Increased levels of pollution reported in the Poleg and Alexander rivers from sewage and agricultural fertilizer
Zafrir Rinat | Feb. 9, 2018 | 2:06 AM

The pollution in Israel’s rivers has been decreasing overall, but many coastal estuaries are polluted by flows of sewage and agricultural fertilizer, according to national monitoring reports of Israel’s coastal waters released on Wednesday. The data on pollution, biodiversity and climate change refers mainly to 2016 and also includes some data from 2017.

The report says that despite the overall decrease in pollution, levels of it in the Alexander and Poleg streams have risen significantly due to extensive agriculture nearby and problems with sewage treatment. Pollution levels of varying severity were also found in other estuaries due to similar pollutants. High concentrations of pollution can harm the fauna in the river and spur the growth of toxic algae in the estuaries. The reports note that the relatively high concentrations of fertilizer pollutants in Israel’s rivers are partly due to the small quantity of freshwater in the rivers.

The quality of the water used by the desalination plant in Ashkelon was found to be adversely impacted by pollution that comes from Gaza, which has increased in the past year. Israel Oceanographic & Limnological Research, the institute that conducts the monitoring program for the Environmental Protection Ministry, determined this through the analysis of satellite photos. If the pollution from Gaza becomes severe enough, it could disrupt the desalination plant’s activity and even cause a temporary shutdown.

Another problem is toxic metals in industrial waste that harm fish. For this reason, the ministry recommends a fishing ban be put in place at several beaches and estuaries, and at all the country’s seaports and marinas. The Agriculture Ministry is said to be working on a bill to address this issue. One quarter of the fish tested in the Haifa Bay were found to have mercury levels that exceed the accepted range.

Regarding biodiversity, one major finding was that invasive species that came into the Mediterranean Sea via the Suez Canal or ships have pushed some local species to the brink of disappearance. For example, nearly 40 percent of the mollusks found in the survey were invasive species. A large number of invasive species were also found among fish and crabs, especially at depths below 20 meters.

The report also found instances where extreme heat caused widespread mortality of fauna in certain areas of the sea. The incidence of extreme heat events has doubled over the past four decades.