Search

The aim of this study, conducted in accordance with both European Union and national legislation, was to evaluate the physicochemical conditions of the Rega River in northern Poland, where efforts are underway to restore its watershed for migratory fish. From 2018 to 2022, water temperature, dissolved oxygen (DO), pH, total suspended solids (TSS), conductivity, alkalinity, total hardness (TH), biochemical oxygen demand (BOD5), chemical oxygen demand (CODCr), nitrite nitrogen (NO2-N), ammonium nitrogen (NH4-N), and total phosphorus (TP) were measured at nine monitoring sites. The results showed that TSS and nitrite nitrogen (NO2-N) were the main factors threatening the suitability of the Rega River as a habitat for salmonid fishes. Additionally, maximum water temperatures occasionally exceeded the tolerance limits for these fishes. Seasonal variations in nitrogen and phosphorus forms, and the dependency of nitrogen forms on DO, indicated disruptions in natural biochemical processes due to surface runoff pollutants from the watershed. This includes fertilizer runoff from agricultural fields and municipal pollution from the towns through which the river flows. The findings underscore the need for continuous monitoring of Rega River waters to safeguard the habitat conditions required by environmentally sensitive fish species.

The seasonal availability of food for Antarctic zoobenthic consumers affects, among other factors, the levels of excreted metabolites that can serve as a source of nitrogen (N) and phosphorus (P) for autotrophs. This study tested the effects of prolonged starvation on N and P excretion by Nacella concinna, Odontaster validus, and Sterechinus neumayeri, as well as changes in their body chemistry. In all animals starved for 65 days, a significant decrease in body protein content was observed (33% for S. neumayeri and approximately 23% for N. concinna and O. validus). Nitrogen excretion rates were higher than phosphorus, with mean values (in µmol N or P h−1 100 g−1) of 1.351 and 0.094 for N. concinna, 0.779 and 0.037 for O. validus, and 0.538 and 0.075 for S. neumayeri, respectively. Ammonium nitrogen accounted for 50% to 69% of total nitrogen, while total reactive phosphorus represented 35% to 42% of total phosphorus. The study confirmed the natural adaptation of zoobenthos to prolonged food scarcity and demonstrated that (i) protein was the primary energy source during starvation, (ii) excretion rates were negatively correlated with invertebrate body size and were higher for N than P, and (iii) the excreted N and P loads may serve as a source of nutrients for autotrophs and act as chemical signals in trophic chemoreception. [ABSTRACT FROM AUTHOR]

In order to ensure the protection of lakes against eutrophication, an ongoing global problem, its causes should be determined on an individual basis. In this study, we investigated Lake Niesłysz in northwestern Poland in terms of (i) the impact of nitrogen and phosphorus on primary production, (ii) the Trophic State Index (TSI), and (iii) the hydromorphological characteristics and watershed features. We determined the thermal conditions, dissolved oxygen, organic matter, and selected forms of nitrogen and phosphorus. TSI was determined using Secchi depth (SD), chlorophyll a, total phosphorus (TP), and total nitrogen (TN). Hypolimnetic anoxia was observed in summer. Surface concentrations of chlorophyll a and organic carbon, total inorganic nitrogen (TIN), and total reactive phosphorus (TRP) were 5 μg L−1, 11.7 mg C L−1, 0.049 mg N L−1, and 0.018 mg P L−1, respectively. The TN:TP ratio was >30, while TIN:TRP was <10. The TSIs for chlorophyll a, SD, and TP ranged from 42 to 59, and for TN it was >145. The total trophic state index (T-TSI) exceeded 72. In conclusion, Lake Niesłysz has an average resistance to degradation and the catchment has little influence on the release and transport of biogenic matter into the lake. The limiting nutrient for primary production was phosphorus, but the influence of nitrogen or covariates of nitrogen cannot be excluded. Based on the oxygen conditions in the hypolimnion, the lake should be classified as eutrophic. Most of the TSIs were in the mesotrophic range, while the TSIs for TN and T-TSI classified the lake as hypertonic. The results show that Lake Niesłysz is currently at a critical stage of progressive degradation, and it is advisable to develop and implement protective measures immediately. [ABSTRACT FROM AUTHOR]

The health benefits and detrimental effects of coffee consumption may be linked to chemical compounds contained in coffee beans. The aim of our study was to evaluate the concentration of sodium (Na), potassium (K), calcium (Ca), magnesium (Mg), iron (Fe), copper (Cu), zinc (Zn), aluminum (Al), nickel (Ni), lead (Pb) and cadmium (Cd) in green and roasted samples of coffee beans purchased in Bosnia and Herzegovina, and to determine the potential health implications at current consumption level.

