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.
As bad as overstocking is, farmers can derive a great benefit from it under certain conditions. Massive stocking can be a blessing to those who have mastered the art and science of catfish management. In some situations, moderate stocking could lead to under utilization of pond resources or sometimes a bad season for catfish farmers. I have listed in this article times when you are permitted to overstock. You are permitted to overstock under the following conditions:
1. When your seed is too small in size and you are not sure of its survival rate, overstocking will not be a bad idea. Usually, during certain periods of the year, reasonable size of fingerlings/juveniles might not be available due to high demand or seasonal change in atmospheric condition. Even when they are available, farmers might not be sure of how many of them will survive as a result of unstable weather related to low or high temperature. To be on a safer side, farmers can increase the normal stock rate by 50 percent or more. This will save proactive farmers resources that would have been lost to space underutilization and unrealistic expectations. When next you aren’t sure of the number of fishes that will survive in your new stock due to sizes/poor grading, I recommend that you overstock. You are left with a good problem if they survive above expectation. Your challenges of massive survival rate can be solved by splitting part of the fishes to other ponds or you can sell part of your stock after some months and retain normal stocking capacity of the pond.
2. When you intend to sell earlier than usual, overstocking will help you to maximize the space utility and profit bench mark. There is a formula to use when you want to overstock in order to sell earlier. Ensure you know the ultimate capacity of your pond (e.g. 4 tons), number of month you want to sell (say 3 months) and expected size of average table size fish you want to produce based on strict reality (e.g.500 grams). Instead of waiting for 2000 pieces of juvenile to attain average weight of 2 kilogram each in six months in order to maximize the ultimate carriage capacity of your pond, a farmer can as well stock 8000 juvenile that will attain average weight of 500 grams to equal same tonnage in 3 months.
U = Ultimate carriage capacity of your Pond
E = Expected average weight achievable within projected months
N = Normal stock
3. When you intend to sell in batches and you can skillfully apply overstocking formula as compounded above, stocking above normal will not be counterproductive. This method fit farmers who produce and sell regularly to retailers/wholesalers (depending on farm capacity). Before you adopt this method, you must have existing buyers who patronize you regularly either weekly or monthly. Once you crop part of your stocks, spaces are created for leftover fishes to grow. Sales are repeated in this format till the whole stock is sold.
4. When you are sure of constant energy and water supply in a re-circulatory or flow through system, overstocking is permitted. This is due to the fact that you can actually double the stocking capacity of your pond with the use of any of these two systems. You can make judicious use of this raining season by planning to increase your stock as well as your water management skill. Professional catfish farmers increase their yield and production per pond with the use of this method.
5. Overstocking is allowed when you have plans to sort and spread your overstocked pond in later days. This method is recommended to farmers who use multiple ponds for their production. Stock your fishes in a protected pond and spread to other ponds at a later date. Regular practice of this method will help you to have better control on your pond and also allow you to use your pond facilities optimally without negative consequences. For those who enjoy stocking fry/fingerlings, this technique of overstocking is for you.
6. When you have unlimited time to feed as many times as possible, all conditions favorable (environment, feed and seed), stocking above normal is for you. Feeding many times a day will help you reduce cannibalism and improve growth potential in your stock.
7. When you intend to use floating feed throughout for your stock, you are encouraged to stock a bit higher than farmers who combine floating and sinking feed systematically.