Bioremediation that helps to relieve challenging pond conditions in shrimp and fish farming is a promising technology.
Intensive shrimp and fish farming produce large amounts of organic wastes. Much of these organic waste materials accumulate in the pond bottom and cannot be utilized by phytoplankton. Oxidation of these organic waste compounds depletes the level of dissolved oxygen deep in pond's soils, and encourages the formation of toxic metabolites such as hydrogen sulfide, ammonia, and nitrite. Such conditions increase the mortality rates in aquaculture farming.
A common procedure used to improve water quality – and therefore the immediate environment of fish and shrimp - is the direct application of beneficial bacteria, probiotics and biodegrading microorganisms to ponds. This form of biotechnology, also known as “bioremediation”, involves the manipulation of microorganisms in ponds to reduce pathogenic bacteria, enhanced mineralization of organic matter, and removal of undesirable waste compounds.
The controlled addition of beneficial bacteria directly or indirectly alters the composition of the microbial community in the rearing environment. These microorganisms also colonize the shrimp and fish gut, preventing intestinal diseases and improving animal health and performance. Their positive microbial activities include the competitive exclusion of pathogenic bacteria in the gut and water, production of bactericidal substances as well as degradation of uneaten feed, organic waste products, and the elimination of toxic substances and organic odors.
Ammonia or nitrite removal processes are important for pond water quality and can be carried out through the addition of chemotrophic denitrifying bacteria such as Thiobacillus and Paracoccus. The specialized biodegrading Paracoccus interrupt the nitrogen cycle by using nitrates and other oxidized nitrogen compounds instead of oxygen, drastically reducing the amounts of nitrogen compounds.
Inorganic oxidation-reduction reactions produce the energy source of autotrophic Thiobacillus with elements such as hydrogen or different reduced-sulfur compounds. This allows the removal of two contaminants (such as H2S and NO3-) in a single step, converting them into environmentally favorable compounds (SO42- and N2).
The addition of specific enzymes (proteases, amylases, cellulases, xylanases) can promote the pre-digestion of certain complex nutrients and facilitate the release of highly digestible nutrients. As a result, this reduces sludge accumulation and anaerobic conditions in the pond´s bottom.
AquaStar® Pond and AquaStar® PondZyme, the bioremediation products of the AquaStar® product line, help with water quality management in aquaculture by reducing undesirable waste compounds as well as accumulated sludge and pathogenic bacteria. The active strains of AquaStar® are well suited to the aquatic environment, as these strains occur naturally in the pond.
The combined application of AquaStar® offers a safe form of preventive treatment that stabilizes water quality through bioremediation. In addition, it also improves the gut health of fish and shrimp, thereby improving performance and efficiency in production.