Research in progress

Propagule pressure of Oreochromis niloticus by aquaculture activity: quantifying size and evaluating structural strategy to prevent escape.

Biological invasions are recognized as the second greatest threat to global biodiversity, representing a major challenge for the conservation of natural resources and sustainable development. Aquatic ecosystems, in particular, are experiencing a significant increase in propagule pressure from non-native species, largely due to the expansion of aquatic organism production activities over recent decades, especially involving fish. In the context of Brazilian aquaculture, the non-native species Oreochromis niloticus (Nile tilapia) is both the most widely produced and extensively introduced species in continental aquatic environments, and is linked to the decline of native stocks and species extinctions. Our proposal aims to quantify the propagule pressure exerted by Oreochromis niloticus resulting from escapes from aquaculture activities in excavated tanks, and to evaluate methods for containing these escapes and mitigating their impacts. This project will provide crucial information for the development of predictive models concerning increased propagule pressure and the risks of biological invasions associated with the expansion of aquaculture.

Anthropogenic effects on the fish community of streams in the Piquiri River basin, PR, Brazil.

The Neotropical region currently hosts the highest taxonomic and functional diversity of freshwater fish globally, alongside significant conservation challenges due to the expansion of high-impact human activities. Consequently, we aimed to assess the influence of various land uses and land occupations on the taxonomic and functional diversity attributes of fish in streams within the Piquiri River basin, which exhibits diverse land use patterns. This study encompasses two small-order streams, with ichthyofauna sampled quarterly at three points along a longitudinal gradient (headwater, middle, and mouth). Utilizing taxonomic and functional diversity indices, the study will evaluate the attributes of fish assemblages affected by different land uses and occupations, as well as identify occurrences of non-native species, their sources of introduction, and potential risks of biological invasions. The findings will provide valuable information for environmental managers and the productive sector to enhance the management of ecosystem resources..