Ecohydrology & Hydrobiology最新文献

Researchers have increasingly integrated machine learning (ML) and deep learning (DL) algorithms to forecast the risk, vulnerability, and susceptibility of various geo-environmental challenges. However, to the best of our knowledge, there is a dearth of studies that have employed DL to predict the health status of wetland habitats, and none have explored a comparative analysis between ML and DL models in this context. This study aims to fill this gap by focusing on the development of wetland habitat health status using both ML and DL models, seeking to determine whether DL models exhibit superior predictability compared to ML models. The assessment of wetland habitat health status reveals that smaller fringe wetlands situated away from main rivers tend to be identified as poor habitats. The transition from phase II to III is marked by a substantial reduction in wetland area, decreasing from 438.76 km² to 235.68 km² across different habitat zones, underscoring the significant loss of wetland areas. The observed 43–46 % decline in very poor and poor habitat areas from phase II to III lends credibility to the predictive capabilities of the models. Notably, among the applied ML and DL models, XGB from the ML category and DNB from the DL category have demonstrated superior performance. In all instances, DL models outperformed ML models, suggesting that deep learning algorithms hold promise for evaluating wetland habitat health status. The mapping and modelling of wetland habitat health status at a spatial scale are pivotal for formulating effective wetland management strategies. The identification of areas with poor and good habitat health provides valuable information for prioritized planning and targeted wetland restoration efforts.

The presence of microplastics (MP) in the organs of five fish species caught in the freshwater reservoirs of northern Poland was evaluated. Gills, liver, and digestive tracts of several commercial fish species such as common perch, silver Prussian carp, roach, and rainbow trout were tested to assess MP uptake due to their high population size as well as they play significant role as biomonitors. Since the mentioned species are gladly consumed they can be considered as a source of MP for humans. MP items were identified in all fish species. The highest contribution of MP was observed in predatory fish such as rainbow trout and perch. None of the correlations between MP abundance and fish body size. The number of items per individual fish ranged from 1 to 12, with an average of 1.78. Among the investigated MP shapes two types were found: fibers (56 %) and particles (44 %). MP were observed in different organs, such as the gills (50 %), liver (11 %), and digestive tract (39 %). The most dominant color observed was blue (58 %). The dominant size range was 1–5 mm (42 %), and 0.1–0.5 mm (42 %) respectively. The FT-IR characterization revealed the presence of polymers predominantly containing polyethylene, polypropylene, polyacrylic acid, cellophane, and polystyrene.

Beaver-created ponds constitute an important element of small water retention in forest catchments and preserving biodiversity as breeding sites for vertebrates and invertebrates. In many areas, these habitats disappear as a result of drainage melioration, drainage formed from agricultural and developmental needs, and liquidation by littering and backfilling. This study was carried out from 2017 to 2019 to understand the transformations of river valley as a result of the beaver activity in the context of newly created ponds and mountain stream and to assess the changes and biodiversity. Beavers modified in-stream habitat by constructing dams, thus creating a series of interconnected dam ponds. Organic matter retention was higher in beaver ponds relative to unmodified river section. In beaver ponds, the invertebrate aquatic assemblages was highly variable. A total of 56 taxa were identified, and significant seasonal variability of benthos assemblages. The values of diversity indices confirmed the instability of benthos assemblage in beaver ponds (variability of species amongst years and sites), which may be related to the short period of their existence. Lotic macroinvertebrate assemblages were common in the beaver-modified section of stream, with some lentic taxa also being present. The unmodified section of stream had more abundant collectors- gatherers and predators and no filter feeders, while scrapers were more abundant in modified section. The environmental variables which significantly influenced invertebrate occurrence were pH, nitrates, iron and the content of organic matter. The results contribute to ecological characteristics of these aquatic environments, and enable determining their functioning in forest areas.

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.

Ever-new cyanotoxins are being discovered, with planktic Cyanobacteria being the most studied communities, although records of cyanotoxins from benthic communities are becoming increasingly common. ​​Thus, the latter also started threatening users of water for recreational or drinking purposes. However, vast areas of the globe, i.a. Central Asia, are still understudied in this respect. Our recent study of benthic Cyanobacteria in the mountains of Eastern Pamir (Tajikistan) suggested that cyanotoxin production in high mountain environments is very limited. Here we present further study of Cyanobacteria, cyanotoxins, and other biologically active compounds such as geosmin and 2-Methylisoborneol (MIB) in microbial mats and water above them. Samples were collected in Eastern Pamirs, in UV (7–11) and altitude gradient (1000–4000 m a.s.l.). In the study, we used microscopic and genetic identification of Cyanobacteria based on NGS of V3-V4 16S rRNA amplicon and toxin assays using LC-QTOF-MS. The analyses demonstrated that the studied microbial mats contained potentially toxic Cyanobacteria (Anabaena, Lyngbya, Nostoc, Oscillatoria, and Phormidium). The production of cyanotoxins and taste and odor compounds (T&O) in natural environments was restricted to altitudes up to 3000 m a.s.l. Three water samples at 1000, 2000 and 3000 m a.s.l. contained MIB and/or geosmin, while debromoaplysiatoxin was noted at 2000 m a.s.l. Additionally, two strains (Hillbrichtia pamiria gen. nov. sp. nov. and Nostoc paludosum) isolated from sites at about 4000 m, in which no cyanotoxins or T&O were identified, produced debromoaplysiatoxin and microginin in laboratory conditions. The results suggest that in a stressful environment Cyanobacteria do not produce toxins.

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.

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.