Solina Reservoir Research Articles

Reservoirs facilitate colonization of river catchments by a native invasive fish through provision of pelagic larval rearing habitat

Dams on rivers are known to facilitate the colonisation and spread of aquatic alien and native invasive species, but the actual mechanisms involved are poorly understood. Since the construction of the Solina Dam on the upper San River system in Poland, European perch (Perca fluviatilis) have expanded their distribution into the headwaters of this river system, becoming a native invader. In this study, we assessed the spread of perch in detail over time upstream of the Solina Reservoir, and used otolith trace element microchemistry to determine the spawning and larval rearing locations of perch in the catchment upstream of the dam. Extensive sampling over several years across the catchment upstream of the Solina Reservoir confirmed the widespread occurrence of perch into the headwaters of the tributary river systems, with smaller size classes dominating locations closer to the Solina Reservoir. Despite perch being widely distributed upstream of the Solina Reservoir, otolith microchemical analysis indicated the populations from various reservoir tributaries mostly shared the same spawning and larval rearing habitat, most likely the Solina Reservoir. Our results suggest that reservoirs can facilitate the colonisation of river systems by providing a critical habitat element that would be otherwise missing from riverine landscapes, i.e., an extensive and productive pelagic larval rearing environment. This research shows that the impacts of large dams can extend many kilometers upstream from the river reaches directly affected by the resulting impoundment.

A new concept for risk analysis relating to the degradation of water reservoirs

This paper presents a proposal for a procedure by which to analyse the risk of reservoirs being degraded. The body of water assessed for its susceptibility to degradation in line with the proposed procedure is Myczkowce Reservoir, SE Poland. This reservoir has a maximum capacity of ten million m3 and helps provide hydropower, by serving as a surge tank located above the main Solina Reservoir. On the basis of an assessment of its morphometric and hydrological parameters, Myczkowce Reservoir was assigned to the low-resilience category where risk of degradation was concerned. The primary factors responsible for that are limited capacity in relation to shoreline length, a lack of thermal stratification, and a high value for the Schindler index. These and other environmental parameters provided for Myczkowce’s assignment to the category of susceptible to the impact of matter supplied by its catchment, with this reflecting the instantaneous nature of the basin, high values for the Ohle coefficient, average catchment slope, and the lack of a septic system. The designated risk level supported Myczkowce’s assignment to a category characterised by an “unacceptable” risk of degradation. The proposed method taking two parameters (resilience and susceptibility) into account represents the first universal method for assessing reservoirs without reference to risks such as drought, flooding, or lack of water supply for human consumption. The risk depends only on the reservoir and catchment parameters.

The content of selected heavy metals and their bioavailable fraction in sediments of Solina Reservoir (Poland)

Research on sediments of Solina Reservoir, Poland, were characterized by a content of copper higher than other heavy metals (Cr, Ni, Cd and Zn). The strongest correlations between pairs of heavy metals were Zn–Cu and Ni–Cr, were revealed while there was also a correlation between total contents of chromium and nickel, and between pH value and sediment percentage of organic matter. The content of copper at levels exceeding the geochemical background (more than 20–fold), sediments could only by classified as of the 3rd purity class (according to the PIG criterion) or the 5th purity class (according to Müller’s classification). Ecotoxicological criteria indicate that levels of chromium, copper, nickel and cadmium are all high enough to affect aquatic life. However, the heavy metals analyzed differ in their mobility and bioavailability. The highest percentage value for the ion–exchangeable fraction was noted for cadmium, the lowest for chromium. This means that sediments have a greater capacity to release cadmium into the water column, with the consequence being secondary pollution source for the aquatic ecosystem.

An isotopic model for the origin of autochthonous organic matter contained in the bottom sediments of a reservoir

Geochemical analysis of surface sediment samples collected in 2005 and 2006 was used to evaluate the potential sources of the organic matter present in sediments of southeast Poland's Solina Reservoir. Statistical analysis of sediment variables (carbon to nitrogen ratio, and the carbon 13 and nitrogen 15 isotope ratios) determined for the organic fraction indicated significant spatial variability with respect to sources of organic matter. A binary mixing model was developed from literature sources to predict the relative contributions of allochthonous and autochthonous production to sediment organic matter. Autochthonous production was shown to account for 60–75% of bulk sedimentation in the lacustrine parts of the reservoir, near the dam. In contrast, autochthonous production accounted for only 25% of sedimentation in the riverine zone receiving stream inputs. Statistical analysis identified the δ15N of organic matter as the best predictor of the source of organic matter. Multiple regression analysis indicated that two water-quality variables (nitrate and dissolved silica) were significantly related to the δ15N signature of organic matter. This led to a conclusion that limnetic nitrate and dissolved silica concentrations were regulating organic matter production in the Solina Reservoir.

