Thousands of Dead Fish Wash Ashore in Netanya; Officials Blame Heat

Thousands of dead fish, primarily young mullet, washed ashore at the mouth of the Poleg Stream on Netanya's southern beach shortly before Rosh Hashanah, creating a foul odor. Experts from the Nature and Parks Authority and the Sharon Drainage and Rivers Authority were unable to identify any external pollution or sewage leaks as the cause.

The prevailing theory among professionals is that the fish died from heat. With minimal rainfall, the stream's flow is weak, preventing it from reaching the sea and causing the water to become stagnant and warm. This, combined with a high concentration of organic matter, likely led to low oxygen levels, which the sensitive young mullet could not survive.

While mass fish die-offs are not uncommon in Israeli streams, they are usually attributed to external factors like sewage spills or industrial pollution, as seen in the nearby Alexander Stream. However, the Poleg Stream is largely free from such external contaminants. The last recorded incident of significant pollution in the Poleg was in November 2020, when a heavy rainstorm caused a sewage pipe to rupture.

Professionals noted that this event is particularly concerning because it appears to be linked to climate change, an issue that is difficult to address directly. Some speculate that the relatively high temperatures in early September, or an increase in the local mullet population, may have contributed to the die-off. To mitigate future occurrences, the Sharon Drainage and Rivers Authority has installed oxygenation devices in the Alexander Stream, and similar measures might be considered for the Poleg if the problem persists.

Nature and Parks Authority teams worked to clear the dead fish from the beach before the holiday, ensuring a more pleasant experience for beachgoers. The incident highlights the vulnerability of the stream's ecosystem to environmental changes.