Jessore district in southwestern Bangladesh is an important source of fish seed in the country. However, hatcheries here have high mortality rates due the quality of the water being pumped from underground reserves.
Oxygen concentration in this water, which is used in brood and nursery ponds and incubation jars, is very low, while the levels of dissolved carbon dioxide are high. This is an unfavorable combination that leads to very low survival rates of hatchlings, even from the best quality eggs and resultant economic losses.
However, owners were unaware that their hatcheries faced this critical problem.
In 2011, WorldFish launched the Aquaculture for Income and Nutrition (AIN) project in the southern region of Bangladesh with the financial support of USAID. The focus of this project is to promote new technologies to address problems associated with aquaculture production and nutrition in the region. Specialists on the project identified poor water quality as the most crucial problem, among others, while assessing the baseline situation in the fish hatcheries.
"This technology has radically changed our fish seed production and profitability scenario."- Firroj Khan, President of Jessore Fish Hatchery Owners Association
The project supported installation of aeration towers to provide additional oxygen to the water. These towers are made of locally available materials and cost $USD300 a piece, which is easily affordable by the hatchery owners.
A simple technique is employed –water flows through four to six layers of perforated galvanized sheets before passing to incubation jars and nursing tanks. This simple process increases the oxygen level from 3 to 8 mg per liter. The increase in oxygen levels boosts hatching rates to 95 percent.
Firroj Khan, President of Jessore Fish Hatchery Owners Association, has championed the technology from the beginning of the project. “We have lived with this problem for more than 30 years without knowing such a simple solution exists. This technology has radically changed our fish seed production and profitability scenario,” he said.
Fish hatchery owners who adopted the technology have now doubled the amount of fish seed they produce by comparison with the pre-intervention period of the project