Water hyacinth grows and reproduces quickly, so it can cover large portions of ponds and lakes. It can easily coexist with other invasive plants and native plants in an area. Particularly vulnerable are bodies of water that have already been affected by human activities, such as artificial reservoirs or
eutrophied lakes that receive large amounts of nutrients. It outcompetes native aquatic plants, both floating and submerged. In 2011, Wu Fuqin et al. tracked the results of Yunnan Dianchi Lake and also showed that water hyacinth could affect the photosynthesis of phytoplankton, submerged plants, and algae by water environment quality and inhibit their growth. The decay process depletes dissolved
oxygen in the water, often killing fish.) and harmful pathogens, posing a potential threat to the health of local residents. It is very critical to monitor areas quickly that are infested in order to efficiently reduce or control the growth of these species. Water hyacinth can also provide a food source for goldfish, keep water clean, and help with oxygenation. Invertebrate species harboring with water hyacinth are dispersed as
phytochores. The invasion of water hyacinth also has socioeconomic consequences. Since water hyacinth is composed of up to 95% water, its
evapotranspiration rate is high. As such, small lakes that have been covered with the species can dry out and leave communities without adequate water or food supply. In some areas, dense mats of water hyacinth prevent the use of a waterway, leading to the loss of transportation (both human and cargo), as well as a loss of fishing possibilities. Large sums of money are allocated to the removal of water hyacinth from the water bodies as well as figuring out how to destroy the remains harvested. Harvesting water hyacinth mechanically requires considerable effort. A million tons of fresh biomass would require 75 trucks with a capacity of 40 m3, per day, for 365 days to get rid of it. The water hyacinth would then be transferred to a dumping site and allowed to decompose, which releases CO2,
methane, and nitrogen oxides. Water hyacinth has been widely introduced in North America, Europe, Asia, Australia, Africa, and
New Zealand. In many areas, it has become an important and pernicious
invasive species. In New Zealand, it is listed on the
National Pest Plant Accord, which prevents it from being propagated, distributed, or sold. In large water areas such as Louisiana, the
Kerala Backwaters in
India,
Tonlé Sap in
Cambodia, and
Lake Victoria, it has become a serious pest. The common water hyacinth has become an
invasive plant species on Lake Victoria in Africa after it was introduced into the area in the 1980s. A 1.22 Gb/8 chromosome reference genome was assembled to study
nuclear and
chloroplast genomes between 10 water hyacinth lines from 3 continents. Results indicate the spread of a limited genotype of water hyacinth from South America, where it has the highest genetic diversity. The paper proposes the spread potentially originating from ships travelling from
Itajaí Port on the Brazilian East Coast. Further, the genomic study also revealed the adaptation in four key pathways; plant-pathogen interaction, plant-hormone signal transduction, photosynthesis and abiotic stress tolerance, which provide water hyacinth to expand its niche and compete with other native flora.
United States Introduction into the U.S. Various accounts are given as to how the water hyacinth was introduced to the
United States. ; The claim that the water hyacinth was introduced to the U.S. in 1884 at the
World's Fair in New Orleans, also known as the
World Cotton Centennial, Canadian biologist
Spencer C. H. Barrett (2004) meanwhile favored the theory they were first cultivated in garden ponds, after which they multiplied and escaped to the environs. The account gains different details as told by children's story-teller
Carole Marsh (1992), who says "Japan gave away water hyacinth seeds" during the exposition, ''
Harper's Weekly'' magazine (1895) printed an anecdotal account stating that a certain man from New Orleans collected and brought home water hyacinths from Colombia, around 1892, and the plant proliferated in a matter of 2 years.
Infestation and control in the Southeast As the hyacinths multiply into mats, they may be detrimental to some species of fish, and choke waterways for boating and shipping. This effect was already observed in the state of Louisiana by the turn of the 20th century. accumulating an estimated plant mass of 50 kg/m2 and clogging
St. Johns River. In
1897 the government dispatched a task force of the
United States Army Corps of Engineers to solve the water hyacinth problem plaguing
Gulf states such as Florida and Louisiana. This herbicide was used until 1905, when it was substituted with a different,
white arsenic–based compound. An engineer charged with the spraying did not think the poison to be a matter of concern, stating that the crew of the spraying boat would routinely catch fish from their working areas and consume them. However, spraying had little hope of completely eradicating the water hyacinth, due to the vastness of escaped colonies and the inaccessibility of some of the infested areas, and the engineer suggested that some biological means of control may be needed. In 1910 the
New Foods Society suggested to import and release
hippopotamus from Africa into the rivers and bayous of Louisiana to eat the water hyacinth and solve another serious problem at the time, the American meat crisis. The invasion into Egypt is dated between 1879 and 1892 by
Brij Gopal. The plant (Afrikaans:
waterhiasint although earlier dates have been claimed. A waterbody extensively threatened by water hyacinth is the
Hartebeespoort Dam near
Brits in
North West Province. The plant was introduced by Belgian
colonists to
Rwanda to beautify their holdings. It then advanced by natural means to
Lake Victoria, where it was first sighted in 1988. There, without any natural enemies, it has become an ecological plague, suffocating the lake, diminishing the fish reservoir, and hurting the local economies. It impedes access to
Kisumu and other harbors. The water hyacinth has also appeared in
Ethiopia, where it was first reported in 1965 at the
Koka Reservoir and in the
Awash River, where the
Ethiopian Electric Light and Power Authority has managed to bring it under moderate control at considerable cost of human labor. Other infestations in Ethiopia include many bodies of water in the
Gambela Region, the
Blue Nile from Lake Tana into
Sudan, and Lake Ellen near
Alem Tena. By 2018, it has become a serious problem on Lake Tana in Ethiopia. The water hyacinth is also present on the Shire River in the
Liwonde National Park in Malawi.
Asia , Philippines due to
the eruption of Taal Volcano in the distance. The water hyacinth was introduced to
Bengal, because of its ornamental flowers and shapes of leaves, but became an invasive weed, draining oxygen from the water bodies and resulting in devastation of fish stocks. The water hyacinth was referred to as the "(beautiful) blue devil" in Bengal and "Bengal terror" elsewhere in India; it was called "German weed" (Bengali:
Germani pana) in
Bangladesh out of belief the German
Kaiser submarine mission Water hyacinths were called "Japanese trouble" in
Sri Lanka because there was a rumor that the British had planted them to entice Japanese aircraft to land on the insecure pads. The plant entered Japan in 1884 for horticultural appreciation, according to conventional wisdom, but a researcher devoted to the study of the plant has discovered that
ukiyo-e artist
Utagawa Kunisada (or Utagawa Toyokuni III, d.
1865) produced a wood-block print featuring the water hyacinth, goldfish, and
beautiful women, dated to 1855. The plant is floated on the water surface of filled (glassware) fishbowls The outbreak of water hyacinth has seriously affected the biodiversity of the local
ecosystem and threatened the production, life, and health of community residents.
Europe In 2016, the
European Union banned any sales of the water hyacinth in the EU. The species features on the
list of invasive alien species of Union concern. This means that not only the sales but also importation, cultivation, or intentional release into the environment are forbidden in the whole of the European Union.
Oceania In
Papua New Guinea, water hyacinth blocks sunlight to other aquatic organisms, creates habitat for malaria-carrying mosquitoes, clogs waterways to the point that boats cannot get through, and reduces the quality of water for purposes such as cooking, washing, and drinking. People have lost income or even died due to being unable to travel to get food or medical care, or due to diseases from contaminated water or mosquitoes. ==Control==