A carregar...
Publicação
Concentração de metais (Cd, Hg e Pb) nas espécies pelágicas Engraulis encrasicolus, Sardina pilchardus e Scomber colias : avaliação tecidual e espacial ao longo da costa continental portuguesa
| Nome: | Descrição: | Tamanho: | Formato: | |
|---|---|---|---|---|
| 2.19 MB | Adobe PDF |
Autores
Orientador(es)
Resumo(s)
A presente investigação teve como principais motivações a preocupação e a preservação do
meio ambiente face ao desenvolvimento industrial e à poluição ambiental, nomeadamente nos
ecossistemas aquáticos. Deste modo, os principais objetivos da mesma foram: (i) estudar a
acumulação de metais não essenciais (Cd, Hg e Pb) em diferentes tecidos/órgãos (brânquias,
fígado e músculo), relacionando com a ecologia de cada espécie em estudo (biqueirão -
Engraulius encrasicolus; sardinha - Sardina pilchardus e cavala - Scomber colis); (ii)
caracterizar a variação espacial da acumulação desses metais nas espécies referidas, ao largo
da costa continental portuguesa; (iii) selecionar tecidos mais adequados para monitorizar a
concentração de metais presentes no ambiente, definindo-os como bioindicadores e identificar
potenciais zonas e espécies mais vulneráveis à contaminação por metais.
As espécies em estudo foram capturadas em três áreas da costa continental portuguesa: Zona
ocidental Norte- Caminha-Peniche, designada por área A, Zona ocidental Sul-Peniche-Sagres,
designada pela área B e Algarve e parte do golfo de Cádis designada área C. Os parâmetros
biológicos, como comprimento, peso, sexo, estado de maturação e variação do conteúdo
estomacal e da gordura, foram avaliados nos espécimes recolhidos. Após dissecção em
brânquias, fígado e músculos, foi determinada a concentração de metais não essenciais. A
determinação da concentração de Cd e Pb foi realizada por espectrometria de massa com
plasma induzido acoplado, enquanto que a deteção de Hg foi efetuada por absorção atómica
após decomposição eletrotérmica das amostras. Aos resultados obtidos para a concentração
dos metais foram aplicados testes Mann-Whitney e Kruskal-Wallis e ainda uma análise
multivariada através do método HJ-Biplot, a qual permitiu detetar similaridades
/dissimilaridades entre diferentes grupos da amostra.
Os resultados deste estudo mostraram que a concentração de metais não variou em função dos
parâmetros biológicos nas três espécies estudadas. Os tecidos/órgãos que acumularam maior
concentração de metais foram o fígado e as brânquias. As áreas onde se verificou maior
acumulação de metais foram as áreas A e C. Relativamente aos órgãos/tecidos, o fígado e o
músculo foram considerados os mais adequados para a monitorização de Cd e as brânquias
para os níveis de Pb.
Todas as espécies estudadas são suscetíveis de serem utilizadas como bioindicadoras de
concentração de metais não essenciais no ambiente aquático marinho, no entanto cada espécie
parece ser mais adequada dependo do metal. Para o estudo da contaminação de Cd, a espécie
S. colias mostrou ser a mais apropriada, a espécie E. encrasicolus para o Hg e a espécie S.
pilchardus para o Pb.
