2.6 Habitat

Water hyacinth rapidly colonizes still or slow-moving water, resulting in thick extensive mats. It occurs in estuarine habitats, lakes, urban areas, water courses, and wetlands (Gopal, 1987). It prefers nutrient-enriched waters and can tolerate considerable variation in nutrients, temperature, pH levels, and toxic substances (Gopal, 1987). Growth occurs in a wide range of temperature from 1 to 40°C but is most favorable under warm conditions with a maximum growth at 25 to 27.5°C (Wilson et al., 2005). Plants tolerate acidity levels as low as pH 3 (DiTomaso & Healy, 2003) but optimum pH for growth is 6 to 8 (Wilson et al., 2005). However, WH does not tolerate salinity above 1.6% (DiTomaso & Healy, 2003) and there is no evidence to indicate that this fresh water plant can adjust to saline water (Penfound & Earle, 1948).