Up to about forty five years ago, clean water flowed in the Yarkon, suitable for fishing, swimming and recreation.
In it were many diverse submerged, floating and protruding aquatic plants. Between the 1950’s and 1980’s species unique to the Yarkon’s wet habitats disappeared, following the accelerated development of the river’s surroundings and drainage basin, and after the Yarkon Sources were streamed to the Negev from 1955 onwards, great changes began in the river’s natural ecosystems.
About 24 years ago, mapping work of the submerged, floating and protruding aquatic vegetation was carried out along the eastern section of the Yarkon, from the Rosh HaAyin springs to about 500 meters west of the Yarkon junction with Nahal Shilo it was found that certain species disappear completely, including common water crowfoot, Yarkon Reed, lakeshore bulrush, common duckweed, different pondweed, giant horsetail and more. The distribution of other species, which previously extended over long parts of the Yarkon, has been reduced to only its eastern sections.
The Yarkon River Authority has been leading the plan to rehabilitate the Yarkon along with many other organizations: the Nature and Parks Authority, the Botanical Gardens, the Institute for Nature Conservation Research at Tel Aviv University, the Society for the Protection of Nature and others. The rehabilitation plan included a remapping of the parts of the river that were mapped in the early 20th century, in order to try and track the changes that occured in the Yarkon’s vegetation in recent years.
It turns out that extreme changes occured in the composition of the species growing in the body of water. Of seven species of plants that once grew in the eastern part- blue waterlily, shore rush (Scirpus), ludwigia stolonifera, holly-leaved naiad, paper reed, london pondweed and yellow water lily- only the last two species remained. The population of the Yarkon reed, which was first collected from the banks of the Yarkon, has become extinct and can now be found along with other original populations from the Yarkon in the “Shelter Garden” in the Tel Aviv University Botanical Gardens.
As part of the plan for rehabilitating the Yarkon, periodically original plant populations cultivated in
“shelter gardens” are returned to their original habitat. In the eastern part of the Yarkon blue water lily, paper reed, scirpus and holly leaved naiad were replanted, and the River Authority monitors the rehabilitation of these habitats year round.
Vegetation unique to the Yarkon River in the process of being returned to the river and its surroundings:
The plant’s level of vulnerability: extreme danger of extinction.
Vulnerability level of the plant: vulnerable.
Vulnerability level of the plant: Severe danger of extinction.