The aim of this study was to compare the quality characteristics of the meat of two genotypes (Lohmann Brown and Lohmann White) of laying hens after the laying period. Studies were conducted on pectoral and leg muscles from 26 females, 13 of each genotype. Breast and leg muscles were evaluated in terms of their basic chemical composition, acidity (pH24), color attributes (L*, a*, b*), electrical conductivity (EC24) and macro- (K, P, Na, Mg, Ca) and microelements (Fe, Zn, Cu, Mn, Cr). Analysis of the texture of the pectoral muscle major and rheological properties (sum of viscosity modules and sum of elasticity modules) was also performed. Breast and leg meat were also subjected to sensory evaluation. The genotype of the birds significantly affected the percentage of intramuscular fat in the pectoral muscle and the percentage of protein, fat and water in the leg muscle. When analyzing pectoral and leg muscles for color attributes, we found no significant (p > 0.05) differences between genotypes. Differences were shown, however, between genotypes in EC24 and phosphorus content in leg muscle. Breast muscles differed significantly (p < 0.05) in iron and zinc content. Sensory analysis revealed significant differences between genotypes in leg muscle tenderness and juiciness, and breast muscle juiciness and aroma desirability. When analyzing the breast muscle in terms of texture, we did not observe any significant differences, nor did we find any differences in the assessment of rheological properties. Not depending on genotype, however, we noted significant differences between protein, fat, water and collagen content, sodium, magnesium, calcium, iron, zinc, copper, manganese, chromium, acidity, color parameters (L*, a*, b*), EC24 and tastiness desirability between breast meat and leg meat. The results of this study showed that meat from old hens obtained after the laying period is a good material for further technological processing, due to its favorable basic chemical composition and high nutritional value expressed in the content of macro- and microelements, and is also characterized by relatively good sensory characteristics, which can be improved by marinating or adding enzymatic preparations during its processing. [ABSTRACT FROM AUTHOR]

River pollution resulting from unregulated and improper water sewage management is a global issue of concern. The discharge of inadequately treated sewage into rivers and the sudden release of excessive quantities during heavy rainfall can result in significant fish mortality. This phenomenon has been observed repeatedly in the case of the Sąpólna River, NW Poland. Consequently, a decision was made to monitor the water quality at two key locations: the drainage channel that feeds into the river and downstream of the channel. Seventeen water quality indicators were measured, including temperature, pH, conductivity, total suspended solids (TSS), dissolved oxygen (DO), biochemical oxygen demand (BOD5), chemical oxygen demand (CODCr), total organic carbon (TOC), alkalinity, total hardness, total reactive phosphorus (TRP), total phosphorus (TP), nitrite-nitrogen (NO2−-N), nitrate-nitrogen (NO3−-N), total ammonia nitrogen (NH4-N), total organic nitrogen (TON), and total nitrogen (TN). It was determined that, at the location farthest from the drainage channel, water quality still falls short of meeting the specified standards. The primary factors leading to the degradation of water quality at this point were TSS, TRP, NO2−-N, and TN. It was concluded that the primary localized source of water pollution in the studied section of the Sąpólna River is the discharge from sewage treatment plants in Nowogard. Consequently, actions should be taken to address sewage quality and reduce discharge quantities. [ABSTRACT FROM AUTHOR]

The aim of the study was to analyze and assess the possibility of using a two-stage filtration system with ceramic membranes: a 3-tube module with 1.0 kDa cut-off (1st stage) and a one-tube module with 0.45 kDa cut-off (2nd stage) for treating effluent water from a juvenile African catfish aquaculture. The study revealed that during the 1st filtration stage of the effluent water, the highest degrees of retention were obtained with respect to: suspended solids SS (rejection coefficient RI=100%), turbidity (RI=99.40%), total iron (RI=89.20%), BOD5 (RI=76.0%), nitrite nitrogen (RI=62.30%), and CODCr (RI=41.74%). The 2nd filtration stage resulted in a lower reduction degree of the tested indicators in comparison to the 1st filtration stage. At the 2nd stage, the highest values of the rejection coefficient were noted in for the total iron content (RIV=100%), CODCr (RIV=59.52%; RV=64.28%, RVI=63.49%) and turbidity (RIV and RV = 45.0%, RVI=50.0%). The obtained results indicate that ceramic membranes (with 1.0 and 0.45 kDa cut-offs) may be used in recirculation aquaculture systems as one of the stages of effluent water treatment.

The objective of the study was to trace the variability of the hydrochemical conditions in three lakes of the West Pomeranian Voivodeship (Poland) - Starzyca, Maszewskie and Nowogardzkie in the annual cycle. The research was done in 2018-2019, and samples for analysis were collected 4 times a year. All analyses were performed applying standard methods. Such hydrochemical indices were determined as dissolved oxygen, chemical oxygen demand, content of orthophosphates, total phosphorus, nitrite, nitrate, ammonium, chlorophyll a and iron. The study showed that all lakes in the research cycle were characterised by a polymictic type of water mixing, and the trophic level, based on the adopted criteria, indicated advanced eutrophy, which may also be caused by anthropogenic pressure. Oxygen conditions characterised by deoxidation of the waters in the bottom layer in the spring and summer seasons, and clear oxygenation in the surface water layer (in Lake Maszewskie reaching even 188.5% in the spring) confirm the significant advancement of the eutrophication process. The supply of phosphorus and nitrogen in spring from pelagic waters in the waters of the examined lakes influences concentrations of chlorophyll a in the summer. The influence of "internal supply" (bottom waters and bottom sediments) on the amount of nutrients available for autotrophs is clearly visible in the analysed lakes - an increase in nitrogen and mineral phosphorus concentrations in relation to surface waters was observed in the bottom layer. [ABSTRACT FROM AUTHOR]

Copyright of Ecological Engineering / Inżynieria Ekologiczna is the property of Polish Society of Ecological Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)