I investigated the effects ofhabitat loss and subsequent restoration on invertebrate community structure and ecosystem functioning in a mined peat bog in the North Island, New Zealand. In an experimental trial, the impact of peat bog habitat loss and isolation on the invertebrate community associated with Sporadanthus ferrugineus (Restionaceae) was investigated. Potted S. ferrugineus plants were exposed to invertebrates at various distances up to 800 m from an intact habitat (the presumed source population) over 18 weeks. Invertebrates rapidly colonised the experimental plants, with all major Orders and trophic groups present on Sc ferrugineus within 6 weeks. However. with increasing distance away from the undisturbed habitat, there was a significant decrease in total richness and abundance of invertebrates associated with the potted plants. Additional tests showed that even a moderate degree of isolation (i.e. greater than 400 m) from the intact habitat caused an almost complete failure of 'Batrachedra' sp. to colonise its host plant, at least in the short-term, The density of eggs and larvae, and the average larval size of 'Batrachedra' sp. (Lepidoptera: Coleophoridae) colonising Si ferrugineus plants, as well as the proportion of Si ferrugineus stems damaged by 'Batrachedra' sp. herbivory, all decreased logarithmically with increasing distance from the intact habitat. Surprisingly, though, the rate of recovery of the insect-plant interaction following experimental habitat restoration was remarkably rapid (i.e. between 3Y2 and 6 years). After just 6 years there was no significant difference in insect-plant interactions between the intact peat bog sites and any of the experimentally restored sites up to 800 m away. These results suggest that the degree of isolation from undisturbed habitat has a major impact on the rate and patterns of restoration recovery in the invertebrate community and that some insect-plant interactions can recover rapidly from habitat loss with restoration management. Restoration of mined peat bogs in northern New Zealand is initiated by establishing a native vegetation cover to minimize further peat degradation. The effects of various restoration techniques on litter decomposition, microbial community activity and beetle community composition were investigated within an experimental trial, These treatments included translocation ofpeat bog habitat (direct transfer of islands), milled peat islands with no seed and milled peat islands with seed, and were compared with an unrestored mined site and an undisturbed peat bog. In all the response variables measured, the undisturbed peat bog sites had significantly higher decomposition rates and microbial respiration rates, and significantly higher abundance and species richness of beetles than any of the restoration treatments. Inaddition, the technique used to restore mined peatlands had a significant effect on the beetle community composition and litter decomposition processes. Despite a rapid initial change in the beetle community following habitat translocation, the direct transfer islands were still the most similar in beetle species composition to the undisturbed peat bog. Microbial activity and decomposition rates were higher in the direct transfer and mined peat surface after 6 months. However, even after 12 months, decomposition rates in the restored habitats were still far from reaching the levels recorded in the undisturbed peat bog. The results suggest that beetle community structure and ecosystem processes such as decomposition and microbial activity rates may be able to recover faster with certain restoration techniques, such as direct transfer of intact habitat islands. Subsequently, I examined long-term beetle community reassembly on islands that had been restored by creating raised areas ofprocessed peat with the addition of Leptospermum scoparium seed. Monitoring of different-aged restored islands representing the full range of restoration ages (up to 6 years) available at the peat mine, indicated that as the peat islands became older and the vegetation structure became more complex, the abundance, species richness and composition of the beetle community became increasingly similar to the community in the undisturbed peat bog. Despite this, distinct differences between the intact peat bog and older restored peat islands still persisted, even after 6 years, particularly at an individual species level. However, it is predicted that within 12 years the restored peat islands will share 100% ofbeetle species in common with the undisturbed peat bog. Taken together, these results indicate that restoration is effective in initiating the recovery of beetle assemblages and ecosystem processes (such as litter decomposition and microbial community activity) in cut-over peat bogs. However, it is estimated to take at least 12 years before pre-mining communities and functions are attained, and ongoing monitoring to develop an understanding of the longer-term dynamics of such ecosystems and processes is clearly required.

