Seafood represents the most important source of long-chain polyunsaturated fatty acids (LC-PUFAs) in the human diet. However, consuming fish can present risks from persistent organic pollutants (POPs) that bioaccumulate in edible tissues following dietary exposure. In farmed fish, POPs accumulate as a result of feeding diets based on fish oil (FO). Fish oil substitution can reduce POP accumulation, but also results in loss of beneficial LC-PUFAs. Fish oil-based finishing diets at the end of production can restore LC-PUFAs, but this strategy also increases POPs. The present study assessed the use of saturated fatty acid (SFA)-rich lipids to replace fish oil in grow-out feeds in conjunction with a fish oil-rich finishing diet to determine if this strategy could produce hybrid striped bass with equal production performance, equivalent LC-PUFA levels, and reduced POP concentrations. Triplicate tanks of hybrid striped bass were raised on diets containing fish oil (100% FO), fish oil spiked with additional POPs (100% FO Spike), or blends (50/50 or 25/75) of FO and coconut (CO) or palm (PO) oils (50% CO, 50% PO, 75% CO, 75% PO) with and without an eight week finishing period with the 100% FO diet prior to harvest. Production performance, fillet LC-PUFA, and POP content were assessed. Production performance was not adversely affected by any of the feeding regimens. However, fatty acid profile was altered, with fillets of fish consuming less fish oil having lower LC-PUFA and POP levels. Finishing yielded a modest increase in fillet LC-PUFAs and POPs, but POPs accumulated more readily than LC-PUFAs during finishing. However, harvest fillet POP and LC-PUFA levels in the experimental groups were lower relative to levels in the 100% FO group. Replacing fish oil in aquafeeds can produce fish with reduced LC-PUFAs, and also reduced POPs. Feeding fish oil results in more rapid accumulation of POPs than LC-PUFA. Overall, the 75% fish oil replacement feeds yielded fish with the highest ratio of LC-PUFAs to POPs. Despite lower LC-PUFA content, fillets of fish fed the 75% fish oil replacement feeds could be incorporated into a weekly meal plan with other dietary sources of LC-PUFAs to meet dietary recommendations for these essential nutrients.

Kyoto University (京都大学) / 0048 / 新制・課程博士 / 博士(工学) / 甲第16386号 / 工博第3467号 / 新制||工||1524(附属図書館) / 29017 / 京都大学大学院工学研究科都市環境工学専攻 / (主査)教授 清水 芳久, 教授 田中 宏明, 教授 藤井 滋穂 / 学位規則第4条第1項該当

Permafrost thaw slumping along lakeshores in lakes of the Mackenzie Delta Uplands, NT is known to alter water chemistry significantly. Its impact on benthic communities and persistent organic pollutant (POP) behaviour in lakes is not known. Benthic invertebrate communities responded to slumps through changes to community composition and size spectra. Larger taxa tended to dominate in lakes with slumps. Variability in biomass size spectra was related to total dissolved nitrogen concentration and slump size. Concentrations of POPs in Gammarus were negatively correlated with total phosphorus and positively correlated with the percentage of the catchment slumped. Lakes with slumps generally had higher mean concentrations of POPs in Gammarus (ex. ΣPCBsDisturbed = 27.54 ng/g lipid, ΣPCBsUndisturbed = 16.97 ng/g lipid; ΣDDT Disturbed =18.47 ng/g lipid and ΣDDTUndisturbed =10.86 ng/g lipid). Benthic invertebrate biomass was also negatively correlated with concentrations of contaminants in Gammarus, supporting the biomass dilution hypothesis. Thaw slumps have large enough impacts on the physico-chemical characteristics of lakes that they alter benthic invertebrate community composition and size-structure, and contaminant concentrations in Gammarus.

