Ecohydrology & Hydrobiology最新文献

The differences in environmental parameters and zooplankton community were studied in the epilimnion of the Carpathian Dobczyce Dam Reservoir on the Raba River (southern Poland) between hydrologically dry (HD), average (HA) and wet (HW) years distinguished on the basis of mean annual flow for 2000-2017. We found significant differences in water chemistry (conductivity, nutrients: P-tot, PO₄³⁻, NH₄⁺) in the epilimnion between the studied hydrological years. The total density and dry weight of zooplankton and the density of Rotifera: Keratella quadrata (Müller, 1786), Copepoda: Copepoda n. det. (immature stages), Cyclops strenuus Fischer, 1851, Eudiaptomus gracilis (Sars G.O., 1863) and Cladocera: Bosmina longirostris (O.F.Müller, 1776), Daphnia cucullata G.O. Sars, 1862, and D. longispina (O.F.Müller, 1776) were significantly higher in HA and HW years than in HD years. The highest densities of many Rotifera, Cladocera and Copepoda species were found in HA and HW years with high flows or floods in the river in spring or early summer. At these times, the epilimnion was rich in P-tot (diffuse pollution), considered as a limiting factor for algal growth in Carpathian reservoirs. The best Generalized Linear Models (GLM) for zooplankton density included 4-6 factors, among which P-tot, NO₃⁻, and pH were always present. We found that river flows prevailing in a given year determine water chemistry and eutrophication processes, which has a significant impact on densities and dry weight of zooplankton communities in HD, HA and HW years. The results obtained have important implications for proper management in mountain catchments.

The purpose of the study was to develop the method of using unmanned aerial vehicles (drones) to map fish fauna habitats in a large lowland river. The intention was to acquire and process spatial data to implement it in the Mesohabitat Simulation system (MesoHABSIM).

At three different water levels, remote sensing data was acquired by unmanned aerial vehicles on the lower Vistula River section. In parallel, depths and velocities of flowing water were measured. Orthophotomosaics were created from the collected images, overlaid with depth and velocity observations to identify hydromorphological units. Maps of fish fauna habitats under different water levels were obtained. The application of the developed procedure algorithm proved successful in habitat mapping studies on a large, deep river with opaque water. The significance of using orthophotomosaics presenting the river under well-defined flow conditions was proven to achieve high accuracy in mapping habitat conditions and reduce errors in habitat usability analyses by fish community.

The superiority of using unmanned aerial vehicles over other methods of collecting data on river habitats and depth and velocity measurements using the Acoustic Doppler Current Profiler (ADCP) method in large rivers with non-clarity water was confirmed. In addition, it was pointed out that drones provide high-resolution images under well-defined flow conditions, which are impossible to obtain using available cartographic materials. The validity of using the incomparably cheaper ADCP technology relative to laser technology, whose application in rivers with opaque water is very complicated, was also confirmed.

Substantial loss of biodiversity and the proliferation of invasive alien species can occur due to land cover anthropogenic transformations on islands. However, the effect of anthropogenic habitat modifications on the distribution of insular freshwater microcrustaceans is unknown. In the present paper, we examine the consequences of human activity on the insular diversity of microcrustaceans in the context of the theories of island biogeography and intermediate disturbances. The samples were collected in Madeira Island at 38 freshwater sampling sites with different anthropopressure. Morphology-based species identification of the copepods and cladocerans was supplemented with genetic analysis (COI) in some species. To estimate the species richness of the island, rarefaction, and extrapolation methods were used. Canonical Correspondence Analysis (CCA) was applied to assess the influence of geospatial and environmental variables on the species distribution. A total of 20 species belonging to six families were identified, of which 16 species are new to Madeira. There was low similarity between the fauna recorded and known previously on the island. The observed species richness was higher than the predictions by the island biogeography models for Madeira. CCA revealed a strong influence of anthropogenic land use on crustaceans. Anthropogenic transformations locally led to the depletion of fauna, but on the island scale they contributed to the increase of species richness including seven putative alien species. An increase in the artificial land cover and a decrease in the forest areas could lead to a further shift in the domination of non-indigenous microcrustaceans.

