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EN
The depletion of natural resources such as freshwater and cropland makes it necessary to find a new solution for sustainable food production. Aquaponic systems seem to be a great alternative to traditional agriculture, however, there are still many unknowns that need to be explored. It is already known how fish stocking affects water quality in aquaponic systems, but not how it affects the plants’ growth, and especially on chlorophyll fluorescence. In this study, we examined how the density of 0, 2, 4, 8, and 16 stocking fish in five aquaria affects lettuce growth. The first tank was only a hydroponic system with plants but without fish (control). In the remaining four aquaria - 2, 4, 8 and 12 specimens of common carp fry with an average weight of 20 grams (average 8.5-33.2 g) were placed in the aquaponic growing system. Physicochemical analysis of water was conducted to determine the levels of pH, electrical conductivity (EC), N-NO3, N-NO2, N-NH4, P-PO4, O2 and physiological parameters of plants (nitrogen balance index - NBI, chlorophyll content index - CCI, quantum yield - QY, flavonoid content - Flv) were analysed. The results showed that fish stocking density has different effects on plant physiological parameters, but in most cases, was insignificant. It seems that the greater number of fishes and higher density indirectly causes growth inhibition (lower photosynthetic efficiency) due to the increase of N-NO3 and a decrease of O2 in the water.
EN
Watercourses serve the needs of agriculture in certain sections and are subject to strong anthropopressure. When agriculture prevails in the catchment, it often has abundant vegetation, macrophytes in particular, and the bottom is covered by a substantial layer of silt. In order to ensure patency of flow and access to water, small watercourses are very often subject to river maintenance works. The aim of the study was to assess the impact of 3 types of works on the diversity of fish species and density of fish in the 1 and 2 year after the works at 21 sites located on 8 rivers in the European Central Plains Ecoregion. As a result of the works, especially in the 1 year after the works, significant changes were found in hydrochemical and hydrological parameters, especially with the increase in velocity and mean depth in watercourses. Additionally, habitat change contributed to differences in the composition of the ichthyofaunal. After 1 year, the diversity of fish species and fish population density increased or remained unchanged after dredging and removal of plants from the river channel, but they decreased after the removal of macrophytes from river banks. After year 2, a decrease in the diversity of fish species and density was observed, associated with re-infestation and siltation of the watercourses. Particularly in the case of dredging and removal of macrophytes from the river bank, maintenance works should not be done too frequently, because some species of natural value disappear.
EN
The pot experiment was conducted to access the soil microorganisms biomass (physiological method - Substrate Induced Respiration) and emissions of N2O, CO2 and CH4 (photoacoustic infrared detection method), and grasses biomass (weight method). The obtained results of analysed gases were converted to CO2 equivalent. There was no effect of the microorganisms biomass on the N2O emissions. The increase in CO2 emissions was accompanied by an increase in the microorganisms biomass (r = 0.48) under the conditions of the I swath and acid soil reaction, as well as the II swath and neutral reaction (r = 0.94). On the other hand, in the case of CH4 emission, such a relationship was noted both swaths under the conditions of neutral reaction (r = 0.51), but a negative correlation (r = –0.71) was noted for the acid reaction only at the II swath. The increase in the grasses biomass with the increase in the microorganisms biomass was recorded only at the II swath in neutral reaction (r = 0.91). In a short period of time, with the neutral soil reaction with the increase in the soil microorganisms biomass, an increase in CO2 sequestration and biomass of cultivated grasses was noted. Information on the determination of the microorganisms groups responsible mainly for the transformation of carbon compounds and CO2 and CH4 emissions from the soils of grasslands would be valuable scientifically.
EN
Drought is regarded as one of the environmental constraints threatening agriculture worldwide. Melatonin is a pleiotropic molecule prevalent in plants capable of promoting plant endogenous resilience to many environmental challenges including drought. Banana is an important staple food consumed in developing countries especially in Africa. In this research, we studied the role of melatonin in the growth of bananas subjected to drought under the Egyptian semi-arid conditions. To achieve this objective, a field experiment on banana (Musa spp., cv. Williams) mother plants and first ratoon was conducted on a private farm for two seasons - 2019 and 2020. Three irrigation treatments, 100, 90 and 80% irrigation water requirements (IWR) were used in conjunction with four concentrations of melatonin as a foliar spray (0 μmol, 40 μmol, 60 μmol, and 80 μmol) to determine the effect of both treatments on banana plant performance under drought. The results showed that there was a substantial difference between treatments, with the foliar application of melatonin at 80 μmol concentration improving most of the yield attributes, relative water content, total chlorophyll and proline with water deficit. However, the foliar application of the molecule lowered the biochemical characteristics mostly at 80% IWR under the Egyptian semi-arid conditions. Overall, there was a concentration-dependent response with regards to IWR for the two seasons 2019 and 2020.
