Impacts of Land Cover Changes on Catches of Nile Perch and Nile Tilapia on Lake Kyoga, Uganda

Abstract

In East Africa, Nile perch and Nile tilapia are major commercial fish species, providing reliable protein and income sources. However, their stocks are dwindling on Lake Kyoga due to land use and land cover (LULC) changes within the surrounding catchment. Thus, this paper aims at assessing the land use land cover on Lake Kyoga and its immediate catchment and how those changes affect the water quality and the local fish catches. The Iso-Cluster tool in ArcGIS was used to analyze Landsat images from the years 1989 to 2021 to obtain LULC information. The LULC classes were classified into water, wetland, agricultural land, rangeland, and settlements. Correction using a 2-tailed test of the water quality parameters with the LULC classes indicated a strong positive correlation of TN with water (0.71), a strong negative correlation of TP with rangelands (−0.83), and a strong positive correlation of Chl-a with settlement (0.98) at a 0.05 confidence level. The correlation of the recorded fish catch data with fishing gear showed a strong negative correlation with cast and monofilament nets. Continued use of illegal fishing gear was ranked number 1 of the causes of LULC by the stakeholders. Thus, the fisheries managers should collaborate with local stakeholders to boost declining fish catches for improved livelihoods and sustainable management.