The aquatic environment is more or less constantly exposed to different types of pharmaceutical pollutants entering via treated waste water effluents. Benzodiazepines constitute one of many common pharmaceutical contaminants, which have been shown to impact fish behaviour in polluted freshwaters. The aim of this study was to assess whether one benzodiazepine (Oxazepam) affects the behaviour (activity and sociability) of guppies and least killifish. 50 fish of each species were studied in behaviour assays measuring the activity and sociability, where each individual was placed in separate aquariums and filmed in a special arena. One half of the individuals were then exposed to 10 μg/l Oxazepam in their respective tank for 7 days, after which the filming procedure were repeated for all fishes. The results show that least killifish significantly change their sociability by becoming less social after exposure to Oxazepam. However, their activity were not significantly affected. The result from guppies suggested a reduced sociability after exposure. Interpretation of the result were complicated by effects on the control group were guppies experienced a significantly reduced sociability during the treatment. This might be an effect of changes in habitat (lack of food, stress and environment) and/or an effect of Oxazepam. The results in the study show that Oxazepam reduces the sociability of least killifish and guppies.

Effects of oxazepam concerning on social behavior in guppies are still unknown. The purpose ofthis thesis is to investigate if the benzodiazepine oxazepam has effects on fish behavior in terms ofsocial preferences and responses to predation risk using an olfactory cue mixture. After anexposure period of 15 days to 100 μg/l of oxazepam, behavioral experiments were performed overtwo days. Results indicate that oxazepam exposed fish were more social at the beginning of theexperiment, which differ from what was expected and from previous social preferences studies.Moreover, less social behavior was found as a result of combining oxazepam treatment andolfactory cue mixture (predator cues and guppy skin extract) treatment.

Pharmaceuticals are environmental pollutants that are a major threat to aquatic ecosystems and very little is known about their ecological consequences. In this study growth, survival and behaviour (sociability, activity and boldness) of perch fry (Perca fluviatilis) were examined in order to study the possible effects of exposure to a benzodiazepine anxiolytic drug, Oxazepam, during embryonic development. The study tested following hypotheses: (1) perch growth is affected positively by exposure during embryonic development; (2) early perch survival is affected positively by exposure during embryonic development; and (3) boldness and activity increases while sociability decreases in perch fry exposed during embryonic development. Embryos of naturally spawned perch were exposed to water with two different concentrations of Oxazepam. The embryos were exposed during different parts (24-hour periods) of the embryonic development, because embryos may be more vulnerable at certain times during embryonic development and/or because the exposure at different times can produce different effects. Embryos were also chronically exposed, which is essential for aquatic systems because the influx of pharmaceuticals is more or less continuous. In line with hypothesis 1 treatment with Oxazepam affected growth positively. Similarly, survival increased with Oxazepam exposure as predicted by hypothesis 2. Perch fry exposed to the high concentration and fry exposed late during embryonic development survived better. In addition, as hypothesized in hypothesis 3, perch fry exposed to both concentrations exhibited increased activity and reduced sociability although boldness did not increase. Further studies are required to demonstrate the ecological consequences of Oxazepam in aquatic systems.

Pharmaceutical contamination is increasing in the environment and the consequences this will bring are of growing concern. The highest contamination of pharmaceuticals can be found in aquatic ecosystems and the organisms of these systems are therefore of utmost importance to research in order to understand the ecological consequences of pharmaceutical contamination. This report will reveal the effect contamination can have on an important apex predator often found in temperate aquatic systems, the Northern pike (Esox lucius) when exposed to the psychiatric pharmaceutical Oxazepam. The predatory performance of pike was studied before and after Oxazepam exposure by monitoring how fast each pike caught three prey of roach (Rutilus rutilus), as well as observing the amount of failed predation attempts when hunting the roach. The exposed pike displayed more failed predation attempts after exposure as opposed to the control group. Furthermore it took the exposed pike longer to catch all three roach after exposure while the mean for the control group decreased. Hence, Oxazepam exposure seem to have an effect on predation performance of pike but no definite conclusion could be drawn about to which extent this affects the foraging success and thereby the survival of the pike considering the complex nature of aquatic systems. More studies are therefore needed in order to determine the full effect pharmaceutical contamination can have on complex aquatic ecosystems and more specifically on an apex predator.

