Investigação de parasitos sanguíneos e elementos-traço em Sula leucogaster (Boddaert, 1783)

Abstract

Seabirds have an important role in marine environments and are considered sentinel species due to their sensibility to environmental changes. Among the stressors that affect seabirds, parasite infections and exposure to trace elements are important because they can compromise their health. Despite the increasing attention to these factors, there are still gaps of knowledge regarding seabirds. Sula leucogaster is a strictly marine bird that reproduces in islands such as the Santana Archipelago, near the coast of Macaé, in the state of Rio de Janeiro. This area is facing strong anthropogenic pressures due to offshore oil exploitations and the disposal of effluents, which can impact marine ecosystems. The aim of this study was to investigate the presence of blood parasites and to assess the concentration of trace-elements in Sula leucogaster. The study was structured in three chapters. The first chapter investigated the presence of Haemosporida and Piroplasmida in S. leucogaster; reviewed the lineages occurring in Suliformes birds, and described a new lineage of Babesia sp. in S. leucogaster. The second chapter investigated the diversity of hemosporidian lineages detected in S. leucogaster and inferred the phylogenetic position of the new lineages in relation to those available in birds. The third chapter assessed the concentrations of lead (Pb) and iron (Fe) in different types of feathers of this species, as well as if they varied according to the individual's age and sex. Our results reinforce the potential role of S. leucogaster as host of a wide variety of blood parasites and broaden the knowledge about Haemosporida and Piroplasmida diversity in seabirds. Likewise, they highlight the importance of using integrated techniques when studying these parasites. Furthermore, the assessment of Pb and Fe suggests it is important to consider multiple biological and ecological factors in future studies evaluating seabirds exposure to trace elements.