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Psychotropic Pharmaceuticals in Aquatic Systems: An Ecological Perspective

Hedgespeth, Melanie LU (2015)
Abstract (Swedish)
Popular Abstract in English

Psychotropic pharmaceuticals include various groups of chemicals that have been designed to affect neurochemistry in human consumers resulting in changes in cognition, mood, and/or behavior; many target specific receptors and subsequently alter neurotransmitter levels in the central nervous system. The use of pharmaceuticals by consumers results in the release of these active substances and their breakdown products into the environment, the main source of which is through domestic wastewater treatment plants connected to households. Pharmaceuticals and their metabolites have been detected in surface water and as a result, pose a potential risk to organisms and ecosystems.



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Popular Abstract in English

Psychotropic pharmaceuticals include various groups of chemicals that have been designed to affect neurochemistry in human consumers resulting in changes in cognition, mood, and/or behavior; many target specific receptors and subsequently alter neurotransmitter levels in the central nervous system. The use of pharmaceuticals by consumers results in the release of these active substances and their breakdown products into the environment, the main source of which is through domestic wastewater treatment plants connected to households. Pharmaceuticals and their metabolites have been detected in surface water and as a result, pose a potential risk to organisms and ecosystems.



Psychotropic pharmaceuticals have also been shown to exert a variety of effects on aquatic organisms, even at low concentrations found in the environment (ng/L to µg/L); hence, the aim of my research has been to determine the effects of some of these chemicals (the antidepressants sertraline and fluoxetine, and the β-blocker propranolol) on behavior and life history in freshwater organisms. The focus of this research is the effects of exposure to these chemicals on interactions between aquatic predators and prey. I have therefore examined how the chemically-induced behavioral changes in individuals may also affect higher levels of organization, such as populations, communities and ecosystems.



The studies included in this thesis indicate that exposure to sertraline resulted in alterations in habitat choice of snails (Radix balthica), but this did not seem to increase risk for predation by fish. Also, fluoxetine exposure altered risk-taking behavior in fish (Perca fluviatilis) linked to decreased vulnerability to predation by birds, but this was potentially at the cost of reduced food-intake in the fish. A separate study directly examined feeding in juvenile fish (Perca fluviatilis) for which those exposed to sertraline exhibited decreased feeding rates at both low and high zooplankton prey densities (Daphnia magna). When examining effects of sertraline on the zooplankton Daphnia magna, I also detected significant reductions in growth, reproduction, and capacity for population increase, especially when exposed to both sertraline and a toxic cyanobacteria species (blue-green algae, Microcystis aeruginosa), simultaneously, i.e. with synergistic effects due to exposure to the two stressors occurring at high sertraline concentrations.



When employed within an ecological framework, scientific research on organism-level traits as endpoints of the short-term effects of chemical contaminant exposure (such as the behavioral and life history traits I have examined in this thesis) can provide valuable information on the potential long-term outcomes of exposure in the environment. The information from these studies could be used in ecological models to predict how changes in predator-prey interactions caused by pharmaceuticals will affect populations of organisms, and this can also lead to changes at the community- or ecosystem-levels in aquatic environments. Information on these ecological effects will enable more reliable risk assessments for pharmaceuticals in aquatic environments.



Popular Abstract in Swedish

Psykofarmaka inkluderar olika grupper av kemikalier som har utformats för att påverka neurokemi hos människor vilket resulterar i förändringar i kognition, humör, och/eller beteende. Många av dessa ämnen påverkar specifika receptorer på nerver, vilket förändrar nivåerna av signalsubstanser i det centrala nervsystemet. Användning av läkemedel resulterar i utsläpp av både aktiva substanser och dess nedbrytningsprodukter i miljön. Den dominerande utsläppskällan är avloppsvatten från hushållen som når miljön via reningsverk. Såväl läkemedel som nedbrytningsprodukter har uppmätts i ytvatten där de utgör en potentiell risk för organismer och ekosystem.



Psykofarmaka har också visats ha en mängd olika effekter på vattenlevande organismer redan vid de relativt låga koncentrationer som finns i miljön (ng/L till µg/L). Syftet med min forskning har varit att studera effekterna av dessa läkemedel (antidepressiva ämnen som sertralin och fluoxetin samt β-blockeraren propranolol) på beteende och livshistoria hos sötvattenslevande organismer. Min forskning har fokuserat på hur dessa läkemedel påverkar interaktionerna mellan akvatiska predatorer och dess byten. Jag har också undersökt hur läkemedelsinducerade beteendeförändringar hos individer påverkar högre organisationsnivåer så som populationer, samhällen och ekosystem.