Polychlorinated Biphenyls (PCBs) are persistent organic pollutants known for their toxicological effects. Though industrial production of legacy PCBs was banned in 1977, they can still be measured in nearly all environmental matrices. The Chicago Sanitary and Ship Canal (CSSC) is lined with industry and the receiving waters to the Stickney Water Reclamation Plant, the World's largest waste water treatment plant and was therefore speculated to be a potential source of PCBs to the Greater Chicago Area. Surficial sediment samples were acquired along a 45 km stretch of the CSSC, from Kedzie Ave. to Lockport. PCBs in the bulk sediment were extracted using accelerated solvent extraction while PCBs in the porewater were extracted using solid phase micro extraction. The PCBs were identified and quantified using a variation on EPA method 1668C. A total of 176 individual and coeluting PCBs were identified and quantified in this study. The sum of PCB concentrations in the bulk sediment was found to range from 70 to 4970 ng/g dry wt. The sum of PCB concentrations in the freely dissolved sediment-porewater was found to range from 2 to 366 ng/L. The bulk and porewater concentrations were used to estimate an average mass flow rate of PCBs through the CSSC of 368 kg/y. The large mass flow rate of PCBs passing through the CSSC and the fact that the CSSC connects Lake Michigan to the Mississippi River suggest that continued monitoring of PCB concentrations are necessary to better understand the transport and fate of PCBs in and out of the Great Chicago Area.

Depuis plusieurs décennies la production mondiale de plastiques ne cesse d’augmenter, menant à une contamination des écosystèmes aquatiques à l’échelle de la planète qui a été récemment estimée à plus de cinq mille milliards de débris de plastiques flottants à la surface des océans. Les microplastiques (particules de plastique < 5 mm), introduits dans l’environnement aquatique directement en tant que microparticules (granulés plastiques industriels, cosmétiques, fibres textiles) ou lors de la fragmentation de plus gros débris plastiques, représentent une préoccupation scientifique et sociétale grandissante. Ces travaux de thèse se sont focalisés sur la contamination par les microplastiques de la rade de Brest (Bretagne, France), un système côtier macrotidal où l’activité anthropique est importante. Les objectifs de ces travaux sont (1) d’évaluer la contamination des matrices environnementales (eau de surface, sédiment subtidal et biote) par les microplastiques, et (2) d’identifier leur rôle potentiel en tant que vecteurs de contaminants chimiques et de bactéries dans la rade de Brest.Pour cela, des développements analytiques ont été nécessaires afin d’améliorer leur extraction des matrices environnementales ainsi que leur caractérisation morphologique et chimique via la microspectrométrie Raman. Les observations in situ ont montré que l’ensemble de l’écosystème de la rade de Brest est contaminé par les microplastiques, avec des concentrations de 0,24 ± 0,35, et 0,97 ± 2,08 (moyenne ± écart-type). L’eau de surface et le sédiment sont contaminés par le polyéthylène, le polypropylène et le polystyrène. Leur distribution à la surface de l’eau semble être liée à l’urbanisation très présente au nord de la rade, mais également à l’hydrodynamisme de cette région marine. Les premiers résultats concernant les bivalves marins ont montré un niveau relativement faible de contamination par les microplastiques (0,01 ± 0,04 et 0,08 ± 0,34 pour les moules et les coques, respectivement), cependant cela est probablement dû aux choix méthodologiques appliqués ici (exclusion des fibres). Les observations in situ ont montré que certains polluants organiques (HAP, PCB et pesticides) étaient détectés sur les microplastiques flottants à des valeurs (non détecté – 49763 ng.g-1, moyenne ± écart-type) similaires de celles retrouvées dans les sédiments et les bivalves locaux, ce qui suggère un risque faible dans le transfert des contaminants chimiques vers les organismes marins en cas d’ingestion. Enfin, les résultats concernant la colonisation bactérienne des microplastiques flottants ont montré des communautés distinctes de celles retrouvées dans l’eau de mer environnante, et l’identification du genre Vibrio en tant que biomarqueur