Determinação da produtividade primária pelo fitoplancton em zona eufótica na Represa Samambaia, Goiânia-GO.

• Autor(a) principal: SOUSA, Alessandro Ribeiro de
• Data de Publicação: 2009
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tde/630
• topic: Fotossíntese, respiração, reservatório, produtividade, fitoplancton.; photosynthesis, respiration, reservoir, productivity, phytoplankton; CNPQ::ENGENHARIAS::ENGENHARIA SANITARIA::RECURSOS HIDRICOS

This study evaluated and determined the productivity of phytoplankton in euphotic zone in Samambaia Reservoir at Goiânia city, GO. The work involved productivity and physical chemistry sampling and measures, in loco, of data related to primary production. It was evaluated 16 physical chemistry parameters where the ranges of variation were: (1) temperature from 24,3ºC to 31,8ºC; (2) dissolved oxygen from 2,8 to 7,2 mg.L-1; (3) tubidity from 5,9 to 54,1 UNT; (4) apparent color 97 to 547 mgPt.L-1; (5) true color from 53 to 301 mgPt.L-1; (6) conductivity from 42,6 to 66,0 Ohm.cm-1; (7) total solids from 0,030 to 3075,000 mg.L-1; (8) suspended solids from 0,009 to 0,160 mg.L-1; (9) total dissolved solids from 0,010 to 3074,000 mg.L-1; (10) chlorophyll-a from 0,0 to 80,1 &#956;g.L-1; (11) alkalinity from 34,06 to 64,10 mg.L-1; (12) pH from 6,2 to 7,39; (13) nitrate from 0,18 to1,76 mg.L-1; (14) ammonia nitrogen from 0,024 to 0,307 mg.L-1; (15) COD 5,81 a 23,60 mg.L-1; total phosphorus < 10,0 &#956;g.L-1. The values of the photosynthesis and respiration were ranged among: 0,0 328,08 mgO2.m-3.h-1 for the photosynthesis and 0,00 301,37 mgO2.m-3.h-1 for the respiration. The multivariate analysis of the data identified 3 inter-related groups as following: (1) photosynthesis, respiration, nitrate, ammonia nitrogen , suspended solids, total phosphorus, alkalinity, COD, temperature, dissolved oxygen, pH, (2) total solids, total dissolved solids, (3) turbidity, true color, apparent color, chlorophyll-a, conductivity. The value of the gross productivity average in the study period was 75,05 mgO2.m-3.h-1, which classified the Samambaia Reservoir as eutrophic. The spatial and temporal variation of photosynthesis and respiration showed that the place with highest values of gross photosynthesis and respiration was the dam with averages of 95,35 mgO2.m-3.h-1 and 81,89 mgO2.m-3.h-1, respectively. The calculations of the coefficients of rate photosynthesis showed that the highest coefficients of photosynthesis, for first order equations, were for the December month whose values were: (1) 0,2067 h-1 for the dam; (2) 0,0608 h-1 for the middle reservoir and (3) 0,0978 h-1 tributary zone. With respect to respiration coefficients the highest values were: (1) for the September month into the dam and middle reservoir, the values were 0,0398 h-1 and 0,0245 h-1, respectively, (2) 0,0216 h-1 for December month in the tributary zone, therefore, the reservoir showed itself anoxic in the September, 2008. In summary, the Samambaia Reservoir presented itself as eutrofic, with higher rates and coefficients of photosynthesis and respiration in the dam and middle reservoir, where the dam zone presented itself more susceptible to eutrophication