Lake victoria, Confronting The Water Hyacinth
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Transcript of Lake victoria, Confronting The Water Hyacinth
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LAKE VICTORIA
Confronting The Water Hyacinth
ROBERT BOB OKELLO
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Presentation Outline
• Location of L. Victoria
• What is the water hyacinth
• Origin w.r.t L. Victoria
• Factors for its bloom
• Ecological & Economic effects
• Control & Economic benefits
• Conclusion
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Location of L. Victoria
• East Africa (Uganda, Tanzania & Kenya)
• Area: 68,800 km²
• Elevation: 1,134 m
• Width: 250 km
• Largest tropical lake in the world
• World's 2nd largest freshwater lake by surface area
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What is Water Hyacinth?
• Botanically known as Eichhornia crassipes
• Free-floating perenial aquatic plant (Hydrophyte)
• Native to Amazon
• Highly Problematic & invasive outside native range
• Overall effects of the Water hyacinth are still unknown
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What is Water Hyacinth?
Classification
Kingdom: Plantae
(Unclassified): Angiosperms
(Unclassified): Monocots
(Unclassified): Commelinids
Order: Commelinales
Family: Pontederiaceae
Genus: Eichhornia
Species: E. crassipes
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How did it get to L. Victoria?
• Introduced in the region by the Belgian colonists to Rwanda
• In the 1980s
• To beautify their holdings
• This slowly advanced to lake Victoria by natural means
• Aid of the River Kagera
• First sighted in 1988
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Why Has it Flourished?
• Optimum growth temperatures (25o-30o)
• Optimum PH of 5.0 – 7.5 (L. Vic = Fresh)
• Optimal salinity (<15% of sea water)
• The plant produces numerous viable seeds
• Shallow shores in Uganda with muddy bottoms thus providing perfect growth conditions
• No competitors
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Detrimental Effects
• Invasion of fish breeding grounds• Aquatic habitat colonisation (80% of Uganda’s shoreline
infested)• Creates anoxic (total depletion of oxygen) conditions in the
lake• Creates breeding grounds for female anopheles mosquitoes
(malaria)• Fishing dificulties• Navigational challenges for water vessels
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Control Measures
1. Chemical Control• Herbicides are used• Expensive on large scale• Have detrimental effects
on the environment• Health related issues
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Control Measures
2. Physical Control• Land based machines
(bucket cranes, drag lines/boorm)
• Aquatic based machinery (aquatic weed harvester, dredges, vegetation shredder)
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Control Measures
3. Biological Control• Use of water hyacinth eating
pests/insects• Neochetina eichhorniae (mottled
water hyacinth weevil)• Megamelus scutellaris (USD’s
Agricultural research)
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Economic Uses
• Bioenergy (1 hec = 70metric tonnes of biogas. 1Kg = 730litres of biogas )
• Phytoremediation (Waste water treatment) – roots naturally absorb pollutants e.g. Lead, mercury
• Food source – it’s a carotene-rich vegetable• Also a source of animal feeds• Medicinal value (Tonic effect) – medicating
horse skin.• Source of organic fertiliser• For making Furniture, hand bags and ropes • Small scale paper production• Job opportunities
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References
http://sabahionline.com/en_GB/articles/hoa/articles/features/2013/09/27/feature-02
http://www.economist.com/node/110585
http://en.wikipedia.org/wiki/Eichhornia_crassipes
http://en.wikipedia.org/wiki/Water_hyacinth_in_Lake_Victoria
http://aciar.gov.au/files/node/2292/pr102chapter21.pdf
http://en.wikipedia.org/wiki/Lake_Victoria
http://en.wikipedia.org/wiki/Lake_Victoria#Water_hyacinth_invasion
http://www.businessdailyafrica.com/image/view/-/1308408/medRes/282736/-/maxw/600/-/8hjvc/-
/DnKisumuCounty1607xx.jpg