discriminant de cette matrice. Dans l’ensemble, ces travaux fournissent une première évaluation approfondie de l’état de contamination de la rade de Brest par les microplastiques ainsi que de solides recommandations méthodologiques pour des travaux futurs. / World production of plastics has increased steadily for the past decades leading to a major contamination of the worldwide aquatic ecosystems recently estimated at more than five trillion plastic pieces floating the surface of the oceans. Microplastics (plastic particles < 5 mm) are introduced into aquatic environments directly as industrial raw material (plastic pellets, cosmetics, clothing) or indirectly via the fragmentation of larger plastics. This emerging contaminant represents an increasing ecological concern for science and society. The present study focused on the microplastic contamination of the Bay of Brest (Brittany, France), a macrotidal coastal ecosystem characterized by intense anthropogenic activity. The main objectives were: (1) to evaluate the contamination of environmental matrices (surface water, subtidal sediment and biota) by microplastics, and (2) to identify their potential role as vector of chemicals and bacteria in the bay of Brest.Methodological developments were first conducted to improve microplastic extraction from environmental matrices as well as their rapid morphological and chemical identification by Raman micro-spectrometry. The field investigations showed that the ecosystem of the bay of Brest is contaminated by microplastics with mean concentrations of 0.24 ± 0.35, and 0.97 ± 2.08 (mean ± standard deviation) in surface water and sediment, respectively. Microplastic contamination in surface water and sediment was dominated by polyethylene, polypropylene and polystyrene microparticles.Spatial microplastic distribution appeared to be related to proximity to urbanized areas and to hydrodynamic in the bay. Preliminarily results of microplastic contamination in marine bivalves demonstrated relatively low contamination (0.01 ± 0.04, and 0.08 ± 0.34 for mussels and cockles, respectively) by microplastics (mainly polyethylene and polypropylene fragments), however this could be partly related to the methodological limitation identified here (e.g. exclusion of fibers). Organic pollutant (PAH, PCB and pesticides) were detected on floating microplastics at levels (not detected – 49,763 ng g-1, mean ± SD) similar to those measured in sediment and bivalves suggesting low risks in transferring hazardous chemicals in local marine organisms upon microplastic ingestion. Finally, distinct bacterial community assemblages were demonstrated on microplastics as compared with surrounding surface water; the Vibrio genus was identified as a discriminant biomarker of the plastic matrix. Overall, this work provides a first and thorough assessment of the microplastic contamination in the bay of Brest and solid methodological recommendations for further work.

Les Québécois sont de plus en plus conscients de l’environnement qui les entoure et de l’importance d’en assurer la qualité et la pérennité. Certains phénomènes, tels les changements climatiques, l’accumulation de polluants organiques persistants et l’amincissement de la couche d’ozone, que nous qualifierons de phénomènes environnementaux diffus, sont engendrés par de multiples émetteurs de polluants et ont des effets globaux qui ne peuvent être liés à un événement précis et dont les impacts sont difficiles à identifier et à quantifier pour le moment. En l’absence de preuve quant aux effets qu’auront ces phénomènes diffus sur les citoyens et les difficultés liées à la preuve scientifique du lien causal entre ce dommage et un émetteur de polluant donné, les recours classiques en responsabilité civile et pour troubles de voisinage, prévus aux articles 1457 et 976 C.c.Q., apparaissent inopérants. Nous nous interrogeons donc sur l’existence d’un droit à l’environnement qui conférerait aux citoyens le droit de vivre dans un environnement sain et leur permettrait ainsi de réclamer que cesse toute atteinte environnementale engendrée par ces phénomènes, même si elle n’a pas d’effet directement sur eux. Considérant l’importance de l’efficacité des recours qui pourraient permettre une mise en œuvre de ce droit, nous procéderons à