EVALUATION OF WATER HYACINTH (EICCHORNIA CRASSIPES (MART.) SOLMS) INFESTATION IN NIGERIAN COASTAL ENVIRONMENT: SOURCES, PREVALENCE AND MANAGEMENT.

Abstract

Globally, water hyacinth infestations are regarded as invasive weeds which tend to obstruct water channel causing considerable socio-economic concerns, decline in biodiversity and water quality. The study seeks to ascertain the quantified mass and impacts of water hyacinth infestation along three designated waterways within the Nigerian coastline; Majidun River (MR), Igbokoda water channel (IWC) and Imo River (IR) (October, 2020 – April, 2021). This project was undertaken by NIMASA, saddled with the responsibility to clear waterways for safety of navigation and prevention of marine pollution. Reconnaissance survey was carried out using ARGIS mapping to identify infested hotspots. Mechanical and manual methods were deployed for evacuation, collection, weighing and documenting the dislodged vegetation for adequate disposal. The quantified water hyacinth evacuated recorded a total of 2,298 bags with weight of 92,449 kg (w/w) across 15 hotspots at Majidum River. At Igbokoda water channel, a total of 1,625 bags with weight of 122,500 kg (w/w) across 11 hotspots, while at Imo River, Ikot Abasi a total of 1,458 bags with weight of 56,055 kg (w/w) across 6 identified hotspots. The percentage total weight of infested water hyacinth had 34.11%, 45.20%, 20.68% and with no significant differences (p>0.05) across MR, IWC and IR respectively. The successful removal of the infested aquatic weeds could be effectively managed through routinely monitoring of the Nigerian aquatic ecosystems protected from immense anthropogenic pressure of constant of nutrients enrichment that could further proliferate the growth of these infested weeds. Keywords: Water hyacinth infestation, Mechanical removal, Nigerian coastal environment.