This presentation looks at water hyacinth with respect to Lake victoria. It explores the biological classification, the origin, factors for its flourishing and its detrimental effects. It further explores the various control measures and the economic uses of this floating water weed.

1. LAKE VICTORIA
Confronting The Water Hyacinth
ROBERT BOB OKELLO

2. 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

3. 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

4. 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

5. What is Water Hyacinth?
Classification
Kingdom: Plantae
(Unclassified): Angiosperms
(Unclassified): Monocots
(Unclassified): Commelinids
Order: Commelinales
Family: Pontederiaceae
Genus: Eichhornia
Species: E. crassipes

6. 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

7. 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

8. 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

9. Control Measures
1. Chemical Control
• Herbicides are used
• Expensive on large scale
• Have detrimental effects
on the environment
• Health related issues

10. Control Measures
2. Physical Control
• Land based machines
(bucket cranes, drag
lines/boorm)
• Aquatic based machinery
(aquatic weed harvester,
dredges, vegetation
shredder)

11. Control Measures
3. Biological Control
• Use of water hyacinth eating
pests/insects
• Neochetina eichhorniae (mottled
water hyacinth weevil)
• Megamelus scutellaris (USD’s
Agricultural research)

12. 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

13. 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