Banca de QUALIFICAÇÃO: MANANA FELIX SOBRAL
Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.STUDENT : MANANA FELIX SOBRAL
DATE: 30/03/2021
TIME: 09:00
LOCAL: Sala virtual - PPG-DIBICT-UFAL
TITLE:
Ecological role of green turtles: a megaherbivore in the reef environment
KEY WORDS:
Herbivory, food preference, ecological paper, green turtles, isotopic niche
PAGES: 20
BIG AREA: Ciências Biológicas
AREA: Ecologia
SUMMARY:
Herbivory is an essential process for the health and resilience of reef environments, where primary producers have their growth limited by the intense grazing of several herbivores. In this context, the knowledge of herbivory is restricted to studies with fish and sea urchins, with a gap in the understanding of the role of megaherbivores, such as the green turtle, in this process. The green turtle is the only species of sea turtle that along its ontogeny adopts a mostly herbivorous diet. In this study, the ecological role of the green turtle in reef environments was investigated, evaluating the feeding ecology of juveniles recruited and sub-adult juveniles. This assessment included analysis of the diet (n = 36), food preference and niche length and overlap. We used the analysis of stable ¹³C and ¹5N isotopes to broaden the understanding of the inter and intraspecific trophic interactions of the green turtle with the other reef herbivores, as well as the assimilation of energy through the selected food resources. In the analysis of the diet the food content, obtained from dead carcasses found along the APA Costa dos Corais during the Beach Monitoring Project, was screened and the items identified had their relative weight and frequency of occurrence calculated. For food preference, analyzed using the Manly index in the ‘adehabitatHS’ package, the diet data were cross-checked with the food availability data that were obtained through the assessment of benthic reef coverage using long transect photoquadrats. The niche width was analyzed by the Levins method, while the overlap was treated based on Moristia, both made with the “spaa” package in software R. The red algae had the greatest relative contribution to the diet in both groups, juveniles and sub-adults, with emphasis on the Gelidiales family, which was the most preferred and had low coverage. The niche overlap was high, but the sub-adult turtles had a greater niche range, with significant contributions from green and brown algae. The preference for red algae indicates a higher foraging pressure on this group, in addition to suggesting that the APA Costa dos Corais is an important feeding area for juvenile green turtles. These results, when added to those of stable isotopes, will help to understand how green turtles use the available resources, and how they contribute to the process of herbivorous reefs.
BANKING MEMBERS:
Externo à Instituição - CRISTIANO QUEIROZ DE ALBUQUERQUE - UFERSA
Externa à Instituição - VICTORIA GONZALEZ CARMAN
Externa à Instituição - CAMILA DOMIT - UFPR