Female reproductive performance is a critical component of sustainable pig production systems. There is abundant evidence of genetic variation in these traits among pig breeds. The aims of this study were to identify quantitative trait loci (QTL) affecting reproductive traits and to identify and characterise positional candidate gene(s) underlying the QTL. A Large White - Meishan F2 population was scanned for QTL with effects on reproductive traits. This analysis revealed 13 putative QTLs on seven different chromosomes with effects on five different traits: ovulation rate (OR), teat number (TN), prenatal survival (PS), total born alive (TBA) and litter size (LS). QTL for PS and LS on chromosome 8 were fine mapped and Secreted Phosphoprotein 1 (SPP1) confirmed as a candidate gene. A genome-wide association study was performed on a diverse population of different breeds and crosses lines, for reproductive traits including LS, TBA, number of stillborn piglets, and number of mummified piglets. Fourteen SNPs were found significantly associated with reproductive traits. The functional study of SPP1 examined the hypothesis that differences in foetal growth may be associated with the effectiveness of conceptus attachment, as measured by SPP1 expression. Patterns of SPP1 mRNA and protein expression in placental and uterine tissues supplying the smallest and a normal-sized foetus from the same uterus were examined in Large White-Landrace (LW-LR), Large White (LW) and Meishan (MS) females 40 and 45 of pregnancy. The smallest LW-LR foetuses tended to have a higher level of SPP1 mRNA in endometrium tissue compared to the normal-sized foetuses. However, placenta expression was higher in the normal-sized foetuses compared to the smallest ones. SPP1 protein levels in normal sized foetuses were significantly higher than in the smallest litter mates for all the tissues. Significantly higher levels of SPP1 mRNA and protein were found in MS compared to LW. In both breeds, significant differences between sizes were found in some tissues, with similar expression patterns in respect to size, for both mRNA and protein in endometrial tissues when compared to contemporary LW. In placenta, the direction of the expression differed between breeds, with a higher expression of mRNA and protein in the normal-sized MS foetuses and in the smallest sized LW foetuses. The comparison of SPP1 expression between different foetal sizes and different breeds revealed associations between breed, foetal size, and SPP1 protein, factors implicated in PS and LS. These results together with the genetic evidence indicate that the potential role of SPP1 in placental and foetal development merits further investigation.

Fine roots constitute a large part of the primary production in northern (arctic and boreal) ecosystems, and are key players in ecosystem fluxes of water, nutrients and carbon. Data on root dynamics are generally rare, especially so in northern ecosystems. However, those ecosystems undergo the most rapid climatic changes on the planet and a profound understanding of form, function and dynamics of roots in such ecosystems is essential. This thesis aimed to advance our knowledge about fine root dynamics in northern ecosystems, with a focus on fine root phenology in natural plant communities and how climate change might alter it. Factors considered included thickness and duration of snow cover, thawing of permafrost, as well as natural gradients in temperature. Experiments and observational studies were located around Abisko (68°21' N, 18°45' E), and in a boreal forest close to Vindeln (64°14'N, 19°46'E), northern Sweden. Root responses included root growth, total root length, and root litter input, always involving seasonal changes therein, measured with minirhizotrons. Root biomass was also determined with destructive soil sampling. Additionally, aboveground response parameters, such as phenology and growth, and environmental parameters, such as air and soil temperatures, were assessed. This thesis reveals that aboveground patterns or responses cannot be directly translated belowground and urges a decoupling of above- and belowground phenology in terrestrial biosphere models. Specifically, root growth occurred outside of the photosynthetically active period of tundra plants. Moreover, patterns observed in arctic and boreal ecosystems diverged from those of temperate systems, and models including root parameters may thus need specific parameterization for northern ecosystems. In addition, this thesis showed that plant communities differ in root properties, and that changes in plant community compositions can thus induce changes in root dynamics and functioning. This underlines the importance of a thorough understanding of root dynamics in different plant community types in order to understand and predict how changes in plant communities in response to climate change will translate into root dynamics. Overall, this thesis describes root dynamics in response to a variety of factors, because a deeper knowledge about root dynamics will enable a better understanding of ecosystem processes, as well as improve model prediction of how northern ecosystems will respond to climate change.