EN
Abiotic and biotic bounty of riparian waters may be affected by inadequate maintenance works. Improper planning and execution of maintenance works cause changes to hydrological and hydrochemical condition of water in small rivers, affecting biocenose of riverbeds by modifying the taxonomic composition of organisms inhabiting the regulated river section. Five (5) rivers were subject to studies - Plonia, Mysla, Tywa, Rurzyca, and Wardynka (Odra river basin), which were monitored before and after maintenance works consisting in desilting, mowing and removal of aquatic plants. This study examined hydrological (mean depth and width of small rivers, speed and flow), physical and chemical parameter of water (temperature, pH, O2, N-NO3, N-NH4, P-PO4) before and after dredging of selected rivers. Obtained results and resulting statistical analysis demonstrated increase in hydrological indices - depth, width, speed and flow. Among other physical and chemical properties that significantly increased following completion of maintenance works, were O2 and NH4. NO3 concentration and temperature dropped, but not statistically significant. Changes in hydrological and hydrochemical properties of waters caused by maintenance works may affect biodiversity of the regulated river sections, including changes in composition of ichthyofauna species.
EN
In 1970-2010, during the period of spring circulation and summer stagnation, hydrochemical studies were conducted in Lake Ińsko (Western Pomeranian Lake Region, Poland) with determination of the lake susceptibility to degradation and trophic changes. Also, the effect of the catchment area on the water quality in this waterbody was assessed. The waters of the study lake were characterised by low static index, which is an additional indicator of low dynamics of water masses, and low susceptibility to degradation. In spite of this, significant changes in the lake quality and trophy were observed. The hydrochemical parameters defining water quality of the study lake continued to improve. In the 70’s, the water quality was at the border of class II and III, while in 2006 and 2010 it reached the level characteristic for class I waters. Moreover, in the 70’s and 80’s of the previous century, Lake Ińsko Duże was a mesotrophic lake. Then, an increase in the lake trophy was observed, resulting in signs of eutrophy. At the end of the 90’s and in the first decade of the 21st century, the study lake returned to the state of mesotrophy. No restoration works were undertaken in Lake Ińsko in the study period. The improvement in water quality, called oligotrophication, resulted most probably from the lake reaction to changes in the soil use in the catchment area, since fewer phosphorus and nitrogen compounds flow into the lake, and also from the regulation of the wastewater management in the town of Ińsko.
EN
Round goby (Neogobius melanostomus (Pallas, 1814)) is an invasive species in the Oder River. In this study, age of 147 fish was determined using scales and otoliths, and the Fraser-Lee back-calculation method was used for population structure and theoretical length growth rates with 3 mathematical models of growth: von Bertalanffy, Ford–Walford and 2nd degree polynomial. Fish condition was determined using Fulton, Le Cren and Clark equations. Average total length and weight of fish was 162.00 mm and 83.00 g, respectively. Males were more abundant than females, representing 70% of the fish caught, and achieved greater total lengths and weights. Age 2+ dominated females and 3+ males age groups. Of the three mathematical models used to estimate fish growth, the 2nd degree polynomial model had the best fit to back-calculated lengths. Males had slightly higher growth rates than females in the first two years of life but comparable in subsequent years. The diet consisted of various benthic organisms that varied with fish age. The most frequently occurring food component was Dreissena polymorpha, which accounted for approximately 70% in the diet of fish with a body length greater than 191 mm.