l’analyse de trois sources potentielles d’un droit à l’environnement sous cet angle. À cet effet, nous étudierons les recours constitutionnels et quasi-constitutionnels liés à la Charte canadienne des droits et libertés, à la Charte des droits et libertés de la personne et au recours institutionnel prévu dans la Loi sur la qualité de l’environnement. Considérant l’absence de reconnaissance suffisante d’un droit à l’environnement et de recours efficaces pour en assurer la mise en œuvre, nous proposerons ensuite des pistes de solution afin que puisse être développé un mécanisme permettant une réponse judiciaire aux phénomènes environnementaux diffus. / The quality of the environment has become a growing concern in the recent years for Quebec citizens. Phenomena such as climate change, persistent organic pollutants and the depletion of the ozone layer are caused by several sources, the effects of which cannot be distinguished one from the other and/or linked to a specific event. Furthermore, these phenomena have yet to create damage to Quebec residents in order to create the necessary standing for the introduction of legal proceedings. Also, the scientific uncertainty related to the source of potential damage and to the proof of said damage makes it impossible to legally attack the emitters of the pollutant contributing to this type of environmental phenomena under 1457 C.C.Q. or 976 C.C.Q. We have identified the 3 potential sources of a right to a clean environment which could entitle Quebec citizens to go before the courts in environmental matters, even in the absence of specific damages to their person or property. We have analysed the Canadian Charter of Rights and Freedoms, the Charter of Human Rights and Freedoms and the Environmental Quality Act and looked at the potential right to a clean environment possibly contained therein and the legal actions that could be taken to ensure their respect. Considering the weakness of what our legal system had to propose, we have developed solutions that could be put forward in order to allow the war against climate change and other environmental phenomena of the same nature to become legally actionable.

As aves marinhas são sensíveis às alterações em todos os níveis tróficos, decorrentes de variações na disponibilidade de presas e contaminação por alguns compostos, capazes de se acumular nos tecidos dos organismos e magnificar-se através da cadeia trófica. As ilhas oceânicas brasileiras abrigam importantes colônias reprodutivas de aves marinhas e, apesar de serem consideradas locais remotos, estão sujeitas à contaminação decorrente de atividades humanas. Este trabalho avaliou a presença de poluentes orgânicos persistentes (POPs) em sangue, uma matriz não-destrutiva, de seis espécies de aves marinhas no Arquipélago de São Pedro e São Paulo e na Ilha da Trindade, que possibilita o monitoramento destes indivíduos ao longo dos anos. Os resultados indicaram que os principais POPs detectados no sangue (em ng g-1 de massa úmida) foram PCBs (0,05 a 55,09), DDTs (0,01 a 17,36) e Mirex (0,01 a 5,53). A migração influenciou nos altos níveis de POPs encontrados em Pterodroma arminjoniana e a massa (g) média dos indivíduos apresentou uma forte correlação negativa com as concentrações dos compostos predominantes no sangue. O sexo das aves não contribuiu significativamente nas concentrações de POPs em espécies monotípicas, exceto para a espécie Sula leucogaster que apresenta dimorfismo sexual acentuado. O comportamento alimentar, avaliado através da análise de isótopos estáveis de carbono e de nitrogênio (&delta;13C e &delta;15N), bem como as condições biológicas de cada animal contribuíram para explicar as variações nos perfis de contaminação entre as diferentes espécies. No geral, observou-se que as concentrações de POPS nos dois locais apresentaram valores baixos e similares sugerindo a via atmosférica como principal mecanismo de entrada desses contaminantes para estas regiões. Os resultados inéditos de POPs em sangue das aves marinhas nas duas mais recentes unidades de conservação marinhas criadas no Brasil, podem contribuir como referência para o monitoramento desses compostos em longo-prazo nessas regiões. / Seabirds are sensitive to changes at all trophic levels, due to variations in prey availability and