Fitoplâncton dynamics and tropical reservoir evolution in brazilian Semi-arid
The present study aimed to analyze the dynamics of phytoplankton functional groups and the degree of trophic degree in the Brazilian semi - arid reservoir during prolonged drought. The study was carried out in the Cordeiro reservoir, in the municipality of Congo, Paraiba, with samples from June to D...
| Authors: | , , , , , |
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| Format: | article |
| Status: | Published version |
| Publication Date: | 2018 |
| Country: | Brasil |
| Institution: | Grupo Verde de Agroecologia e Abelhas (GVAA) |
| Repository: | Revista Verde de Agroecologia e Desenvolvimento Sustentavel |
| Language: | Portuguese |
| OAI Identifier: | oai:ojs.gvaa.com.br:article/5629 |
| Online Access: | https://www.gvaa.com.br/revista/index.php/RVADS/article/view/5629 |
| Access Level: | Open access |
| Keyword: | Eutrophication Cyanobacteria Shallow Lake Eutrofização Grupos Funcionais Lago Raso. |
| Summary: | The present study aimed to analyze the dynamics of phytoplankton functional groups and the degree of trophic degree in the Brazilian semi - arid reservoir during prolonged drought. The study was carried out in the Cordeiro reservoir, in the municipality of Congo, Paraiba, with samples from June to December 2015, with a quarterly frequency, near the reservoir bus. The phytoplankton species were identified and quantified to obtain the density, later the species were classified according to their strategies and functional groups. The trophic state was determined from the Index of the trophic state, for tropical environments. The study period was characterized by the reduction of water levels accumulated in the reservoir. The transparency of the Secchi was low, whose values were less than 1m. Total phosphorus concentrations during the study period were high (above 200 μg / L). Chlorophyll-a concentrations had a minimum of 8.17 μg/L in July 2015 and a peak of 93.67 μg/L in October 2015, with fluctuations throughout the study period. The environment was classified as mesotrophic in the month of June and eutrophic in the months of October and December. Ten descriptive species, grouped into four life strategies (CS, C, R, and S) and 08 functional groups (D, F, H1, N, P, X1 and Z) were identified. The functional groups reflected the environmental changes, being typical the presence of typical groups of meso-eutrophic shallow lakes. The potentially toxic species found in the study may pose health risks to people who use this water for consumption. |
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