No abstract

Fish feed is one of the main constraints on the growth of aquaculture in Kenya. The lack of high-quality and competitively priced feeds means that the fish farmers are unable to expand their production. To ensure that aquaculture remains viable and sustainable, it is necessary to optimize production through the utilization of locally available feeding materials. Insect-based feeds are alternative least-cost feeding resource in fish production. Using alternative protein sources such as black soldier fly larvae (BSF) and daphnia meal in place of fishmeal (Omena and Dagaa) is an ingenious strategy for sustainable fish aquaculture. This study evaluated the effect of four treatments: BSF, daphnia, Omena from Lake Victoria and Dagaa from Lake Tanganyika on the fish pond environmental parameters and fish fries' performance (body weight and length). The experiment was carried out in a greenhouse with 30 fingerlings in each experimental unit. The feeding trials took 23 days. Results indicated that the four treatments have a varied effect on the BW and L of fish fries. A high growth rate was observed in Daphia, followed by BSF, Omena and Dagaa in that order. On the other hand, the treatments have varied effects on pond parameters with BSF promoting too much growth of algae. BSF have higher amounts of ammonia, nitrates and phosphorus, which stimulate the high growth of algae.

Aquifers are dug very deep in many areas. When they are near the sea or an island the sea water tends to seep to the aquifers. This ultimately leads the aquifers to be salty and hence they don't achieve the objective of providing fresh water to the community. This study was conducted in 2020 with a name of coming up with preventive measures of the sea water seepage to the aquifers. This paper is only a review paper of how far the impact can be felt as the data is being analyzed.

This research carried out in Mombasa Island links research done in 2020 on the effects of sea-water intrusion and the current state. The aquifer in Mombasa Island is semi-confined and consists of limestone and coral rock. Water samples were collected and tested from 32 boreholes to determine chemical qualities. Results showed that chloride levels ranged from 74 mg/l to 412 mg/l, with 34% of boreholes having high chloride concentration. After modelling using MT3D program results indicated that the boreholes near the ocean were interfered by sea-water intrusion because chloride concentration was high. Control measures to prevent further sea-water intrusion should be put in place. Therefore, from a practical point of view, individuals who have sunk boreholes since 2020 try to mitigate the problem by installing Reverse Osmosis systems within their facilities, to reduce chloride levels from borehole water. The current research analyses the impact of intrusion on the installed RO systems on Mombasa Island, including cost implications, with the view of proposing viable mitigation measures. The reverse osmosis system though expensive would save a lot of chloride entering the bore holes. It is a little bit expensive though but the end results are positive and the chloride levels will reduce the cost of using too much soap.