The common marmoset is the most frequently used New World primate in laboratory research and testing. In the UK, their use is strictly controlled by the Animals (Scientific Procedures) Act, which is underpinned by the principles of humane science: Replacement, Reduction and Refinement. Despite their use, there are a number of problems associated with the breeding of marmosets, including low dam longevity and increasing litter sizes. Large litters have led to high infant mortality and the need for human intervention to improve infant survival, which involves removal from the family for substantial periods of time. Previous research in a range of primate species shows that early life family separation is associated with numerous adverse behavioural and physiological effects. This project therefore sought to systematically investigate the effects of breeding and infant rearing practices, integrating a number of measures to assess the welfare of laboratory- housed marmosets. Potential predictors of dam longevity and litter size were first identified in three captive UK colonies, over four decades. Dam longevity was found to be approximately 6 years, with heavier dams living longer, but overall there was no consistent improvement in longevity over the decades. As longevity varied widely between colonies and over time, environment may be one of the most important factors. Approximately half of all births at each colony were litters larger than two, and these larger litters had greater infant mortality. Only dam weight at conception was useful in predicting litter size, with heavier dams producing larger litters. The consequences of large litters and early separation from the family for supplementary feeding were then investigated. Although twins had lower body weight than 2stays (two infants remaining with the family after death of the other littermate/s) and supplementary fed triplets, they also had the fewest health problems. There was also some evidence that animals from larger litters were more at risk of suffering from extreme low weight. Some minor differences were found in behavioural development between litter sizes. Singleton infants received more rejective rearing, while 2stays received more protective rearing, perhaps following the loss of an infant. While twin infants gained independence earlier than singletons or 2stays, they did not appear to cope better with stress in adulthood, displaying more significant increases in stress-related behaviour following the routine stressor of capture and weighing, compared to 2stays and supplementary fed triplets. While overall cortisol unexpectedly decreased from baseline to post capture, there were only significant fluctuations in 2stay marmosets. Instead, there were some increases in positive behaviour in supplementary fed triplets following the stressor, suggesting enhanced coping ability. However, in another group of supplementary fed triplets, there were subtle increases in depressive-like symptoms, measured using cognitive bias and preference tests, suggesting a reduced expectation of and interest in rewards. There were however no differences between family-reared and supplementary fed marmosets in time to learn a visual discrimination task, or in responses to temperament tests. Therefore, while it was hypothesised that early family separation would have adverse developmental consequences, there were actually very little differences between marmosets of different litter sizes and rearing backgrounds, across the range of measures. Results suggest that the current supplementary feeding programme, along with a regular human socialisation programme, minimises any potential negative effects. However, we should always be finding ways to improve the lives of animals in our care. Possible Refinements include reducing dam weight to increase twin births and improve infant survival, and training to allow supplementary feeding on the carrier’s back, to prevent infant separation and reduce disruption to the family. These Refinements could reduce fear and allow monkeys to become more resilient to the laboratory environment.

Fine roots constitute a large part of the primary production in northern (arctic and boreal) ecosystems, and are key players in ecosystem fluxes of water, nutrients and carbon. Data on root dynamics are generally rare, especially so in northern ecosystems. However, those ecosystems undergo the most rapid climatic changes on the planet and a profound understanding of form, function and dynamics of roots in such ecosystems is essential. This thesis aimed to advance our knowledge about fine root dynamics in northern ecosystems, with a focus on fine root phenology in natural plant communities and how climate change might alter it. Factors considered included thickness and duration of snow cover, thawing of permafrost, as well as natural gradients in temperature. Experiments and observational studies were located around Abisko (68°21' N, 18°45' E), and in a boreal forest close to Vindeln (64°14'N, 19°46'E), northern Sweden. Root responses included root growth, total root length, and root litter input, always involving seasonal changes therein, measured with minirhizotrons. Root biomass was also determined with destructive soil sampling. Additionally, aboveground response parameters, such as phenology and growth, and environmental parameters, such as air and soil temperatures, were assessed. This thesis reveals that aboveground patterns or responses cannot be directly translated belowground and urges a decoupling of above- and belowground phenology in terrestrial biosphere models. Specifically, root growth occurred outside of the photosynthetically active period of tundra plants. Moreover, patterns observed in arctic and boreal ecosystems diverged from those of temperate systems, and models including root parameters may thus need specific parameterization for northern ecosystems. In addition, this thesis showed that plant communities differ in root properties, and that changes in plant community compositions can thus induce changes in root dynamics and functioning. This underlines the importance of a thorough understanding of root dynamics in different plant community types in order to understand and predict how changes in plant communities in response to climate change will translate into root dynamics. Overall, this thesis describes root dynamics in response to a variety of factors, because a deeper knowledge about root dynamics will enable a better understanding of ecosystem processes, as well as improve model prediction of how northern ecosystems will respond to climate change.

Microbial diversity plays an important role in the decomposition of soil organic matter. However, the drivers of this dependence still remain unclear. The work is based on long-term monitoring of soils of different successional stages of different diversity. Soil sampling was conducted on two dumps after brown coal mining in the Sokolov. Soils were X ray sterilized and inoculated by inoculum from both soils in two inoculation density which create gradient of microbial diversity. Then microbial respiration was measured in either supplied or not supplied by litter of Calamagrostis epigejos. Results showed a strong positive correlation between the microbial diversity and decomposition of organic matter if the microbial community is limited by available carbon. If there isn't carbon limit available, the decomposition rate is controlled by the amount of microbial biomass. Results demonstrated positive correlation between the rate of decomposition and the amount of fungal biomass. The soils with the addition of leaf litter showed priming effect in the initial stage of decomposition. In the control samples without addition of litter priming effect wasn't observed. Increasing humidity led to increase of decomposition rate. We can conclude with a clear conscience that similarly conclusive results associated...