contamination by some compounds, which can be accumulated in the tissues of organisms and to be magnified through the trophic chain. The Brazilian oceanic islands harbor important seabird breeding colonies and, although they are considered remote sites, they are subject to contamination from human activities. This work evaluated the presence of Persistent Organic Pollutants (POPs) in blood, a non-destructive matrix, of six species of seabirds in the São Pedro and São Paulo Archipelago (SPSPA) and Trindade Island (TI), that allows the monitoring of these individuals over the years. The results indicated that the major POPs detected in blood (ng g-1 in wet weight) were PCBs (0.05 to 55.09), DDTs (0.01 to 17.36) and Mirex (0.01 to 5,53). Migration influenced the high levels of POPs found in Pterodroma arminjoniana and the mean mass (g) of the individuals drove a strong negative correlation with the concentrations of the predominant compounds in the blood. The gender of the individuals did not contribute significantly to the concentrations of POPs in monotypic species, except for the species Sula leucogaster that presents marked sexual dimorphism. The feeding behavior was evaluated through the analysis of stable isotopes of carbon and nitrogen (&delta;13C and &delta;15N) as well as the biological conditions of each animal contributed to explain the variations in the contamination profiles between the different species. In general, we observed that POPS concentrations at both sites presented low and similar values suggesting the atmospheric transport as the main input mechanism of these compounds for these regions. The unpublished results of POPs, in blood of seabirds from the two most recent marine conservation units created in Brazil, can contribute as reference values for their long-term monitoring in those regions.

<p>Месо шарана, најзаступљеније врсте рибе на рибњацима у<br />Републици Србији, али и других ципринидних врста, представља<br />значајан нутритивни извор n-3 високо незасићених масних киселина,<br />које имају важну улогу на здравље људи. У раду су испитани<br />фактори који делују на хемијски и маснокиселински састав меса<br />шарана и других ципринидних врста које се гаје на подручју Србије.<br />Установљено је да је садржај масти и маснокисeлински састав риба<br />су под утицајем врсте рибе, чак и када припадају истој фамилији,<br />различитих фактора животне средине, начина гајења, а посебно<br />начина исхране. Утврђен је значај добре технологије производње на<br />рибњаку за одговарајућу структуру планктонских и бентосних<br />организама, што игра велику улогу у добијању меса шарана, али и<br />других ципринидних врста, које се могу гајити у поликултури са<br />њим, доброг хемијског и маснокиселинског састава. Указано је на<br />значај који формулисане смеше имају у исхрани риба на њихово<br />здравствено стање, производне параметре и квалитет меса. Извршено<br />је испитивање замене компоненти анималног порекла са<br />алтернативним компонентама биљног порекла и добијени су<br />задовољавајући резултати у погледу производних перформанси и<br />умерених промена квалитета меса, када је у питању маснокиселински<br />ДВМ Драгана Љубојевић<br />Коришћење репичиног уља у исхрани шарана и лињака као фактора променa квалитета меса<br />iii<br />састав. Анализом седимента, воде у рибњацима, као и меса риба из<br />рибњака и отворених вода установљен је степен загађености животне<br />средине. Представљен је нови производ од меса шарана и других<br />ципринидних риба. По први пут је успостављена ћелијска култура<br />масног ткива шарана, која омогућава анализирање молекуларних и<br />биохемијских механизама који се не могу изучавати на живим<br />рибама, који настају као последица промена у исхрани.</p> / <p>Meso šarana, najzastupljenije vrste ribe na ribnjacima u<br />Republici Srbiji, ali i drugih ciprinidnih vrsta, predstavlja<br />značajan nutritivni izvor n-3 visoko nezasićenih masnih kiselina,<br />koje imaju važnu ulogu na zdravlje ljudi. U radu su ispitani<br />faktori koji deluju na hemijski i masnokiselinski sastav mesa<br />šarana i drugih ciprinidnih vrsta koje se gaje na području Srbije.