Question

Aquaculture (fish farming) shows great potential in the Zomba district of Malawi, Africa. Scientists designed an experiment to study the effect of pond structure, like those shown to the right, on fish growth.
The researchers added one of three species of Tilapia shown below to ponds of varying size and depth. The ponds were fertilized with chicken manure and the fish were fed a supplement of corn bran. The average weight of fish in the ponds were measured monthly for a total of six months.


What is different about the two ponds?

Answer 1

They differ in their size/depth (i.e., volume and surface area). One pond is larger and deeper, the other is smaller and shallower — which changes water volume, temperature regime, oxygen levels and nutrient distribution and thus can affect fish growth.