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Aquaponics, defined as a sustainable technology combining aquaculture and hydroponics, integrates plant and fish production into one system. Aquaponics technology offers several major advantages over conventional methods of raising fish and/or plants. In this system, plants act as a natural biological filter, purifying the water so that the same amount can be used repeatedly. Fish, on the other hand, are a natural source of nutrients. This contributes to the aquaponics system's substantial economic potential, thanks to its use of virtually free nutrients, dramatically reduced water consumption, and the elimination of filter systems, making this system innovative and sustainable. On the other hand, the use of medicinal plants for the needs of the pharmaceutical, cosmetics, and food industries is often associated with a decrease in their natural reserves. Utilizing aquaponics for the production of medicinal plants could reduce the pressure on these natural reserves. As a result, aquaponics has emerged as one of the most environmentally friendly methods of cultivating plant species. The concept of aquaponics, which evolved from traditional hydroponic systems, has gained worldwide recognition through the effective use of symbiosis. It refers to the coexistence and interaction of different organisms, facilitating their growth and life cycle processes. Unlike hydroponics, which requires the purification of nutrient solutions due to plant waste, aquaponics takes advantage of the natural cycle of waste and nutrient exchange between plants and fish. Fish waste serves as organic fertilizer for the plants, while the plants help purify the water for the fish. This symbiotic relationship not only reduces the environmental impact associated with aquaculture wastewater but also provides a sustainable method of food production. The integrated system reduces infrastructure costs, conserves water, and minimizes the potential for environmental pollution. Furthermore, it provides an opportunity for increased profitability from both crop and fish production. Cultivation of medicinal plants within aquaponic systems can be carried out year-round, offering a continuous supply of valuable pharmacological resources. This review examines suitable medicinal plants for aquaponic cultivation and evaluates their pharmacological benefits to humans. [ABSTRACT FROM AUTHOR]

Aquafarms should reduce the use of fishmeal and fish oil in nutritional feed. One such accessible and relatively inexpensive food component that could successfully meet the challenge posed by aquaculture is algae. The objective of the present study was to evaluate the algae meal inclusion of Chlorella and Spirulina sp. in a diet for rainbow trout, evaluating its effects on fish growth, histological parameters and fillet quality. Experiments were carried out to replace 50% and 100% of fishmeal with Spirulina sp. and Chlorella vulgaris in feed for rainbow trout (Oncorhynchus mykiss W.) cultured in a recirculation system. At the end of the experimental period, the highest mean live weight was measured in rainbow trout fed a feed containing 50% algal meal in the feed. The absorptive vacuolization of cells was increased the most and lamina propria was average thickened when fed 50% algae diets. Fat droplets in the hepatocytes were larger in the 50% algae meal fed group, and their nuclei were replaced in the peripheral zone of the cells. Substitution of fishmeal with 50% algal meal in fish feed resulted in a 36.44% reduction in the lipid content of rainbow trout fillets compared to control fish. [ABSTRACT FROM AUTHOR]

Probiotics with antimicrobial activity are important alternative to antibiotics, which are ever more restricted because of the developing microbial resistance and some adverse effects following frequent application. The aim of the present study is to determine the antibacterial and antifungal activity of supernatants of eleven Lacticaseibacillus paracasei strains (FR1-11) isolated from mountain anthills and identified by Amplified Ribosomal DNA Restriction Analysis (ARDRA). Antimicrobial activity was determined against reference strains of Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Penicillium chrysogenum, Aspergillus niger, Aspergillus carbonarius, Aspergillus ochraceus, Aspergillus parasiticus, Fusarium oxysporum, Fusarium graminearum and clinical isolates of Bacillus cereus, Listeria monocytogenes and Salmonella enteritidis using agar well diffusion method. All strains of Lacticaseibacillus paracasei inhibited the growth of Staphylococcus aureus, Listeria monocytogenes, Salmonella enteritidis and Penicillium chrysogenum, 10 strains - Pseudomonas aeruginosa, 9 strains - Aspergillus carbonarius, 6 strains - Fusarium oxysporum, 5 strains - Escherichia coli, and 3 strains - Bacillus cereus. There are no active strains against Aspergillus niger, Aspergillus ochraceus, Aspergillus parasiticus and Fusarium graminearum. The highest antibacterial activity was measured against Pseudomonas aeruginosa with 14.7 mm inhibition zone of FR3 strain. The largest zones of inhibition against fungal strains were 12 mm, determined by the activity of FR2 and FR4 strains against Penicillium chrysogenum. As a whole, the supernatants of Lacticaseibacillus paracasei strains showed higher activity against bacterial strains compared to fungal strains. [ABSTRACT FROM AUTHOR]

