Mercury effects in natural populations of sea anemone Actinia equina
Autor(a) principal: | |
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Data de Publicação: | 2011 |
Tipo de documento: | Dissertação |
Idioma: | eng |
Título da fonte: | Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
Texto Completo: | http://hdl.handle.net/10773/6369 |
Resumo: | Mercury (Hg) is considered to be one of the most toxic metals to biota, being capable of biomagnification and bioaccumulation in food chains. High concentrations of Hg were associated with developmental and behavioral abnormalities, impairment in growth and reproduction, and reduced survival. Though this metal has been extensively studied, several knowledge gaps still exist, mainly regarding its effects in different types of organisms. Accordingly, this study aimed at assessing the effects of a short-term exposure to Hg in natural populations of the sea anemone Actinia equina. To attain this objective, four natural population of A. equina were sampled in the NW Atlantic coast with different levels of contamination for Hg. From each population, forty individuals were collected and acclimated in laboratory, under optimal conditions, for one month. Afterwards, organisms were weighed (7.09 ± 0.18 g mean ± SE), and using a flow-through system were exposed to 100 μg L-1 of Hg and to artificial sea water solely, during 96h. At the end of exposure, organisms were immediately deep-frozen (-80°C) until further analysis. The tissue of pedal disc was analyzed for bioaccumulation and biomarkers (biochemical: glutathione S-transferase–GST, catalase–CAT and lipid peroxidation–LPO and metabolic: lactate and alanine) to compare the uptake, oxidative damage and metabolic patterns among populations after being exposed to Hg. All population exhibited significant bioaccumulation of Hg and a significant change in LPO when exposed to Hg, as in lactate/alanine ratio. On the contrary, exposure to Hg caused no significant changes in the activities of GST and CAT. Furthermore, significant differences in the response patterns to Hg among the four populations were observed. With the two populations originated from sites with a higher Hg contamination showing a lower bioaccumulation of Hg and a higher oxidative damage. Also, the ratio of lactate/alanine (an index of redox state of the cell) revealed that those two populations exhibited a healthier redox state. These findings suggest that the use of several endpoints at different levels of biological organization is important for the evaluation of Hg effects in the biota. |
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Mercury effects in natural populations of sea anemone Actinia equinaBiologiaMercúrio (Metal) - ToxicidadeEcossistemas marinhosEcotoxicologiaAnémonas do marBioacumulaçãoInteracções tróficasStresse oxidativoMercury (Hg) is considered to be one of the most toxic metals to biota, being capable of biomagnification and bioaccumulation in food chains. High concentrations of Hg were associated with developmental and behavioral abnormalities, impairment in growth and reproduction, and reduced survival. Though this metal has been extensively studied, several knowledge gaps still exist, mainly regarding its effects in different types of organisms. Accordingly, this study aimed at assessing the effects of a short-term exposure to Hg in natural populations of the sea anemone Actinia equina. To attain this objective, four natural population of A. equina were sampled in the NW Atlantic coast with different levels of contamination for Hg. From each population, forty individuals were collected and acclimated in laboratory, under optimal conditions, for one month. Afterwards, organisms were weighed (7.09 ± 0.18 g mean ± SE), and using a flow-through system were exposed to 100 μg L-1 of Hg and to artificial sea water solely, during 96h. At the end of exposure, organisms were immediately deep-frozen (-80°C) until further analysis. The tissue of pedal disc was analyzed for bioaccumulation and biomarkers (biochemical: glutathione S-transferase–GST, catalase–CAT and lipid peroxidation–LPO and metabolic: lactate and alanine) to compare the uptake, oxidative damage and metabolic patterns among populations after being exposed to Hg. All population exhibited significant bioaccumulation of Hg and a significant change in LPO when exposed to Hg, as in lactate/alanine ratio. On the contrary, exposure to Hg caused no significant changes in the activities of GST and CAT. Furthermore, significant differences in the response patterns to Hg among the four populations were observed. With the two populations originated from sites with a higher Hg contamination showing a lower bioaccumulation of Hg and a higher oxidative damage. Also, the ratio of lactate/alanine (an index of redox state of the cell) revealed that those two populations exhibited a healthier redox state. These findings suggest that the use of several endpoints at different levels of biological organization is important for the evaluation of Hg effects in the biota.O mercúrio (Hg) é considerado um dos metais mais tóxicos para o biota, podendo biomagnificar e bioacumular nas cadeias tróficas. Concentrações elevadas de Hg nos organismos foram associadas a anomalias no desenvolvimento, comportamento, crescimento, na reprodução e a taxas de sobrevivência reduzida. Embora atualmente este metal seja extensivamente estudado, ainda existem falhas no conhecimento, principalmente no que respeita aos efeitos que pode provocar em diferentes tipos de organismos. Assim, este estudo teve como objetivo avaliar os efeitos de uma exposição, de curta duração, a Hg, em populações naturais da anémona-do-mar Actinia equina. Para atingir este objetivo, foram amostradas quatro populações naturais de A. equina, na costa NW Atlântica. Em cada população, foram recolhidos quarenta indivíduos e posteriormente aclimatados em laboratório, sob condições óptimas, durante um mês. Após aclimatação, os organismos foram pesados (7,09 ± 0,18 g, média ± erro padrão), e com a utilização de um sistema de fluxo contínuo, foram expostos a 100 μg L-1 de Hg e a água do mar artificial sem adição de Hg, durante 96h. No final da exposição, os organismos foram imediatamente congelados (-80 °C) até se proceder à análise. O tecido do disco pedal foi analisado para determinar níveis