O presente trabalho teve como objetivo estudar a viabilidade da utilização de cinzas de resíduos agroindustriais (bagaço de cana-de-açúcar, cama de frango e casca de arroz) como aditivos minerais substitutos ao cimento Portland, na produção de compósitos fibrosos e concreto leve. As cinzas foram obtidas através da queima e moagem controlada dos resíduos, e tiveram suas características químicas e físicas analisadas. Além do \"compósito referência\" (0% de substituição), os compósitos fibrosos foram produzidos com teores de substituição de cimento Portland de 10%, 15% e 20%, e os concretos leves foram produzidos com 10% de substituição. Foram realizados ensaios físicos e mecânicos nos compósitos fibrosos e concreto leve. Os resultados mostraram que as cinzas de casca de arroz apresentaram propriedades pozolânicas e que podem ser empregadas para a produção dos compósitos fibrosos e concretos leve. No estudo com compósitos fibrosos, os resultados físicos e mecânicos em sua maioria indicaram que a cinza de casca de arroz apresentou os melhores resultados. Como não apresentaram propriedades pozolânicas, as cinzas de bagaço de cana-de-açúcar e cama de frango, mesmo apresentando bons resultados, podem ser utilizadas como \"micro-fillers\". No estudo com concreto leve, a cinza de casca de arroz também se apresentou como melhor substituto para o cimento Portland por apresentar os melhores resultados nos ensaios realizados. / This research examines the viability of the use of waste agro industrials ashes (sugar cane bagasse, poultry litter and rice husk) and mineral additives substitutes to Portland cement in the production of composite fiber and lightweight concrete. The ashes were obtained through controlled burns and milling waste, and had their chemical and physical characteristics analyzed. Besides the \"composite reference\" (0% substitution), the fiber composites were produced with levels of replacement of Portland cement, 10%, 15% and 20%, and lightweight concrete were produced with 10% of replacement. Were tested on physical and mechanical fiber composites and lightweight concrete. The results showed that the ashes of rice husk had pozolanic properties and can be used for the production of fiber composite and lightweight concrete. In the study with fiber composites, the results physical and mechanical mostly indicated that the rice husk ash showed the best results. As there had pozolanics properties, the ashes of sugar cane bagasse and poultry litter, even showing good results, can be used as \"micro-fillers\". In the study with lightweight concrete, the ash of rice husk is also presented as a better replacement for Portland cement by presenting the best results in tests.

Dois experimentos foram conduzidos com o objetivo de avaliar a utilização de dietas com níveis crescentes de glicerina de biodiesel apenas na fase pré-inicial (1 a 7 dias) e apenas na fase final (35 a 42 dias de idade) de frangos de corte, respectivamente. As variáveis analisadas incluíram o desempenho, o rendimento de carcaça e cortes, a retenção de umidade em pintos aos 7 dias, a umidade de cama, a incidência de pododermatite, os níveis plasmáticos de colesterol e triglicerídeos e o custo da ração referente ao ganho de peso. Os tratamentos consistiram de dietas formuladas com 0%, 5% ou 10% de glicerina, sendo isonutritivas e formuladas à base de milho, farelo de soja e óleo de milho. A glicerina usada continha 83,6% de glicerol, 11,2% de água, 1,83% de sódio e 397 mg/kg de metanol, com energia metabolizável estimada de 3258 kcal/kg. No Experimento I, as dietas com glicerina foram fornecidas apenas na fase pré-inicial ou durante todo o ciclo de criação com 1610 aves em um delineamento inteiramente casualizado com 5 tratamentos e 7 repetições. Na primeira semana, as dietas com glicerina promoveram melhora significativa no ganho de peso e na conversão alimentar, sem afetar o consumo de ração e viabilidade. Essa melhora não foi mantida após os 14 dias de idade. Não houve efeito de tratamentos sobre