Water Hyacinth Fact Sheet

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Water Hyacinth Fact Sheet Powered By Docstoc
					         Water hyacinths are Native to Central and             seek new habitat areas, leaving fish such as catfish,
South American but were brought into the United                carp and gar, all of which can tolerate lower
States for the Cotton States Exposition held in New            oxygen levels than the more desirable fish. Once
Orleans in 1884. Because of their beauty, they were            oxygen levels become so low that even these less
given as gifts for visiting the Japanese Pavilion at the       desirable fish cannot survive, the waters below
expo. Attendees took them home to add to backyard              water hyacinth masses become devoid of most life.
ponds. By 1900, water hyacinths had escaped
cultivation and had become a serious pest, clogging                Humans are also affected by the invasive
waterways throughout the coastal states.                       overgrowth of water hyacinths. Dense mats of the
                                                               plants interfere with boat navigation, clog drainage
        Water hyacinth’s success in its new habitats           systems, and prevent fishing, swimming and other
within the United States can be traced to number               recreational activities.
characteristics:
                                                               EFFORTS TO CONTROL WATER
       Water hyacinths reproduce very effectively by          HYACINTH POPULATIONS HAVE MET
        two vegetative methods. They can make new              WITH MIXED RESULTS
        plants by the process of fragmentation, or
        breaking into smaller pieces. Fragmentation                   Mechanical methods used to chop up the
        can be caused by the churning propellers of                    water hyacinth cannot reach all the water
        motor boats, the thrashing of swimming                         hyacinth in a given water body and result
        animals, grazing by animals and by being                       in fragmentation – one of water hyacinth’s
        tossed around by wave action during storms.                    reproductive strategies.
        They can also reproduce by forming plantlets                  Herbicides are very effective in killing
        at the end of a shoot that grows from the base                 water hyacinth plants. Spray programs are
        of the stems. This method of reproduction is                   costly and in many cases are only used on
        very effective at making many new plantlets in                 waterways necessary for navigation or
        a relatively short time.                                       heavily used in recreation.
       Water hyacinth stems are spongy and filled                    The use of natural predators, in particular a
        with air spaces, which allow them to stay                      weevil species from Argentina and a carp
        afloat easily.                                                 species from the Soviet Union, both of
       Water hyacinth leaves are fanlike and slightly                 which use the water hyacinth as a food
        cupped. This shape makes a very effective sail                 source, would mean introducing other
        and allows the plants to spread easily over                    exotics species that may, in time, become
        water bodies when the wind blows.                              as serious a pest as water hyacinth has
       Water hyacinths have a feathery network of                     become.
        roots, which allow them to gather nutrients
        very easily from the water.                                    When growing out of control, water
                                                           hyacinths are a nuisance, but some researchers have
    All these characteristics give the water hyacinth a    suggested uses for this exotic that would make it a
    tremendous advantage over other native floating        harvestable resource.
    aquatic plants. A small number of plants are able to                     Use as food for cattle.
    cover the surface of their new aquatic habitat in a                      Use as fertilizer and soil
    relatively short period of time. Today, water                               conditioner.
    hyacinths are found in 13 states within the United                       Produce a biogas fuel similar to
    States and in 53 countries.                                                 natural gas to meet some energy
                                                                                needs.
        The effects of water hyacinths on natural                            Use the plants as part of a
    systems in which they are not native can be                                 filtration system for water
    devastating. As hyacinths cover the water’s                                 purification systems.
    surface, they restrict life-sustaining sunlight that
    submerged native plants need in order to grow.                 Even though these are all possible uses, so far
    Eventually the shaded underwater plants die and        the negative impact of the aquatic plants on their
    decay. They decaying process depletes the amount       adopted habitat far outweighs their contributions to the
    of dissolved oxygen in the water. As the oxygen        environment.
    level declines, fish such as bass, perch, and bream,

				
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