Bioinvasão marinha e mudanças na comunidade: Análises de diversidade, caracterização trófica e nicho isotópico

Abstract

Marine bioinvasion represents one of the direct drivers of changes in nature with the greatest global impact, leading to the loss of biological diversity and ecosystem functions. Although the consequences caused by the introduction of a non-native species (NS) are uncertain, they can cause almost imperceptible effects up to the complete domination and displacement of native communities. The mechanisms behind the success of a NS are determined by both species and community characteristics, however, there is still no consensus on what makes a NS successful. The present work, divided into 5 chapters, has as main objective to evaluate the effect of marine NS on the diversity and trophic structure in benthic communities of rocky shore and to disseminate the concepts related to the study of marine bioinvasion and marine science beyond the academy. We initially gathered information currently available on marine NS in Brazil and noted that between 1950 and 2010, the number of marine NS doubled at least every decade, which shows that Brazil should be more efficient in combating introduction of NS and use more effective tools, for example a national database to monitor trends in marine NS introductions. In the second chapter, we use the fit and selection approach of species abundance distribution models, taxonomic diversity indices, and functional diversity indices based on hierarchical cluster matrices to assess the effects of four invasive marine species on biological and functional diversityon rocky shores along the coast of the state of Rio de Janeiro. We consider that the taxonomic and functional diversity indices are useful tools to identify processes that determine biological diversity, however, the functional characteristics of the species better reflected the number and biomass of NS. In the third chapter, we use δ13C and δ15N values and isotopic niche metrics to investigate trophic relationships in rocky shores invaded by the corals Tubastraea tagusensis and T. coccinea. Both proved to be successful food competitors occupying a specific niche within the niche occupied by other functionally equivalent species. Still using δ13C and δ15N analysis, in the fourth chapter we provide the first characterization of a food web on a rocky shore of an area invaded by invasive soft coral Sansibia sp., corroborating field-documented observations of a possible predator, we also identified changes since the last survey conducted in 2017 (year of introduction) and an increase in NS abundance and distribution to more favorable areas. The fifth and last chapter represents a university extension work developed in parallel to the doctoral project where we analyze different dimensions of the project's performance and the response of those who participated in the workshops, showing the importance of taking information and debates restricted to academia beyond the university