o ganho de peso, consumo de ração e conversão alimentar. Entretanto, houve redução significativa na viabilidade aos 35 dias de idade das aves com 10% de glicerina por todo ciclo, mas não aos 42 dias; ao final do experimento, o índice de eficiência produtiva desse tratamento sofreu redução significativa. A umidade da cama das aves do tratamento com 10% de glicerina por todo ciclo de criação foi mais alta que dos demais a partir dos 21 dias, entretanto a incidência de pododermatite foi mais severa tanto para 5% como para 10% de glicerina por todo ciclo. Os níveis e tempos de fornecimento de glicerina não afetaram o rendimento de carcaça e de cortes ou a gordura abdominal. No experimento II, as dietas experimentais foram fornecidas a 819 frangos apenas na semana final de criação em um experimento inteiramente casualizado com 3 tratamentos e 7 repetições. O desempenho e o custo de ração por kg de ganho de peso não foram afetados pelos tratamentos. Nos Experimentos I e II, as rações contendo glicerina durante todo o ciclo ou apenas na última semana não resultaram em alteração nas concentrações plasmáticas de triglicerídeos e colesterol dos frangos. Dietas contendo 5% ou 10% de glicerina na fase pré-inicial ou 5% de glicerina continuamente não afetam a produtividade de frangos de corte, enquanto o nível de 10% durante todo o ciclo foi prejudicial. Esse mesmo nível de glicerina pode ser usado na dieta dos 35 aos 42 dias de idade sem afetar as aves. / Two experiments were conducted to evaluate the use of diets with increasing levels of biodiesel glycerin only in pre-starter (1-7 days) and only in the final phase (35-42 days of age) of broilers, respectively. The variables analyzed included the performance, carcass and parts yield, moisture retention in chicks at 7 days, litter moisture, incidence of foot pad dermatitis, plasma levels of cholesterol and triglycerides and diet cost related to weight gain. Treatments were isonutritive diets based on corn, soybean meal and corn oil containing 0, 5 and 10% glycerin. The glycerin used contained 83.6% glycerol, 11.2% water, 1.83% sodium and 397 mg/kg methanol, with estimated metabolizable energy value of 3,258 kcal/kg. In the first experiment, diets with glycerin were provided only in the pre-starter or for the entire growth period with 1610 birds in a completely randomized design with 5 treatments and 7 replications. In the first week, diets with glycerin resulted in significant improvement in weight gain and feed conversion without affecting feed intake and viability. This improvement was not sustained after 14 days of age. There was no effect of treatments on weight gain, feed intake and feed conversion. However, there was a significant reduction in viability at 35 days of age for the birds with 10% glycerin throughout the cycle, but not at 42 days; at the end of the experiment, the productivity index of this treatment was significantly decreased. Litter moisture for the treatment with 10% glycerin throughout the cycle was higher than the for the others from the 21 days, however the incidence of foot pad dermatitis was more severe for both 5% and 10% glycerin treatments for the entire period. The levels and periods of glycerin feeding did not affect carcass and parts yield and abdominal fat. In experiment II, the experimental diets were provided to 819 chickens only in the final week of growth in a completely randomized design with 3 treatments and 7 replications. The performance and feed cost per kg of weight gain were not affected by treatments. In Experiments I and II, the diets containing glycerin throughout the cycle or just in the last week resulted in no change in plasma concentrations of triglycerides and cholesterol of chickens. Diets containing 5% or 10% glycerin in the pre-starter phase or 5% glycerin continually did not affect the productivity of broilers, while the 10% level throughout the cycle was detrimental. This same level of glycerin can be used in the diet from 35 to 42 days without affecting the birds.

