Controlling Water Hyacinth in Lake Tana Using Biological Method at Green House and Pond Level

ABSTRACTWater hyacinth (Eichhornia crassipes) is one of the most dangerous aquatic weeds for Lake Tana and other water body in Ethiopia. To reduce its invasion biological, chemical and physical control methods can be used. Use of natural biological enemies of the weed to discourage its propagation is one of the best recommended options by scientfic society. Among them, there are more fungi naturally a pathogen for water hyacinth and other plants. To use those patogenes to manage water hyacinth infestation in Lake Tana infected plant material by fungi were collected from three weredas (Amba Gyorgese, Dabat and Debarke) around Gondar at 20 Peasant associations (PAs) since Novmber 2015. The collection was done from infected Faba bean leaves and roots. All isolated fungus was attempted to infect the collected healthy water hyacinth in laboratory and green house. Among isolated fungus species Rhizoctonia solani, Aspergillus flatus, Tricothcium roseum, Fusarium spp and Aspergillus niger fungi show high moderate disease severity on the healthy water hyacinth at temporarey green house and laboratory. Disease severity scale was recorded using modified NAHEMA et al. (200). By following those experiments to show its efficiency, the effective pathogens on laboratory and green house were released to 16 m2 open ponds since September 2016, in University of Gondar. In this study, we have recorded scientific data that shows the fungi were high potencial to attack healthy water hyacinth at above 26 oc and at less than 25 % humidity. From this research also we have observed the most infected water hyacinth by fungi have not produced flower and it can not re generate by seed in the next propagation sesaon.Finally, before directly release the fungi on Lake Tana its impacts were studied in the Goregora, at Kuame Michel kebela for a year in open ponds and in controlled wet land areas that not linked to the Lake by taking some common aquatic plants and fish from the Lake. Fortunatelly, those fungi have not impact on aquatic plant like Echinochloa and Cyperus papyrus grass, water quality and fish.

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Dynamics of Eutrophication and Its Linkage to Water Hyacinth on Lake Tana, Upper Blue Nile, Ethiopia: Understanding Land-Lake Interaction and Process

Lecture Notes of the Institute for Computer Sciences, Social Informatics and Telecommunications Engineering - Advances of Science and Technology ◽

10.1007/978-3-030-43690-2_15 ◽

2020 ◽

pp. 228-241

Author(s):

Minychl G. Dersseh ◽

Aron Ateka ◽

Fasikaw A. Zimale ◽

Abeyou W. Worqlul ◽

Mamaru A. Moges ◽

...

Keyword(s):

Water Hyacinth ◽

Lake Tana ◽

Blue Nile

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Potential of Water Hyacinth Infestation on Lake Tana, Ethiopia: A Prediction Using a GIS-Based Multi-Criteria Technique

Water ◽

10.3390/w11091921 ◽

2019 ◽

Vol 11 (9) ◽

pp. 1921 ◽

Cited By ~ 6

Author(s):

Dersseh ◽

Kibret ◽

Tilahun ◽

Worqlul ◽

Moges ◽

...

Keyword(s):