The present investigation had as main motivations the concern and preservation of the environment facing industrial development and environmental pollution, namely in aquatic ecosystems. Thus, its main aims were: (i) to study the accumulation of non-essential metals (Cd, Hg and Pb) in different tissues/organs (gills, liver and muscle), relating to the ecology of each species under study (anchovy - Engraulius encrasicolus; sardines - Sardina pilchardus and mackerel - Scomber colis); (ii) to characterize the spatial variation of the accumulation of these metals in the mentioned species, along the Portuguese mainland coast; (iii) to select the most suitable tissues to monitor the concentration of metals in the environment, defining them as bioindicators and identifying potential areas and species most vulnerable to contamination by metals. The species under study were captured in three areas of the Portuguese mainland coast: North West Zone- Caminha-Peniche, designated as Area A, South West Zone- Peniche-Sagres, designated as Area B, and Algarve and part of the Gulf of Cádiz, designated as Area C. The biological parameters, such as length, weight, sex, maturation state and variation of the stomach and fat content, were analysed in the collected species. After dissection in gills, liver and muscle, the non-essential metals concentration was determined. The Cd and Pb concentration were determined by mass spectrometry with coupled induced plasma, whilst the Hg detection was carried out by atomic absorption following electro-thermal decomposition of the samples. The tests Mann-Whitney and Kruskall-Wallis were applied to the results obtained for the metals’ concentration. Furthermore, a multivariate analysis was also applied using the HJ-Biplot method, which made it possible to detect similarities/dissimilarities between the different sampled groups. The results of this study showed that the metals’ concentration did not vary according to the biological parameters in the three studied species. The tissues/organs which accumulated the highest concentration of metals were the liver and the gills. The areas where there was greater accumulation were areas A and C. Regarding the organs/tissues, the ones considered most suitable for monitoring metals were the liver and the muscle for Cd and Hg levels and the gills for Pb levels. In conclusion, all the studied species are susceptible to be used as bioindicators for nonessential metals’ concentration in the marine aquatic environment, however each species seems to be more adequate depending on the metal. For the contamination study of Cd, it appears to be the species S.colias, the species E. encrasicolus for the Hg and the species S. pilchardus for the Pb.
The present investigation had as main motivations the concern and preservation of the environment facing industrial development and environmental pollution, namely in aquatic ecosystems. Thus, its main aims were: (i) to study the accumulation of non-essential metals (Cd, Hg and Pb) in different tissues/organs (gills, liver and muscle), relating to the ecology of each species under study (anchovy - Engraulius encrasicolus; sardines - Sardina pilchardus and mackerel - Scomber colis); (ii) to characterize the spatial variation of the accumulation of these metals in the mentioned species, along the Portuguese mainland coast; (iii) to select the most suitable tissues to monitor the concentration of metals in the environment, defining them as bioindicators and identifying potential areas and species most vulnerable to contamination by metals. The species under study were captured in three areas of the Portuguese mainland coast: North West Zone- Caminha-Peniche, designated as Area A, South West Zone- Peniche-Sagres, designated as Area B, and Algarve and part of the Gulf of Cádiz, designated as Area C. The biological parameters, such as length, weight, sex, maturation state and variation of the stomach and fat content, were analysed in the collected species. After dissection in gills, liver and muscle, the non-essential metals concentration was determined. The Cd and Pb concentration were determined by mass spectrometry with coupled induced plasma, whilst the Hg detection was carried out by atomic absorption following electro-thermal decomposition of the samples. The tests Mann-Whitney and Kruskall-Wallis were applied to the results obtained for the metals’ concentration. Furthermore, a multivariate analysis was also applied using the HJ-Biplot method, which made it possible to detect similarities/dissimilarities between the different sampled groups. The results of this study showed that the metals’ concentration did not vary according to the biological parameters in the three studied species. The tissues/organs which accumulated the highest concentration of metals were the liver and the gills. The areas where there was greater accumulation were areas A and C. Regarding the organs/tissues, the ones considered most suitable for monitoring metals were the liver and the muscle for Cd and Hg levels and the gills for Pb levels. In conclusion, all the studied species are susceptible to be used as bioindicators for nonessential metals’ concentration in the marine aquatic environment, however each species seems to be more adequate depending on the metal. For the contamination study of Cd, it appears to be the species S.colias, the species E. encrasicolus for the Hg and the species S. pilchardus for the Pb.
Descrição
Tese de Mestrado, Ecologia Marinha, 2022, Universidade de Lisboa, Faculdade de Ciências
Palavras-chave
Espécies pelágicas Metais Tecidos Variação espacial Teses de Mestrado - 2023