Banca de DEFESA: LARISSA DOS SANTOS SILVA AMARAL

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : LARISSA DOS SANTOS SILVA AMARAL
DATE: 25/04/2024
TIME: 09:00
LOCAL: on-line
TITLE:

Long-term changes in fish assemblages of sandy beaches of Ilha Grande Bay – RJ

KEY WORDS:

sandy beaches, juvenile fishes, shelf area, assemblage composition, structure of habitat

PAGES: 58
BIG AREA: Ciências Biológicas
AREA: Zoologia
SUBÁREA: Zoologia Aplicada
SUMMARY:

Sandy beaches are dynamic ecosystems that shelter diverse marine biota with significant
ecological and economic importance. Despite their widespread distribution, there are
knowledge gaps regarding the characterization of biota and environmental influences for this
type of ecosystem. The aim of the present study was to investigate temporal changes in the
structure of juvenile fish assemblages on sandy beaches in the Ilha Grande Bay. Sampling was
conducted between the periods of 2002/2003 and 2017/2018, from January to December, in 6
sandy beaches defined based on geomorphological characteristics, continental drainage
influence, and human occupation. Fish were collected using a "picaré" net, measuring 12m in
length x 2.5m in height, with a mesh size of 7.5 mm at the center. Three perpendicular beach
seine hauls were conducted manually on 6 BIG beaches, corresponding to an approximate
area of 240m² per haul, during daylight hours. A total of 27,142 individuals weighing
26,072.70 grams were collected, representing 24 families, 25 genera, and 80 species. Families
with the highest representation included Sciaenidae (10 species), Carangidae (8), Haemulidae
(5), followed by Engraulidae, Gobiidae (4), and Ariidae (4). The most abundant species/taxa
were Atherinella brasiliensis, Anchoa spp, Trachinotus carolinus, and Menticirrhus spp.
Atherinella brasiliensis (65.35%) and Eucinostomus argenteus (9.39%) were the most
captured species, representing half of the captures for the families Gerreidae and Carangidae,
respectively. The second period recorded a higher number of representative families
compared to the first period 2002/2003, such as Engraulidae (66.71%), Atherinopsidae
(22.59%), Carangidae, and Gerreidae (>3.29%). Samples from the 2002/2003 period
associated with predictors of higher transparency and rocky outcrop mosaics corresponded to
7.9% of variation explanation for the species Trachinotus falcatus, Lutjanus synagris, and
Strongylura timucu, while the period from 2017/2019 was more associated with anthropized
areas and beaches influenced by the contribution of small to large rivers, environmental
conditions that favored a higher incidence of Albula vulpes, Anchoa januaria, Anchoa spp,
Eugerres brasilianus, Genidens genidens, Genidens barbus, and Cathorops spixii. The size
structure of species differed between periods, with smaller individuals (TL < 5 mm) abundant
in the period from 2017/2019, whereas in 2002/2003, there was a greater dominance of
species with TL >9cm, indicating a higher incorporation of juveniles into the sandy beach
community when temporal patterns are observed over the 15 years. Additionally, a
homogenization of fish assemblages with the dominance of Anchoa spp. species is noted. The
results highlight the importance of conservation and integrated management of coastal
ecosystems, considering the complex interactions between local environmental factors and
biological communities.

COMMITTEE MEMBERS:
Externo ao Programa - 1767348 - FABIO SOUTO DE ALMEIDA - nullInterno - 2143107 - LEONARDO MITRANO NEVES
Externo à Instituição - MARCUS RODRIGUES DA COSTA - UFF
Interno - 1341945 - RAFAEL DE ALMEIDA TUBINO
Externa à Instituição - SIMONE JAQUELINE CARDOSO - UFJF