Control of water hyacinth: a short review.
Water hyacinth (Eichhornia crassipes) is an aquatic weed native from South America that invades waterbodies of tropical and sub-tropical sites worldwide. Mechanical, chemical and biological efforts are been used to control water hyacinth. Each method of control shows advantages and disadvantages. There are no water-use restrictions associated with mechanical control and it does not require much technical expertise, especially when plants are removed from the waterbody. However, changes in dissolved oxygen and trophic structure can accelerates eutrophication when plants are cut, leading to a subsequent increase in water hyacinth blooms. Chemical control is less labor intensive and expensive than mechanical control, especially at large scales. However, herbicides can kill non-target algae and non-target macrophytes, resulting in far reaching ecological impacts. Biological control is an alternative to mechanical and chemical control. It is not labor or equipment intensive, and has the potential to be self-sustaining. However, host specificity is critical to the success of biological control and the and long-term results can discourage one to use this method. Probably, biological control is the most efficient and safety method for water hyacinth management, especially for long-term results. Mechanical and chemical control are effective for short-term results, but they can seriously impact on ecological conditions of waterbodies.