Effect of Water Management Technology Used in Trout Culture on Water Quality in Fish Ponds

Pond management requires that a specific fish culture is conducted while taking into account both production possibilities and profitability, as well as the impact it may have on the natural environment. This study aimed to evaluate the effect of three water management systems used in rainbow trout culture on water quality in fish ponds. It was conducted at six trout farms and differing in water management strategy. After water had flown through the fishing ponds, its quality was significantly less impaired at farms operating in the flow and cascade systems. In turn, waters discharged from farms using the recirculation system were characterized by the poorest quality and lowest values on the Water Quality Index (WQI). It was found that the flow and cascade systems can be used to maintain the water quality and give less fish mortality for trout. It has been shown that the use of a water recirculation system in rainbow trout cultures significantly affects the quality of water in fishponds and can potentially lead to suppression of fish resistance and in extreme cases, to fish death. This study will help fish farmers in choosing the optimal variant of water management, taking into account both the best fish health with the least negative impact of fish farms on the environment

Aktualne i przyszłe warunki agroklimatyczne w Polsce w perspektywie globalnych zmian klimatu

The paper is a compilation of results, which indicate the scale of possible changes of agroclimate that will occur as a result of the ongoing global warming on Polish territory. Calculations on the future meteorological elements were performed using WGENK weather generator. The 300 variants were obtained of possible annual weather courses dating to the beginning of the second half of this century, and corresponding annual indices of the A1 scenario developed by the IPCC (The Intergovernmental Panel on Climate Change). According to the local climate-factors, obtained data indicate that there are possible situations satisfying assumptions A1 main scenario, exceeding the current climate indicators in terms of temperature, radiation and precipitation, both downward and upward. Apart from this it is possible to greatly expend of the growing season as well as a higher frequency of certain adverse events such as frosts and drought periods. Due to the inability to accurately predict the weather in the perspective of decades and because the main indicators of climate can be realized locally in the form of multiple variants of weather on an annual agricultural production results are difficult to unambiguously determine. Agricultural productivity will certainly significantly be changed, but regardless of global change will have important local factors.Przedstawione w artykule wyniki wskazują na skalę ewentualnych zmian agroklimatu w porównaniu ze stanem obecnym. Nastąpią one w efekcie trwającego globalnego ocieplenia na terytorium Polski. Obliczenia dotyczące przyszłych warunków meteorologicznych przeprowadzono przy użyciu generatora pogody WGENK. Pozyskano w ten sposób 300 wariantów możliwych rocznych przebiegów pogody datowanych na początek drugiej połowy aktualnego stulecia, przy przyjęciu wskaźnika ogólnego wzrostu temperatury według scenariusza A1 opracowanego przez IPCC (The Intergovernmental Panel on Climate Change). Zgodnie z lokalnymi uwarunkowaniami klimatycznymi uzyskane dane wskazują, że możliwe są bardzo różnorodne sytuacje pogodowe, spełniające ogólne założenia A1. Najbardziej prawdopodobne jest zatem wydłużenie wegetacji, jak i znaczne jej skrócenie, częstość zjawisk ekstremalnych może się zwiększyć, jak i obniżyć (np. mrozy, susze). Wskaźniki przyszłego klimatu mogą się spełnić lokalnie w postaci różnych wariantów pogody w układzie rocznym, kiedy w przyszłości temperatura globalna wzrośnie, to agroklimat lokalny może okazać się w tej samej mierze korzystny, jak i niekorzystny. Zatem trudno jednoznacznie przewidzieć przyszły stan agroklimatu i wynikający z tego poziom produkcji rolnej, gdyż niezależnie od tendencji globalnych, rola czynników lokalnych będzie znacząca

Potential Possibilities of Using Groundwater for Crop Irrigation in the Context of Climate Change

