Abstract Lake Tana is the most important freshwater lake in Ethiopia. Besides pressures on water quality resulting from urbanization and deforestation, the invasion of the exotic water hyacinth (Eichhornia crassipes) poses new threats to the ecosystem. Water hyacinth, endemic to South America, is widely considered as the world’s worst aquatic invasive weed. In 2011, the weed appeared on the northern shores of Lake Tana, expanding in south-eastern direction. The lake area affected by water hyacinth was last estimated in 2015 at 34,500 ha, which equals 16% of the total lake surface. In this research, the benefits of water hyacinth control and eradication for the rural population inhabiting the northern and north-eastern villages bordering Lake Tana, are investigated. In the area, the population largely depends on farming and fishing. An assessment of the total economic benefit of eradication was conducted. The stakeholder-centered approach led to measuring the willingness to contribute in labor and cash terms. Results showed smallholders in the study are willing to contribute over half-a-million euros annually. Costs of management actions can be weighed to the benefits, where further research is needed on the impact on other stakeholder groups. Moreover, wetland management should advance to explore multiple pathways in an integrated approach: water hyacinth control, water hyacinth utilization and sustainable waste water management.

中文翻译：

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农民对水葫芦控制的偏好：条件评估研究

摘要 塔纳湖是埃塞俄比亚最重要的淡水湖。除了城市化和森林砍伐对水质造成压力外，外来水葫芦（Eichhornia crassipes）的入侵也对生态系统构成了新的威胁。水葫芦是南美洲特有的，被广泛认为是世界上最严重的水生入侵杂草。2011年，该杂草出现在塔纳湖北岸，向东南方向扩展。受水葫芦影响的湖泊面积上一次估计是在 2015 年，为 34,500 公顷，占湖面总面积的 16%。在这项研究中，调查了控制和根除水葫芦对居住在与塔纳湖接壤的北部和东北部村庄的农村人口的好处。在该地区，人口主要依靠农业和渔业。对根除的总经济效益进行了评估。以利益相关者为中心的方法导致衡量在劳动力和现金方面做出贡献的意愿。结果显示，研究中的小农愿意每年贡献超过 50 万欧元。管理行动的成本可以权衡收益，需要进一步研究对其他利益相关者群体的影响。此外，湿地管理应推进以综合方法探索多种途径：水葫芦控制、水葫芦利用和可持续废水管理。结果显示，研究中的小农愿意每年贡献超过 50 万欧元。管理行动的成本可以权衡收益，需要进一步研究对其他利益相关者群体的影响。此外，湿地管理应推进以综合方法探索多种途径：水葫芦控制、水葫芦利用和可持续废水管理。结果显示，研究中的小农愿意每年贡献超过 50 万欧元。管理行动的成本可以权衡收益，需要进一步研究对其他利益相关者群体的影响。此外，湿地管理应推进以综合方法探索多种途径：水葫芦控制、水葫芦利用和可持续废水管理。