Dam reservoir affects diet of otters inhabiting mountain river in SE Poland

The diet of otters was studied by the means of spraint analysis in the Bieszczady Mountains, in southeastern Poland. The study area extended over 25 km long stretch of the River San, about 1 km above Solina dam reservoir. Spraints were collected on seven 2 km long sections in 1993, and on three sections in 2010. In both study periods, otter spraints were collected in August, when the weather conditions were similar. The study revealed high contribution of mountain fish species such as Phoxinus phoxinus, Cottus spp., and Barbatula barbatula in otter diet. Diet composition along the River San showed little variation in 1993, except from the section closest to dam reservoir where it was characterised by the highest frequency of occurrence of perch Perca fluviatilis, cyprinids and amphibians. The share of perch in otter diet decreased, while that of noble crayfish Astacus astacus increased with the distance from Solina reservoir. Changes in otter diet between 1993–2010 were characterized by an increase of the consumption of perch and cyprinids on the one hand, and a decrease of the consumption of crayfish, on the other. Both spatial and temporal changes in otter diet reflected the effect of Solina reservoir on the river community and the availability of prey to otters. The results indicate the ongoing changes in fish community influenced by the construction of Solina reservoir.

Methane and carbon dioxide emission from some reservoirs in SE Poland

Methane and carbon dioxide emission from some reservoirs in SE PolandThe results of emission measurements of carbon dioxide and methane from the surfaces of three man-made lakes in southeastern Poland (two little dam reservoirs - in Rzeszów and Wilcza Wola, and the biggest Polish reservoir situated in Solina) are presented in this paper. The experiments were conducted in summer and autumn of 2009. The gas fluxes on the water - atmosphere interface were measured in the littoral area by so called "static chamber" method. Carbon dioxide and methane concentrations in collected gas samples were measured using a Pye Unicam gas chromatograph (model PU-4410/19) equipped with a methanizer to detect low levels of CO2concentrations. The fluxes of determined gases ranged from -24.98 to 162.51 mmol m-2d-1for carbon dioxide and from 0 to 235.60 mmol m-2d-1for methane. The highest values of flux for both CH4and CO2were observed for Rzeszów Reservoir, the lowest ones - for Solina Reservoir. In some studied cases emission of CO2and CH4was as much high as in tropical reservoirs.

The distribution and isotopic composition of carbon and nitrogen as indicators of organic-matter fluxes in the Solina Reservoir (south-east Poland)

The feasibility of using carbon and nitrogen isotope ratios of sediment organic matter (OM) to elucidate the source and fate of bottom sediment was studied in the Solina Reservoir (south-east Poland). Horizontal and vertical changes in OM, total organic carbon (TOC) and total nitrogen (TN) content, as well as δ15N and δ13C values, in bottom sediments were analysed to establish the extent to which these sediments are terrestrial or internal in origin. Increased proportions of TOC along with slight decreases in TN were noted in the surface layer of shallow water sediment compared with the profundal sites. Upstream shallower C : N and δ15N values amounted to ~15 and ~2‰, respectively, pointing to the allochthonous origin of the OM. In turn, profundal C : N ratios of less than 10 and δ15N values of ~4‰ indicated autochthonous sediment. Values for δ13C did not differ between stations and ranged from –27.39 to –27.66‰. It is therefore suggested that the sediment from the upper shallower stations contains more allochthonous, refractory OM, whereas the profundal stations have planktonic OM enriching the sediment. This combined with the vertical distribution observed for δ15N signalled an intensification of eutrophication over the past few years.

Carbon and nitrogen and their elemental and isotopic ratios in the bottom sediment of the Solina-Myczkowce complex of reservoirs

Abstract The studies concerned the ecosystem of the Solina-Myczkowce cascade of reservoirs. While the elemental C:N ratio was higher in the Solina Reservoir branches and in the Myczkowce Reservoir (>10), the values for stations located near the Solina Dam were low (<10). Markedly, the lowest values for δ13C were noted in the Myczkowce Reservoir (-28.5‰), and these contrasted with the higher values found in the Solina Reservoir (ca. -27‰). δ15N varied from 2‰ in the upper Solina to above 3.5-4‰ downstream. While the data obtained indicate the autochthonous origin of sedimentary matter, primary production influences the properties of the bottom sediments in the lower part of the Solina reservoirs.

RATES OF DISSIMILATORY NITRATE REDUCTION TO AMMONIUM IN TWO POLISH RESERVOIRS: IMPACTS OF TEMPERATURE, ORGANIC MATTER CONTENT, AND NITRATE CONCENTRATION

Dissimilatory nitrate reduction to ammonium was examined in the bottom sediment of selected reservoirs. In vitro measurements of DNRA rates were made with undisturbed sediment cores, using an 15N stable isotope technique. 15NH4 + analysis was conducted using a C and N Elemental Analyzer, model EA 1112 (ThermoQuest) on line with IRMS (DELTA+ Finnigan). Multiple regression was applied to examine the combined influence of selected abiotic factors on the rate of the DNRA process occurring in the bottom sediment of Poland's Rzeszów and Solina Reservoirs. The resulting models revealed that temperature, the concentration of nitrate in overlying water, and organic matter (OM) content in bottom sediment have a significant influence on DNRA rates in the bottom sediment of the Rzeszów Reservoir, while temperature and OM content in bottom sediments have a significant influence on the rate in the Solina Reservoir. The correctness of the model was verified using the Fisher – Snedecor test at a significance level of p < 0.001. The importance of DNRA in comparison with denitrification was also analysed.

