Effects of fertilization frequencies and probiotic supplement on development of wild microalgae

Abstract

This experiment was conducted to determine the effect of fertilization frequencies and probiotic supplement on development of wild algae to feed Artemia. The experiment was carried out in the Artemia farm at Vinh Chau – Soc Trang province, using 9 ponds and each pond 150m2 and 0.4m deep was set-up the experiment. The experiment consisted of 2 experiments with 4 treatments for each: determination of appropriate fertilization frequency on the optimal growth of algae and effect of supplement probiotic in fertilization pond on the growth of microalgae. The results after 15 days in experiment 1 showed that at treatment 4 (F1day) with the ratio N:P = 40:1 and fertilized every day gave the highest algae density throughout the experiment (286±10.4c) and was significant with other experiments. And treatment 1 (using commercial probiotics) in experiment 2 gave the highest microalgae density, this can prove that probiotic can really help in increasing the density of algae and control the environmental conditions compared to experiment 1. The dominant algae species were Nannochloropsis sp (green algae), and Chaetoceros sp (diatom), which are edible for Artemia also increase during the culture period and grow stronger. In brief, the growth of wild algae in natural sea waters in Vinh Chau coastal area is not only dependent on fertilizer frequencies and probiotic supplement but also on the interaction with dominant algae species.