The study analyzed the structure of water shortages in plant crops and the available groundwater resources that can be used to satisfy these needs. The research was carried out in Braniewo poviat, which can be considered representative of the conditions of Central and Eastern Europe. A clear upward trend in the temperature value was observed, which influenced the changes in the duration of thermal seasons and agricultural periods. It also increases the intensity of the evapotranspiration process, which results in the reduction of water resources. The presence of significant water shortages, especially in the cultivation of root crops, such as, for example, late potato or sugar beet, justifies the need to irrigate these plants. Due to unevenly distributed surface water resources, groundwater is used as a source of irrigation. It was found that in the case of many crops, the areas with the greatest water shortages were those with average or high abundance in available groundwater. When indicating the possibility of abstracting large amounts of groundwater for use in plant production in Braniewo poviat, one should consider the fact that, in the long term, their exploitation may cause negative environmental effects

Potential Possibilities of Using Groundwater for Crop Irrigation in the Context of Climate Change

The study analyzed the structure of water shortages in plant crops and the available groundwater resources that can be used to satisfy these needs. The research was carried out in Braniewo poviat, which can be considered representative of the conditions of Central and Eastern Europe. A clear upward trend in the temperature value was observed, which influenced the changes in the duration of thermal seasons and agricultural periods. It also increases the intensity of the evapotranspiration process, which results in the reduction of water resources. The presence of significant water shortages, especially in the cultivation of root crops, such as, for example, late potato or sugar beet, justifies the need to irrigate these plants. Due to unevenly distributed surface water resources, groundwater is used as a source of irrigation. It was found that in the case of many crops, the areas with the greatest water shortages were those with average or high abundance in available groundwater. When indicating the possibility of abstracting large amounts of groundwater for use in plant production in Braniewo poviat, one should consider the fact that, in the long term, their exploitation may cause negative environmental effects

CHANGES IN THE MIDDLE SECTION OF THE NAREW RIVER (BETWEEN OSTROŁĘKA AND ŁOMŻA) IN VIEW OF NATURAL FACTORS AND ANTHROPOGENIC PRESSURES

Contemporary and archive cartographic materials illustrating horizontal profile of the middle channel of the Narew River (between Ostrołęka and Łomża) were compared in the GeoMedia application. The results of the analysis revealed that natural and anthropogenic factors had not significantly contributed to changes in the channel profile over a period of two centuries. Narew is a meandering river, and its activity is associated with intensified erosion of right-bank bends and lateral movement along its flat-bed channel. The most noticeable changes include reduced area of oxbow lakes, mainly due to succession, and suburban settlement in floodplains that had been regarded as unfit for development in the 20th century

Nitrate nitrogen and phosphate concentrations in drainflow: An example of clay soil

Nutrients dissolved in water and not taken by plants leach into deeper soil layers or flow out to surface water through pipe drainage systems, causing ground or surface water contamination. Thus, drainflow from agricultural areas has significant influence on surface water eutrophication. The objectives of this study were to evaluate nitrate nitrogen and phosphate concentrations and load changes in drainflow using as an example clay soil analyzed in period spanning the years 2010 and 2013. Field research was conducted at an experimental site in Lidzbark Warmiński, in the Province of Warmia and Mazury (województwo warmińsko-mazurskie) in Poland. Mollic Gleysols developed from loam and clay dominate in this area. The experimental field has a tile drainage system with 21 m drain spacing and average 0.9 m drain depth. Winter wheat (Triticum L.) and oilseed rape (Brassica napus) were cultivated in 2009–2012 and in 2012–2013, respectively. Chemical analysis of water samples was performed with a Hach Lange DR 3900 spectrophotometer. Annual rainfall ranged from 555 mm in 2013 to 814 mm in 2012. Average nitrate nitrogen daily loads ranged from 0.07 to 0.58 kg ha-1, while the total annual nitrate load varied from 7.5 to 34.6 kg ha-1. Daily loads of phosphate were about ten times lower than daily loads of nitrate and the total annual phosphate load ranged from 0.1 to 2.0 kg ha-1. Neither nitrate nor phosphate concentrations are strongly depended on drainflow, but the nitrate nitrogen concentration indicates some relationship with the season. A substantial increase in the nitrate nitrogen concentration appears at snow melting (March) and continues until the end of May, peaking in the third decade of April, when the cultivated crops begin the vegetative growth. The phosphate concentration did not undergo significant changes during the investigated period

