Influência do estado da barra de acesso em comunidades bênticas de uma lagoa intermitente e praia arenosa adjacente

Le résumé fourni par la source

The structural connectivity gradient between the coastal lagoons and the sea alters the movement of resources and consumers, the internal physical-chemical gradients, and directly affects the regional diversity of species. Understanding the effects of the process of opening and closing bar on benthic fauna, and the consequent reflection in the trophic currents, is fundamental for better management of coastal areas. Thus, the study aimed to evaluate the influence of the access bar state on the benthic fauna of the Ibiraquera lagoon and the adjacent beach. For this, monthly sampling of benthic fauna and environmental variables was carried out in the Ibiraquera lagoon and on the adjacent sandy beach in a one-year period, covering two opening and closing cycles of the bar. The results indicate that, in general, the opening and closing dynamics of the bar causes changes in the structure of the benthic fauna, especially in the lagoon. The density of the macrofauna, meiofauna and the nematode assembly declines significantly after the bar opening. The descriptors of richness and diversity are also affected by the opening of the bar; for macrofauna and Nematoda both tend to decay, with greater intensity in the lagoon. As for meiofauna, the richness increases on the beach and decreases in the lagoon, while diversity has an increase in both places. The analyzes also showed that, while closed, the lagoon was less similar to the beach, and with the opening of the bar, there is an increase in similarity between environments. As for the interactions between the biotic data and the environmental variables, it was observed that in the periods when the lagoon was closed, the fauna was associated with higher concentrations of chlorophyll a, while the fauna of the beach, as well as of the lagoon in the periods of was associated with higher values of salinity and average grain size. Through this study, it is possible to perceive that the processes of opening and closing of the lagoon of Ibiraquera can negatively affect both the structure of the benthic fauna of the lagoon as well as the immediately adjacent beaches. Because these organisms form the basis of trophic chains, including species of commercial importance, flows from pond opening can play a key role in structuring environments and environmental services.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.