The significance of denitrification in relation to external loading and nitrogen retention in a mountain reservoir

Nitrogen retention (Nret) and denitrification were studied in the mesotrophic Solina reservoir (south-east Poland) between spring and autumn in 2002 and 2003. Nret was calculated on the basis of the input-output mass balance. The rate of denitrification was measured using the 15N isotope pairing technique in two types of areas; in deep areas, where the bottom sediment makes contacts with the hypolimnion (Dprof), and in the unstratified shallows (Dlitt). The calculated daily load of removed nitrogen (Dtot) varied somewhat from 11.0 to 19.1 mg N m–2 day–1 with a standard deviation of 3.0 mg N m–2 day–1. The limited oscillation noted for Dtot results from the major participation of the deep areas of the reservoir, which are characterised by stable Dprof, as distinct from Dlitt, which varied seasonally from 5.8 mg N m–2 day–1 in November to 109.9 mg N m–2 day–1 in August. The primary factor limiting the denitrification rate was temperature, the other being availability of substrates, mainly organic matter. Nitrogen retention ranged seasonally between –25.0 and 175.9 mg N m–2 day–1. The contribution of denitrification to Nret ranged from 9.0% to 49.8% (mean 16.4%). On average, only 4.9% of the nitrogen external load was denitrified (range 2.6–7.9%, s.d. 1.5%). After comparing obtained data with others available in the literature, we concluded that reservoirs, estuaries and highly-loaded lakes in a river system experience a more limited contribution of Dtot to Nload than is the case in natural lakes.

A simple model of nitrogen retention in reservoirs

The total nitrogen mass balance was studied over a two-year period in two reservoirs located in south-eastern Poland. Theobserved nitrogen retention (Nret) inthe reservoirs ranged from 0.18 to 2.12g m-2d-1 (mean 0.83g m-2d-1) in case of theRzeszow Reservoir and from -0.02 to0.41 g m-2d-1 (mean 0.13g m-2d-1) in case of the SolinaReservoir, while the percentage retention(Nret) ranged from 7 to 42% (mean22%) and -15 to 73% (mean 35%),respectively. A good relationship betweenNret and nitrogen loads was observedfor the Solina Reservoir. The data obtainedby the author and collected from theresearches of 6 other reservoirs located insouthern Poland were used to develop anempirical model suitable to predict thenitrogen seasonal dynamics in a reservoir.The model allows for the determination ofboth the annual mean Nret value andits seasonal variation in a reservoir.

Hydroacoustical parameters of fish in reservoirs with contrasting levels of eutrophication

Hydroacoustical estimation of fish abundance and distribution is performed in three reservoirs that are characterised by different levels of eutrophication. The Biosonics 101 dual beam echosounder with a frequency of 420 kHz and the ESP software for acoustical data analyses are used. A clear dependence between fish density and the level of eutrophication is observed. In the mesotrophic Solina reservoir, fish abundance is over an order of magnitude lower than that in the eutrophic Dobczyce and Sulejów reservoirs. Fish length distributions have different shapes in the three reservoirs, which indicates the changes in fish size structure due to eutrophication; however, the mean target strength of fish does not differ significantly. These results suggest that hydroacoustically collected data may help to assess the ecological state of inland waters and may be used together with other methods in monitoring the water quality.

Trophic structure of the benthic invertebrate community in the littoral zone of a mountain cascade system

Abstract. The cascade of Solina/Myczkowce dam reservoirs situated in the West Carpathian Mts was investigated. The cascade consists of two reservoirs, the upper one built 35 yr ago on the San and Solinka Rivers of 2100 ha area separated from another one, of 190 ha area, with hypolimnion cold water supplied from the upper one. The offshore zone was investigated monthly (6 sites of upper, 3 sites of lower reservoir) using a tube bottom sampler. Besides numbers, biomass and biodiversity indices, the proportion of predators, plant/detritus-feeders and filter-feeders was assessed. In upper reservoir Solina, with a lack of filter-feeders, a clear preponderance of plant-detritus feeders was observed. Predators, consisting mostly of leeches and hydranchnellids were present. In lower reservoir Myczkowce, all three trophic classes were present in the first year of study in almost equal proportions and in 1998 with slight preponderance of plant/detritus feeders was observed. The Oligochaeta/Chironomidae index in both reservoirs was low, indicating low degree of eutrophication. Only one site in Solina reservoir (near a fish culture) and one in Myczkowce (influenced by tourist activity) showed a high value of this index.

The relationship between the spatial distribution of fish, zooplankton and other environmental parameters in the Solina reservoir, Poland

The hydroacoustic estimation of fish abundance and distribution in the Solina reservoir was related to other biological and hydrological parameters. The increase of fish abundance corresponded to increased levels of eutrophication expressed by Secchi-disc visibility and chlorophyll a concentration. A negative correlation between fish and zooplankton abundances was observed, with changes in the zooplankton population structure, caused by fish grazing. Vertical distribution of zooplankton and fish were affected by the thermocline. Maximal concentrations were observed in a well-illuminated surface layer at the highest temperature and oxygen concentration.