Ladislav Hamerlík

Littoral benthic macroinvertebrates of mountain lakes in the Tatra Mountains (Slovakia, Poland)

Littoral benthic macroinvertebrates of 45 mountain lakes in the Tatra Mountains were sampled using a semi-quantitative method in September 2000. A total of 32,852 specimens were identified to 93 taxa belonging to 14 higher taxonomic groups. Multivariate statistics (CCA, RDA) and nine biotic metrics (AQEM/STAR) were used to explain relationships between macroinvertebrate assemblages and environmental variables. Up to 57% of the ecological position of littoral macroinvertebrate assemblages were explained by variance of environmental variables divided into chemical, trophic, physical, catchment and location. Five types of Tatra lakes were recognized using CCA: A — strongly acidified lakes (small catchment, low pH, high concentration of TP, DOC, highest amount of POM in littoral); B — alpine acidified lakes (low amount of POM, low values of biotic metrics); C — alpine non-acidified lakes (high value of diversity index, predominance of Diptera); D — subalpine acidified lakes (high values of biotic metrics: number of families, proportion of crenal and rhithral taxa/total taxa); E — subalpine non-acidified lakes (high values of biotic metrics: number of families, number of genera, BMWP score, number of taxa and abundance of EPT taxa). RDA was used to design five levels of macroinvertebrate taxa acidification tolerance. The Tatra Acidification Index (TAI) was established to assess the acidification status of the lakes in the Tatra Mts.

Non-biting midges (Diptera: Chironomidae) from fountains of two European cities: micro-scale island biogeography

We studied chironomid assemblages of 12 fountains located in Olomouc (Czech Republic) and in Copenhagen (Denmark). In total, 45 taxa of three subfamilies were recorded. The typical fountain assemblage was constituted of common species with very wide geographical distribution and ecological requirements as Cricotopus ornatus, C. sylvestris, Orthocladius fuscimanus, Psectrocladius limbatellus, Chironomus spp., along with tap-water species (Paratanytarsus grimmii), hygropetric and semi-terrestrial taxa (e.g. Orthocladius fuscimanus, Metriocnemus eurynotus). There was no linkage between taxa richness and fountain area or distance from the colonisation source. However, in Olomouc, with a single main colonisation source, a strong correlation between similarity of chironomid assemblage structures and distance to river was recognised. In Copenhagen, with a number of small water bodies, fountains were not correlated significantly with distance to sources. However, similarities of chironomid assemblage structures were negatively correlated with their geographical distances. Species temperature optima and preferences did not relate to distribution patterns. Generally, distance to natural aquatic sources, fountain proximity and regional factors determine the taxonomic composition of the non-biting midges.

Assessment of running waters (Slovakia) using benthic macroinvertebrates — derivation of ecological quality classes with respect to altitudinal gradients

A method is presented for defining the five classes of ecological quality based on a multimetric index (MMI) of macroinvertebrates, as required for implementation of the Water Framework Directive for small (catchment area 10–100 km2), medium (101–1000 km2) and large (> 1000 km2) streams. Our method (expert judgment) allows us to overcome an absence of reference sites for some stream types. The key was selection of suitable metrics for all stream types. The whole procedure was divided into two parts. 1. Small streams with reference sites: suitable metrics were selected according to their ability to distinguish reference and monitoring sites — SI, Oligo [%], BMWP, RhiTI, Rheoindex, IBCR, % Aka+Lit+Psa [%] and EPT. Here the high-good boundary value was set as the 25th (for metrics decreasing with increasing pollution) or 75th percentile (for metrics increasing with increasing pollution). 2. Medium and large streams which lack reference sites: here the idea was applied that some metrics, the values of which change along an altitudinal gradient, also react to anthropogenic stress — SI, Oligo [%], BMWP, [%] metarhithral, RhiTI, Aka+Lit+Psa [%] and EPT for both medium and large streams with, in addition, IBCR and NFam for medium streams. This assumption was supported by regression analysis of altitude and metrics from small streams. Not all the metrics were related to altitude but metrics with a good ability to separate reference and monitoring sites did show a significant relationship to altitude. The boundary between high and good class for medium and large streams was set as the 95th or 5th percentiles.