One innovative technology where fish and plants are cultivated in the same recirculation system is aquaponic. The usage of growth promoting substances like therapeutic antibiotics is not possible solution for this sustainable and biological production technology. This lead to the need for alternative growth promoters supplements to be tested. One possible solution is a probiotics and the current studies connected with this topic in aquaponic systems are still very rare explored. The aim of this study was to retrace the effect of probiotic ProViotic® added to feed of common carp (Cyprinus carpio L.) on its growth, blood parameters and meat quality as well as on growth of heads and lengths roots in lettuce (Lactuca sativa), raised in the aquaponic recirculation system. The fish were fed with two feeds: control feed (CF) - without addition of supplement and experimental feed (EF) (with supplementation of 460 mg. kg-1 ProViotic® in fish feed). The density of carp in recirculation system was 50 spc.m-3. The initial average weight of fish in CF variant was 41.83 ± 1.80 g and in EF variant was 41 ± 2.71 g without differences being statistically significant (P ≥ 0.05). The continuation of the experiment was 60 days. The average final weight, meat quality, and blood biochemical parameters were measured at the end of the experiment. The blood samples were examined by the colorimetric method with blood analyzer (Mindray SC - 120). The meat quality (moisture (%), dry matter (%), crude protein content, fat and ash content were determined respectively to Bulgarian State Standard (BSS)11374-86, BSS-ISO 5983, BSS-ISO 6492, BSS 11374-86). The data were analyzed statistically with ANOVA single factor and T-test STATISTICA 6.0 software (StatSoft Inc., 2002). The average final weight in carp from the experimental group was higher with 4.3%, compared with the value of this parameter, found for the fish from the control variant (P < 0.05). The quantity of glucose, triglycerides and alkaline phosphatase (ALP) in the blood of fish fed with feed supplemented with ProViotic were lower, respectively with 15%, 11.83%, and 38.2%, compared with the average values in these blood parameters found out for fish from the control variant, but the differences were not statistically proven (P < 0.05). Concerning the parameters of meat quality in fish from experimental groups the quantities of fat and ash were higher respectively with 8.11% and 2.17% compared with values of these parameters found in the carp from the control group, but the differences were not statistically significant (P ≥ 0.05). The weight of head and length of roots in lettuce cultivated in the aquaponics system were respectively 142.34 ± 4.73 g and 62.10 ± 1.15 cm at the end of the trial. The supplemented diet with ProViotic® increased the growth of carp and did not affect negatively the meat quality and blood biochemical parameters in fish as well as the weight of head and length of roots in lettuce cultivated in the aquaponic system. [ABSTRACT FROM AUTHOR]

Different plants and their parts can be used as a supplement in food for human and animal. The purpose of this study is to establish the growth rate, meat quality and biochemical blood parameters (glucose, urea, creatinine, total protein, albumin, ASAT, ALAT, Ca, P, Mg, triglycerides, cholesterol) of rainbow trout (Oncorhynchus mykiss), fed with sweet flag extract (Acorus calamus). The fish from the control group C (without supplement) and the experimental A.c (supplemented with 1% Acorus calamus extract), each with two repetitions, were placed in a recirculating system at the Aquaculture Base of the Faculty of Agriculture of the Trakia University. Thirty specimens of rainbow trout with average fish weight of 42.55±7.48g (C) and 45.01±8.94g (A.c) in good health were placed in each tank and cultivated for 60 days. At the end of the experiment, average final weight, specific growth rates, feed conversion factor, meat quality and blood parameters were established. At the end of the experiment, the average live weight of fish fed with sweet flag extract was 6.53% higher than the value of the same indicator of the trout in the control group (P <0.05). The calcium, phosphorus and magnesium levels in the blood of rainbow trout from the experimental group were 71.2%, 37.36% and 37.5% higher respectively than the levels of the same minerals in the control group (P< 0.05). Fish fed with sweet flag extract supplement have better growth rate and lower feed conversion ratio. [ABSTRACT FROM AUTHOR]

