Behaviour and cardiac response to stress in signal crayfish exposed to environmental concentrations of tramadol.

Evidence of the ecological and biological impact of pharmaceuticals in surface waters on aquatic organisms is increasing. Tramadol is a synthetic opioid analgesic used to treat chronic and acute pain. To investigate its long-term effects at environmentally relevant levels, we evaluated heart rate (HR) and locomotion of signal crayfish Pacifastacus leniusculus during a 21-day exposure to 1 µg L-1 tramadol followed by 14 days depuration. Locomotion and HR were recorded over a period 30 min before and 30 min after exposure to physiological fluids of an injured conspecific, a natural stressor, four times during the tramadol exposure and four times during depuration. A significant increase in HR following stress induction was found in the majority of tramadol-exposed and control crayfish, as well as significant group-specific HR changes between both groups. Locomotor activity during tramadol treatment differed from that during depuration, in general showing less time spent in locomotion and lower distance moved. The tramadol exposed crayfish exhibited higher velocity during depuration than during the exposure period. Results may suggest a potential shift in prey-predator relationships.

Environmentally relevant concentrations of tramadol and citalopram alter behaviour of an aquatic invertebrate.

Environmental pollution by pharmaceutically active compounds, used in quantities similar to those of pesticides and other organic micropollutants, is increasingly recognized as a major threat to the aquatic environment. These compounds are only partly removed from wastewaters and, despite their low concentrations, directly and indirectly affect behaviour of freshwater organisms in natural habitats. The aim of this study was to behaviourally assess the effects of an opioid painkiller (tramadol) and antidepressant drug (citalopram) on behaviour patterns of a clonal model species, marbled crayfish. Animals exposed to environmentally relevant concentrations of both tested compounds (∼1 µg l-1) exhibited significantly lower velocity and shorter distance moved than controls. Crayfish exposed to tramadol spent more time in shelters. Results were obtained by a simple and rapid method recommended as suitable for assessment of behaviour in aquatic organisms exposed to single pollutants and combinations.

Radio-telemetry shows differences in the behaviour of wild and hatchery-reared European grayling Thymallus thymallus in response to environmental variables.

Juvenile wild and hatchery-reared European grayling Thymallus thymallus were tagged with radio-transmitters and tracked in the Blanice River, River Elbe catchment, Czech Republic, to study their behavioural response to stocking and environmental variation. Both wild and hatchery-reared T. thymallus increased their diel movements and home range with increasing light intensity, flow, temperature and turbidity, but the characteristics of their responses differed. Environmental variables influenced the movement of wild T. thymallus up to a specific threshold, whereas no such threshold was observed in hatchery-reared T. thymallus. Hatchery-reared fish displayed greater total migration distance over the study period (total migration) than did wild fish, which was caused mainly by their dispersal in the downstream direction.

A passive sampling method for detecting analgesics, psycholeptics, antidepressants and illicit drugs in aquatic environments in the Czech Republic.

The goal of this study was to assess the bioavailable concentrations of analgesics, psycholeptics, antidepressants and illicit drugs in the surface waters of the Czech Republic. All of the sampling sites are located within the most important water quality monitoring profiles at the Czech Hydrometeorological Institute. The total concentrations of the compounds ranged from 463 to 6,447 ng POCIS(-1) (Polar Organic Chemical Integrative Sampler). Carbamazepine (196-2,690 ng POCIS(-1)) and tramadol (160-2,250 ng POCIS(-1)) were the most abundant compounds at every site. The most polluted sites were those that received communal wastewater effluent and had a low dilution factor (ratio of wastewater effluent and river flow). The aqueous concentrations of the target compounds were estimated using sampling rate values obtained during a field calibration experiment. Patterns in the aqueous concentrations of the compounds (after back calculation from POCIS extracts) and the POCIS concentrations are different, possibly leading to discrepancies between the toxicity assessments conducted using POCIS extracts and those conducted using grab samples of water from the same location.

Changes in concentrations of hydrophilic organic contaminants and of endocrine-disrupting potential downstream of small communities located adjacent to headwaters.

Endocrine-disruptive potential and concentrations of polar organic contaminants were measured in seven headwaters flowing through relatively unpolluted areas of the Czech Republic. Towns with Wastewater Treatment Plant (WWTP) discharges were the first known sources of anthropogenic pollution in the areas. River water was sampled several kilometers upstream (US) and several tens of meters downstream (DS) of the WWTP discharges, by use of Pesticide and Pharmaceutical Polar Organic Integrative Samplers (POCIS-Pest, POCIS-Pharm). Extracts of passive samplers were tested by use of a battery of in vitro bioassays to determine overall non-specific cytotoxicity, endocrine-disruptive (ED) potential and dioxin-like toxicity. The extracts were also used for quantification of polar organics. There was little toxicity to cells caused by most extracts of POCIS. Estrogenicity was detected in all types of samples even though US locations are considered to be background. At US locations, concentrations of estrogen equivalents (EEq) ranged from less than the detection limits (LOD) to 0.5 ng EEq/POCIS. Downstream concentrations of EEqs ranged from less than LOD to 4.8 ng EEq/POCIS. Concentrations of EEq in POCIS extracts from all DS locations were 1 to 14 times greater than those at US locations. Concentrations of EEq measured in extracts of POCIS-Pest and POCIS-Pharm were in a good agreement. Neither antiestrogenic nor anti/androgenic activities were detected. Concentrations of 2,3,7,8-TCDD equivalents (TEq(bio)) were detected in both types of POCIS at concentrations ranging from less than the LOD to 0.39 ng TEq(bio)/POCIS. Nearly all extracts of POCIS-Pharm contained greater concentrations of TEq(bio) activity than extracts of POCIS-Pest. Concentrations of pesticides and pharmaceuticals in extracts of POCIS were generally small at all sampling sites, but levels of some pharmaceuticals were significantly greater in both types of POCIS from DS locations. Chemical analyses along with the results of bioassays documented impacts of small towns with WWTPs on headwaters.