EN
For the last few decades there have been reports not only of the occurrence of new invasive species of European watercourses, but also their increasing expansion. One of such species is the Amur sleeper (Perccottus glenii). The present work contains assessment of age and length distribution, condition as well as growth rate and analysis of the parasite fauna of the Amur sleeper from the waters of the Vistula River tributary in its middle course (the Habdziński Canal). During the catch performed in 2017 and 2019, the total of 177 Amur sleepers were recorded in the studied watercourse and a statistically significant sex structure disproportion was observed. Among the specimens caught in 2017 dominant were fishes with lengths of 50.1–60.1 mm whereas in 2019 the majority of the Amur sleeper specimens measured 30.1–50.0 mm. Six age groups were recorded among the caught fish with a clear prevalence of specimens aged 1+ (70.06%). The most frequently recorded parasite of P. glenii was non-quantifiable Trichodina rostrata ciliate for which the Amur sleeper from the Polish waters appeared to be a new host. Moreover, the presence of an acanthocephalan Acanthocephalus lucii, not recorded in Poland in this host before, was observed in the chyme. Also, accidental presence of larvae of the Opisthioglyphe ranae tremadote, which is a parasite typical of amphibians, was also recorded. Despite unfavourable habitat conditions and increased volumes of biogenic substances in the waters of the Habdziński Canal, the Amur sleeper found convenient conditions to reside in this small watercourse.
EN
Increasing anthropopressure affects natural ecosystems and may express itself in regional or spot contamination of water and soil environment. The quality of ground and surface waters depends to a large extent on drainage area management, where biogenic substances (i.e. nitrogen, phosphorus and potassium) are transported with surface run-offs to the environment. The article discusses results of studies on the drainage area of Lake Czolnowskie (Zachodniopomorskie Province). Studies covered physical and chemical assessment of soil conditions and water quality; additionally, fish was caught using two independent methods - gillnets and power generator (pursuant to CEN EN 14011 2003 and PN-EN 14011 2006). Results obtained confirm regular run-off of biogenic materials from the surface of farmed drainage area to Lake Czolnowskie. During the period of studies, the reservoir was exposed to i.e. reduction of water oxygen (3.56 mg/dm3) and permanently elevated level of general phosphorus (0.15-0.27 mg/dm3) and ammonium acid (0.16-0.27 mg/dm3), which degraded the quality of life for ichthyofauna inhabiting the lake.
EN
An important source of contamination of inland waters is the content of nitrogen and phosphorus compounds, which in agricultural areas constitute a significant threat by getting into flowing waters. The runoff of mineral substances from areas with high intensification of agriculture contribut to increase of nutrient content in rivers, which often causes disturbances in water quality, with excess nutrients supporting the growth of phytoplankton (algae receipts) and macrophytes and associated with it loss of habitats and desirable plant and animal species. The small rivers play an important role in the water quality of large rivers. The purpose of this work is to assess the quality of water in small lowland rivers, which are tributaries of the Odra and Wisła rivers, with particular emphasis on the content of biogenic compounds (nitrogen and phosphorus forms). The study was carried out on 10 small rivers from the Odra river basin (Płonia, Myśla, Tywa, Rurzyca and Wardynka River), and the Wisła river basin (Habdziński Channel, Zielona, Czarna-Cedron, Kraska and Molnica River). The analyzed water samples in all rivers had increased content of reactive phosphorus, which allows to classify the waters into non-class waters. The highest exceedences were recorded in the Płonia River (on average 1.505 mg P-PO43-/L) in the Odra river basin, while in the in the Wisła basin the highest exceedances were recorded in the Molnica watercourse (average 2.023 mg P-PO43-/L). Also high concentrations of the nitrate-nitrogen content were recorded, and the highest amounts of N-NO3-/L were found in the Rurzyca River (the Odra catchment – 7.321 mg N-NO3-/L) and in Molnica River (Wisła catchment – 5.092 mg N-NO3- /L). Lower values of ammonium nitrogen were found in all tested watercourses, classifying water to the first class of water quality according to Minister of the Environment Regulation (21.07.2016r.). Only increased concentrations classifying the examined waters up to the 2nd water quality class were recorded in the Rurzyca river (Odra catchment - 0.350 mg N-NO3- /L average, and in the Habdziński Channel (Wisła catchment - 0.293 mg N-NO3- /L). Significant increases in the content of biogenic compounds classifying tested waters to the 2nd class and above, were also conducive to low values of oxygen concentration in water and high conductance. For example in the Molnica river, high nitrate nitrogen and phosphate content influenced on low water oxygenation. In addition, there was a very low water level in the watercourse, which could have triggered nutrient loads in bottom sediments. Contamination of waters from agricultural areas with nitrogen and phosphorus compounds may pose a threat to larger rivers to which they can pass without proper monitoring.