In the study was determined the impact of organic fertilizers as anti-stress agents and their impact on the particular species. Also was carried out an evaluation of the plant anti-stress response, by applying different methods of reporting and looking for ways to overcome it. Climate change and coming with them abiotic stressors, a consequence of extreme weather conditions, especially affect on salad grown outdoors. What are the climate fluctuations in hydrothermal conditions and how they can affect the growth and development conditions? This question is very relevant at the moment. Therefore a general hydrothermal characterization of the climate in the Plovdiv region for the period 1990-2019 has been made. In the study were made analyses of the basic conditions during the period investigated, the presence of stressors, as well as an assessment of the impact of major meteorological factors on salad crop productivity, on three different varieties, using four different formulations of organic fertilizers, and also control variants with mineral fertilizer and without fertilizing. The goal was to increase plant resistance to abiotic stress and to guarantee the yield by optimizing nutrition. [ABSTRACT FROM AUTHOR]

The purpose of this study was to investigate the influence of aquaponically grown L. minuta used as a part of biofilter in recirculation aquaculture systems, with its subsequent inclusion in the composition (50 and 100% content of daily feed ratio) in sustainable diets on hydrochemical, biochemical blood and technological parameters in common carp (Cyprinus carpio L.) fingerlings cultivated in aquaponics recirculation systems. At the end of the experiment were calculated average final weight, specific growth rates, feed conversion ratio, meat quality and blood biochemical parameters. The inclusion of up to 100% duckweed (L. minuta) in feed for common carp fingerlings decreases the quantity of ammonium, nitrite, nitrate and phosphate accordingly with 66%, 71.4%, 38.8% and 44.1%compared with the quantities of these parameters found for experimental groups fed with feed without inclusion of L. minuta. The carps fed with inclusion of up to 50% duckweed showed better growth of fish, SGR and FCR compared with fish fed with a diet without substitution of duckweed. [ABSTRACT FROM AUTHOR]

The use of eco-technologies, such as duckweed insetting, for wastewater treatment is becoming popular because of its affordability and efficiency of pathogen removal. The purpose of the current research was to study the influence of Lemna minuta as a single plant in aquaponic recirculation system on the indicator microorganisms and pathogens in water. The aquaponic recirculation system consisted of 10 fish cultivation tanks and 4 plant tanks. The cleaning block of the system consisted of one mechanical filter (settling tank) and moving bed biofilter. Weekly samples of control water, fish tanks, and tanks with L. minuta were taken in four replicates. For the quantitative detection of some sanitary indicator microorganisms ( coliforms, Enterobacteriaceae ), pathogens (Salmonella spp.) and total count in the treated water, medium plates (Compact Dry EC; Compact Dry ETB; Compact Dry SL and Compact Dry TC, RBiopharm AG, Germany) coated with dry culture medium were used. [ABSTRACT FROM AUTHOR]

The medicinal herbs as natural products can be use like not expensive additives in artificial diets for aquatic animals which are safe for fish and the environment. The purpose of this study is to determine the effect of the Angelica archangelica L. extract on the growth performance, meat quality and biochemical blood parameters (glucose, urea, creatinine, total protein, albumin, ASAT, ALAT, ALP, Ca, P, Mg, triglycerides, cholesterol) of rainbow trout (Oncorhynchus mykiss). Thirty specimens from the rainbow trout with anaverage weight of 42.55±7.48 g (control, C) and 42.51±6.02 g (experimental, Ang.a.) in good health condition were placed in each tank and cultivated for 60 days. A control group (no added) and an experimental (with added 433 mg.kg-1 of angelica extract) option, each with a two repetition, were set in a recirculating system in the Aquaculture Base of the Faculty of Agriculture at the Trakia University. At the end of the experiment were calculated average final weight, specific growth rates, feed conversion ratio, meat quality and blood biochemical parameters. The average individual weight gain of rainbow trout from the group fed with A. archangelica extract supplemented was 84.61±0.06 g which was with 15.01% higher compared to this one of control fish and the differences were statistically significant (P < 0.05). The blood biochemical parameters glucose, urea, albumin, ALP, ASAT, cholesterol in control variant were higher compare to values of this parameter of fish from the experimental (P > 0.05). Better growth performance and blood parameters were measured in trout fed with angelica supplement. [ABSTRACT FROM AUTHOR]