<br />Ustanovljeno je da je sadržaj masti i masnokiselinski sastav riba<br />su pod uticajem vrste ribe, čak i kada pripadaju istoj familiji,<br />različitih faktora životne sredine, načina gajenja, a posebno<br />načina ishrane. Utvrđen je značaj dobre tehnologije proizvodnje na<br />ribnjaku za odgovarajuću strukturu planktonskih i bentosnih<br />organizama, što igra veliku ulogu u dobijanju mesa šarana, ali i<br />drugih ciprinidnih vrsta, koje se mogu gajiti u polikulturi sa<br />njim, dobrog hemijskog i masnokiselinskog sastava. Ukazano je na<br />značaj koji formulisane smeše imaju u ishrani riba na njihovo<br />zdravstveno stanje, proizvodne parametre i kvalitet mesa. Izvršeno<br />je ispitivanje zamene komponenti animalnog porekla sa<br />alternativnim komponentama biljnog porekla i dobijeni su<br />zadovoljavajući rezultati u pogledu proizvodnih performansi i<br />umerenih promena kvaliteta mesa, kada je u pitanju masnokiselinski<br />DVM Dragana LJubojević<br />Korišćenje repičinog ulja u ishrani šarana i linjaka kao faktora promena kvaliteta mesa<br />iii<br />sastav. Analizom sedimenta, vode u ribnjacima, kao i mesa riba iz<br />ribnjaka i otvorenih voda ustanovljen je stepen zagađenosti životne<br />sredine. Predstavljen je novi proizvod od mesa šarana i drugih<br />ciprinidnih riba. Po prvi put je uspostavljena ćelijska kultura<br />masnog tkiva šarana, koja omogućava analiziranje molekularnih i<br />biohemijskih mehanizama koji se ne mogu izučavati na živim<br />ribama, koji nastaju kao posledica promena u ishrani.</p> / <p>Meat of common carp, the most common fish species which is farmed in<br />the Republic of Serbia and meat of other cyprinid species, represent an<br />important nutritional source of n-3 highly unsaturated fatty acids, which<br />play an important role in human health. This paper examined the factors<br />that affect the chemical and fatty acid composition of carp and other<br />cyprinid species that are grown in Serbia. It was found that the fat content<br />and fatty acid composition of fish are influenced by fish species, even<br />when they belong to the same family, and also by different environmental<br />factors of cultivation, especially by diet. It was established the importance<br />of proper rearing technology in the pond for the appropriate structure of<br />planktonic and benthic organisms, which play a significant role in getting<br />carp meat, and meat of other cyprinid species that can be grown in<br />polyculture with carp of desirable chemical and fatty acid composition. It<br />was pointed out on the significance of formulated feed mixtures in fish<br />nutrition on fish health, production parameters and meat quality. An<br />investigation was done on replacing components of animal origin with<br />alternative components of plant origin and satisfactory results were<br />obtained in terms of production performance and moderate changes in the<br />quality of meat, regarding to fatty acid composition. The degree of<br />environmental pollution was established by analysis of sediment and<br />water in the ponds, and the flesh of fish from ponds and open water. The<br />new food product made from fish meat was presented. For the first time, it<br />was established cell cultures carp preadipocytes, which allows analysis of<br />the molecular and biochemical mechanisms that arise as a result of<br />ДВМ Драгана Љубојевић<br />&nbsp;</p>

Les Québécois sont de plus en plus conscients de l’environnement qui les entoure et de l’importance d’en assurer la qualité et la pérennité. Certains phénomènes, tels les changements climatiques, l’accumulation de polluants organiques persistants et l’amincissement de la couche d’ozone, que nous qualifierons de phénomènes environnementaux diffus, sont engendrés par de multiples émetteurs de polluants et ont des effets globaux qui ne peuvent être liés à un événement précis et dont les impacts sont difficiles à identifier et à quantifier pour le moment. En l’absence de preuve quant aux effets qu’auront ces phénomènes diffus sur les citoyens et les difficultés liées à la preuve scientifique du lien causal entre ce dommage et un émetteur de polluant donné, les recours classiques en responsabilité civile et pour troubles de voisinage, prévus aux articles 1457 et 976 C.c.Q., apparaissent inopérants. Nous nous interrogeons donc sur l’existence d’un droit à l’environnement qui conférerait aux citoyens le droit