Quality of fauna studies in environmental impact assessments in Brazil's Atlantic rainforest: Trends across time periods and project types

The installation and operation of infrastructure, mining, landfills, and residential developments have several impacts on fauna, including habitat loss, fragmentation, and disturbance due to noise and light pollution. Therefore, fauna studies are a key component of Environmental Impact Assessments (EIA) to evaluate the effects on biodiversity. The Atlantic Rainforest is a biodiversity hotspot in Brazil, extending across seventeen states, including Paraná, Rio de Janeiro, and São Paulo. Given the importance of this biome and the impacts of licensing projects on fauna, we aim to assess the quality of fauna studies in EIAs from three study areas under the influence of the Atlantic Rainforest. Four types of projects were selected for evaluation: infrastructure, mining, landfills, and residential development. A quality index was used to assess the fauna study quality. Our results revealed that all evaluated fauna studies had a Quality Index below 70 %, which is considered unsatisfactory. No significant differences in the quality index were found between states or project types, suggesting that the issues with fauna studies are consistent across both states and projects. In São Paulo, however, the recent EIAs (2021−2023) showed a significantly higher Quality Index compared to older EIAs (2012–2014), indicating improvements in fauna studies over time. A positive correlation was observed between the number of pages in fauna studies and the Quality Index, suggesting that comprehensive studies require more detailed documentation. Our findings highlight the need to improve fauna studies by focusing on scientific questions, hypotheses, and conceptual models to make the studies more analytical.