Informações sobre a fitossociologia e produção de serapilheira foram obtidas em 20 transversais distribuídas ao longo dos manguezais do sistema estuarino de Santos. Em cada transversal avaliou-se a estrutura do bosque em quatro parcelas de 100 m2 e a produção mensal da serapilheira coletada em 12 cestos ao longo de um ano. Analisou-se o conjunto de dados principalmente no nível de paisagem, encontrando-se que os descritores fitossociológicos não revelaram diferenças significativas ao longo do gradiente de inundação, embora ao mesmo tempo, os bosques tenham mostrado grandes variações desses descritores. As espécies Rhizophora mangle e Avicennia schaueriana mostraram valores de importância (sensu Curtis) estatisticamente iguais e substancialmente maiores que de Laguncularia racemosa. A produção de serapilheira, ao contrário, mostrou diferença significativa conforme a distância da água. O conjunto de dados foi submetido à análise de agrupamento e de componentes principais. A análise conjunta desses resultados permitiu verificar que os bosques foram agrupados, em quatro grupos: um com características de bosque mais maduro, outro bem mais jovem e os outros dois grupos revelaram-se intermediários e menos definidos. Verificou-se que a grande diversidade estrutural observada pode ser atribuída fundamentalmente ao fato do manguezal do sistema estuarino de Santos estar implantado em um ambiente com geomorfologia complexa, com inúmeros canais, oito bacias de drenagem e pluviosidade diferenciada conforme a distância da Serra do Mar. Isso gera um ambiente hídrico muito variado ao longo dos canais, de forma que essas diferenças no ambiente amplificam as diferenças naturalmente já encontradas nos ecossistemas de manguezal. Eventuais impactos antrópicos sobre este sistema podem ser fatores adicionais para explicar a diversidade estrutural observada. / Information about the phytosociology and litter production were obtained in 20 transects distributed along the mangroves of Santos estuarine system. The forest structure in each transect was evaluated in four parcels of 100 m2 and the monthly litter production was collected in 12 baskets through one year. The data set was analyzed mainly under landscape aspect. The phytosociologic descriptors did not reveal significant differences along the flood gradient, but at the same time, the mangrove forests showed wide variations in these descriptors. Rhizophora mangle and Avicennia schaueriana presented statistically equal importance values (sensu Curtis) which were higher than those of Laguncularia racemosa. Litter production showed significant difference according to the water distance. Data set was submitted to cluster and principal components analysis. The joint analysis of these results indicated four groups: one with mature forest characteristics, other with young forest characteristics whereas the other two groups revealed intermediate and less defined characteristics. The large structural diversity found can be attributed mainly to the fact of the Santos estuarine system to present a complex geomorphology with countless channels, eight drainage basins and differentiated rainfall according to Serra do Mar distance, which produces a widely variable hydrologic environment along the channels. In such a way these environmental variability amplify the differences naturally found in the mangrove ecosystems. Eventual anthropic impacts on this system can be additional factors to explain the observed diversity structure.

Microplastic pollution (particles < 5mm) is one of the most widespread impacts from modern society. Here, microplastic impacts were investigated through experimental assessments considering different exposure scenarios using mussels and micro-PVC as models. These aimed to investigate mussels\' physiological signs of stress under acute and chronic exposures and microplastics transference, assimilation and retention along food chains. In acute exposures, PVC intake affected mussels\' physiology over time, also influenced by plastics additives and particle concentration. Interactions among exposure factors (time, presence of additives and concentration) were more relevant than their individual effect, indicating the singularity of each contamination scenario. Long-term contact did not affect mussels, indicating the influence of time to acclimation. Microplastics were not assimilated and retained along food chains, but only biotransferred from prey tissues to predators\' tract, showing the influence of prey contamination on the effectiveness of microplastics biotransference. To evaluate risks in nature, microplastic ingestion was investigated in mussels from the Santos Estuary. Santos Estuary contained microplastics in 75% of sampled mussels, an issue of environmental and human concern. This study illustrated that microplastics impacts on mussels vary with microplastics characteristics, exposure scenario and species vulnerability, highlighting the need for more toxicological and risk evaluation studies. / Os microplásticos (< 5mm) são um dos impactos mais difundidos da sociedade moderna. Aqui, eles foram estudados em ensaios experimentais, considerando diferentes composições de exposição de mexilhões à micro-PVCs. O objetivo foi investigar: sinais fisiológicos de estresse sob exposições aguda e crônica; e transferência, assimilação e retenção de microplásticos em cadeias tróficas. Para avaliar seus potenciais riscos na natureza, a ingestão por mexilhões também foi investigada no Estuário de Santos. As exposições agudas afetaram a fisiologia dos mexilhões, sendo influenciadas pelo tempo e concentração de exposição, e pela presença de aditivos plásticos. Interações entre esses fatores (tempo, concentração e aditivos) foram mais relevantes do que eles individualmente, sugerindo a singularidade dos cenários de poluição. A exposição de longo prazo não afetou os mexilhões, indicando a influência do tempo na aclimatação ao microplástico. O PVC não foi assimilado e retido nas cadeias tróficas, mas biotransferido do tecido das presas para o trato dos predadores, mostrando a influência do estado da presa na efetividade da biotransferência dos microplásticos. Dentre os mexilhões coletados, 75% estavam contaminados, revelando uma importante questão socioambiental. Esse trabalho ilustrou a complexidade dos impactos dos microplásticos para a biota marinha, ressaltando a necessidade de mais estudos sobre seus riscos.