FAO Regional Office for Near East and North Africa

FAO organizes regional workshop on Water Hyacinth management and control in Al Nahr Al Kabir River


Tripoli, 27 June 2019 -

About 25 plant protection, bio-control and water management specialists from Syria and Lebanon participated in a workshop held by the Food and Agriculture Organization of the United Nations (FAO) in the cities of Tripoli and Al Abdeh in northern Lebanon to identify methods used to control water hyacinth, which has widely spread in the Wadi al Kabir River for years. The four-day workshop was held in cooperation with the Lebanese Ministry of Agriculture, the Lebanese Ministry of Energy and Water, and the Syrian Ministry of Agriculture and Agrarian Reform. The aim was to share Egypt’s successful experience in controlling the weed through biological means.

Representatives of the Lebanese and Syrian ministries discussed the danger of the spread of water hyacinth in streams and water bodies and the national efforts being made in both countries to control the spread of this harmful weed.

Dr. Thaer Yaseen, Plant Protection Officer at the FAO Near East and North Africa Office in Cairo, noted that water hyacinth endangers the livelihoods of many farmers and fishermen who depend on the Al Nahr Al Kabir River for their living. He said the wide and rapid growth of the weed blocked irrigation channels and pump pipes. The weed also causes the loss of huge amounts of water as a result of evaporation and erosion, disrupts river navigation, and hampers fishing operations. It also has a negative impact on aquatic organisms as it prevents sunlight from the reaching the river.

The FAO response came after the governments of Syria and Lebanon requested the UN agency’s help to manage water hyacinth and reduce its harmful effects. FAO brought in biological control experts to transfer the successful Egyptian experience in controlling the weed through biological agents.

Dr. Yahya Fayyad, a bio-control expert at the Plant Protection Research Institute, Egypt's Agricultural Research Center, explained that it is possible to control the weed using two types of weevils that feed on water hyacinth. He said Egypt brought the two types from the original home of water hyacinth in the Amazon River Basin in South America in the seventies and conducted many experiments to make sure the insects did not feed on any other plants.  Studies were also made on the lifecycles of those insects and their ability to control water hyacinth.

“Based on the results of those studies, a number of those insects were released in many water bodies in Egypt, such as the lakes of Mariout and Idku, between 2000 and 2009, and the results showed that the insects were able to reduce water hyacinth by 70- 95%,” he said.

In addition to theoretical lectures, the workshop included field visits to the sites in Nahr Al Kabir River basin on the Lebanese-Syrian border where the weed is spread to train the participants on ways to deal with the herb, evaluate its spread, and identify the different parts of the plant and ways to examine them to find the biological enemies.

The participants explained that mechanical control methods over the past years did not yield the desired results. The population in the river basin area increasingly complain about the damage that the weed causes to their livelihoods. Biological control specialists from the Syrian side reviewed successful experiments to eradicate the weed from some water bodies in Lattakia as well as the national plans to establish laboratories to produce biological enemies of the weed in Tartous Governorate. They also explained some initial experiments that were conducted by releasing biological enemies in Mahrada Dam (on the Orintos) in Hama Governorate.

Discussions continued during the four days of the workshop to come up with a joint action plan that would allow for effective measures to control the weed in Al Nahr Al Kabir. The most important points in the plan of action is the need to accelerate the establishment of centers for the production of pathogens in Tartous in Syria as well as centers for receiving and preserving these agents in the province of Akkar in northern Lebanon. The action plan also stressed the need to use modern remote and satellite imaging techniques to follow the weed and the impact of the biological control agents. It also encourages full coordination among the different ministries within and between countries so that control measures can succeed.

Water hyacinth is one of the most dangerous invasive plants in the world, as it was able to spread from its place of origin in South America to all other continents with the exception of The Arctic Ocean. The weed’s capacity to double its population in 10-12 days makes it the fastest growing plant on Earth. These plants absorb billions of cubic meters of water, resulting in water scarcity in many areas, and causing the death of aquatic organisms in rivers and lakes.

Many experiments have shown that these plants are of no use because they absorb toxic heavy metals, which in turn may be transmitted to animals feeding on them or even to the land in which they are buried. Moreover, the roots of the water hyacinth contain many intermediate hosts of parasites, such as snails that cause Schistosomiasis, and can be a breeding habitat for female mosquitoes. The larvae of mosquitoes then stick to the roots of the plant triggering the spread of mosquitoes and mosquito-borne diseases.

The beauty of water hyacinth flowers led to its introduction into Egypt during the reign of Mohammed Ali to decorate water bodies around the royal palaces, but the plant spread out of control causing a lot of problems until it was finally controlled after 2000 by means of planting certain species of weevil that were imported from South America, feeding exclusively on water hyacinth and thus destroying its capacity to reproduce and spread.

The participants in the workshop made recommendations to manage the harmful weed, and these were discussed with the concerned experts. At the end of the workshop, a joint program to control water hyacinth in Al Nahr Al Kabir River will be worked out.

The workshop also helped the participants develop control programs for a number of rivers infested with water hyacinth in Syria. The workshop also came up with important recommendations regarding the activation of laboratories to produce biological enemies in Tartus in Syria and the cooperation between the two countries on the use of these agents and on continuous monitoring of the weed in the river to remove it at an early stage before it covers the water body.