Verapamil does not modify catalytic activity of CYP450 in rainbow trout after long-term exposure.

Little is known about the effects of the cardiovascular drug verapamil (VRP) on metabolic processes in fish. Most calcium channel blockers including VRP are metabolized by cytochrome P450 (CYP450) enzymes. In this study we investigated the in vivo effect of VRP on some CYP450-mediated reactions in juvenile rainbow trout (Oncorhynchus mykiss). Fish were exposed to sublethal concentrations of VRP (0.5, 27 and 270 µg l(-1)) for 0, 21, and 42 day. The following CYP450-mediated reactions were studied in hepatic microsomes: O-dealkylation of ethoxyresorufin, methoxyresorufin, and pentoxyresorufin, hydroxylation of coumarin, tolbutamide, and p-nitrophenol, and O-debenzylation of 7-benzyloxy-4-trifluoromethylcoumarin. The amounts of products of these reactions did not differ among fish exposed to different levels of VRP and control fish. This suggests that the levels of VPR used did not alter catalytic activity of the selected CYP450 enzymes. In conclusion, none of the investigated CYP450-mediated reactions has potential as a biomarker to monitor VRP contamination of the aquatic environment.

Post-release growth and dispersal of pond and hatchery-reared European grayling Thymallus thymallus compared with their wild conspecifics in a small stream.

The growth, and dispersal of stocked European grayling Thymallus thymallus, reared in a hatchery (fed dry food pellets) or in a pond (fed natural food), compared with their wild conspecifics was assessed from the recapture of individually tagged fish 168 days after their release into the Blanice River, Czech Republic. Recapture rates and site fidelity were higher for wild T. thymallus than for artificially reared fish. Specific growth rate and upstream or downstream dispersal did not significantly differ between any of the groups of fish. An influence of rearing conditions (pond v. hatchery) on the overall performance of stocked fish was not demonstrated. Initially, lower condition factors of reared T. thymallus were equal to wild fish after recapture, suggesting adaptation of artificially reared fish that remained in the sections studied.

Sex differentiation and vitellogenin and 11-ketotestosterone levels in chub, Leuciscus cephalus L., exposed to 17 beta-estradiol and testosterone during early development.

The effects of 17 beta-estradiol (E(2)) and testosterone (T) singly and in combination were tested on juvenile chub (Leuciscus cephalus L.). Vitellogenin (VTG) and 11-ketotestosterone (11-KT) were determined by ELISA in whole body homogenates and the gonads were examined histologically. Testosterone and estradiol, in combination, significantly increased whole body VTG (p < 0.01), but not 11-KT, compared to controls and the T treated groups. The only intersex observed (1/80) was in the combined treatment group. We suggest that VTG measured in whole body homogenates could be used to determine the effects of exogenous steroids in juvenile chub.

Effects of pollution on chub in the River Elbe, Czech Republic.

The Elbe River is one of the most polluted aquatic ecosystems in the Czech Republic. The effect of three major chemical plants located on the Elbe River (at Pardubice, Neratovice, and Usti nad Labem) on fish was studied in 2004. Health status, chemical concentrations (Hg, PCB, DDT, HCH, HCB, OCS, 4-tert-nonylphenols, 4-tert-octylphenol) in muscle, and biomarkers (hepatic ethoxyresorufin-O-deethylase (EROD), plasma vitellogenin, and plasma 11-ketotestosterone) were assessed in male chub (Leuciscus cephalus L.). Differences between localities upstream (US) and downstream (DS) from the monitored source of pollution were identified. Fish from DS sampling sites showed significantly higher levels of contaminants than fish from US sampling sites. Generally, the concentrations of pollutants in fish from the Elbe sites were significantly higher compared to the reference site. Reduced gonad size, decreased plasma levels of 11-ketotestosterone, EROD and vitellogenin induction, and histopathologies of male gonads indicated harmful effects of aquatic pollution in fish from the Czech portion of the Elbe River.

Chub (Leuciscus cephalus) as a bioindicator of contamination of the Vltava River by synthetic musk fragrances.

Synthetic musk fragrances, which are contained in almost all scented consumer products, enter aquatic environment mainly by way of wastewater paths. To monitor contamination of the Vltava River by these relatively persistent chemicals in the surroundings of Prague industrialized agglomeration, chub (Leuciscus cephalus) was employed as a bioindicator. Validated gas chromatography-mass spectrometry method was used for fish sample examination. Polycyclic musks, represented by 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethyl-cyclopenta-(gamma)-2-benzopyran (galaxolide) and 1-(5,6,7,8-tetrahydro-3,5,5,6,8,8-hexamethyl-2-naphthalenyl)-ethanone (tonalide) were the most abundant representatives of this group; their levels in fillets were in the range of 1.7 to 105.9 microg/kg and 0.9 to 19.3 microg/kg wet weight, respectively. Nitro-musks, musk ketone, and musk xylene were also detected in most samples; nevertheless, their levels were lower,