In his official report of the expedition, Graham wrote that "The ngege or satu Tilapia esculenta, is the most important food fish of the lake, whether for native or non-native consumption.

It is convenient size for trade, travels well and is found in much greater numbers than other important fish, such as semutundu (Luganda), Bagrus sp.''.

[3] Furthermore, Graham noted that "The introduction of the European flax gill-net of 5 inch mesh has undoubtedly caused a diminution in the number of ngege in those parts of the Kavirondo Gulf, the northern shore of the lake, the Sesse Islands and Smith's Sound which are conveniently situated to markets".

[3] Oreochromis esculentus has been introduced into the Pangani River basin,[1] where it presents a threat to the native relative O.

[2] The ngege has declined precipitously in Lake Victoria due to early overfishing with the initial introduction of flax gill nets, followed by the introduced predatory Nile perch (Lates niloticus) and the highly competitive Nile tilapia (Oreochromis niloticus), with possible effects also attributable to the introduce Oreochromis leucostictus, Coptodon rendalli, and Coptodon zillii.