Water HyacinthEichhornia crassipes(Mart.) Solms-Laubach Dynamics and Succession in the Nyanza Gulf of Lake Victoria (East Africa): Implications for Water Quality and Biodiversity Conservation

Abstract

This study, conducted in Nyanza Gulf of Lake Victoria, assessed ecological succession and dynamic status of water hyacinth. Results show that water hyacinth is the genesis of macrophyte succession. On establishment, water hyacinth mats are first invaded by native emergent macrophytes, Ipomoea aquatica Forsk., and Enydra fluctuans Lour., during early stages of succession. This is followed by hippo grass Vossia cuspidata (Roxb.) Griff. in mid- and late stages whose population peaks during climax stages of succession with concomitant decrease in water hyacinth biomass. Hippo grass depends on water hyacinth for buoyancy, anchorage, and nutrients. The study concludes that macrophyte succession alters aquatic biodiversity and that, since water hyacinth infestation and attendant succession are a symptom of broader watershed management and pollution problems, aquatic macrophyte control should include reduction of nutrient loads and implementing multifaceted approach that incorporates biological agents, mechanical/manual control with utilization of harvested weed for cottage industry by local communities.

Invasion of Water Hyacinth (<i>Eichhornia crassipes</i>) Is Associated with Decline in Macrophyte Biodiversity in an Ethiopian Rift-Valley Lake—Abaya

“…This species had higher abundance in non-infested site-1 where there was no shading influence. It is understandable that submerged plants would be more prone to the effect of shading than emergent macrophytes [17]. Our current study confirmed this general notion: the abundance of emergent macrophytes was more than twice that of the submerged ones (Figure 3).…”

“…Arille [16] and [18] reported a similar species reduction when invasive species colonize wetlands. Also, Gichugi [17] and Shibu [5] showed, the former in Africa lake environment, that the invasion of water hyacinth and other related alien species affect the abundance and diversity of macrophytes resulting in largely monotypic floral community structure.…”

Current Trend of Water Hyacinth Expansion and Its Consequence on the Fisheries around North Eastern Part of Lake Tana, Ethiopia

“…Even though originally perceived as a practical problem for fishing and navigation, recent research indicates that aquatic weeds are now also considered a threat to biological diversity affecting fish fauna, plant diversity and other freshwater life and food chains Mitchel [21]. Moreover, Gichuki et al [25] reported that the weed forms thick mats over the infested water bodies causing obstruction to economic development activities and impacting negatively on the indigenous aquatic biodiversity.…”

Water hyacinth (Eichhornia crassipes (Mart.): Land use/land cover changes and community-based management in east Shoa zone, Ethiopia

“…The seeds are long-lived and can live up to 20 years [1]. While seeds may not be viable at all sites, water hyacinth commonly colonizes new areas through vegetative reproduction and propagation of horizontally growing stolons [13]. Studies have also shown that the weed favors water bodies with high-nutrient levels, such as those found downstream of agricultural or urban areas.…”