Mediterranean algae bloom exposes fragility of Israel's desalination infrastructure

Key points

• The bloom, identified as cyanobacteria (Synechococcus), originated near the Nile Delta and was carried north by currents, affecting plants along a 50km stretch of Israel's coast.
• Five of six major desalination facilities (Ashkelon, Ashdod, Palmachim, Sorek A, and Sorek B) were shut down or operated at reduced capacity; they now function at up to 50% capacity.
• Experts link the bloom's severity to untreated sewage from Gaza, with approximately 40,000 to 60,000 cubic meters of raw wastewater discharged daily into the Mediterranean due to destroyed infrastructure.
• Israel's Water Authority used tankers to distribute water in Jerusalem and over-pumped from the Sea of Galilee and groundwater to compensate for the shortfall.
• The incident has prompted calls for a re-evaluation of desalination strategies in the Middle East, as the event exposed the system's susceptibility to single-point environmental failures.

Background

Israel has increasingly relied on desalination for over 60% of its drinking water, a shift driven by climate change and population growth. Previous coverage in September 2026 highlighted the initial shock of the bloom, which caused nationwide water restrictions and reduced pressure in major cities like Jerusalem and Rishon Lezion. The current situation represents a continuation of that crisis, with the algae remaining present for nearly three weeks, unlike typical blooms that last only days.

How outlets are covering it

BBC reports that the microalgae likely originated from the Nile Delta but emphasizes that the destruction of Gaza's sewage treatment plants by Israel's military is a contributing factor, citing Gidon Bromberg of EcoPeace Middle East. PressTV argues more aggressively that the crisis is a direct result of the 'genocidal war' in Gaza, stating that the destruction of civilian infrastructure created a 'nutrient bomb' that boomeranged back to Israel. Middle East Monitor focuses on the broader humanitarian and environmental catastrophe in Gaza, noting that 90% of the strip's water and sanitation infrastructure has been destroyed. While BBC and PressTV agree on the link between Gaza's sewage and the bloom, PressTV places greater emphasis on the political and moral implications of the war, whereas BBC focuses more on the technical and environmental aspects of the water security crisis.

Why it matters

The incident serves as a wake-up call for the global water sector, particularly in the Middle East, where desalination is a primary strategy for water security. It demonstrates that centralized water infrastructure is vulnerable to environmental shocks and that the destruction of civilian infrastructure in conflict zones can have unintended ecological consequences that affect even the aggressor. The crisis also highlights the long-term environmental damage caused by the war in Gaza, as untreated sewage continues to pollute the Mediterranean Sea.

What to watch

Authorities are monitoring the algae bloom, which remains present after nearly three weeks. There is concern that similar events could occur again, especially given the ongoing destruction of Gaza's wastewater infrastructure and the rising temperatures in the Mediterranean. Israel is expected to continue relying on alternative water sources, such as the Sea of Galilee and groundwater, while the desalination plants operate at reduced capacity. The incident may also lead to a re-evaluation of desalination strategies and the development of more resilient water infrastructure in the region.