The purpose of the study was to determine the effect of the addition of NuPro® as a substitution of fish meal in feeding of rainbow trout (O. mykiss) on the functional properties of extruded feed as well as on growth intensity, blood biochemical and meat quality parameters in experimental fish, cultivated in recirculating system. Rainbow trout received extruded feed (2.5 mm pellets), produced by extrusion process in "University of food technologies - Plovdiv". Two hundred and twenty five rainbow trout were divided into three groups: control (A), experimental B and C, each of them with three replicates, with a mean initial live weight, respectively 24.3±7.3, 24.3±7.3 and 24.4±8.5 g. The feed content for fish from experimental groups was as follows: for the control group (A) - without Nu Pro, for the group B - 33% fishmeal and 7% Nu Pro®, and that for the group C 25% fishmeal, with a content of 15% Nu Pro. The duration of the trial period was 60 days. The addition of Nu pro® on functional properties of extruded feed was retraced. At the end of the experiment, fish growth (g), their survival (%) and feed conversion ratio (K) were calculated. The blood biochemical and meat quality parameters in fish from experimental groups were also measured. The evaluation of functional properties in extruded feed showed that the use of Nu Pro® as a substitute of fishmeal has a number of advantages that include-increasing the mass flow rate during extrusion, reducing the energy consumption during extrusion, increasing shelf life due to the higher absorption index. The main disadvantage that can be indicated is the faster dissolution of the product in contact with water. At the end of the experiment, with the live weight, being highest in the rainbow trout from the experimental group (C) - 69.76±25.41 g, followed by that of fish from the experimental group (B) - 67.82±20.00 g and this one of individuals from group (A) - 64.01±17.07 g and the statistical differences haven't been proven (p > 0.05). The supplementation of feed with NuPro® in the diet of rainbow trout decreased the level of alkaline phosphatase (ALP), cholesterol and triglycerides respectively with 9.29%, 16.4% and 9.47% compared with the values of these parameters in fish from control group, but the differences were not significant (P ≥ 0.05). The partial replacement of fish meal with Nu Pro® in rainbow trout did not affect the meat quality parameters. [ABSTRACT FROM AUTHOR]

Plants, their parts and products have been used to treat diseases and pathogens. The aim of the present study was to test different extracts from three species of genus Amaranthus L. -- A. deflexus L., A. retroflexus L. and A. hybridus L. for antifungal activities. The plant extracts (methanol and ethanol) from ground and underground plant parts were tested for antimicrobial activity by agar well diffusion method. Five fungal strains (Penicillium verrucosum var. verrucosum NBIMCC 2003 NRRL F-143, Penicillium expansum, Fusarium graminearum NBIMCC 2294 IMI 155426, Aspergillus ochraceus NBIMCC 2002 IM-BAS, Aspergillus niger) were used. Antimicrobial activity was evaluated by measuring zones of inhibition of microbial growth surrounding plant extracts in the wells. The most eff ective extracts, which showed activity against all tested strains of microorganisms, were A.deflexus and A.hybridus ethanol flower extract, A.retroflexus ethanol root extract and A. retroflexus methanol leaves and stem extract. [ABSTRACT FROM AUTHOR]

The study examined indumentum, stomata and pollen morphology of Amaranthus defl exus L., A. hybridus L. and A. retroflexus L. from their Bulgarian populations. Mature pollen and herbarized plant parts have been observed and photographed with a scanning electron microscope (SEM). The indumentum of the three species is of multicellular, un-branched, uniseriate, glandular trichomes. Three types of stomata have been registered -- anomocytic, paracytic and anisocytic with the latter type being the dominant one. Paracytic type were observed only in A. deflexus. Pollen grains were spheroidal, pantoporate, scrabrate, with diameter from 15.4 to 24.2 μm. Among the studied three species differences in pollen morphology have been found in A. deflexus. [ABSTRACT FROM AUTHOR]

