Banca de QUALIFICAÇÃO: LORENA SOARES AGOSTINHO

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : LORENA SOARES AGOSTINHO
DATE: 13/12/2024
TIME: 08:00
LOCAL: SALA DE REUNIÕES DO DECOL
TITLE:

Ecology and population genetics of scaled sardine (Harengula sp.) in Brazilian oceanic islands

KEY WORDS:

Feeding ecology; Zooplankton; Spatial ecology; Swell; Population genetics; Clupeidae

PAGES: 64
BIG AREA: Ciências Biológicas
AREA: Ecologia
SUMMARY:

The scaled sardine (genus Harengula) plays a fundamental role in tropical marine ecosystems, acting as an intermediary link connecting lower and upper trophic levels and significantly contributing to ecological dynamics. In Fernando de Noronha, the scaled sardine (Harengula sp.) holds ecological and socioeconomic importance, having been used in artisanal fishing for many years as the primary bait. This fishery serves as a vital source of income and subsistence for many fishers, meeting approximately 80% of the local demand for fish. Given their ecological and socioeconomic significance, particularly in insular habitats, this thesis, entitled "Ecology and population genetics of scaled sardine (Harengula sp.) in Brazilian oceanic islands”, investigates the feeding and spatial ecology of the Fernando de Noronha population, as well as the population genetics of the scaled sardine from this archipelago and Trindade and Martins Vaz. The first chapter addresses feeding ecology, focusing on the diet composition and selectivity of the scaled sardine in Fernando de Noronha. Analyses based on the frequency of occurrence and the number of food items revealed a diet dominated by Copepoda (98.34%), with the genus Oithona (83.22%) standing out, while other items, such as Mysidacea and bivalves, represented less than 0.03% of the available food. Dietary selectivity highlights the scaled sardine role as key consumers in the insular ecosystem. The second chapter investigates spatial ecology, analyzing the frequency of occurrence of schools across 17 beaches in Fernando de Noronha, considering periods of swell and absence of swell in the “mar de dentro”, seasons, and moon phases. The results indicated that swell events in the “mar de dentro” and the dry season increase the likelihood of schools occurring on sandy-bottom beaches. Finally, the third chapter explores population genetics, assessing the dynamics of expansion in Fernando de Noronha and signs of isolation in Trindade. Samples were sequenced by Macrogen and analyzed in partnership with LISE-UFRN. Preliminary results suggest that the Fernando de Noronha population is potentially expanding, while Trindade shows signs of genetic isolation. These findings underscore the need for integrated conservation strategies that account for the specificities of each archipelago. The integration of these chapters provides essential insights for the sustainable management of scaled sardines (Harengula sp.) and the preservation of Brazilian insular ecosystems.

COMMITTEE MEMBERS:
Presidente - 1378974 - LIANA DE FIGUEIREDO MENDES
Interno - 1545394 - FULVIO AURELIO DE MORAIS FREIRE
Externo à Instituição - ARTHUR DE BARROS BAUER - UFRJ