Desxifrant el perill del (micro)plàstic: el cas d'estudi de la ingestió de plàstics en aristeus antennatus i nephrops norvegicus al no del mar mediterrani i el seu impacte potencial sobre l'estat de salut
- Autores: Ester Carreras Colom
- Directores de la Tesis: Maite Carrassón López de Letona (dir. tes.), Joan Cartes Rodríguez (codir. tes.)
- Lectura: En la Universitat Autònoma de Barcelona ( España ) en 2021
- Idioma: catalán
- Tribunal Calificador de la Tesis: Roser Sala Pallarès (presid.), Marta Muñoz Frigola (secret.), Alessandro Cau (voc.)
- Programa de doctorado: Programa de Doctorado en Acuicultura por la Universidad Autónoma de Barcelona y la Universidad de Barcelona
- Materias:
- Enlaces
- Tesis en acceso abierto en: TDX
- Resumen
The impact of plastic pollution, especially microplastics, has attracted media attention over the past decades. Their widespread distribution and ease of interaction with many organisms, especially through their ingestion, has raised questions about their potential impact on marine organisms. This thesis aims to characterise plastic ingestion in two key species of the Mediterranean Sea, the crustaceans Aristeus antennatus and Nephrops norvegicus. Both species, due to their proximity and relationship with the seabed, where plastics are supposed to accumulate, as well as a digestive system of complex morphology that would facilitate the retention of plastics, may be experiencing higher levels of exposure to plastics than most organisms. Given its high commercial value and ecological relevance, it is of particular interest to analyse the potential impact of microplastics in these species. Plastic ingestion levels, as well as their characteristics, are described in detail in both species and along spatial and temporal gradients. Moreover, their potential impact on organisms' health status is assessed with a multidisciplinary approach using various health markers, including body condition indices, enzymatic activities and histological techniques. Overall, plastic ingestion was common in both species and extended to depths of 1870m in the case of the blue and red shrimp. In both species, plastics identified were mostly synthetic fibres of varied dimensions, colours, and compositions, although polyester, polyamide and acrylic, three commonly used polymers in the textile industry, were the most abundant. Analysis of the presence and characteristics of plastics in the environment revealed that plastics ingested by Norway lobsters might primarily come from the water column. In contrast, in blue and red shrimp, correlations between the intake of plastics and a diet with endobenthic prey might be associated with passive ingestion of plastics located in the sediment or a trophic transfer. In any case, once plastics were ingested, they would be mostly retained in the stomach, as suggested by the low number of fibres identified in intestine contents. In addition to the digestive's morphology, the formation of tangled balls of fibres, observed in some locations in up to one-third of the population, would contribute to greater retention of plastics by increasing the overall size of items ingested. Spatial and temporal comparisons highlighted differences in plastic ingestion that may be related to differences in environmental pollution. For example, the area close to Barcelona was recurringly pointed out as a high plastic ingestion area. Regarding temporal comparisons, however, no noticeable differences were observed in terms of abundance. Only changes in the composition of polymers were observed, which may be related to changes in the production and usage trends. In general, levels of plastics ingested did not show significant relationships with body condition indices, nor with enzymatic markers, with some particular exceptions. However, given the absence of general patterns as well as significant histopathological alterations potentially associated with a plastic impact, individuals were considered in good health status overall, and that they might be able to cope with current levels of plastics ingested. Finally, the use of the prevalence of tangles as a potential indicator of plastic ingestion is discussed concerning the need for affordable indicators of plastic pollution in monitoring programs.
