Banca de DEFESA: GILCIDEYA SILVA PRADO

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : GILCIDEYA SILVA PRADO
DATA : 30/05/2019
HORA: 15:00
LOCAL: Prédio anexo à unidade Amazônia - Sala 15
TÍTULO:

Influence of anthropic impacts on tropic dynamics of ictiofauna from Curuá-Una
reservoir

PALAVRAS-CHAVES:

Amazon, ichthyofauna, isotopic composition, carbon, nitrogen, artificial
eutrophication.

PÁGINAS: 93
GRANDE ÁREA: Outra
ÁREA: Ciências Ambientais
RESUMO:

Artificial eutrophication in a reservoir makes the use of water unviable by the
human population, destabilizes all ecosystemic attributes and can promote irreducible
changes in biodiversity in the aquatic environment. Thus, to understand how fish play
their trophic functions and their ecological role in the face of limnological changes, the
present study aimed to evaluate the relationship between the water quality of the reservoir
of the Curuá-Una hydroelectric power plant, the energy flow and the trophic structure of
the food chain of the main species of fish belonging to different guilds. The samples were
taken at the Curuá-Una reservoir, the first in Central Amazonia, in two periods of a
hydrological cycle, upstream and downstream of the dam. In the first part of the study,
the diet of 22 fish species was evaluated through the calculation of the Food Importance
Index (IAi). The results obtained allowed the identification of trophic interactions that
suggest the development of trophic stabilization after four decades of reservoir formation.
In the second part of the study, the correlations between energy flow and food chain
structure were investigated with changes in limnological parameters as a function of a
possible artificial eutrophication. Carbon (δ13C) and nitrogen (δ15N) isotopic
compositions of fish and autotrophic sources were analyzed and nine limnological
parameters were measured. According to the results obtained, the reservoir does not
present an advanced artificial eutrophication, but the isotopic enrichment of nitrogen in
the fish and in the autotrophic sources indicates that there is an increase in the
concentration of nutrients in the aquatic environment and this in turn is incorporated in
the base of the chain and transferred to the other trophic levels. Although conventional
water analysis methods do not yet detect changes in nutrient content, the nitrogen isotope
has proved to be a sensitive ecological indicator for such a diagnosis. On the other hand,
there were no significant changes in the energy flow of the food chain. Thus, it was
concluded that after forty years of formation of the Curuá-Una reservoir the ichthyofauna
reached trophic stabilization, but this stage has signs of anthropogenic disturbance that
are likely to compromise the ecological homeostasis of the reservoir.

MEMBROS DA BANCA:
Externo ao Programa - 1834356 - ANDREIA CAVALCANTE PEREIRA
Externo ao Programa - 2391001 - DAVIA MARCIANA TALGATTI
Externo ao Programa - 1961826 - FRANK RAYNNER VASCONCELOS RIBEIRO
Externo ao Programa - 1549200 - LUCINEWTON SILVA DE MOURA
Externo ao Programa - 1836832 - RUY BESSA LOPES
Presidente - 1693122 - SERGIO DE MELO