Banca de DEFESA: WAGNER UEHARA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : WAGNER UEHARA
DATE: 28/08/2024
TIME: 13:15
LOCAL: on-line
TITLE:

Taxonomic and functional patterns of fish assemblages in oceanic and estuarine beaches along the Brazilian coast: a latitudinal, regional, and local approach

KEY WORDS:

β-diversity, sandy beaches, latitudinal gradients, Niche Theory vs. Neutral Theory, multiscale analysis, macroecology, trait-environment relationships

PAGES: 200
BIG AREA: Ciências Biológicas
AREA: Zoologia
SUBÁREA: Zoologia Aplicada
SUMMARY:

The analysis of biodiversity patterns at different spatial scales is fundamental to ecology, biogeography, and conservation biology, as underlying processes are scale-dependent. While recent advances have contributed to our understanding of how biodiversity is organized, there is a significant gap in the scientific literature from the Global South regarding macroecological studies that integrate approaches across different spatial scales and simultaneously consider environmental, anthropogenic, and biological factors. The central aim of this thesis is to analyze the composition and processes shaping fish assemblages on sandy beaches (coastal and estuarine) along the Brazilian coast, using primary and secondary data at different spatial scales (local, regional, and latitudinal) and employing diverse approaches (taxonomic, functional, and environmental), thereby providing a comprehensive and detailed perspective to fill this gap. The thesis is organized into three chapters. In Chapter 1 (C1), the processes of fish assemblage formation on estuarine and oceanic beaches are analyzed at latitudinal and regional scales along the Brazilian coast, using taxonomic and functional ß-diversity from the perspective of two ecological hypotheses: Hubbell's Neutral Theory and Hutchinson's Niche Theory. In Chapter 2 (C2), the relationships between fish species occurrence, their functional traits, and environmental variables are analyzed at the same scales and beach types mentioned in C1, using an RLQ approach and Fourth-corner statistics. In Chapter 3 (C3), the effects of environmental and anthropogenic factors on the structuring of fish assemblages are evaluated at the local scale for insular and coastal beaches in Southeastern Brazil, using permutation tests (PERMANOVA) and Generalized Additive Mixed Models (GAMM). Overall, the results reveal that fish assemblage formation is influenced by a complex interaction between ecological, environmental, anthropogenic, neutral, and niche processes, varying according to spatial scale and habitat type. It was demonstrated in C1 that niche processes predominate through selective extinction associated with environmental gradients, while neutral processes are restricted to tropical zones, associated with environmental stability, ecological drift, and species dispersal. In C2, it was found that the associations between species occurrence, functional traits, and environmental variables in both estuarine and oceanic beaches are not random, being stronger in the estuarine beaches. In C3, fish assemblages varied at the local scale (bays, beach type, and seasons), with anthropogenic impact being the most important environmental predictor for the descriptors of fish assemblages, positively related to species abundance and richness. Effective coastal biodiversity management should integrate multiscale actions that address both local habitat conservation and the protection of ecological processes at regional and latitudinal levels. By demonstrating the predominance of niche processes and the influence of anthropogenic impacts, the results provide a critical foundation for the implementation of conservation policies that ensure the sustainability of coastal ecosystems in Brazil.

COMMITTEE MEMBERS:
Externa à Instituição - ANA PAULA PENHA GUEDES - UNEB
Interno - 387200 - FRANCISCO GERSON ARAUJO
Externo à Instituição - HAMILTON HISSA PEREIRA - FIPERJ
Externa à Instituição - HELAINE DA SILVA MENDONÇA - IFRJ
Interno - 1728466 - JAYME MAGALHAES SANTANGELO
Externo à Instituição - JOAQUIM NETO DE SOUSA SANTOS - IFNMG
Interno - 1341945 - RAFAEL DE ALMEIDA TUBINO