Resultaten av studierna i denna avhandling visar att sötvattenssnäckor (Radix balthica) som exponerats för sertralin ändrar sitt val av livsmiljö, men detta tycks inte medföra en ökad risk för predation från fisk. Abborrar som exponerats för fluoxetin uppvisade förändringar i risktagande beteende, vilket kunde kopplas till minskad predationsrisk från fågel. Detta skedde trogligtvis på bekostnad av minskat födointag hos exponerade individer. En separat studie av födointag hos unga abborrar visade att individer som exponerats för sertralin hade ett lägre födointag, vid såväl höga som låga bytestätheter av djurplankton (Daphnia magna), än individer som inte exponerats för läkemedlet. När jag vidare undersökte effekter av sertalin hos djurplankton (Daphnia magna) såg jag att detta ledde till minskad tillväxt, reproduktion och populationstillväxt, framförallt när djurplanktonen exponerades för både sertralin och giftiga cyanobakterier (blågröna alger, Microcystis aeruginosa) samtidigt. Vid höga koncentrationer av sertralin såg jag alltså synergistiska effekter till följd av exponering för båda stressfaktorerna samtidigt.



Ur ett ekologiskt perspektiv kan vetenskaplig forskning om beteendeförändringar på organismnivå efter kortare exponering för kemiska föreningar ge värdefull information om de potentiella långsiktiga effekterna av exponering i miljön. Resultaten från mina studier skulle kunna användas i ekologiska modeller för att förutse hur förändringar i predator/bytesinteraktioner, orsakade av läkemedel, kan komma att påverka populationsstruktur, samt om detta även kan leda till förändringar på samhälls- eller ekosystemnivå i akvatiska miljöer. Informationen om sådana ekologiska effekter kommer att möjliggöra mer tillförlitliga riskbedömningar för läkemedel i akvatiska miljöer. (Less)
Abstract
Psychotropic pharmaceuticals have been shown to exert a variety of sublethal effects on non-target organisms, even at low concentrations found in the environment (ng/L to µg/L); hence, the aim of my research has been to determine the individual-level effects of psychotropic pharmaceuticals (the selective serotonin reuptake inhibitors sertraline and fluoxetine, and the β-blocker propranolol) on behavioral and life history traits in freshwater organisms. Further, this research was directed towards assessing the potential large-scale impacts of these effects on population growth and predator-prey interactions (with community-level implications) via the application of traditional, ecological concepts and models. This work has therefore... (More)
Psychotropic pharmaceuticals have been shown to exert a variety of sublethal effects on non-target organisms, even at low concentrations found in the environment (ng/L to µg/L); hence, the aim of my research has been to determine the individual-level effects of psychotropic pharmaceuticals (the selective serotonin reuptake inhibitors sertraline and fluoxetine, and the β-blocker propranolol) on behavioral and life history traits in freshwater organisms. Further, this research was directed towards assessing the potential large-scale impacts of these effects on population growth and predator-prey interactions (with community-level implications) via the application of traditional, ecological concepts and models. This work has therefore incorporated the exposure of organisms to key biotic stressors connected with predator-prey interactions (e.g. non-consumptive effects, variations in diet composition or prey density) that serve as vital links across levels of organization.



The studies included in this thesis indicate that exposure to sertraline resulted in alterations in habitat choice of snails (Radix balthica), though this did not affect the predator-induced, non-consumptive effects in snail behavior. This suggests that sertraline may not increase risk for predation by fish. Also, fluoxetine exposure altered risk-taking behavior in fish (Perca fluviatilis) linked to decreased vulnerability to avian predation, but this was potentially at the cost of reduced food-intake. A separate study directly examined feeding in juvenile fish (Perca fluviatilis) for which those exposed to sertraline exhibited decreased feeding rates at both low and high zooplankton prey densities (Daphnia magna). When examining effects of sertraline on the zooplankton Daphnia magna, I also detected significant reductions in growth, fecundity, and capacity for population increase, especially when exposed to both sertraline and a toxic cyanobacterium, Microcystis aeruginosa, simultaneously, i.e. with synergistic effects due to exposure to the two stressors occurring at high sertraline concentrations.



