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

Water hyacinth, Eichhornia crassipes (Martius) Solms- Laubach, is fast growing aquatic free floating fresh water plant indigenous to Brazil, Amazon basin and Ecuador region [1]. It was introduced as an ornamental species to adorn the water bodies in many countries more than a century ago for their attractive blue or purple flowers, oblong to oval glossy leaves with bulbous petioles. Later, this supposed-to-be prized plant was discovered to be an invasive species and posed serious socioeconomic and environmental problems affecting millions of people in riparian communities [2]. The sturdy plant has emerged as a major weed interfering with anthropogenic activities and is recognized as one of the top 10 worst weeds in the world [3].

 In Ethiopia, water hyacinth was first reported in Lake Koka in 1956, the Awash River and since then, it has been found in different regions of Ethiopia. It is considered as a constraint to the development of the country [4] which has multifaceted problems such as obstructing electricity generation, irrigation, navigation, and fishing; increasing evapo-transpiration resulting in water loss, increase cost of crop production, providing habitat for vectors of malaria and bilharzias, harbors poisonous snakes, causing skin rashes, and hosting agents of amoebic dysentery and typhoid [4, 5] [5] and these effects have also been documented elsewhere in the world [2, 3]. The weed has infested water bodies in the two intervention districts (Lume and Bora) of the Livestock and Irrigation Value Chain for Ethiopian smallholders (LIVES) project in east Shoa zone of Oromia Region and with connection to the Awash River includes Koka Dam, lakes Ellen and Elletoke. 

Local farmers in Bora district grow a number of crops for home consumption and sale mainly maize, wheat, haricot bean and tef (Eragrostis tef) while vegetable production (tomato, onion and others) is practiced along the shores of the lakes, mainly by private investors. Koka reservoir and lakes Ellen and Elletoke are the main water bodies in the district and are mainly used for irrigation and fishery. Koka dam is also used for recreation while the primary purpose is for hydro-electric power generation. Koka dam and the Awash River are also found in Lume district and their use is similar to that in Bora. Similar to Bora, the livelihood of farmers in Lume is based mainly on crop production which is followed by livestock production in the form of cattle, sheep, goats, chickens, and equines although the intensity of cropping is more in Lume than in Bora district. 

The economic importance of these water bodies in the study districts for many families and nationally is significant [4]. However, the extent of land covered, the spatial and temporal cover changes of water hyacinth and associated land covers/uses is not documented although there is a growing global concern about land use/cover changes which emerged due to realization that changes of the land surface influences climate and impact on ecosystem goods and services [6]. Furthermore, despite the long history of this weed in the study districts and compared to complex and diverse nature of the problem, the interventions undertaken to control the weed particularly, in the open community field, does not much with its expansion which justifies the need to assess the possibility of applying community-based management (CBM).

 The objectives of this paper were to determine water hyacinth and associated land cover/use changes over the past three decades (1986 to 2015) along water hyacinth infested water bodies and capture perceptions regarding CBM, to enhance proper control/eradication of the weed in Lume and Bora districts.