Experimental research on intensive aquaculture systems established in closed ponds

The global need for food is increasing every year, yet aquaculture production in most countries has stagnated or increased relatively slowly in the last decade. The primary goal is to increase annual production using sustainable aquaculture, delivering many social, economic, and environmental long-term benefits. Closed fish farming systems are attractive solutions for intensive production, because they can provide favourable development conditions and allow a strong input and output control, avoiding damaging the ecosystems and wild populations. The current study includes a series of experimental investigations related to intensive growth of cyprinids in polyculture system, employing various renewable energy sources in order to provide the daily energy requirement. The research was carried in a high-capacity impermeable concrete pond, covered with a presocratic PVC membrane, equipped with an automatic system for regulating oxygen and food. The energy independence of the fish pool is ensured by a hybrid photovoltaic-wind turbine-diesel system, which helps the optimal growth of fish by maintaining a high-quality of water. Water quality characteristics must be accurate and reliable evaluated in order to ensure a successful and sustainable aquaculture business, using environmentally friendly methods. Without a comprehensive understanding of growth circumstances, fish health may suffer, and incorrect feeding practices may be employed, resulting in unsatisfactory output levels, high input costs, water contamination, and even diseases. The composition of the water from the fishing pond (dissolved oxygen, pH, turbidity, EC, salts, dissolved solids, nitrates, and so on) had been determined weekly during the tests carried out over a one-year growth cycle. At the same time, the health and development of the fish material were being monitored. Our aim was to analyse different nutrition recipes in order to increase productivity in intensive aquaculture systems. The proposed diet showed very good results, especially for the growth of Cyprinus carpio Linnaeus. Due to the pond covering system, which better preserves the interior heat and provides a more pronounced thermal inertia, all fish species have seen constant growth, even throughout the colder months.