PL
Istotnym źródłem zanieczyszczenia wód śródlądowych są zawartości związków azotu i fosforu, które na obszarach rolniczych stanowią znaczące zagrożenie przedostając się do wód płynących. Do nadmiernego wzrostu zawartości związków biogennych w rzekach przyczyniają się spływy substancji mineralnych z terenów o dużej intensyfikacji rolnictwa, co niejednokrotnie jest przyczyną zaburzeń jakości wody, przy czym nadmiar składników odżywczych sprzyja wzrostowi fitoplanktonu (zakwitów glonów) i makrofitów oraz związanej z tym utraty siedlisk i pożądanych gatunków roślin i zwierząt. Dużą rolę w kształtowaniu jakości wody dużych rzek pełnią niewielkie dopływy stanowiące małe cieki wodne. Celem niniejszej pracy jest ocena jakości wód w wybranych małych nizinnych ciekach wodnych będących dopływami rzeki Odry i rzeki Wisły ze szczególnym uwzględnieniem zawartości związków biogennych (formy azotu i fosforu). Badaniami objęto 10 niewielkich cieków z obszaru zlewni rzeki Odry (rzeki: Płonia, Myśla, Tywa, Rurzyca i Wardynka), oraz zlewni rzeki Wisły (Kanał Habdziński, Zielona, Czarna-Cedron, Kraska i Molnica). Analizowane próby wody we wszystkich rzekach miały podwyższone zawartości fosforu fosforanowego, co pozwala zaklasyfikować badane wody do wód pozaklasowych. W zlewni rzeki Odry największe przekroczenia norm odnotowano w rzece Płonia (średnio 1.505 mg P-PO43-/L), natomiast w zlewni Wisły największe przekroczenia zanotowano w cieku Molnica (średnio 2.023 mg P-PO43-/L). Również wysokie stężenia odnotowano analizując wody pod kątem zawartości azotu azotanowego, a największe ilości N-NO3-stwierdzono w rzece Rurzyca (zlewnia Odry – 7.321 mg N-NO3-/L) i w Molnicy (zlewnia Wisły – 5.092 mg N-NO3-/L). We wszystkich badanych ciekach stwierdzono niższe ilości azotu amonowego, klasyfikując wody do I klasy czystości wg Rozp. MŚ z 21.07.2016r. Jedynie podwyższone stężenia klasyfikujące badane wody do 2 klasy czystości wód zanotowano w rzece Rurzyca (zlewnia Odry – średnio 0.350 mg N-NH4+/L, oraz w Kanale Habdzińskim (zlewnia Wisły – 0.293 mg N-NH4+/L). Znaczące podwyższenia zawartości związków biogennych klasyfikujące badane wody doII klasy i powyżej II klasy czystości wód sprzyjały również niskim wartościom stężenia tlenu w wodzie oraz wysoką konduktancją. Przykładem jest tu rzeka Molnica, w której wysokie zawartości azotu azotanowego oraz fosforanów przekładały się na niskie natlenienie wody i wysokie przewodnictwo właściwe. Ponadto w cieku była bardzo niski stan wód, co mogło uruchomić pokłady ładunków biogennych w osadach dennych. Zanieczyszczenia wód z terenów rolniczych związkami azotu i fosforu mogą stanowić zagrożenie dla większych rzek, do których bez odpowiedniego monitoringu mogą się przedostawać.
