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Wastewater generated as a result of the fish brining process has a very high contamination load. Application of appropriate technologies of wastewater treatment in order to reuse it in the production process once the NaCl content has been supplemented can provide an alternative to its costly recycling. The experiment included ultrafiltration tests conducted on waste brine originating from food processing industry. The results of physicochemical tests indicated very high reductions of fat content (100%) and turbidity (99.8%). Reductions were also revealed in the case of other indicators, i.e., chemical oxygen demand, biochemical oxygen demand, protein and histamine content: by 24.4, 35.2, 27.6 and 22.7%, respectively. Furthermore, it was reported that the obtained permeate retained its quality and microbiological stability. The studied ultrafiltration (UF) process can be successfully used for recirculation of brine in salted fish processing, and at the same time constitute an easily monitored critical control point in the hazard analysis and critical control point (HACCP) system.

aspects of the embryonic development of ruffe, Gymnocephalus cernuus (L.) under different thermal conditions. Acta Ichthyol. Piscat. 34 (1): 51-72. Background. Ruffe, Gymnocephalus cernuus is a small fish inhabiting vast areas of Europe, Asia, and also North America. Its substantial geographical dispersal range in different climatic zones, in waters of different parameters indicates that it is a particularly plastic species. Recent implementation of new fish-processing machinery has increased dramatically the economical importance of ruffe, which is now treated as a gourmet food. In the wake of the increased interest in this fish we decided to study aspects of its developmental biology. Methods. Fertilised eggs and the developing embryos of ruffe were incubated under five different temperature regimes. They were monitored in two planes, horizontal and vertical, using a light microscope fitted with a digital camera and connected to a computer with a monitor and a VCR. The data collected were processed using MultiScan software. Results. Perivitelline space in ruffe constitutes as much 65% of the egg volume. This facilitates movements of an embryo and enhances processes of gas exchange through mixing of perivitelline fluid. It finally contributes to the distribution of the hatching enzyme on the inner surface of the egg shell. Similarly as in the other percid fish, the lack of integration between the "lipid raft" with the embryonic disc, causes the fall of the disc on the lateral side of the vitelline sphere. This lateral position persists throughout all sequential stages of the embryogenesis. The diversified thermal regimes of the development affect the timing of the embryogenesis, as well as the condition, weight, and the size of newly-hatched ruffe larvae. The highest rate of specimens hatched in good condition-marked by the highest weight and body length-was observed at the optimal temperature range of 16-18°C. Newly-hatched larva is small

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Physical and chemical properties of river water are subject to both temporal and spatial changes and depend mainly on the environment of the catchment area and its condition. Continuity of ecological processes and the gradient character of river zones (so-called river continuum) are characteristic features of rivers. The flow of matter and energy is one-directional, the same as the direction of the river flow, and a gradual increase of dissolved substances concentrations is natural [1,2]. Human activity is responsible for deviations from a model water flow because geochemical cycles of carbon, nitrogen, and phosphorus undergo significant modifications [3]. The most important anthropogenic factors influencing river ecosystems include agriculture, industry, and urbanization. The supply of pollution from these sources affects water quality in the river and its biocenosis. It is especially damaging for small watercourses that constitute environmentally valuable ecosystems. Therefore, constant monitoring of water quality, providing the possibility to trace the sources of pollution, is an important element of natural environment protection.In light of the above, the objective of the present study was to analyze and assess select physico-chemical indicators of water in the middle reaches of the Ina River and point out those that determine its quality. The analysis of horizontal variability of the studied water quality indicators allowed for assessing purity of the examined stretch of the Ina River and identifying the sources of pollution.Pol. J. Environ. Stud. Vol. 24, No. 1 (2015), 207-214 AbstractOur paper presents a study on the middle reaches of the Ina River. Select physical and chemical indicators were analyzed in order to evaluate water quality. It was determined that the studied river was subjected to strong anthropopressure, and factors declassifying river water included COD Cr , TP, general hardness, and alcalinity. A high level of biogenic elements was additionally increased by pollution discharged to the river in the proximity of a factory specializing in agricultural production and processing food and agricultural produce near the town of Stargard Szczeciński. The process of self-purification was noted, which can be considered as a factor modifying changes and dynamics of nitrogen and phosphorus in the studied river, leading to an internal enrichment with biogenic elements. Those processes were multi-directional as confirmed by PCA analysis, where component 1 accounted for just 36.7% of the total variance, and the total variance exceeding 90.0% was only noted for 7 components.