Till följd av samhällets konsumtion av psykofarmaka, återfinns rester av preparaten i utgående avloppsvatten som oförändrade eller i form av metaboliter. Avloppsvattnet utgör därför en betyd-ande källa till att vår akvatiska miljö exponeras för psykofarmaka, vars verkningsmekanismer på-verkar akvatiska organismsamhällens struktur och funktion. Det är således betydelsefullt att skapa experimentellt underlag om hur primärproducerande akvatiska system reagerar på exponering för vanligt utskriven psykofarmaka. Denna studie syftar till att undersöka eventuella effekter till följd av exponering för utvald psykofarmaka; fluoxetin och oxazepam, i planktonsamhällen från en sötvattenrecipient. Under sju dagars testperiod exponerades identifierade organismer; Mesocyclops leuckarti, Chlorella vulgaris, Monoraphidium mirabile, Monoraphidium contortum, Monoraphidium griffithii och Glaucoma scintillans, mot fluoxetin; 500 och 50 μg/l samt oxazepam; 1700 och 170 μg/l. C. vulgaris och G. scintillans visade sig vara mer känsliga mot höga halter fluoxetin än andra identifierade arter. C. vulgaris och G. scintillans minskade med 70 respektive 100 %  till följd av 500 ug/l fluoxetin. Exponeringshalten är emellertid högre än uppmätt maxvärde i utgående avloppsvatten, och bedöms därför inte utgöra akut risk för planktonsamhällen i recipienter vars förhållanden är jämförbara med denna undersökning. / As a consequence of society's consumption of psychotropic drugs, sources of these substances is detected in municipal wastewater plants as unchanged, including their metabolites. Reaching the aquatic environment, effluents contributes with a significant source of these substances which has been shown to affect the structure and function of aquatic organisms. It is important to create experimental evidence on how primary-producing aquatic ecosystems respond to the exposure of commonly prescribed psychotropic drugs. The aim of this study was to investigate possible effects of selected psychotropics; fluoxetine and oxazepam, to plankton communities from a freshwater recipient. Over an 7-day period identified organisms; Mesocyclops leuckarti, Chlorella vulgaris, Monoraphidium mirabile, Monoraphidium contortum, Monoraphidium griffithii och Glaucoma scintillans, were exposed to fluoxetine; 500 and 50 μg/l and oxazepam; 1700 and 170 μg/l. C. vulgaris and G. scintillans, turned out to be most sensitive to high levels of fluoxetine than other identified species. C. vulgaris and G. scintillans decreased by 70 and 100 % respectively, as a result of 500 ug/l fluoxetin. However, exposure levels in the experiment are much higher than measured values ​​in outgoing wastewater, and is therefore not considered to be acute toxic to non-target species comparable to those in this study.

Pharmaceuticals polluting natural environments pose a greater and greater threat in today’s society. Benzodiazepines, the most common form of anxiolytic drug, can commonly be found in nature as a result of the release of human wastewater containing the drug, and have been shown to affect both fish and frog species in several different ways related to predator evasion. This study aims to determine whether a common benzodiazepine, oxazepam, has any inhibitory effect on induced behavioral defenses in the boreal frog species Rana temporaria. Larvae of R. temporaria were exposed to an oxazepam gradient, paired with three different predator regimes consisting of a control, an ambush-predator setting, and a pursuing-predator setting. The larvae were then filmed at three different Gosner stages during simulated predator encounters, while measuring maximum velocity and acceleration, as well as activity- and exploration level, and the duration of avoidance following each encounter. Tail related morphological traits were also measured in order to correlate velocity and acceleration with trait properties. Avoidance duration was found to decrease when exposed to ambush predators, regardless of oxazepam concentration. No other effect of predators could be found during this study, and no significant correlations between tail properties and velocity or acceleration were seen. Oxazepam was not found to inhibit any induced behavioral defenses, nor did it alter any of the examined behavioral traits.

