Transgenic maize MON88017, expressing the Cry3Bb1 toxin from Bacillus thuringiensis (Bt maize), confers resistance to corn rootworms (Diabrotica spp.) and provides tolerance to the herbicide glyphosate. However, prior to commercialization, substantial assessment of potential effects on non-target organisms within agroecosystems is required. The MON88017 event was therefore evaluated under field conditions in Southern Bohemia in 2009–2011, to detect possible impacts on the above-ground arthropod species. The study compared MON88017, its near-isogenic non-Bt hybrid DK315 (treated or not treated with the soil insecticide Dursban 10G) and two non-Bt reference hybrids (KIPOUS and PR38N86). Each hybrid was grown on five 0.5 ha plots distributed in a 14-ha field with a Latin square design. Semiquantitative ELISA was used to verify Cry3Bb1 toxin levels in the Bt maize. The species spectrum of non-target invertebrates changed during seasons and was affected by weather conditions. The thrips Frankliniella occidentalis was the most abundant species in all three successive years. The next most common species were aphids Rhopalosiphum padi and Metopolophium dirhodum. Frequently observed predators included Orius spp. and several species within the Coccinellidae. Throughout the three-year study, analysis of variance indicated some significant differences (P<0.05). Multivariate analysis showed that the abundance and diversity of plant dwelling insects was similar in maize with the same genetic background, for both Bt (MON88017) and non-Bt (DK315) untreated or insecticide treated. KIPOUS and PR38N86 showed some differences in species abundance relative to the Bt maize and its near-isogenic hybrid. However, the effect of management regime on arthropod community was insignificant and accounted only for a negligible portion of the variability.

Can thiol compounds be used as biomarkers of aquatic ecosystem contamination by cadmium?: Due to anthropogenic activities, heavy metals still represent a threat for various trophic levels. If aquatic animals are exposed to heavy metals we can obviously observe considerable toxicity. It is well known that an organism affected by cadmium (Cd) synthesize low molecular mass thiol compounds rich in cysteine (Cys), such as metallothioneins (MT) and glutathione (GSH/GSSG). The aim of this study was to summarize the effect of Cd on level of thiol compounds in aquatic organisms, and evaluate that the concentrations of thiol compounds are effective indicators of Cd water pollution and explain their potential use in biomonitoring applications.

The aim of the study was to determine the amino acid composition in fillet proteins of newly bred mirror carp lines. In the experiments, the Hungarian mirror carp (M2) were used at the maternal position. These were crossed with male carp of other breeds (top crossing). They included the Hungarian mirror carp (M2) for the production of a pure line, the Hungarian mirror line (L15), the Israeli breed (DOR70) and the Northern mirror carp (M72). The scaly hybrid of the Ropsha (ROP) and the Tataj (TAT) carp was used as a control. In view of the genetic specification of the carp groups monitored, numerous differences ( P < 0.01 and P < 0.05) in the composition of specific amino acids (EAA: Val, Leu, Lys, Arg, Met; NEAA: Asp, Glu, Tyr) and their total amounts (EAA _sum , NEAA _sum ) were found between the scaly control (ROP × TAT) and the pure line M2. Higher amino acid values were found in control hybrids. Compositions of amino acids in fillet muscle tissue of experimental mirror carp (M2 × L15, M2 × DOR70) were practically identical. Compared to the controls (ROP × TAT), these carp groups contained less ( P < 0.01) Leu, Lys, Arg and Glu. A composition of amino acids statistically comparable with the controls (ROP × TAT) was found only in the M2 × M72 hybrid with the exception of Glu, which was found in smaller quantities in this hybrid ( P < 0.01). In terms of sex differences, the greatest amounts of amino acids were found in fillets of male ROP × TAT controls, the amino acid compositions in male and female mirror carp were practically the same. In this type of evaluation, i.e. regarding amino acid composition, the only carp comparable with the ROP × TAT control is the M2 × M72 hybrid.

The aim of this survey was to compare total mercury (THg) in canned fish in terms of species and fishing area. A number of 110 samples of canned fish, which were divided by fish species and fishing area, were analysed. The highest THg content in muscle tissue was found in the escolar. In other fish species, the highest level was detected in tuna. Mercury content in tuna differed significantly from mackerel, sardine, and sprat. Mercury content in herring differed significantly from sprat. The order of the fish according to their THg content corresponds to their status in the aquatic food chain. A significant difference was also found between fish caught from the closed Mediterranean and Black Sea and fish caught in the open oceans. In terms of THg content, the results of this study indicate good quality of various species of canned fish caught in worldwide locations.