Israel Coastline Remains Murky After Phytoplankton Bloom
More than two weeks after an unusual phytoplankton bloom began, the waters along a significant portion of Israel's Mediterranean coast remain discolored and turbid, exhibiting a greenish-yellow hue. The phenomenon is particularly noticeable from Ashkelon and Ashdod in the south up to the coast of the Gush Dan region in the center. This bloom, which started in late August, led to the shutdown or severe reduction in operations at five of Israel's six major desalination plants.
Research by the Israel Oceanographic and Limnological Research Institute (IOLR) indicates the bloom is not a single type of "algae" but a complex mix of phytoplankton. A key component identified is the microscopic cyanobacterium Synechococcus, a type of picophytoplankton. Other photosynthetic microorganisms, including green algae and diatoms, were also found. Importantly, no toxic bloom indicators were detected in the analyzed samples.
According to IOLR, the unusual water mass originated from the south, with satellite and oceanographic data pointing to the Nile Delta region as its source. The affected waters showed reduced salinity and abnormally high concentrations of nutrients like phosphates and silicon. These levels were highest in southern Israel and decreased northward.
As of September 9, the IOLR had not observed any significant weakening of the bloom. The crisis continues to impact desalination. By September 14, five plants (Ashkelon, Ashdod, Palmahim, and two Sorek facilities) were operational but not at full capacity. The Hadera plant, located further north, remained the only major facility operating at full capacity throughout the event, consistent with the observed weakening of the bloom towards the north. Public water supply has been maintained.
While the northern Mediterranean coast is faring better, it is too early to declare the sea fully clear north of Hadera. A precise timeline for the bloom's end is unavailable. Based on current trends, gradual improvement is expected in the coming days. However, full restoration of normal water clarity along the central and southern coasts may take another one to two weeks, potentially extending to the end of September. The speed of recovery will depend on currents, wave action, and the continued influx of nutrient-rich waters.