INFLUENCE OF THE CHANGE OF USING SOIL TO THE WATER QUALITY ON THE DRAINAGE SYSTEMS IN OBJECT LIDZBARK WARMIŃSKI

The study included groundwater outflow drainage systems and collected in the pond located at the agricultural use area in the portion of the drainage facility Lidzbark Warminski located on the Sępopolska Plain. The study was performed in two periods: the first one was in 1998–2000 (just after was made drainage), in which the discussed area was used as pasture, and the second in 2008–2010, in which after plowed of the soil was cultivated winter wheat. The aim of the study was to determine changes in water quality after the change of the way of land use. Examinations showed that as a result of the change of the way of using the area and ceasing of mineral fertilizing in waters of the pond was a reduction in the concentrations of the most mineral components, but an increase of pH reaction and concentrations of potassium, magnesium of sulfates and bicarbonates. In groundwaters observed increased the content of concentrations of mineral forms of nitrogen, phosphatic phosphorus, potassium, magnesium, general iron and bicarbonates, and a reduction in the concentrations of calcium, sodium, sulfates and chlorides. However in the water which outflow from drainage pipelines system from the research area was an increase of concentrations most of the determined substances, apart from ammonia nitrogen and chlorides

Heavy Metal Contamination in the Surface Layer of Bottom Sediments in a Flow-Through Lake: A Case Study of Lake Symsar in Northern Poland

River-lake systems most often behave as hydrographic units, which undergo complex interactions, especially in the contact zone. One such interaction pertains to the role of a river in the dispersal of trace elements carried into and out of a lake. In this study, we aimed to assess the impact of rivers on the accumulation of heavy metals in bottom sediments of natural lakes comprised in postglacial river-lake systems. The results showed that a river flowing through a lake is a key factor responsible for the input of the majority of available fraction of heavy metals (Zn, Mn, Cd and Ni) into the water body and for their accumulation along the flow of river water in the lake. The origin of other accumulated elements were the linear and point sources in catchments. In turn, the Pb content was associated with the location of roads in the direct catchment, while the sediment structure (especially size of fraction and density) could have affected the accumulation of Cr and Zn, which indicated correlations between these metals and fine fraction. Our results suggest that lakes act as filters and contribute to the self-purification of water that flows through them. As a result, the content of most metals in lake sediments showed a decrease by approx. 75% between the upstream (inflow) and downstream (outflow) sections. The increased content of two metals only, such as chromium and cadmium (higher by 2.0 and 2.5 times, respectively, after passing through the lake), was due to the correlation of the metals with fine sand. Both the content and distribution pattern of heavy metals in lake sediments are indicative of the natural response of aquatic ecosystems to environmental stressors, such as pollutant import with river water or climate change. The complex elements creating the water ecosystem of each lake can counteract stress by temporarily removing pollutants such as toxic metals form circulation and depositing them mostly around the delta

RISK ASSESSMENT OF SURFACE WATERS ASSOCIATED WITH WATER CIRCULATION TECHNOLOGIES ON TROUT FARMS

Dynamic development of aquaculture has led to an increasing impact on the status of surface waters. Fish production generates wastes that, at high concentrations, may present a serious risk to the aquatic environment. Studies on the assessment of the impact of water management technologies in trout production on the quality of surface waters were conducted in 2011. Six farms were selected for the studies and were divided into two groups based on water management solutions (n = 3): farms with a flow through system (FTS) and farms with a recirculation aquaculture system (RAS). On all farms, water measurement points were set and they depicted the quality of inflow water, the quality of water in ponds and the quality of outflow water. The studies did not demonstrate any impact of applied technology on electrolyte conductivity or calcium and magnesium concentrations in outflow water from a trout operation. In addition, it was found that the use of water for production purposes resulted in a slight increase in phosphorus and total nitrogen concentrations in waste waters