A greater consumption of pharmaceutical drugs entails an increased concentration of active benzodiazepines in aquatic ecosystems. Consequently, aquatic organisms are experiencing altered behavior that may affect dominance hierarchies since social status (among other variables) is associated with behavioral traits. The aim of this study was to determine whether dominance hierarchies of brown trout (Salmo trutta) were affected by exposure to a benzodiazepine (oxazepam). Hypothetically, aggression (in dominants) and anxiety (in subordinates) will reduce following exposure. The fish should consequently display a significant disparity between treatment groups regarding the frequency of dominance change (i.e., who is dominant versus subordinate). This research included behavioral coding of 150 juvenile brown trout (Salmo trutta) divided into 50 size-matched social groups of 3 individuals. Each group was exposed to one of three oxazepam concentrations (30 µg/L, 1.5 µg/L and 0 µg/L). The results indicate no relationship between an altered aggression and oxazepam exposure. In addition, the level of aggression reduced over time (regardless of social status and concentration) and the initial subordinates remained significantly less aggressive than the initial dominants. The frequency of dominance change did not differ significantly between different treatment groups. Body size did not affect social status. The results in low treatment groups may be due to a low bioconcentration since previous research exhibited similar results. However, the lack of results in high treatment groups could be due to something else. In conclusion, the dominance hierarchy was not disrupted by oxazepam exposure because aggression was unaffected.

Excreted pharmaceuticals are leaking out into aquatic environments via effluent water where they are hypothesized to be potent enough to alter fish behavior. Central for this hypothesis is oxazepam, an anti-anxiety drug that have been shown to make fish behave more bold, more active, and less social. However, some laboratory trials have also failed to find these effects and have been poor predictors of fishes’ behavior in situ. The aims of my meta-analysis were; i) investigate the strength of oxazepam induced behavior changes in wild-caught fish, and ii) assess eventual impact of citation bias (i.e., that researcher prefer citing studies showing effects) on published literature relating to oxazepam induced behavior changes. I found, when combining existing literature on oxazepam impact on wild caught fish behavior, that exposure concentrations ranging between 0.5-100µg/L, did only change the activity (increased) of the fish. In high (>100 µg/L) concentration exposures activity and boldness increased, and sociality decreased as previously suggested. I also noticed a significant citation bias, where studies showing effects of oxazepam on behaviors were more frequently cited. Several studies report absence of behavior effects caused by oxazepam in controlled laboratory trials, despite using >1000 times higher concentrations that ever been measured in fresh water. Therefore, I find it unlikely that this drug has strong effects on fish in nature. Citation biases towards studies showing effects seems likely to have had a strong influence on the current notion that oxazepam is altering fish behavior.

Environmental pollution by pharmaceuticals is an issue of concern that is currently attracting attention around the world. Although environmental effects of pharmaceutical contaminants are not yet well documented, studies have shown that these substances may have the potential to disrupt the biotic component of an ecosystem. Particularly worrisome contaminants are the neuroactive pharmaceuticals which have the potentiality to induce behavioral modifications in non-target species. In the present study, I examined the effects of a benzodiazepine anxiolytic pharmaceutical (oxazepam) on the behavior of Atlantic salmon (Salmo salar) juveniles (fry). The hypothesis of this study was that oxazepam reduces the anxiety-like behavior of the Atlantic salmon juveniles. To test the hypothesis and assess the impact of oxazepam exposure on Atlantic salmons fry behavior, two different concentrations of this drug; a low-level (1.9 ug L-1) and a high-level concentration (1000 ug L-1) were used. Exposures lasted for 48 hours and afterwards, the fish were recorded to evaluate their behavioral responses. The results of this study reveal that oxazepam in a high concentration (1000 ug L-1 ) alters specific behavioral endpoints related to the fitness (feeding/predator avoidance) of Atlantic salmons fry. Individuals exposed to the high oxazepam concentration exhibited significant lower average speed and acceleration as well as they traveled a shorter mean distance compared to the unexposed (control) individuals. These findings confirm the hypothesis and show that psychotropic pharmaceutical contaminants modify animal behaviors, which can ultimately lead to ecological consequences. However, the concentration that generated behavioral effects in this study was three magnitudes higher than concentrations measured in the environment and thus, should not be viewed representative for oxazepam contaminated ecosystems.