etude de la gestion de l’eau et son influence sur les couleurs d’eaux et les parametres d’elevages dans les bassins de grossissement de penaeus monodon : cas de l’oso farming-lga ambilobe nord ouest de madagascar

Abstract

The appropriate of breeding shrimp is based on controlling the water quality of the ponds, such
as the physical, chemical and biological parameters of the water. The color of the water is a
good sign to recognize the corrective actions taken into. So, the water change was considered
as a relevant element to correct the values of these parameters to have targeted favorable
conditions for breeding shrimp. The objective of this study is to recognize the characteristics
and values of the physico-chemical parameters of water breeding shrimp at OSO Farming -
LGA Ambilobe according to its color and to correct these parameters in a target of good
breeding behavior.
The oxydo-reduction values of all ponds decreased when the loads were high. On the whole of
the mean weights of the herd (0 to 25g): The mean Redox for the green, dark and turbid pools
are respectively 125.27mV; 117.91mV; 120.86mV. The oxygen consumption of organisms in
a pond becomes more important while the loads increase.
The results show that all the correlation coefficient values between the Redox and the mean
weights (charge) of the herd in the ponds are negative. The density of phytoplankton and the
difference in the rate of oxygen sampled in the morning (AM) and in the afternoon (PM) in
green water and in dark water are strongly positive correlates, this is the case against for turbid
ponds. The load and the water change rate are strongly positive correlated with the 5% threshold
(α = 0.05) for green ponds (11.37%) and dark ponds (14.67%) (with r = 0.8 / green; r = 0.99 /
dark). Experience shows that green ponds are the most desirable ponds to look for because they
have a good ecosystem equilibrium.
Keywords: Aquaculture, Shrimp, Colors, Water change, LGA-Ambilobe