Water Hyacinth ◽

Geographical Information ◽

Lake Depth ◽

Invasive Weed ◽

Lake Tana ◽

The North ◽

Multi Criteria Evaluation ◽

The World ◽

Major Factors ◽

And Control

Water hyacinth is a well-known invasive weed in lakes across the world and harms the aquatic environment. Since 2011, the weed has invaded Lake Tana substantially posing a challenge to the ecosystem services of the lake. The major factors which affect the growth of the weed are phosphorus, nitrogen, temperature, pH, salinity, and lake depth. Understanding and investigating the hotspot areas is vital to predict the areas for proper planning of interventions. The main objective of this study is therefore to predict the hotspot areas of the water hyacinth over the surface of the lake using the geographical information system (GIS)-based multi-criteria evaluation (MCE) technique. The main parameters used in the multi-criteria analysis were total phosphorus (>0.08 mg L−1), total nitrogen (>1.1 mg L−1), temperature (<26.2 °C), pH (<8.6), salinity (<0.011%), and depth (<6 m). These parameters were collected from 143 sampling sites on the lake in August, December (2016), and March (2017). Fuzzy overlay spatial analysis was used to overlay the different parameters to obtain the final prediction map of water hyacinth infestation areas. The results indicated that 24,969 ha (8.1%), 21,568.7 ha (7.1%), and 24,036 ha (7.9%) of the lake are susceptible to invasion by the water hyacinth in August, December, and March, respectively. At the maximum historical lake level, 30,728.4 ha will be the potential susceptible area for water hyacinth growth and expansion at the end of the rainy season in August. According to the result of this study, the north and northeastern parts of the lake are highly susceptible for invasion. Hence, water hyacinth management and control plans shall mainly focus on the north and northeastern part of Lake Tana and upstream contributing watersheds.

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Water hyacinth: review of its impacts on hydrology and ecosystem services—Lessons for management of Lake Tana

Extreme Hydrology and Climate Variability ◽

10.1016/b978-0-12-815998-9.00019-1 ◽

2019 ◽

pp. 237-251 ◽

Cited By ~ 1

Author(s):

Minychl G. Dersseh ◽

Assefa M. Melesse ◽

Seifu A. Tilahun ◽

Mengiste Abate ◽

Dessalegn C. Dagnew

Keyword(s):

Ecosystem Services ◽

Water Hyacinth ◽

Lake Tana

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Determinants of manual control of water hyacinth expansion over the Lake Tana, Ethiopia

AFRREV STECH An International Journal of Science and Technology ◽

10.4314/stech.v8i1.1 ◽

2019 ◽

Vol 8 (1) ◽

pp. 1

Author(s):

M. Yitbarek ◽

M. Belay ◽

A. Bazezew

Keyword(s):

Water Hyacinth ◽

Manual Control ◽

Lake Tana

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Spatiotemporal Dynamics and Environmental Controlling Factors of the Lake Tana Water Hyacinth in Ethiopia

Remote Sensing ◽

10.3390/rs12172706 ◽

2020 ◽

Vol 12 (17) ◽

pp. 2706

Author(s):

Abeyou W. Worqlul ◽

Essayas K. Ayana ◽

Yihun T. Dile ◽

Mamaru A. Moges ◽

Minychl G. Dersseh ◽

...

Keyword(s):

Water Level ◽

Air Temperature ◽

Best Management Practices ◽

Water Hyacinth ◽

Lake Level ◽

Management Practices ◽

Satellite Image ◽

Spatiotemporal Dynamics ◽

Lake Tana ◽

Spatial Coverage

The largest freshwater lake in Ethiopia, Lake Tana, has faced ecological disaster due to water hyacinth (Eichhornia crassipes) infestation. The water hyacinth is a threat not only to the ecology but also to the socioeconomic development of the region and cultural value of the lake, which is registered as a UNESCO reserve. This study aims to map the spatiotemporal dynamics of the water hyacinth using high-resolution PlanetScope satellite images and assesses the major environmental variables that relate to the weed spatial coverage dynamics for the period August 2017 to July 2018. The plausible environmental factors studied affecting the weed dynamics include lake level, water and air temperature, and turbidity. Water temperature and turbidity were estimated from the moderate resolution imaging spectroradiometer (MODIS) satellite image and the water level was estimated using Jason-1 altimetry data while the air temperature was obtained from the nearby meteorological station at Bahir Dar station. The results indicated that water hyacinth coverage was increasing at a rate of 14 ha/day from August to November of 2017. On the other hand, the coverage reduced at a rate of 6 ha/day from December 2017 to June 2018. However, the length of shoreline infestation increased significantly from 4.3 km in August 2017 to 23.4 km in April 2018. Lake level and night-time water temperatures were strongly correlated with water hyacinth spatial coverage (p < 0.05). A drop in the lake water level resulted in a considerable reduction of the infested area, which is also related to decreasing nutrient levels in the water. The water hyacinth expansion dynamics could be altered by treating the nutrient-rich runoff with best management practices along the wetland and in the lake watershed landscape.

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