Publicação
Population of marine, estuarine and Minho river basin fish
| Resumo: | Biodiversity is a key element of ecosystem functioning and provides several services such as fisheries and recreational activities. The Minho River has a diverse fish population, including marine, freshwater, and migratory species, but also exotic species introduced mostly during the 1990’s. The last can change communities’ composition, functional roles, and ecological niche spaces. This study aimed to investigate patterns of biodiversity in the Minho River, including its variability according to habitats (tributaries and estuary) and over time (tributaries). Also, changes in trait modalities were analyzed from upstream areas to the estuary, and the potential for niche overlap between native and exotic species was evaluated. For that, data from ongoing monitoring programs were used to estimate α and β diversity, and to analyze fish traits’ composition. The potential for niche overlap was investigated by combining the information from traits’ composition with trophic niche data obtained through stable isotope analysis. The study showed that the fish communities became dissimilar over time, when comparing to the historical information (1988), with an increase in both the number of native and exotic species (2018-2021). No exotic species were recorded in 1988. Among all the sites analyzed between 2018 and 2021, the estuary was the one with more species, both native and exotic. The functional dispersion, a measure of functional diversity, and the proportion of exotic species were negatively linked. Environmental variables such as distance to the mouth of the river, total dissolved solids, and pH partly explained the observed patterns of functional diversity. Furthermore, the functional traits analyzed suggested a potential overlap between the ecological niches of exotic species and most of native species. In general, native species presented a wider trophic niche than the exotic species in the Minho River basin and the estuary had the highest niche overlap between native and exotic species, with Cyprinus carpio being the exotic species with the highest niche trophic overlap with native species. It is important to prevent new invasions of exotic species and improve the habitat of native species in the Minho River basin. |
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| Autores principais: | Antunes, Catarina Mafalda Faria dos Santos |
| Assunto: | Species richness Functional diversity Exotic species Niche overlap Minho River |
| Ano: | 2026 |
| País: | Portugal |
| Tipo de documento: | dissertação de mestrado |
| Tipo de acesso: | acesso embargado |
| Instituição associada: | Universidade de Aveiro |
| Idioma: | inglês |
| Origem: | RIA - Repositório Institucional da Universidade de Aveiro |
| Resumo: | Biodiversity is a key element of ecosystem functioning and provides several services such as fisheries and recreational activities. The Minho River has a diverse fish population, including marine, freshwater, and migratory species, but also exotic species introduced mostly during the 1990’s. The last can change communities’ composition, functional roles, and ecological niche spaces. This study aimed to investigate patterns of biodiversity in the Minho River, including its variability according to habitats (tributaries and estuary) and over time (tributaries). Also, changes in trait modalities were analyzed from upstream areas to the estuary, and the potential for niche overlap between native and exotic species was evaluated. For that, data from ongoing monitoring programs were used to estimate α and β diversity, and to analyze fish traits’ composition. The potential for niche overlap was investigated by combining the information from traits’ composition with trophic niche data obtained through stable isotope analysis. The study showed that the fish communities became dissimilar over time, when comparing to the historical information (1988), with an increase in both the number of native and exotic species (2018-2021). No exotic species were recorded in 1988. Among all the sites analyzed between 2018 and 2021, the estuary was the one with more species, both native and exotic. The functional dispersion, a measure of functional diversity, and the proportion of exotic species were negatively linked. Environmental variables such as distance to the mouth of the river, total dissolved solids, and pH partly explained the observed patterns of functional diversity. Furthermore, the functional traits analyzed suggested a potential overlap between the ecological niches of exotic species and most of native species. In general, native species presented a wider trophic niche than the exotic species in the Minho River basin and the estuary had the highest niche overlap between native and exotic species, with Cyprinus carpio being the exotic species with the highest niche trophic overlap with native species. It is important to prevent new invasions of exotic species and improve the habitat of native species in the Minho River basin. |
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