Banca de QUALIFICAÇÃO: TAILAN MORETTI MATTOS

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
DISCENTE : TAILAN MORETTI MATTOS
DATA : 26/07/2018
HORA: 14:00
LOCAL: Sala 35 do ICBS
TÍTULO:

Taxonomic distinctness, functional diversity and food web modelling as tools for conservation of fish fauna in Reservoirs of the State of Rio de Janeiro

PALAVRAS-CHAVES:

Functional Traits; Ecopath; Tropical Reservoirs; Keystone species

PÁGINAS: 84
GRANDE ÁREA: Ciências Biológicas
ÁREA: Zoologia
SUBÁREA: Taxonomia dos Grupos Recentes
RESUMO:

The hydrological regulation of rivers by dams is among the main threats to the biodiversity of
continental aquatic organisms. In the last two decades, numerous studies have described the
severe impacts caused by dams, ranging from changes in river geomorphology to extinction
loss. The main aim of this study was to evaluate the structure of the fish community of eight
reservoirs in the Paraíba do Sul River (PSR) basin, using functional diversity indeces,
taxonomic distinction as well as to develop a trophic modeling in one of the reservoirs (Lajes
Reservoir) where a more comprehensive database is available. The functional traits approach is
an important tool that improves the ability to predict possible changes in the community
structure in relation to the variations that the environment may suffer while modeling can
organize and systematize high quality sampling information and convert observed values into
information necessary to parameterize ecological models. We expect that reservoirs built in the
main channel of the PSR (Santa Branca, Funil and Ilha dos Pombos) have a higher functional
diversity compared to reservoirs in cascade built by water abstraction of RPS (Santana, Vicar
and Pereira Passos) and these, in turn, present higher values of functional diversity than isolated
reservoirs that are fed by streams (Lajes and Tocos). A total of 30 functional traits were
measured, being 26 quantitative and 4 categorical, with at least five adult individuals analyzed
from each species. Seven independent indexes of Functional Diversity were calculated:
functional richness, functional uniformity, functional divergence, RaoQ, functional dispersion,
functional specialization and functional originality. Six different functional groups were
identified. The greatest functional diversity was found in the Santana and Vigário reservoirs
(0.679 and 0.661, respectively, cascade type), followed by the reservoirs that were built in the
PSR river channel (Pombos and Funil, 0.626 and 0.492, respectively). On the other hand, the
lowest was observed in the Tocos reservoir (0.127, isolated environment) that drains a small
hydrographic basin with the smallest flooded area. Tocos and Ribeirão das Lajes presented the
highest values of functional divergence (0.827 and 0.807, respectively), indicating that fish
species with more extreme functional traits within the assembly have considerable abundance.
We also described the parameterization process for the development of a trophic web model
(using Ecopath) to understand the structure, to identify the main key species, to evaluate the
dynamics and interactions of the ecosystem web in the Lajes Reservoir (RRL). This is the
oldest, most preserved and strategic reservoir built in the state of Rio de Janeiro. In the Ecopath

model, 33 compartments were identified (among them, Generalist / Selective Birds, 19 fish
species, Benthic and Planktonic Invertebrates, Protozoa, Bacteria, Periphyton, Phytoplankton
and Follices/debris), as well as Detritus. The model outputs showed that RRL is a mature
ecosystem, highly dependent on the input of terrestrial invertebrates and allochthonous plant
material. Three compartments (Generalist Birds, and the fishes Rhamdia quelen and Hoplias
malabaricus) were the most important keystone species for the ecosystem. The Cichlas
compartment was identified as being a group with high relative biomass and high impact in the
trophic web. A rapid and drastic reduction of the RRL water level would lead to a strong
negative direct and indirect impacts on almost all aquatic organisms.

MEMBROS DA BANCA:
Interno - 387200 - FRANCISCO GERSON ARAUJO
Presidente - 387289 - ILDEMAR FERREIRA
Externo à Instituição - LUISA RESENDE MANNA - UERJ
Externo ao Programa - 1341945 - RAFAEL DE ALMEIDA TUBINO