Giorgis, J. Massaferro. Algal flora of lakes in the High Tatra Mountains, Slovakia J. Lukavsky. Acidification and weathering processes in high mountain lakes in the Southern Alps A. Marchetto, A. Barbieri, R. Mosello, G.A. Tartari. Reconstruction of pH by chrysophycean scales in some lakes of the Southern Alps A. Marchetto, A. Lami. A survey of water chemistry and plankton in high mountain lakes in Northern Swedish Lapland A. Nauwerck. Cyclops scutifers Sars in Lake Latnjajaure, Swedish Lapland A. Nauwerck. Comparison of diatom communities in remote high mountain lakes using index B and cluster analysis P. Niederhauser, F. Schanz. Zooplankton decline in the Cerne Lake (Sumava Mountains, Bohemia) as reflected in the stratification of cladoceran remains in the sediment M. Prazakova, J. Fott. Characterization of carbonaceous particles from lake sediments N.Rose. Autotrophic picoplankton community dynamics in a pre-alpine lake, British Columbia, Canada J.G. Stockner, K.S. Shortreed. Chemical properties of an acidified humic headwater lake H. Thies. Limnological research on northern Apennine lakes (Italy) in relation to eutrophication and acidification risk P. Viaroli, I. Ferrari, G. Paris, G. Rossetti, P. Menozzi. The effect of anthropogenic acidification on the hydrofauna on the lakes in the West Tatra Mountains M. Varnovsky, I. Krno, F. Sporka, J. Tomajka. Chlorophyll--phosphorus relationship in acidified lakes of the High Tatra Mountains (Slovakia) V. Vyhnalek, J. Fott, J. Kopacek. Acidification of small mountain lakes in the High Tatra Mountains, Poland K. Wojtan, J. Galas.

Small scale distribution and diurnal migration of zooplankton were investigated in lake Naardermeer, a shallow lake largely covered by uniform Chara beds. For sampling, pattern samplers with a number of inverted funnels facing towards the lake bottom and held in a frame were used. Samplers were placed near the water surface and just above the plants, during one diel cycle (noon and midnight). Ceriodaphnia and Bosmina showed the highest levels of aggregation, both in the Chara bed and in the water above it. Chydorus sphaericusMuller and Diaphanosoma brachyurumLeivendid not aggregate in open water at daytime. Chydorus sphaericus and Eurytemora velox Lilljeborg ascended from the Chara bed into the open water during the night. Sida crystalina Muller and Chydorus sphaericus individuals collected at night were larger in size than those collected during daytime, both in the Chara bed and in the water above it. The results indicate that larger Sida crystallina individuals have a stonger preference to stay in the Chara bed at night than smaller individuals. In lakes with extensive and uniform Chara beds with a large overlying water column, zooplankton appear to migrate vertically rather than horizontally.

Three lakes were studied in the High Tatra Mountains at altitudes from 2000 to 2157 m a.s.l., which represent three categories of acidity status recognised in the Tatra lakes in the 1980s: non-acidified, acidified, and strongly acidified. Subfossil chironomid remains from dated sediment cores covering ca. throughout 200 years were analysed. The chironomid thanatocoenoses of all cores layers reflected ultra-oligotrophic non-acidified conditions in L’adove pleso. Nevertheless, the finding of the acid-tolerant species Zalutschia tatrica in littoral samples in 1980s indicates that the littoral zone was more influenced by acidification than deeper areas of the lake. Three stages of lake developmental history can be distinguished in the acidified lake Vysne Wahlenbergovo pleso based on the chironomid subfossil record: the pre-acidification stage before the 1920s, the anthropogenic acidification stage between the 1920–1980s, and the recovery of the lake from the end of the 1980s. The period of acidification was accompanied by a decline in chironomid numbers, while chironomid fauna composition was unchanged during the whole investigated history of the lake. None of the chironomid taxa present prior to the acidification period disappeared during the peak of acidification. The most apparent change in the sediment record taken from the strongly acidified lake Starolesnianske pleso was recognised in the layers corresponding to the period 1960–1980. It is characterised by the disappearance of the dominant acid-sensitive Tanytarsus lugens group and the dominance of acidtolerant Tanytarsus gregarius group. The most recent chironomid assemblage probably benefits from the amount of food resources as a result of increased lake productivity induced by acidification.