The mew gull (Larus canus), little tern (Sternula albifrons) and black-headed gull (Chroicocephalus ridibundus) are threatened in Poland by the loss of breeding habitats due to changes in the hydrological regime of rivers and the frequency and length of inundation. Analysis of daily flows generated from the SWAT model allowed us to obtain the values of hydrological characteristics expressed as Indicators of Hydrological Alteration (IHA) and find the relationship with collected data on nesting success on islands and sandbanks in the Middle Vistula from 2004 until 2018. For each bird species, a set of adjusted IHA was calculated for future scenarios (2021-2050 and 2071-2100). The projections were prepared on the basis of EURO-CORDEX and contain two scenarios of changes in greenhouse gas concentrations: RCP4.5 and RCP8.5. Catastrophic breeding seasons quantification was carried out to assess the number of years that will have unsuitable hydrological breeding conditions in the projected climate change. The mew gull noted the lowest nesting success (during 2004-2018) but it seems that hydrology is not the principal factor causing it. This species will experience an increase in high flows due to climate change in the far future scenarios. The black-headed gull is projected not to be affected by an increase in the percentage of catastrophic breeding seasons due to climate change. The little tern seems to be the most affected by projected climate change due to an increase in high flows and, in consequence, an increasing percentage of catastrophic breeding seasons. The results confirmed the importance of hydrologic change for avian nesting success.

Individual processes scale up: these are the unique phenotypes that undergo selection, constitute populations, interact with other species, and thus shape biological reality. Understanding how individual animals differ in behaviour, that is understanding how behavioural individualities (personalities) emerge and are selected, leads us to a better understanding of how higher level systems, such as food webs, communities, or ecosystems, function. As amidst the contemporary global environmental crisis, freshwater habitats and their fish inhabitants are disproportionately both biodiverse and threatened, it is of crucial importance to understand how individual fishes cope with the anthropogenic change. In the present work we first provide a snapshot view of what personalities in freshwater fish are, how they manifest in different species, are shaped under different selective pressures, emerge over ontogeny, and form complex traits. This includes the review of research on fish boldness, exploration, activity, aggressiveness and sociability, and on their consistency and correlations. We then focus on three major threats to freshwater fish, on how fish cope with them behaviourally, and on where personalities may have profound ecological and evolutionary outcomes. The chosen focus on habitat fragmentation by damming, climate change and chemical pollution provides us with an insight into the pervasive role fish personalities play in the contemporary world.

Eutrophication of lakes, as one of the most challenging global environmental problems for more than half a century has been addressed by a vast number of publications. Issues hitherto not considered or treated superficially have been discussed here. They concern: i. breakthrough phases in the 100-year period of development of the Eutrophication Concept (EC) and, ii. concepts and theories derived from EC and their complementarity in terms of assumptions and terminology. The paper traces the history of perception of the primary factors responsible for lake eutrophication. It presents the evolution of the approach to the problem, initially focusing on point and then non-point external sources of pollution, supplemented with internal nutrient supply, bottom-up and top-down regulation, with increasing emphasis on the role of interactions in the food web. The article addresses the justification of the Lake Aging Concept (LAC), assuming an inevitable increase in the trophic status during the development of a lake, and unjustly identifying eutrophication with progressing disappearance of lakes in a geologically-relevant timescale. It also discusses the assumptions of the Theory of Alternative Stable States (TASS) and discrepancies between EC and TASS regarding the application of different terminology in reference to the same phenomena and lake classifications.

Salinization is an emerging problem for freshwater biodiversity. Road salt treatment results in salinization of local freshwater, influencing its entire ecosystem throughout the year. The present study examines the impact of road salt on the hatching success of two zooplankton species, Daphnia magna and Thamnocephalus platyurus, using pure laboratory lines from MicroBioTest. Hatching success was determined without incubation (T0) and after 3, 7 and 28 days of incubation at 5°C (T3, T7 and T28, respectively), at different NaCl concentrations. The low-temperature incubation was intended to simulate winter conditions - 5°C corresponds to the water temperature at the bottom of the ponds during winter in a temperate climate. The number of hatchings decreased with increasing NaCl concentration for T. platyurus, and decreased rapidly after a crucial value of 7 600 mg NaCl/L for D. magna. At the second hatching (eggs washed after first incubation and put into standard freshwater), D. magna demonstrated a low hatching rate regardless of NaCl concentration, while most T. platyurus hatchings were observed at the highest NaCl concentration; hence, the highest (15 200 mg/L) and lowest (1 900 mg/L) NaCl concentrations resulted in similar total hatching for the two species. The incubation time for three and seven days in NaCl at 5°C had no significant impact on hatching success; however, T28 resulted in significantly lower hatching success at all NaCl concentrations and controls. No significant differences in hatching success were noted if the eggs were first washed after incubation in NaCl and then put into the standard freshwater for hatching.