de bioacumulação e efeito a nível de vários biomarcadores (bioquímicos: glutationa S-transferase-GST, catalase-CAT e peroxidação lipídica LPO, e metabólicos: lactato e alanina), de modo a comparar concentrações do metal, danos oxidativos e padrões metabólicas entre as populações após terem sido expostos a Hg. Todas as populações apresentaram bioacumulação significativa de Hg relativamente ao respectivo controlo, assim como alterações significativas, na LPO e no rácio lactato/alanina. Pelo contrário, a exposição a Hg não causou mudanças significativas na atividade das enzimas GST e CAT. No entanto, foram observadas diferenças significativas nos padrões de resposta a Hg entre as quatro populações naturais de A. equina. As duas populações provenientes de locais com historial de contaminação por Hg mais elevado apresentaram menor bioacumulação de Hg e maior dano oxidativo, em laboratório. Além disso, a proporção de lactato/alanina (um índice do estado redox da célula), revelou que as duas populações apresentaram um melhor estado redox. Estes resultados sugerem que o uso de vários critérios de avaliação em diferentes níveis de organização biológica, são importantes para a avaliação dos efeitos Hg no biota.Universidade de Aveiro2012-02-14T16:58:18Z2011-01-01T00:00:00Z2011info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesisapplication/pdfhttp://hdl.handle.net/10773/6369engJordão, Rita Marisa Gomesinfo:eu-repo/semantics/openAccessreponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãoinstacron:RCAAP2024-02-22T11:11:07Zoai:ria.ua.pt:10773/6369Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-20T02:44:32.088818Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãofalse |
dc.title.none.fl_str_mv |
Mercury effects in natural populations of sea anemone Actinia equina |
title |
Mercury effects in natural populations of sea anemone Actinia equina |
spellingShingle |
Mercury effects in natural populations of sea anemone Actinia equina Jordão, Rita Marisa Gomes Biologia Mercúrio (Metal) - Toxicidade Ecossistemas marinhos Ecotoxicologia Anémonas do mar Bioacumulação Interacções tróficas Stresse oxidativo |
title_short |
Mercury effects in natural populations of sea anemone Actinia equina |
title_full |
Mercury effects in natural populations of sea anemone Actinia equina |
title_fullStr |
Mercury effects in natural populations of sea anemone Actinia equina |
title_full_unstemmed |
Mercury effects in natural populations of sea anemone Actinia equina |
title_sort |
Mercury effects in natural populations of sea anemone Actinia equina |
author |
Jordão, Rita Marisa Gomes |
author_facet |
Jordão, Rita Marisa Gomes |
author_role |
author |
dc.contributor.author.fl_str_mv |
Jordão, Rita Marisa Gomes |
dc.subject.por.fl_str_mv |
Biologia Mercúrio (Metal) - Toxicidade Ecossistemas marinhos Ecotoxicologia Anémonas do mar Bioacumulação Interacções tróficas Stresse oxidativo |
topic |
Biologia Mercúrio (Metal) - Toxicidade Ecossistemas marinhos Ecotoxicologia Anémonas do mar Bioacumulação Interacções tróficas Stresse oxidativo |
description |
Mercury (Hg) is considered to be one of the most toxic metals to biota, being capable of biomagnification and bioaccumulation in food chains. High concentrations of Hg were associated with developmental and behavioral abnormalities, impairment in growth and reproduction, and reduced survival. Though this metal has been extensively studied, several knowledge gaps still exist, mainly regarding its effects in different types of organisms. Accordingly, this study aimed at assessing the effects of a short-term exposure to Hg in natural populations of the sea anemone Actinia equina. To attain this objective, four natural population of A. equina were sampled in the NW Atlantic coast with different levels of contamination for Hg. From each population, forty individuals were collected and acclimated in laboratory, under optimal conditions, for one month. Afterwards, organisms were weighed (7.09 ± 0.18 g mean ± SE), and using a flow-through system were exposed to 100 μg L-1 of Hg and to artificial sea water solely, during 96h. At the end of exposure, organisms were immediately deep-frozen (-80°C) until further analysis. The tissue of pedal disc was analyzed for bioaccumulation and biomarkers (biochemical: glutathione S-transferase–GST, catalase–CAT and lipid peroxidation–LPO and metabolic: lactate and alanine) to compare the uptake, oxidative damage and metabolic patterns among populations after being exposed to Hg. All population exhibited significant bioaccumulation of Hg and a significant change in LPO when exposed to Hg, as in lactate/alanine ratio. On the contrary, exposure to Hg caused no significant changes in the activities of GST and CAT. Furthermore, significant differences in the response patterns to Hg among the four populations were observed. With the two populations originated from sites with a higher Hg contamination showing a lower bioaccumulation of Hg and a higher oxidative damage. Also, the ratio of lactate/alanine (an index of redox state of the cell) revealed that those two populations exhibited a healthier redox state. These findings suggest that the use of several endpoints at different levels of biological organization is important for the evaluation of Hg effects in the biota. |
publishDate |
2011 |
dc.date.none.fl_str_mv |
2011-01-01T00:00:00Z 2011 2012-02-14T16:58:18Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
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info:eu-repo/semantics/masterThesis |
format |
masterThesis |
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publishedVersion |
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http://hdl.handle.net/10773/6369 |
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http://hdl.handle.net/10773/6369 |
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eng |
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eng |
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Universidade de Aveiro |
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Universidade de Aveiro |
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Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
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Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
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