Trophic Modeling of upwelling ecosystem in Cabo Frio, Rio de Janeiro

Author(s)

Gabriela Rodrigues Vera

• Document type: Doctoral Thesis
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Instituto Oceanográfico (IO/DIDC)
• Defense date: 2010-11-05

Examining board members

Lucy Satiko Hashimoto Soares; Katia de Meirelles Felizola Freire

• Advisor: Lucy Satiko Hashimoto Soares

Abstract

The structure and trophic functioning of the ecosystem of Cabo Frio were analyzed considering the seasonal variation of the upwelling events. Two different seasonal models (Ecopath) and an annual model were constructed. The seasonal models did not show great differences, except for a higher biomass of producers during the spring-summer period, when the upwelling is more intense. Possibly, this difference was due to the small seasonal variation in the diet among trophic groups and lack of information on fishery catch data. The annual model could be considered as representative of the system of Cabo Frio, and according to the ecological descriptors it is a developing system with a high degree of disorganization, common characteristic in upwelling regions. The trophic levels calculated by the model were similar to the isotope trophic levels available in the literature for similar trophic groups, showing the confidence of the obtained results. (AU)