This project can be roughly divided into two sections; the work of the School of Engineering and its handling of water, and the work of the Faculty of Fisheries and its handling of fish. I am involved in the water-aspect of this project.
Lake Victoria is utilized not only as a means of transportation, for fishery activities, and as a tourist destination, it is also used as a source of water to support life. Analysis of the water is also one aspect of this project. In this project, we focused on the toxins that are produced by phytoplankton, and installed a device on the lake shore for biodegrading those toxins so that they can be evaluated.
Also, we are thinking about how to purify wastewater that flows from homes into the Lake Victoria basin. By reusing domestic wastewater, lake water will be needed less frequently and can help decrease household burdens.
I am involved in research of the fishing grounds and the catch hauls of Lake Victoria. I am also working on a recipe for Kenyan-style boiled fish paste from fish caught in the lake.
We are experimenting with using Nile perch and tilapia purchased directly from local fisherman to make Kenyan-style boiled fish paste. This effort is being done with the purpose of spreading a more fish-based diet throughout Kenya and providing a more protein-rich food source. We also hope that this will result in the improvement of local economies.
The people of Kenya typically cook their meat and fish until it is well-done and tend to prefer their food to be particularly hard or tough. Thus, to make the traditional Japanese dish more appealing to Kenyans, we are experimenting with making the boiled fish past with different flavors, saltiness, and texture.
Aquaculture is not a new word for Kenyans. They knew that tilapia and catfish can be cultured in captivity, and in fact, intensive aquaculture of tilapia is practiced in many parts of the country. However, if someone is talking about Nile perch aquaculture, people will be asking you “Is it possible?” Fishermen and aquaculturists thought that Nile perch is a very sensitive fish, thus, taking them out of the water will kill them. But then, we are here to teach them that like other fishes, Nile perch can also be cultured in fishpond. We collected fingerlings (around 2-5cm total length) from the lake, transport them alive using an oxygenated plastic bags and culture them in fishpond. At present, we have Nile perch in fishpond at KMFRI, Kegati station where we co-culture with tilapia. Small tilapia produced by these tilapia served as food for Nile perch. We are also monitoring if Nile perch will mature in fishpond so that we can induce them with hormones to spawn, and later on produce larvae which will serve as seeds/fingerlings for fishpond culture.
So why are we promoting Nile perch aquaculture? Nile perch is the main export fish product of Kenya, and if we can culture them in captivity, Kenyans will not depend too much on the lake for the supply. Because of its demand for export, Nile perch command higher price in domestic market. If Nile perch can be cultured in fishpond intensively just like tilapia, Kenyans will have more choices of affordable and delicious fish in the market.
In addition, we also tried to culture in captivity two endangered carp species of Lake Victoria: the “Ningu” or Labeo victorianus and Barbus altianalis. These carps are once favorites of Riparian community around Lake Victoria but due to over fishing and use of illegal fish traps, their population declined dramatically, and presently considered as endangered. Because of this, we aimed to produce “Ningu” and B. altianalis larvae in captivity so that we can re-stock the wild population as well as to promote its aquaculture. We sourced some brood stocks from the wild and induced them with hormone to spawn. At present, we produced thousands of “Ningu” larvae at the hatchery. We are testing several indigenous feed growing in the fishpond as feed for the larvae and locally available materials to formulate diet for the grow-out culture. In this way, we could promote cheaper feeds to aquaculturists who are interested to culture “Ningu”. We hope that we can produce enough and suitable fingerlings for re-stocking the wild stock as well as to provide culturists who wanted to culture “Ningu” in their fishponds. These two carp species can also a good choice in Kenyan restaurants because of their good taste.