Evaluación de las microalgas asociadas al cultivo de tilapia (Oreochromis sp.) en el sistema Biofloc.
Resumen
The Biofloc system has gained recognition in Central America for its effectiveness in
aquaculture production by promoting the growth of phytoplankton, thereby providing live
feed. However, research on microalgae in aquaculture ponds in Panamá is limited, making
this study highly potential for the country's development, particularly in a productive
region like Chiriquí. In this study, the growth of microalgae in two cultivation systems,
Biofloc and traditional, using Oreochromis sp., was compared. Through the Mann
Whitney U statistical test with a significance level of 5 %, significant differences were
confirmed, showing greater development in the Biofloc system, especially in Scenedesmus
spp. (U = 37.5, Z = 3.1976, p = 0.0014) and Chlorella spp. (U = 20, Z = 3.8168, p = 0.0001).
Although no significant differences were found in the development of Nitzschia spp. (U =
94.5, Z = 0.8063, p = 0.4201) and Oscillatoria spp. (U = 91, Z = 0.8745, p = 0.3819),
differences were observed in the presence of Pediastrum spp. and Selenastrum spp., which
were exclusive to Biofloc. Additionally, Biofloc showed temperature stability, with an
average of 28.34 ± 0.01 °C, while the traditional system had a mean temperature of 27.52
± 0.01 °C. Dissolved oxygen levels were significantly higher in Biofloc (6.10 ± 0.64 mg/L)
compared to the traditional system (4.12 ± 0.13 mg/L). Regarding pH, the Biofloc system
recorded 6.46 ± 0.12, while the traditional system showed a pH of 6.91 ± 0.06. Concerning
luminance, no significant differences were observed between the two systems, with an
average of 694.4 ± 12.90 μmol∙m⁻² s⁻¹ for Biofloc and 713.9 ± 8.2 μmol∙m⁻² s⁻¹ for the
traditional system. However, the results highlight the importance of Biofloc in the growth of microalgae, environmental stability, and nutrient availability. Biofloc recorded a
maximum ammonia concentration of 1,910 mg/L, while the traditional system had 0.049
mg/L. Regarding nitrate, Biofloc maintained an average level of 31.61 ± 5.14 mg/L,
surpassing the traditional system, which recorded 2.81 ± 0.99 mg/L. During the maturation
process, the chemical oxygen demand (COD) significantly decreased in the Biofloc
system, dropping from 491 ± 3.54 mg/L to 106 ± 2.83 mg/L over 13 days, while in the
traditional system, the COD reduction was from 1 ± 0.00 mg/L to 0 ± 0.00 mg/L in the
same period. However, after the fry were stocked, the oxygen demand in the Biofloc system
increased significantly, reaching a maximum peak of 674 ± 73.54 mg/L, compared to the
traditional system, which recorded a maximum peak of 96 ± 0.00 mg/L. This study
evidences the Biofloc system's capacity to sustain aquatic life at various stages of
cultivation.