Impacts Of Water Hyacith On The Fishing Industry At The Winam Gulf, Kisumu County

ABSTRACT

Fresh water bodies constitute a vital component of a wide variety of living environments as integral water resource base in many human societies in the world. Water hyacinth has invaded

Freshwater systems in over 50 countries on five continents and changes to its density have the potential to affect other ecological and human communities in areas where it is established either positively or negatively. The hyacinth, since its introduction in Kenya, has been a menace to the riparian communities, causing several problems. However, the range of problems with water hyacinth infestation is in general terms widely known, the real extent of the influence on the socioeconomic status and welfare of the people who depend on the affected water for fish. The study focused on the impacts of water hyacinth on the fishing industry at the Winam Gulf, Kisumu County, the study methodology was mainly GIS and Remote Sensing to show the spread and pattern of water hyacinth throughout the years from the year 2000 to 2010. The study also relied on secondary data to show the impacts of water hyacinth on the fishing industry. The study describes an approach based on the time-series of MODIS to derive the temporal behavior, the abundance and distribution of the floating macrophytes in the Winam Gulf (Kenyan portion of the Lake Victoria). To this end, the study consider the NDVI values computed from the MODIS imagery time-series from 2000 to 2009 to identify the floating macrophytes cover and an appropriate bio-optical model to retrieve, by means of an inverse procedure, the concentrations of chlorophyll a, colored dissolved organic matter and total suspended solid. The maps of the floating vegetation based on the NDVI values allow us to assess the spatial and temporal dynamics of the weeds with high time resolution. The studies finding was that the Area covered by water hyacinth at the Winam Gulf in the year 02/12/2000 was 531.99 Hectors and in 14/12/2010 the area was 37,000 Hectors. The study finding was also that fish production has drastically fallen and therefore income for those whose income generation activities revolve around fish production has fallen, during the pre- water hyacinth period (1986-1991), the weekly benefits from the fish production was KShs 68,000 and during the post-water hyacinth period (1992-2010), the weekly catch was reduced to KShs 53,820. Some fish processing plants have closed down and water transport operators are almost out of business due to Water hyacinth. The findings therefore suggest that the lifestyle of the people living near Lake Victoria and depend on it, in one way or another has changed considerably. On the basis of the findings, it is generally recommended that the government, NGO's and other interest groups should involve the local residents in both policy making and practical removal of the weed from the lake. It is also recommended that this be treated with urgency as the effects of the weed are growing with time.