Consensus-building univariate and multivariate data analyses were used to identify patterns in space and time over seven years among 12 sampling stations in a 720 km2 hardwater Canadian lake (Lake Simcoe, Ontario, Canada). There were 15 copepods and 26 cladoceran species identified in samples collected throughout the May-October periods of 1986-1992 from Lake Simcoe. Eleven crustacean zooplankters accounted for 88% of the total average density of all recorded species in the lake. Most of these (the main exceptions being Eubosmina coregoni and Daphnia pulicaria) are ubiquitous taxa with wide environmental tolerances. Multivariate analyses of these data identified spatial differences and a temporal trend in community composition. The use of Cao et al.’s (1997a) "CY-dissimilarity" measure combined with Ward's Linkage clustering algorithm and non-metric multidimensional scaling ordination resulted in several clearly defined groups of sampling units (SUs), which apparently were separated predominantly on the basis of variables related to space (sampling station) and time (year). The 7-year record suggested several lines of evidence for trends in community structure. Averaged over all stations, the yearly intra-station dissimilarities steadily increased 78% by 1992. The greatest rates of increase in yearly intra-station dissimilarity with 1986 baselines were found for the deeper sampling stations. These whole community-level trends were the net results of a many different patterns of change identified in species-level analyses. Such patterns included increasing densities over the 7-year period of Daphnia longiremis and Diaphanosoma birgei and declining densities of Daphnia pulicaria. Many other taxa showed highest values in the middle years of the study. Community-level temporal trends were least evident at sampling locations in the shallower and warmer Cook’s Bay, despite clear trends in several individual species. A significantly greater representation by large-bodied zooplankton species in the latter years of the study was consistent with declining stocks of rainbow smelt (Osmerus mordax) and lake herring (Coregonus artedii), suggesting the associated relaxation of predation pressure as a possible cause. Several species indicative of eutrophic states (Acanthocyclops vernalis, Chydorus sphaericus and Bosmina longirostris) were common in the samples. The scarcity of the calanoid Senecella calanoides and the absence of another classic oligotrophic indicator calanoid, Limnocalanus macrurus in the Lake Simcoe samples suggests impairment of their deep, cold-water habitat and is consistent with the modelled historical loss of hypolimnetic dissolved oxygen in Lake Simcoe.

There are noted 11 species of plankton crustaceans (7 – Cladocera and 4 – Copepoda (Calanoida and Cyclopoida)) from the reservoirs of the Ukrainian part of the Marmarosh Mountains. The high mountain glacial lake Kryvave, the forest lake of the overflow type (landslide) Shchevora, small swamp and some of the puddles are investigated. Lake Kryvave is located at an altitude of 1620 m above sea level in the glacial crust of Mt. Pip Ivan Marmarosky within the subalpine vegetation. Its size is 38.8 by 19.4 m, the maximum depth is 0.5 m. Lake Shchevora is located at an altitude of 1209 m above sea level in a hollow in a spruce forest with an admixture of beech. The size of the lake is 61.5 by 21.8 m. The recorded maximal depth is 1.6 m, but the lake might be much deeper. The most common species in this area are Chydorus sphaericus (O. F. Müller, 1776) and Acanthocyclops vernalis (Fischer, 1853). The others species has a more local distribution in the Marmarosh Mountains. Daphnia obtusa Kurz, 1874, Chydorus sphaericus, Acanthocyclops vernalis and Mixodiaptomus tatricus (Wierzejski, 1883) inhabited in the subalpine reservoirs upper 1515 m above sea level. These communities are typical for high mountain shallow reservoirs of Chornohora, Svydivets massifs too. This indicates that the hydrofauna of the Marmarosh Mountains belongs to the high mountain fauna of Carpathians. Mixodiaptomus tatricus, which inhabits the reservoirs of subalpine and alpine zones of southeastern Europe is specific stenotopic species to the communities of the Ukrainian Carpathians and is present by an isolated population in the reservoirs on the slopes of Mt. Pip Ivan Marmarosky. The total density of planktonic crustaceans in the lakes is very low (0.5–1.3 thous. ind./m3), because of cold water, a small amount of organic matter, absence or lack of aquatic macrophytes. The most numerous planktonic crustaceans are in subalpine puddles – up to 138.5 thous. ind./m3. The total density of planktonic crustaceans in road puddles does not exceed 6 thous. ind./m3. The maximum density was reached Daphnia obtusa – to 54,5 and Chydorus sphaericus – to 51,3 thous. ind./m3 from other species. Lake Kryvave and the puddle on the slopes of Mt. Stig are oligosaprobic, while the other reservoirs are β-mesosaprobic.

SUMMARY This study compares small‐scale (i.e. neighbourhood) associations among distributions of phytoplankton, zooplankton, and zooplankton grazing rates using a combination of correlations and analyses of spatial patchiness. All zooplankton and phytoplankton populations had patchy distributions. On average, individuals experienced members of their same taxon at a density that was 42% greater than the mean sample density. The various zooplankton taxa experienced different average neighbourhoods, even within the same stratum of the lake. For example, Daphnia galeata mendotae (Birge) experienced phytoplankton concentrations that were nearly 50% greater than those experienced by Daphnia pulicaria (Forbes) at the same depth. The distributions of the various phytoplankton taxa were positively correlated with each other, but the distributions of zooplankton were negatively correlated, or more often, unrelated to each other. Phytoplankton abundance was negatively correlated with zooplankton grazing rates. We hypothesize that while phytoplankton distributions are driven by common external factors, the factors that determine horizontal distributions of zooplankton are species specific. In addition, zooplankton grazing appears at least partially responsible for the generation of patchiness in the distribution of phytoplankton.

Latest Pleistocene glacier advances and post-Younger Dryas rock glacier stabilization in the Mt. Kriváň group, High Tatra Mountains, Slovakia