EN
Monitoring studies of ichthyofauna, in particular non-indigenous species, are an important element of research on aquatic ecosystems. This information is essential for modelling population growth and predicting rates of expansion, quantifying ecological impacts and assessing the efficacy of removal and control strategies. Actually, the most compelling fish invasion in Polish freshwaters is arguably the accidental introduction of the topmouth gudgeon (Pseudorasbora parva). Age and lengths structure, condition factor and growth rate of the invasive populations of the topmouth gudgeon from small Polish rivers was examined. The samples were collected from the rivers: Molnica (n = 41), Myśla (n = 21) and Wardynka (n = 101) soon after the invasion was recorded (2017). Estimated ages of topmouth gudgeon ranged from 1+ to 3+ for the Myśla River, from 1+ do 4+ for the Molnica River, and from 1+ to 5+ for the Wardynka River. The fish from the Molnica River was characterised by the lowest total and standard length (TL, SL), weight, and highest condition. The results of back-calculations and the parameters of von Bertalanffy’s growth equation revealed distinct disproportions in the standard length (mm) in individual age groups (Molnica River: Lt = 54.94 [1 – e–0.68885 (1 – 0.003404)], Myśla River: Lt = 55.39 [1 – e–0.74921 (1 – 0.030962)], Wardynka River: Lt = 66.33 [1 – e–0.69348 (1 – 0.369505)]). The introduction of the topmouth gudgeon occurred in the upper and medium sectors of small rivers, but in subsequent years the species migrated to new sites further downstream and this may have affected the native ichthyofauna.
PL
Badania monitoringowe ichtiofauny, w szczególności gatunków nierodzimych, są ważnym elementem badań nad ekosystemami wodnymi. Informacje te są niezbędne do modelowania wzrostu populacji i przewidywania tempa ekspansji, ilościowego określania skutków ekologicznych i oceny skuteczności strategii eliminacji tych ryb z wód rodzimych oraz ich kontroli. Jednym z najbardziej interesujących gatunków inwazyjnych w świecie ryb w polskich słodkowodnych wodach jest prawdopodobnie przypadkowe wprowadzenie czebaczka amurskiego (Pseudorasbora parva). W pracy analizowano strukturę wieku i długości, współczynnik kondycji i tempo wzrostu inwazyjnych populacji czebaczków amurskich z małych cieków w Polsce. Ryby złowiono w 2017 r. z rzek: Molnica (n = 41), Myśla (n = 21) i Wardynka (n = 101). Szacowany wiek czebaczków amurskich wynosił od 1+ do 3+ (Myśla), od 1+ do 4+ (Molnica) i od 1+ do 5+ (Wardynka). Ryby z Molnicy cechowały się najmniejszą długością całkowitą i długością ciała (TL, SL) oraz masą osobniczą. Odczyty wsteczne i parametry równania wzrostu von Bertalanffy’ego ujawniły wyraźne dysproporcje w długości całkowitej w poszczególnych grupach wiekowych (rzeka Molnica: Lt = 54,94 [1 – e–0,68885 (1 – 0,003404)], rzeka Myśla: Lt = 55,39 [1 – e–0,74921 (1 – 0,030962)], rzeka Wardynka: Lt = 66,33 [1 – e–0,69348 (1 – 0,369505)]). Wprowadzenie czebaczka amurskiego miało miejsce w górnej i środkowej strefie małych cieków, ale w kolejnych latach gatunek ten może migrować do nowych miejsc zlokalizowanych w dolnych odcinkach rzek i może wpływać na rodzimą ichtiofaunę.
EN
The studies were conducted in the summers of 2017 and 2018 on three watercourses in Central and North-Western Poland, the where maintenance works involving disposal of sediment and silt were performed in the autumn of 2017. Monitoring of the ichthyofauna in the Rurzyca River and the Tywa River before (year 2017) and after the maintenance works (year 2018) indicated a decrease in the number of species. Altogether, 23 fish species were caught in all the watercourses. Out of these, 12 species were not recorded after the studied rivers had been dredged. A slight decrease in the number of fish species was observed in each studied river after the maintenance works. The values of physicochemical parameters obtained for each watercourse indicate a low quality of the waters. After silt had been removed from the watercourses, lower N-NO3values were observed at most research sites, whereas the N-NH4+ values increased significantly (except for one site on the Kanał Habdziński). Additionally, high volumes of P-PO43-were observed (except for sites 2 and 3 on the Kanał Habdziński and site 2 on the Rurzyca River). Maintenance works performed on small watercourses have a negative impact on the quality of waters and a less significant impact on the number of fish and biodiversity. This appears to be connected with migration of fish in the river during the maintenance works and avoidance of the consequent unfavourable conditions to gradually return to their habitats afterwards.
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