masterThesis
Comunidade fitoplanctônica e qualidade de água em cultivo de camarão em sistema convencional e com bioflocos: interfaces da pesquisa e ensino para aquicultura sustentável
Fecha
2019-09-30Registro en:
SOUZA, Josielma Priscila Pedro de. Comunidade fitoplanctônica e qualidade de água em cultivo de camarão em sistema convencional e com bioflocos: interfaces da pesquisa e ensino para aquicultura sustentável. 2019. 143f. Dissertação (Mestrado em Desenvolvimento e Meio Ambiente) - Centro de Biociências, Universidade Federal do Rio Grande do Norte, Natal, 2019.
Autor
Souza, Josielma Priscila Pedro de
Resumen
The present work aims to characterize and evaluate the phytoplankton community and water
quality in cultivation of conventional marine shrimp and with biofloc, and to promote an
educational action to form a critical socio-environmental vision of sustainable aquaculture.
The study was carried out in a farm of marine shrimp cultivation of the species Litopenaeus
vannamei (BOONE, 1931) and in Lagoa de Guaraíras, an environment for capturing water
and receiving effluents from cultivation, located in the municipality of Nísia Floresta, on the
southern coast of the state Rio Grande do Norte, northeastern Brazil, from April to July 2018.
Physico-chemical parameters of the water and phytoplankton community were analyzed
during the final growth phase until shrimp harvesting. An analysis of the students' perception
about aspects of sustainable aquaculture and an interactive exhibition was carried out during a
school science fair on the theme Life in the water, with elementary school students in a public
school in the rural area of the municipality of Nísia Floresta / RN. Considering the high
values of NT and Chl-a and the dominance of cyanobacteria in the Guaraíras lagoon, the
water quality of this environment tended to eutrophicate. Differently from what was expected,
the results reveal the decrease in the productivity of the nurseries and the quality of the water
in the BFT system, due to weaknesses in the management, especially of the OD and SS
parameters. For a BFT system to be truly sustainable, it is essential to strictly follow technical
management principles. The richness and dominance of phytoplankton species in the studied
environments were represented by the group of cyanobacteria in all environments (> 90% of
the total biomass). Regarding the cultivation modes, the conventional system showed greater
species richness and lower phytoplankton density, the reverse was observed in the BFT
system. The relative contribution of cyanobacteria was more representative in conventional
nurseries and the greatest richness was identified in natural environments. Potentially toxic
and off-flavor producing cyanobacteria such as circular Anabaenopisis, Aphanizomenon
gracile, Aphanocapsa delicatissima, Cylindrospermopsis raciborskii, Oscillatoria sp.,
Planktothrix sp., Pseudanabaena sp. and Snowella sp., emphasizing the importance of these
microorganisms as bioindicators of water quality in cultivation and in the natural environment. The result of the questionnaire showed that 79% of the students had not heard
about sustainability. Regarding aquaculture, 73% of students were unaware of what they were
referring to and 79% reported not knowing what shrimp farming was. The interactive
exhibition proved to be a potential tool to foster interest and discussion on socio-scientific
aspects of curricular content, contributing to the development of students' critical thinking and
more meaningful learning. In this way, the school exercises its role in building the
relationship between the environment and citizenship, strengthening the awareness that the
environment is a common public heritage and, its defense, a political right of all citizens.