When employed within an ecological framework, scientific research on organism-level traits as endpoints of the short-term effects of chemical contaminant exposure can provide valuable information on the potential long-term outcomes of exposure in the environment. Not only are these effects of exposure interesting in themselves, but more importantly, the goal of this work has been to enable a holistic approach to ecotoxicology by determining how these behavioral and other trait-related effects impact the interactions among organisms, and the potential consequences thereof at higher levels of organization. (Less)
Please use this url to cite or link to this publication:
author
supervisor
opponent
  • Dr. Ford, Alex, University of Portsmouth
organization
publishing date
type
Thesis
publication status
published
subject
keywords
ecotoxicology, aquatic, trophic level, pharmaceutical, SSRI, beta-blocker, sertraline, fluoxetine, propranolol, fish, daphnia, snail, predator, prey, behavior, life history, multiple stressor
pages
120 pages
publisher
Department of Biology, Lund University
defense location
Blå Hallen, Ekologihuset
defense date
2015-05-28 13:00
ISBN
978-91-7623-320-7
978-91-7623-319-1
language
English
LU publication?
yes
id
cdfc9a64-ef90-4685-b805-a913557ce2c1 (old id 5364087)
date added to LUP
2015-05-13 14:11:54
date last changed
2016-09-19 08:45:03
@phdthesis{cdfc9a64-ef90-4685-b805-a913557ce2c1,
  abstract     = {Psychotropic pharmaceuticals have been shown to exert a variety of sublethal effects on non-target organisms, even at low concentrations found in the environment (ng/L to µg/L); hence, the aim of my research has been to determine the individual-level effects of psychotropic pharmaceuticals (the selective serotonin reuptake inhibitors sertraline and fluoxetine, and the β-blocker propranolol) on behavioral and life history traits in freshwater organisms. Further, this research was directed towards assessing the potential large-scale impacts of these effects on population growth and predator-prey interactions (with community-level implications) via the application of traditional, ecological concepts and models. This work has therefore incorporated the exposure of organisms to key biotic stressors connected with predator-prey interactions (e.g. non-consumptive effects, variations in diet composition or prey density) that serve as vital links across levels of organization. <br/><br>
<br/><br>
The studies included in this thesis indicate that exposure to sertraline resulted in alterations in habitat choice of snails (Radix balthica), though this did not affect the predator-induced, non-consumptive effects in snail behavior. This suggests that sertraline may not increase risk for predation by fish. Also, fluoxetine exposure altered risk-taking behavior in fish (Perca fluviatilis) linked to decreased vulnerability to avian predation, but this was potentially at the cost of reduced food-intake. A separate study directly examined feeding in juvenile fish (Perca fluviatilis) for which those exposed to sertraline exhibited decreased feeding rates at both low and high zooplankton prey densities (Daphnia magna). When examining effects of sertraline on the zooplankton Daphnia magna, I also detected significant reductions in growth, fecundity, and capacity for population increase, especially when exposed to both sertraline and a toxic cyanobacterium, Microcystis aeruginosa, simultaneously, i.e. with synergistic effects due to exposure to the two stressors occurring at high sertraline concentrations. <br/><br>
<br/><br>
When employed within an ecological framework, scientific research on organism-level traits as endpoints of the short-term effects of chemical contaminant exposure can provide valuable information on the potential long-term outcomes of exposure in the environment. Not only are these effects of exposure interesting in themselves, but more importantly, the goal of this work has been to enable a holistic approach to ecotoxicology by determining how these behavioral and other trait-related effects impact the interactions among organisms, and the potential consequences thereof at higher levels of organization.},
  author       = {Hedgespeth, Melanie},
  isbn         = {978-91-7623-320-7},
  keyword      = {ecotoxicology,aquatic,trophic level,pharmaceutical,SSRI,beta-blocker,sertraline,fluoxetine,propranolol,fish,daphnia,snail,predator,prey,behavior,life history,multiple stressor},
  language     = {eng},
  pages        = {120},
  publisher    = {Department of Biology, Lund University},
  school       = {Lund University},
  title        = {Psychotropic Pharmaceuticals in Aquatic Systems: An Ecological Perspective},
  year         = {2015},
}