Evaluation of sodium chloride (NaCl) effects on water hyacinth Eichhornia crassipes development : Preliminary results

Abstract

Ability of water hyacinth to live in different basins (lakes and lagoons) tropical regions makes this species an adventitious by excellence. Its high multiplication capacity poses enormous problems to the fisheries sector due to the dense carpet that it forms on the surface of the water thus preventing navigation, the penetration of light, the dissolution of oxygen and causing death of some aquatic organisms. This plant strictly subject to freshwater is considered as aquatic species among the most harmful in the world because of its excellent reproductive power. Salinity generally limited its development in coastal and estuarine areas. The present study examines the development of water hyacinth subjected to a salinity gradient. Experiments were conducted in buckets of 15 L plastic at the rate of ten (10) treatments including one (01) control, repeated four times.The salinity gradient consisted of ten levels : 0 g/L, 5 g/L, 9 g/L, 13 g/L, 15 g/L, 18 g/L, 21 g/L, 24 g/L, 27 g/L and 30 g/L. The results of these studies showed, firstly, that for the direct supply of salt in the Middle, water hyacinth can’t survive at a salinity of the environment greater than or equal to 9 g/L. On the other hand, the effective salinity for transfoliaire spraying of Eichhornia crassipes is 24 g/l.