Macroinvertebrates of inlets and outlets of the Tatra Mountain lakes (Slovakia)

The composition of invertebrates of inlets and outlets of selected West Tatra and High Tatra lakes (Slovakia, 49°10′ N, 20°00′ E) was analyzed. Twenty-seven sampling sites representing 11 inlets and 16 outlets of 19 mountain lakes were investigated. In total, 10,692 aquatic invertebrates from 27 samples were sorted, 7,314 from inlets and 3,378 from outlets. Altogether, 110 zoobenthic taxa (81 in inlets and 85 in outlets) belonging to 12 higher taxonomic groups were identified. The most constant benthic groups found both in lets and outlets, at more than half of all sites, were Oligochaeta (93% of all sites), Chironomidae (78%), Trichoptera (63%), Plecoptera (59%) and Turbellaria (56%). The most abundant groups were Chironomidae (4,697 ind.), Oligochaeta (2,473 ind.) and Turbellaria (2,236 ind.). No statistically significant differences were found between the benthic communities of inlets and outlets. On the contrary, significant differences (P < 0.05) were found in some parameters of benthic communities of inlets situated in different altitudes (< 1800 m a.s.l., 1800–2000 m a.s.l., > 2000 m a.s.l), outlets of different altitudes, and finally, outlets of lakes with different areas (< 5 ha and ≥ 5 ha). Cluster analysis relatively clearly separated outlets of subalpine lakes from the alpine lakes. Also, outlets of lakes with the lowest pH were separated from the other sites. In the case of inlets, West Tatra sites were separated from the High Tatra sites.

Diversity and composition of macroinvertebrate assemblages in high-altitude Tibetan streams

Abstract Knowledge on the ecology of streams at extreme altitudes is relatively sparse. We conducted a preliminary survey of the macroinvertebrate fauna of Tibetan streams in June 2009 and August 2011 and compared streams with different water sources. We collected quantitative samples of macroinvertebrates and measured physicochemical variables at 16 sites (8 each sampling year) at altitudes ranging from 4315 to 5065 m a.s.l. and grouped the sites into 3 types according to origin: glacier-fed, rain-fed, and lake-outlets. We identified 38 taxa, with a mean of 8.9 taxa per site. Overall the benthic fauna was dominated by insects (71%), mainly Diptera (especially Chironomidae). Ephemeroptera, Plecoptera, and Trichoptera were found at nearly all sites but mostly in low numbers; however, the fauna was significantly different in the 2 sampling years, especially due to the proportions of Chironomidae (68% in June 2009 and 10% in August 2011) and Baetidae (6% vs. 35%, respectively). The 3 stream types had significantly different faunas. Rain-fed streams had the highest total taxon richness (γ-diversity), but glacier-fed streams had a slightly higher taxon turnover rate (β-diversity). Percent glacial cover in the catchment and water turbidity explained most of the variability in taxon richness. Although not particularly taxon rich compared to other high-altitude streams, the Tibetan stream fauna showed considerable spatial variability. The fast retreat of the glaciers and permanent snow fields in Tibet makes further studies on distribution patterns and driving forces for aquatic biodiversity urgent.

First records of chironomids (Diptera, Chironomidae) from Slovakia

Faculty of Sciences, Matej Bel University, Tajovskeho 40, SK–97401 Banska Bystrica, Slovakia; e-mail: peter@blatna.cuni.cz Department of Biology and General Ecology, Faculty of Ecology and Environmental Sciences, Technical University in Zvolen, SK–96053 Zvolen, Slovakia Institute of Zoology, Slovak Academy of Sciences, Dubravska cesta 9, SK–84506 Bratislava, Slovakia; e-mail: ladislav.hamerlik@savba.sk Water Research Institute, Nabr. arm. gen. L. Svobodu 5, SK–81249 Bratislava, Slovakia; e-mail: matushaviar@hotmail.com

Relict chironomid communities surviving in the coldest High Tatra Mountain lakes confirmed by a palaeolimnological survey

Abstract The climatically most extreme lakes in the High Tatra Mountains are populated with species-poor chironomid communities dominated by Micropsectra radialis and Pseudodiamesa nivosa. Based on paleolimnological studies from other parts of Europe this community had been hypothesized to be a relict of the Late Glacial period, however, this assumption has not been proved in the Tatras. A paleolimnological survey of a subalpine Tatra lake demonstrated that this community was indeed occupying lakes located even in relatively low altitudes as long as they were glacially influenced, i.e., until the early Holocene. Due to the restricted distribution and specific ecological requirements of the species creating this relict community, it is extremely prone to extinction.

