As said in one of my articles on this blog, overstocking is one of the most common reasons why catfish farmers fail. Overstocking could lead to unnecessary competition for food, oxygen, space, and other limited aquatic resources. Sometimes, overstocking could lead to rapid spread of infection. If infection is not well managed in an overstocked pond, high level of mortality will be recorded. Also, poor growth in catfish can also be caused by stocking more than pond capacity at a time.
A pond is overstocked when the carriage capacity of such a pond cannot support healthy growth of certain number of fishes for a period of time between stocking and maturity. Maturity mentioned here is a relative term. For instance, 3 months may be the maturity period for a fish that will be sold in dry fish market (average weight of 600 grams to 900 grams) whereas it could be up to 6 months for fishes that will be sold at Abuja market (average weight of 1kg to 2.5kg). A pond that carries a particular number of fishes successfully for 3 months might not be able to support the same number of fishes for 6 months. Therefore, the concept of overstocking is best explained by making reference to the ultimate carriage capacity of a pond.