Heavy metals cause some physiological and biochemical changes if they present with toxic concentrations in aquatic environments. The study was conducted in order to trace the potential of the aquatic plant Lemna minuta for the bioaccumulation of Zn, Mn, and Fe from contaminated water at low levels of these elements. The duckweed species was treated separately with ZnCl, MnCl2x4H2O, FeCl3 (Valerus, Bulgaria) at 1 mg.l-1 concentrations for 96 hours period. In response to metal exposure, relative growth rate (RGR), bioconcentration factor (BCF), tolerant index (Ti) and photosynthetic pigments of L. minuta were studied. The highest relative growth rate reduction of this aquatic plant was found with Fe (1 mg.l-1) treatment which is 50% lower compared to control. The BCF of the metals on the species were in decreasing order: Fe > Zn > Mn. The manganese content of 1 mg.l-1 led to an increase in photosynthetic pigments. [ABSTRACT FROM AUTHOR]

Two varieties of wheat were grown on different soil types (chernozem carbonate and humus-carbonate). The influence of experimentally polluted water was investigated on the structural characteristics on the leaves of the two varieties. A positive impact is detected under the influence of Mg600 and Cu300 on the thickness of leaves, leaflamina and mezophils. Variety "Yantar" with humus-carbonate soils has better characteristics of structural leafy parameters in comparison with a variety "Sadovo" in the same soil parameters, which indicates that it is more resistant to the effects of the pollutants. [ABSTRACT FROM AUTHOR]

Aquatic plants play a major role in sustaining life and are among the most productive ecosystems in the world. The aim of present study was to test different extract from Spirulina sp., Chlorella vulgaris and Lemna minuta for antibacterial, anti-yeast and antifungal activities. The plant extracts (methanol and ethanol) were tested for antimicrobial activity by the agar well diffusion method. Eleven bacterial, yeast and fungal strains were used. The antimicrobial activity was evaluated by measuring zones of inhibition of microbial growth surrounding the plant extracts in the wells. The most effective extract was L. minuta ethanol which showed activity against all tested strains of microorganisms with the exception of B. cereus. Ethanol extracts of the three studied aquatic plants showed better activity than the methanol extracts. [ABSTRACT FROM AUTHOR]

One of the main challenges for the development of biomass algal system production is the high operational and capital costs for these technologies. A great opportunity to overcome these challenges may however exist in the integration of wastewater treatment with algal biomass production. The algae are used for treatment of industrial wastewater, for purification of effluent originating from livestock production, while the studies concerning the use of algae species for the treatment of aquaculture effluent are very few. The aim of our research was to compare the nitrogen and phosphate removal efficiency and the growth of two microalgae species - Scenedesmus dimorphus and Botryococcus braunii, cultivated in wastewater, originating from freshwater aquaculture production. A laboratory bioreactor was used for algae cultivation. It consisted of 500 mL Erlenmeyer flasks, containing wastewater from semi closed recirculation aquaculture system. Light regime was adjusted at 15:9 h light:dark cycle, the air was enriched with CO2 up to 1% and the water temperature was kept between 25 and 27oC. Samples for water chemical analysis and growth measurement were taken at the beginning of the trial, at the 24th, 96th and the 168th hour after the start of the experiment. A better removal efficiency of nitrogen compound from wastewater originate from aquaculture was determined for B. braunii and the concentration of ammonia, nitrite, nitrate and total nitrogen decreased at the end of trial by 50%, 84.4%, 63.1% and 61.5% respectively. A better phosphate removal efficiency (77.8%) and better growth rate were found for Sc. dimorphus when aquaculture effluent was used as a growing media. [ABSTRACT FROM AUTHOR]

In current study the antibacterial activity of different medicinal herbs against fish pathogen Aeromonas hydrophila was evaluated. The water extract of medicinal herbs (Glycyrrhiza glabra, Rhodiola rosea, Althaea officinalis, Sambucus nigra, Inula helenium, Pinus sylvestris, Ocimum basilicum, Salvia officinalis) were prepared by the following method: the plants were extracted in water solution at proportion 1:10. The received homogeny solutions were filtered and centrifuged at 7000 rpm for 30 minutes. Afterwards the extracts were filtered with sterile syringe filters with the size 0.2 μm. The bacterial strain of Aeromonas hydrophila (ATCC 7965) was used in current research. The bacterial activity of plant extract against Aeromonas hydrophila were tested with disk diffusion method. The highest antibacterial effect against Aeromonas hydrophila were determined in water extract of Salvia officinalis and its inhibition zone was higher with 33.34% compared with the size of zone measured for the control variant. [ABSTRACT FROM AUTHOR]

