doctoralThesis
Fluxo de nutrientes em um sistema de aquicultura orgânica
Fecha
2014-02-26Registro en:
OLIVEIRA, Sérgio Ricardo de. Fluxo de nutrientes em um sistema de aquicultura orgânica. 2014. 130f. Tese (Doutorado em Ecologia) - Centro de Biociências, Universidade Federal do Rio Grande do Norte, Natal, 2014.
Autor
Oliveira, Sérgio Ricardo de
Resumen
The cultivation of marine shrimp in organic system has become an alternative
less harmful to the environment. The union of this system with the integrated
cultivation (seaweed–shrimp) is an economically and socially beneficial way of
reducing environmental impacts from this activity. This study focuses on the
nutrient flow in an organic shrimp (Litopenaeus vannamei) farming system and
on the ability of macroalga Gracilariopsis tenuifrons, Gracilaria caudata, Ulva
lactuca and Gracilaria domingensis to absorb nitrogen and phosphorus when
grown in this system. This thesis is composed of four chapters. The chapter 1 is
in the form of introduction that highlights the current state of aquaculture, the
cultivation systems, the current knowledge of integrated cultivation and the most
commonly used algal species as biofilters. This chapter also justifies and
emphasizes the need to undertake the current research. The chapter 2
analyzes the nutrient (NH4
+
, NO2
-
, NO3
-
and PO4
-
) flow and assesses the
environmental parameters in the organic shrimp (Litopenaeus vannamei) farm.
In this study, the water and sediment quality from the shrimp farm were
determined for a period corresponding to one cycle of the shrimp. These data
were combined with information on the physical and chemical parameters in
order to investigate which variables influence the shrimp growth and survival.
The chapter 3 evaluates the relationship among nutrient loading and nutrient
removal and assimilation rate by macroalgae Gp. tenuifrons when grown in
organic farming wastewater. Aspects related to algal physiology, such as
pigment composition, photosynthetic rate and growth were evaluated in the
laboratory. Finally, in the chapter 4, the bioremediation potential and nitrogen
and phosphorus assimilation of G. Caudata, G. domingensis and U. lactuca
were estimated in outdoor. Evaluation of the integrated organic farming role is
also discussed. All these chapters give shape to this research and they may be
seen as important data for organic aquaculture.