The proper care and right knowledge is the key to reap maximum benefits from the fish farming in the summer season. These views were expressed by Meera D Ansal, College of Fisheries at Guru Angad Dev Veterinary and Animal Sciences University, Ludhiana.
She emphasised that farmers should provide sufficient comfortable zone to fish below the surface layer, “which gets heated up far beyond optimum temperature range (28-320C)”. “Maintain six feet water depth and to mitigate heating up of water, partial shading of pond with trees is also recommended,” she added.
“Oxygen is the most important issue to be addressed, which may fall to lethal levels, especially during dawn, due to the enhanced biological activity in the pond. Hence, aerate ponds during early hours of the day before sunrise either by adding fresh water or by aerators. High oxygen content will keep fish healthy and increase its food converting efficiency,” she said.
Meera said that farmers needed to check diurnal variation in water pH that might cross 9.5 during peak day and fall below 7.5 during night due to excessive growth of algal blooms in the pond.
“Algae also grow very fast during summers and nutrient enrichment leads to formation of algal blooms. The fertilisation of pond will be suspended in case water turns dark green, dark brown or greenish brown in colour and a green or brown or sometimes red coloured algal mat appears on the water surface,” she added.
“It is also important to sustain regular plankton, natural fish food, production in the pond and provide a nutritionally balanced supplementary diet. Keep the pond rich in plankton through mixed utilisation of organic manures and inorganic fertilisers. Suspend feeding in case fish come to the surface for gasping atmospheric air or some kind of disease is observed in the fish,” said Meera.