Publicação
Adaptation of marine organisms to environmental changes: native vs invasive species
| Resumo: | Ria de Aveiro is a shallow coastal lagoon located in the northwest of Portugal that supports highly diverse communities of benthic invertebrates. Polychaetes are the most abundant group found, some of which are socio-economically important, as the case of the polychaete Hediste diversicolor. H. diversicolor is a native species in Ria de Aveiro and inhabits in soft-bottom communities of estuaries playing a crucial role in sedimentary processes and ecosystem functioning due to its unique traits. Recently, Arenicola marina was detected at Ria de Aveiro, being considered an invasive species in this ecosystem. A. marina is also a bioturbator and it is expected that its constant disturbance of the sediment surface can alter the infauna of the ecosystem. The production and applications of the nanomaterial graphene oxide (GO) has increased of in the last years, conducting to the release of this nanomaterial in the aquatic ecosystems, with consequences for benthic organisms, such as polychaetes. This study aims to assess the effects, isolated or in combination, of an abiotic stressor (GO nanosheets) and a biotic stressor (A. marina) on H. diversicolor. To achieve this, the study conducted several behavioral assays and biochemical markers. The obtained results demonstrated that exposure to different concentrations of GO had negative effects on burrowing activity of H. diversicolor. This species showed an unusual avoidance behavior, fleeing from lower contamination to higher ones. They were unable to escape from higher contamination compartments, but at the highest concentrations (1 and 10 mg GO/L) the bioturbation activity was significantly higher, which may indicate that H. diversicolor tended to move deeper in the sediment. Moreover, the presence of A. marina affected the behavior of H. diversicolor. Regarding A. marina, its bioturbation activity significantly decreased when exposed to GO, which could be related with the decrease of energy reserves, as protein content. Additionally, this species also showed an escape behavior from compartments with a higher GO concentration. Regarding oxidative stress, H. diversicolor seems to be more impacted, since LPO levels were higher in all GO concentrations and SOD activity significantly increased in lowest levels of GO. The obtained results indicate that A. marina may be able to some extent search for more prone areas for feeding, predation, reproduction, and migration under contaminant exposure. On the other hand, H. diversicolor spatial distribution may be severely constrained under both abiotic and biotic stress, while A. marina’s higher foraging activity may promote its propagation in the estuary. Concerning our results, behavioral tests, combined with biomarkers showed to be relevant tools and could be applied for the development of more environmental-realistic assessment and monitoring frameworks for estuaries. |
|---|---|
| Autores principais: | Ferreira, Maria João Figueiredo |
| Assunto: | Graphene oxide Hediste diversicolor Arenicola marina Invasive species Behavior Biochemical responses |
| Ano: | 2023 |
| País: | Portugal |
| Tipo de documento: | dissertação de mestrado |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Universidade de Aveiro |
| Idioma: | inglês |
| Origem: | RIA - Repositório Institucional da Universidade de Aveiro |
| Resumo: | Ria de Aveiro is a shallow coastal lagoon located in the northwest of Portugal that supports highly diverse communities of benthic invertebrates. Polychaetes are the most abundant group found, some of which are socio-economically important, as the case of the polychaete Hediste diversicolor. H. diversicolor is a native species in Ria de Aveiro and inhabits in soft-bottom communities of estuaries playing a crucial role in sedimentary processes and ecosystem functioning due to its unique traits. Recently, Arenicola marina was detected at Ria de Aveiro, being considered an invasive species in this ecosystem. A. marina is also a bioturbator and it is expected that its constant disturbance of the sediment surface can alter the infauna of the ecosystem. The production and applications of the nanomaterial graphene oxide (GO) has increased of in the last years, conducting to the release of this nanomaterial in the aquatic ecosystems, with consequences for benthic organisms, such as polychaetes. This study aims to assess the effects, isolated or in combination, of an abiotic stressor (GO nanosheets) and a biotic stressor (A. marina) on H. diversicolor. To achieve this, the study conducted several behavioral assays and biochemical markers. The obtained results demonstrated that exposure to different concentrations of GO had negative effects on burrowing activity of H. diversicolor. This species showed an unusual avoidance behavior, fleeing from lower contamination to higher ones. They were unable to escape from higher contamination compartments, but at the highest concentrations (1 and 10 mg GO/L) the bioturbation activity was significantly higher, which may indicate that H. diversicolor tended to move deeper in the sediment. Moreover, the presence of A. marina affected the behavior of H. diversicolor. Regarding A. marina, its bioturbation activity significantly decreased when exposed to GO, which could be related with the decrease of energy reserves, as protein content. Additionally, this species also showed an escape behavior from compartments with a higher GO concentration. Regarding oxidative stress, H. diversicolor seems to be more impacted, since LPO levels were higher in all GO concentrations and SOD activity significantly increased in lowest levels of GO. The obtained results indicate that A. marina may be able to some extent search for more prone areas for feeding, predation, reproduction, and migration under contaminant exposure. On the other hand, H. diversicolor spatial distribution may be severely constrained under both abiotic and biotic stress, while A. marina’s higher foraging activity may promote its propagation in the estuary. Concerning our results, behavioral tests, combined with biomarkers showed to be relevant tools and could be applied for the development of more environmental-realistic assessment and monitoring frameworks for estuaries. |
|---|
Atividades financiadas
Não foram encontrados projetos financiados.