The occurrence, abundance, contribution, and size structure of protected and alien fish species were studied in 535 lakes situated in the northern and central parts of Poland in 2014-2021. We hypothesised that protected fish species, due to their status, would be rare in terms of abundance within certain lakes and/or less distributed. Four protected (Cottus poecilopus, Cobitis taenia, Misgurnus fossilis, and Rhodeus amarus) and eight alien species of fish (Ctenopharyngodon idella, Neogobius fluviatilis, Pseudorasbora parva, Acipenser baerii, Carassius gibelio, Ameiurus nebulosus, Hypophthalmichthys molitrix, and Cyprinus carpio) were identified in the studied lakes. Among protected species, the most common and frequent were R. amarus (65% of the studied lakes) and C. taenia (47% of the studied lakes). Other two species (C. poecilopus and M. fossilis) were recorded in one (0.2%) and 18 lakes (3.4%), respectively. Alien species were most often represented by C. gibelio, which occurred in 96 lakes (18% of the studied lakes). The presence of the remaining seven alien species was found in not many lakes (0.2-5.2% of the studied lakes). The abundance of C. gibelio was positively, while A. nebulosus was negatively related to the trophic state of lakes. Cobitis taenia was positively correlated with morphometric parameters of lakes (area and maximum depth). It came as surprise to us that some protected species were quite frequent and sometimes numerous, in contrast to the majority of alien species.

Catchment land use/land cover (LU/LC) is one of the crucial determinants of the water quality and condition of biota in aquatic environments. The aim of this study was to investigate how LU/LC in lake catchments influences the physicochemical and biological indicators used to assess the ecological status of lakes in Poland and whether these relationships vary depending on the spatial range. We analysed the catchment LU/LC forms of 114 flow-through lakes in three spatial ranges, i.e., a 100 m-wide buffer strip (BUF100), the direct catchment (DIR), and the total catchment (TOT). The water quality and biological variables were derived from the state monitoring conducted in the period 2012–2013. The redundancy analyses (RDA) and the Monte Carlo permutation tests depicted that the strength in explaining the parameter followed the order: TOT > DIR > BUF100 for physicochemical parameters, DIR = TOT > BUF100 for phytoplankton indicators and BUF100 > DIR > TOT for macrophyte indicators. In the direct and total catchment, the proportion of arable lands was decisive in shaping the macrophyte and physicochemical status, while the proportion of artificial surfaces affected phytoplankton status. It was also found that forested buffer zones promoted good macrophyte ecological status. The other types of LU/LC, i.e., meadows and pastures, wetlands, and surface waters exhibited little to no or marginal impact on the physicochemical and biological indicators, regardless of the spatial scale considered. Our results contribute to the rational planning of land development in lake surroundings, including the design of protected areas for inland waters.

This study investigated the zooplankton community structure in Gołdap Lake, located in the northeastern part of Poland. Due to the many years of uncontrolled inflows of pollutants, the ecological condition of the lake has deteriorated. Despite many remedial actions in the catchment, the internal nutrient load of the lake was too great to improve its condition. This goal required additional in-situ activities. The restoration of Gołdap Lake started in 2017. The substance which was used for restoration purposes was Phoslock®. It is lanthanum-modified clay that can bind phosphate into insoluble rhabdophane-(La). Water and zooplankton samples were collected from September 2017 to August 2021. A total of 70 species, including 44 rotifers, 16 copepods, and 10 cladocerans species, were detected during the research period. The whole zooplankton community was divided into 7 functional groups: rotifer filter feeders (RF), rotifer carnivores (RC), small crustacean filter feeders (SCF), mid-sized crustacean filter feeders (MCF), mid-sized crustacean carnivores (MSC), large crustacean filter feeders (LCF) and large crustacean carnivores (LCC). The most abundant were species from the rotifer filter feeder functional group. This study showed a significant correlation between dominant zooplankton groups and environmental variables such as nitrite nitrogen, water temperature, dissolved oxygen, conductivity, biological oxygen demand, and dissolved organic carbon. According to the values of zooplankton-based indices, the ecological state of Gołdap Lake hadn't changed during the research period. The major driving factors which affect the structure of zooplankton were: poor quality of food base, top-down pressure of planktivorous fish, and competition between zooplankton groups.