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Distribuição e Abundância de Microplásticos nas Águas do Atlântico Nordeste
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Resumo(s)
A poluição marinha por plásticos é um tema de preocupação crescente, tendo em considera-
ção os danos ambientais que vêm ocorrendo em vários ecossistemas marinhos. Embora os
plásticos apresentem um vasto número de benefícios para a sociedade, representam também
uma preocupação crescente para o meio marinho. O aumento da produção de plásticos asso-
ciado ao uso abundante de plástico descartável e a uma má gestão deste tipo de materiais,
tem originado um aumento destes resíduos.
Esta dissertação tem como objetivos a identificação, caracterização e quantificação de micro-
plásticos em amostras de água, recolhidas ao largo da costa oeste de Portugal Continental,
entre Praia de Mira e Vieira de Leiria. Os dados utilizados nesta dissertação foram obtidos no
âmbito do projeto i-plastic:
Dispersion and impacts of micro and nanoplastics in the tropical
and temperate oceans: from regional land-ocean interface to the open ocean. Foram efetuadas
duas campanhas oceânicas a bordo do N.R.P. Andrómeda tendo sido selecionados 19 pontos
de amostragem para colheita de amostras de águas por arrasto vertical e por arrasto horizon-
tal.
A colheita de microplásticos à superfície foi efetuada através de arrasto horizontal de uma rede
tipo manta de 150 μm de malha enquanto a colheita da coluna de água foi efetuada através
de arrasto vertical de uma rede de plâncton de formato cónico de 150 μm de malha.
A deteção, quantificação e caracterização química dos microplásticos consistiu na análise visual
para caracterizar física e morfologicamente as partículas (tipologia, cor e dimensão) e na sua
caracterização química (análise do polímero), sendo que as formas encontradas foram frag-
mentos, fibras, filamentos e filmes.
A concentração de microplásticos nas amostras colhidas por arrasto horizontal varia até 0,4
MP m-3 e 0,45 MP m-3, no outono e na primavera, respetivamente. Nas amostras de colheita
vertical, no outono, a abundância variou até 6 MP m-3 e, na primavera a abundância varia entre
até 1,6 MP m-3. No outono a média de dimensões dos microplásticos encontrados nas amostras de colheita
horizontal foi de (1496,5±975,1) μm enquanto na primavera foi de (1251,7±1005) μm, en-
quanto nas amostras de colheita vertical, no outono a média de dimensões de microplásticos
foi de (1551,8±1236,6) μm e na primavera de (1120,6±1149,3) μm.
O estudo permitiu confirmar que na coluna de água encontram-se mais microplásticos que à
superfície sendo possível sugerir que as fontes principais de microplásticos, nesta localização
poderão ser as descargas de águas residuais e as atividades de pesca.
Marine plastic pollution is a growing concern, given the environmental damage that is occur- ring in various marine ecosystems. Although plastics have a vast number of benefits for society, they also represent a growing concern for the marine environment. The increase in plastic pro- duction, coupled with the abundant use of single-use plastics and poor management of this type of material, has led to an increase in this waste. This dissertation aims to identify, characterize and quantify microplastics in water samples collected off the west coast of mainland Portugal, between Ovar and Vieira de Leiria, and the data used for this dissertation were obtained as part of the i-plastic project: Dispersion and impacts of micro and nanoplastics in the tropical and temperate oceans: from regional land- ocean interface to the open ocean. Two oceanic campaigns were carried out on board the N.R.P. Andrómeda, selecting 19 sampling points to take water samples by vertical trawl and horizontal trawl. Microplastics were collected at the surface by horizontal trawling using a 150 μm mesh blanket net, while they were collected from the water column by vertical trawling using a 150 μm mesh conical plankton net. The detection, quantification and chemical characterization of microplastics consisted of visual analysis to physically and morphologically characterize the particles (type, color and size) and their chemical characterization (polymer analysis). The forms of microplastics found were frag- ments, fibers, filaments and films. The concentration of microplastics in the samples collected by horizontal trawling ranged up to 0.4 MP m-3 and 0.45 MP m-3 in the autumn and spring, respectively. In the vertical collection samples, the abundance varied up to 6 MP m-3 in the autumn and up to 1.6 MP m-3 in the spring. In the autumn, the average size of the microplastics found in the horizontal collection samples was (1496.5±975.1) μm, while in the spring it was (1251.7±1005) μm, while in the vertical collec- tion samples, in the autumn the average size of the microplastics was (1551.8±1236.6) μm and in the spring (1120.6±1149.3) μm. The study confirmed that more microplastics are found in the water column than on the sur- face, suggesting that the main sources of microplastics in this location could be wastewater discharges and fishing activities.
Marine plastic pollution is a growing concern, given the environmental damage that is occur- ring in various marine ecosystems. Although plastics have a vast number of benefits for society, they also represent a growing concern for the marine environment. The increase in plastic pro- duction, coupled with the abundant use of single-use plastics and poor management of this type of material, has led to an increase in this waste. This dissertation aims to identify, characterize and quantify microplastics in water samples collected off the west coast of mainland Portugal, between Ovar and Vieira de Leiria, and the data used for this dissertation were obtained as part of the i-plastic project: Dispersion and impacts of micro and nanoplastics in the tropical and temperate oceans: from regional land- ocean interface to the open ocean. Two oceanic campaigns were carried out on board the N.R.P. Andrómeda, selecting 19 sampling points to take water samples by vertical trawl and horizontal trawl. Microplastics were collected at the surface by horizontal trawling using a 150 μm mesh blanket net, while they were collected from the water column by vertical trawling using a 150 μm mesh conical plankton net. The detection, quantification and chemical characterization of microplastics consisted of visual analysis to physically and morphologically characterize the particles (type, color and size) and their chemical characterization (polymer analysis). The forms of microplastics found were frag- ments, fibers, filaments and films. The concentration of microplastics in the samples collected by horizontal trawling ranged up to 0.4 MP m-3 and 0.45 MP m-3 in the autumn and spring, respectively. In the vertical collection samples, the abundance varied up to 6 MP m-3 in the autumn and up to 1.6 MP m-3 in the spring. In the autumn, the average size of the microplastics found in the horizontal collection samples was (1496.5±975.1) μm, while in the spring it was (1251.7±1005) μm, while in the vertical collec- tion samples, in the autumn the average size of the microplastics was (1551.8±1236.6) μm and in the spring (1120.6±1149.3) μm. The study confirmed that more microplastics are found in the water column than on the sur- face, suggesting that the main sources of microplastics in this location could be wastewater discharges and fishing activities.
Descrição
Palavras-chave
microplásticos oceano Atlântico água Portugal μFTIR