Assess the impact of Macrophytes on fisheries, a case study of Lake Victoria, Uganda.

Abstract

A macrophyte is an emergent, submergent, or floating aquatic plant that grows in or near water. Water hyacinth, an invasive aquatic macrophyte also known as Eichhornia crassipes is the most well-known of these invasive weeds. Water hyacinth is thought to have reached Lake Victoria around 1990 via the Kagera River, which drains the Rwanda and Burundi water catchments. Monitoring of water bodies is necessary for estimating the size of a water hyacinth infestation and providing data for management and control strategies. Water hyacinth infestation monitoring has traditionally relied on time-consuming and labor-intensive field surveys with limited spatial coverage. This limits the amount of data that could be gathered, resulting in a lack of understanding of the factors that influence the emergence and spread of water hyacinth in different parts of the world. The increasing availability of open satellite data sources over the last decade has opened up new possibilities for low-cost, large-scale monitoring of water bodies. This research therefore sought to access the impact of macrophytes on the fishing activities carried out on Lake Victoria. Using Sentinel-2 MSI image data for 12 months ranging from Sept 2021 to August 2022. It was found that Water hyacinth is prominent in the wet seasons of September, October, November, March, April and May. However, eutrophication is popular through the year but for these nutrients to support water hyacinth, rainfall is needed. Water hyacinth is seen to suppress other macrophytes cyanobacteria inclusive.