Lemna sp. have an important role indifferent aspect of aquatic ecosystems serving as a food source, by providing shelter to fish and aquatic invertebrates, changing water quality by regulating oxygen balance, nutrient cycles, and accumulating heavy metals. The aim of present study was to investigate a new found species of Lemna in Bulgarian water reservoirs regarding their protein content and bioaccumulation of heavy metals. Two water bodies located on the territory of South East Bulgaria-Tvardica Dam Lake with growing L. minuta and Nikolaevo fishpond with growing L. valdiviana were studied. Crude protein, lipid, ash contentin two species of Lemna were analysed. The heavy metal in water andaquatic plants was determined on an atomic absorption spectrometer (AAS) "A Analyst 800" - Perkin Elmer. The highest quantity of protein was measured in L. minuta (26.42%), which was 8.71% more compared to L. valdiviana (24.12). The concentrations of metals in the L. minuta and L. valdiviana followed a downward trend: Mn>Fe>Zn>Cu>Ni>Cr>Pb>Cd. The series of bioaccumulation is in descending order: Mn>Fe>Cu>Zn>Cr> Cd>Pb>Ni for L. minuta, and Mn>Fe>Zn>Cu>Cd>Pb>Cr>Ni for L. valdiviana. [ABSTRACT FROM AUTHOR]

Two of the main parameters, which defined the cleaning capacity of cultivated plants and productivity of aquaponic systems, are the type of hydroponic compartment and plant's growing media. The aim of current research was to compare the cleaning capacity and plant's productivity of media bed and raft hydroponic sections as a part of a model aquaponic recirculation system. The impact of different plant growing mediums (cotton wool and rockwool) on lettuce yields was also retraced. For the purpose of this research two types of hydroponic sections (media bed and deep water sections) were constructed and integrated into an existing recirculation aquaculture system. For the trial 36 lettuce seedlings were used. Half of the plants were transferred to cotton wool and the other half of the lettuce plants were transferred to rockwool (Grodan®) substrates and afterwards all plants were placed in hydroponic pots. Eighteen lettuce seedlings (half planted on cotton wool and the other half on rockwool (Grodan®) substrate) were planted on the hydroponic section filled with lightweight expanded clay aggregate (LECA) and the other eighteen plants (half planted on cotton wool and the other half on rockwool (Grodan®) substrate) were planted on the floating raft hydroponic section. The hydrochemical parameters were measured during the trial. At the end and middle of the trial the fresh weight of lettuce plants was measured. A better removal capacity in ammonium, nitrate and ortho-phospahte were observed in the LECA section compared with the cleaning capacity in the raft section as a part of experimental aquaponic system. The raft technology showed better plant productivity compared with the one found for the LECA bed technology. The productivity of lettuce plants is highly dependent on the type of plant growing medium, when they are cultivated in the floating raft technology. [ABSTRACT FROM AUTHOR]

A new species of cyanobacterial genus Anabaena Bory ex Born. et Flah. (Nostocales) from Rhodope Mountains in Bulgaria is described. Anabaena rhodopensis sp. nova. has akinetes with sculptured cell walls. Biometrical data for size of vegetative cells, heterocytes and akinetes are given. [ABSTRACT FROM AUTHOR]

The aim of current studies was to determinate the levels of heavy metals like Zn, Pb, Ni and Cd in flesh of some important fish species - mackerel (Scomber scombrus); European sprat (Sprattus sprattus); horse mackerel (Trachurus mediterraneus ponticus) and bluefish (Pommatomus saltatrix). The received concentrations are analyzed and compared against the maximum levels allowed for fish, purposed for human consumption and nutritional value of fish was evaluated. The concentration of heavy metals were, measured by atomic absorption spectrophotometry after digestion of the samples, using heating digester. The muscles of mackerel were characterized by the highest content of protein (19.20%), which was higher respectively with 1.4%, 6.8% and 5.31% compared with its content in horse mackerel, sprat and bluefish. The lipids in mackerel's muscles showed the highest content (18.09%) compared with its value in the muscles of horse mackerel, sprat and bluefish and it was higher respectively with 37.5%, 63.0% and 33.1%. The highest concentration of metals in the muscles of the studied fish species were determinate for Zn, and the lowest for Cd. The highest levels of Pb, Cd and Zh were found in muscles of sprat and the content of Ni was found to be highest in the muscles of horse mackerel. The examined fish were safe for human consumption, regarding the daily intake and safety aspect. [ABSTRACT FROM AUTHOR]