Impacto do manejo de viveiros na qualidade da água e dos efluentes durante a recria de tambaqui, Colossoma macropomum

AUTOR(ES)
FONTE

IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia

DATA DE PUBLICAÇÃO

06/05/2005

RESUMO

Tambaqui is the main specie raised in the Amazon state. However there is no information regarding the potential pollution for this activity, therefore this work objective was to evaluate water quality and effluents during tambaqui second growth phase in differently managed ponds. Fish (0.410.25g and 2.810.52cm) were confined at random in 9 excavated 600m2 ponds at a density of 8 fish/m2 for a period of 60 days, where they were submitted to three treatments: 1) fertilized and limed pond, 2) limed pond, 3) no management. A commercial feed with 34% crude protein was offered at a frequency of 3x/day. There were no significant differences for growth and productivity parameters studied. Three main items were found in tambaqui stomach, insect, zoo/phytoplankton and commercial feed, without a significant difference among treatments regarding the ingestion proportionality of these items. Insect and zoo/phytoplankton consumption decreased, while commercial feed consumption increased along the experiment (p=0.017). As for the limnological variables analyzed in the ponds: alkalinity (p=0.00036), hardness (p=0.00008) and CO2 (0.0054) presented differences among treatments. At the same time chlorophyll (p=0.359), transparency (0.228), ammonia (p=0.301), nitrite (p=0.1128), temperature (p=0.86) and dissolved oxygen (p=0.45), did not presented significant statistical differences among treatments. In the effluents analysis, the variables biochemical oxygen demand (p=0.0067), total phosphorus (p=0.0012), orthophosphate (p=0.0017), ammonia (p=0.018) and nitrite (p=0.0213) presented significantly differences among treatments. Fertilization with a phosphorus source should be avoided, since the effluents are potentially impacting. It was observed that pond fertilization and liming are not indispensable management for tambaqui second growth phase, since growth and productivity were similar among the three pond management tested.

ASSUNTO(S)

tambaqui piscicultura aqüicultura colossoma macropomum qualidade de água efluentes, manejo limnologia impactos recursos pesqueiros e engenharia de pesca

ACESSO AO ARTIGO

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