Identifying white spots on the roadmap of Late Pleistocene and Holocene palaeolimnology in Slovakia: Review and future directions

Abstract Paleolimnological research in the territory of Slovakia has relatively short history with the beginning in the 1990s primarily as a response to the ecological changes in mountain lakes due to air pollution and missing data from the pre-industrial period as well as a need to quantify anthropic impact on the landscape. In the present paper, we reviewed 53 publications, including research papers, monographs, conference abstracts and theses, dealing with aquatic proxies in Holocene lake sediments to identify (1) the location of surveyed sites, (2) proxies used, and (3) the object of the paleolimnological reconstructions. The vast majority (37) of the analysed paleolimnological localities (51) took place in the High Tatra Mountains, focusing on the alpine lakes of glacial origin. The most frequently used biological proxy was Chironomidae remains (44%). In contrast, Cladocera, Ostracoda, loss-on-ignition, molluscs and stable isotopes were used only in 10–12% of studies. Most studies (84%) focused on a simple ecological reconstruction of the past environment, and only 24% of the studies attempted to reconstruct specific ecological variables, properties and processes, such as acidification (10%), temperature (8%) and eutrophication (4%). Only 2% of the studies used molecular techniques. Sixteen out of the 51 cores analysed (i.e., 31%) were dated by radiometric methods. In the end of our review we pinpoint the weaknesses of the local paleolimnological research and sketch possible future directions.

Bioassessment of streams based on macroinvertebrates — can sampling of some substrate types be excluded?

Abstract Attempting to help reduce the costs of bioassessment of aquatic habitats, the aim of this study was to estimate how particular substrate types influence the ecological quality evaluation based on a multihabitat scheme proposed by the AQEM/STAR consortium. Samples of macroinvertebrates were taken from the Stupavský potok brook, a small, 4th order calcareous stream in the Small Carpathians in Slovakia (Central Europe). Eight most suitable metrics for small Slovakian streams forming the Slovak multimetric index on seven substrate types were tested and compared with the multihabitat sample. The Saprobic Index (SI) and Index of Biocenotic Region (IBR) showed considerably worse (higher) values in the psammal and the best (lowest) values on coarse mineral substrates (lithal, akal). Similarly, values of the metrics Oligo (%), BMWP Score, Rheoindex, Rhithron Typie Index (%) and EPT reached their worst (lowest) values on psammal and the best (highest) values on coarse mineral substrates. Psammal sample showed the worst ecological quality expressed by the lowest EQR (Ecological Quality Ratio) value, most significantly differing from the multihabitat sample (Multiple Comparisons of Means: Dunnett Contrasts: –8.25, P < 0.01). We conclude that substrate types considerably influence selected metrics. Because of a relatively substantial proportion of psammal in some small Slovakian streams and its marginal influence on the overall ecological quality of the site, we suggest conduct further research addressing the effectiveness of its usage in the water management.

Fish on the roof of the world: densities, habitats and trophic position of stone loaches (Triplophysa) in Tibetan streams

The fast increase in temperature on the Tibetan Plateau, with anticipated future changes in aquatic ecosystems and biodiversity, highlights the urgent need for ecological data on the sparsely studied Tibetan running waters. In the present study we surveyed eight Tibetan streams to obtain data on densities, feeding selectivity and trophic position of the stone loach Triplophysa. Benthic algae, detritus, macroinvertebrates and fish were quantified and collected for stable isotope and stomach content analysis. Triplophysa density (mean 0.70 individuals m–2, maximum 1.6 individuals m–2) decreased with altitude and increased with the percentage cover of fine substratum. Glacier-fed sites tended to have the lowest fish densities, whereas the highest densities were found near lakes. Mean fish length (4.1–9.6cm) was positively related to the percentage cover of coarse substratum. Triplophysa was omnivorous, but the composition of the stomach contents varied greatly between sites and among individuals. Algal matter was ingested at most sites, but macroinvertebrates (Chironomidae, Baetidae and Simuliidae) dominated the ingestion (average 50–100%). The trophic position of Triplophysa, identified from δ15N (‰) of the biota, varied between 2.6 and 4.2 among localities (mean 3.6) and was inversely related to the biomass of benthic algae, but unrelated to quantities of other potential food sources.