de vivre dans un environnement sain et leur permettrait ainsi de réclamer que cesse toute atteinte environnementale engendrée par ces phénomènes, même si elle n’a pas d’effet directement sur eux. Considérant l’importance de l’efficacité des recours qui pourraient permettre une mise en œuvre de ce droit, nous procéderons à l’analyse de trois sources potentielles d’un droit à l’environnement sous cet angle. À cet effet, nous étudierons les recours constitutionnels et quasi-constitutionnels liés à la Charte canadienne des droits et libertés, à la Charte des droits et libertés de la personne et au recours institutionnel prévu dans la Loi sur la qualité de l’environnement. Considérant l’absence de reconnaissance suffisante d’un droit à l’environnement et de recours efficaces pour en assurer la mise en œuvre, nous proposerons ensuite des pistes de solution afin que puisse être développé un mécanisme permettant une réponse judiciaire aux phénomènes environnementaux diffus. / The quality of the environment has become a growing concern in the recent years for Quebec citizens. Phenomena such as climate change, persistent organic pollutants and the depletion of the ozone layer are caused by several sources, the effects of which cannot be distinguished one from the other and/or linked to a specific event. Furthermore, these phenomena have yet to create damage to Quebec residents in order to create the necessary standing for the introduction of legal proceedings. Also, the scientific uncertainty related to the source of potential damage and to the proof of said damage makes it impossible to legally attack the emitters of the pollutant contributing to this type of environmental phenomena under 1457 C.C.Q. or 976 C.C.Q. We have identified the 3 potential sources of a right to a clean environment which could entitle Quebec citizens to go before the courts in environmental matters, even in the absence of specific damages to their person or property. We have analysed the Canadian Charter of Rights and Freedoms, the Charter of Human Rights and Freedoms and the Environmental Quality Act and looked at the potential right to a clean environment possibly contained therein and the legal actions that could be taken to ensure their respect. Considering the weakness of what our legal system had to propose, we have developed solutions that could be put forward in order to allow the war against climate change and other environmental phenomena of the same nature to become legally actionable.

Using a comparative spatial and temporal analysis on sediment cores from 8 lakes in the Mackenzie River Delta uplands region, NT, Canada, this study assessed how persistent organic pollutant (POP) deposition to lake sediments was affected by: (1) the presence of retrogressive thaw slumps on lake shores; and (2) changes occurring with increased autochthonous primary productivity. POPs examined included polychlorinated biphenyls (PCBs), penta- and hexachlorobenzenes (CBzs), and dichlorodiphenyltrichloroethane and metabolites (DDTs). Surface sediments of slump-affected lakes contained higher total organic carbon (TOC)-normalized POP concentrations than nearby reference lakes unaffected by thaw slumps. Inorganic sedimentation rates were positively related to contaminant concentrations, suggesting that the influx of siliciclastic material reducing organic carbon in slump-affected lake water indirectly results in higher concentrations of POPs on sedimentary organic matter. This explanation was corroborated by an inverse relationship between sedimentary POP concentrations and TOC content of the lake water. Deposition proxies of autochthonous carbon were not significantly correlated to POP fluxes of surface sediments, and historical profile fluctuations did not coincide with variation in POP deposition. Thus this study does not support the contention that algal-derived organic carbon increases the delivery of organic pollutants to sediments (the algal-scavenging hypothesis), as previously proposed for mercury. Higher POP concentrations observed in surface sediments of slump-affected lakes are best explained by simple solvent switching processes of hydrophobic contaminants onto a lower pool of available organic carbon when compared to neighbouring lakes unaffected by thaw slump development.