The article presents the dynamics of concentrations and export of nitrogen, phosphorus, TOC in the upper Szeszupa River (tributary of the River Neman) in the period from 2000 to 2014 (15 years) based on monthly analyses performed in Poland in the scope of the National Environmental Monitoring. The lakeland river with a mean discharge of 1.6 m3 s−1 and catchment dominated by agricultural land exports approximately 20 kg ha−1 of organic carbon compounds per year. The export of nitrogen is insignificant (3.8 kg ha−1) with 55% accounting for the element in the form of organic compounds and 31% for nitrates. Phosphorus export is also relatively low (0.12 kg ha−1), with 30% of the load of TP constituted by orthophosphates. During four months (February–May), 40–60% of annual export of nutrients was discharged, whereas the load of nitrates and organic nitrogen was higher than the contribution of outflowing water. From 2010, an increasing tendency has been observed in organic nitrogen export. This may be related to the intensification of animal production in NE Poland and an increase in livestock density.
The subject of the article is the integration of a new CO2 fire extinguishing weighing system to the panel displaying the status of Compact Muon Solenoid (CMS) detector safety systems (CMS Safety Panel) at CERN. The CO2 fire extinguishing system is responsible for protection of unique control devices, so safety of its operation and the weighing system was designed to monitor the state of it and make it reliable. CMS Safety Panel displays status of safety systems used in CMS Experiment and it is based on JCOP Framework that guarantee compatibility of all the projects. The integration of the new CO2 fire extinguishing system to the CMS Safety Panel requires that the system meets the assumptions that other projects fulfil and allows for clear monitoring of its situation along with the rest of the security systems.
The study covered a complex of 16 lakes of the East Suwałki Lakeland, distinguished by high differentiation of morphometric parameters determining their polymictic or dimictic character. In half of the lakes studied, the occurrence of summer water thermal stratification was observed. It strongly influenced the vertical qualitative and quantitative diversification of phytoplankton. The majority of the lakes studied were classified as eutrophic waters. Only lakes Szelment Wielki and Pejcze had the Carlson chlorophyll index at the boundary of mesoeutrophy. In the case of the majority of the lakes, the concordance of all the trophy indices was recorded. In 6 mesoeutrophic lakes, the character of water was only suggested by phytoplankton parameters
This study describes summer phytoplankton communities in 27 lakes in the Suwałki Landscape Park (SLP) using in situ fluorescence methods. Low chlorophyll-a concentrations were noted in most of the studied lakes, particularly in the deepest lakes with highest surface area. Green algae, diatoms and cryptophyta were dominant components of lake phytoplankton. Higher chlorophyll-a concentrations in the shallow or more eutrophicated lakes were connected with an increase of cyanobacteria and cryptophyta concentrations as well as with a decrease in the share of diatoms inphytoplankton structure. Vertical distribution of phytoplankton in stratified lakes revealed the presence of deep chlorophyll layers just below the thermocline where the maximum concentrations of phytoplankton were up to 15 times higher than in the epilimnion zone. The deepest maximum concentration of phytoplankton was noted at a depth of 16.5 metres in Lake Jeglówek. In some lakes two or three significant increases of phytoplankton concentration in the vertical profile were observed, caused by intensive development of different algae groups.
Studies of summer rotifer fauna of 11 shallow and 6 deep lakes of the Suwałki Landscape Park were conducted in an aim to assess the role of lake depth and biotic and abiotic factors in determining the diversity of rotifer communities in lakes undergoing a natural rate of eutrophication not accelerated by anthropopression. Some differences were observed when the group of shallow lakes was compared with that of deep lakes. The former were more differentiated as regards a list of rotifer species, partly due to the high proportion of species with low frequency. Consequently, their faunal originality was markedly higher and values of the percentage similarity of rotifer communities were much lower than in deep lakes. Species richness of rotifer fauna was also dependent on the trophic state of the studied lakes, the character of a nutrient limiting primary production, as well as biomass of diatoms and green algae.
Physicochemical studies in four dystrophic lakes (Suchar Wielki, Suchar II, Suchar IV, and Wądołek) were carried out in Wigry National Park, NE Poland. Total manganese concentrations oscillated within the range of 386.6-647.5 μg Mn dm-3, while those of soluble reactive manganese, 112.5-328.2 μg Mn dm-3. Fairly high boron contents were recorded in the studied lakes, which amounted to 0.09-2.20 mg B dm-3. The increase in dissolved reactive manganese (DRMn) and decrease in dissolved boron concentration with the lake depth were observed. Almost half (47%) of the total manganese pool was composed of dissolved reactive soluble fraction (DRMn), then dissolved organic form (DOMn, 41%), whereas the particulate fraction (PMn) made up the smallest share (12%). Microbial decomposition of lake organic matter disappears and requirements of authotrophic plankton for Mn2+ decreases when the water temperature drops, thus the fraction prevails. The following regularity was recorded in all analysed dystrophic lakes: iron concentration decreases along with the depth, hence boron content can also be observed due to precipitated borates to bottom sediments, where they are accumulated.
Summer field research and chemical analyses in 2015 provided the basis for the presentation of the trophic status of waters of 28 lakes of the Suwałki Landscape Park in NE Poland, located in the catchment of the River Neman, in the Natura 2000 area – Ostoja Jeleniewska. Lakes Hańcza and Szurpiły are currently mesotrophic ecosystems. The remaining lakes are moderately eutrophic, while four lakes in the group, in addition to anaerobic hypolimnion, have infertile epilimnion similar to that of mesotrophic lakes. Lake Hańcza shows considerable multiannual dynamics of water fertility, periodically reaching a status approximate to eutrophy. In Lake Szurpiły and the majority of smaller lakes of the Suwałki Landscape Park, reduced precipitation in 2015 resulted in an inconsiderable decrease in trophic status. The lakes are under the strong influence of their catchment area, as confirmed by statistically significant correlations between TSI and the Ohle and Schindler ratios. Lakes Kluczysko and Kopane currently remain the most fertile lakes in the Park. Unless rapidly developing cattle breeding leads to excessive fertilisation of waters in the catchment, the forecasted variability of weather conditions during global climate transformations will lead to fluctuations in the fertility of the majority of the analysed lakes at the threshold of meso- and eutrophy. A hypothesis is also stated regarding the considerable role of groundwater alimentation and short retention time in the maintenance of higher than average resources of silica in limnic waters.
Rotifer abundance and species composition in lakes of the Suwalki Landscape Park were studied in the years 1983–1985, 2009, 2012 and 2015. Rotifer trophic state indices (TSIROT) were used to assess changes in the trophic state of the studied lakes. In most lakes of the Suwalki Landscape Park, there were no changes in rotifer communities over the 25–32 year period to indicate a decline in trophy of the lakes. However, in lakes with the strongest decline in TSIROT values, the values of indicative parameters widely varied in 2015, which may indicate that the status of rotifer communities in the lakes may be dependent on non-trophic factors.