Coral reefs at risk after ship sunk in Red Sea

LONDON - When the Rubymar sank in the Red Sea after a Houthi attack, the ship went down carrying 21,000-tonnes of fertiliser which could trigger massive algal blooms that could create “dead zones” for marine life and starve coral reefs of light.

Alongside a slick of leaking fuel, the ammonium phosphate sulphate fertilisers could deliver an extreme pulse of nutrients into waters harbouring rare corals, marine mammals and reef fish, creating a spread of foamy scum on the water.

According to a maritime warning circulated to ships in the area, the Uk-owned Rubymar, the first vessel lost since Houthi militants began targeting commercial ships in November, sank at the weekend in a narrow area between Yemen and Eritrea at around 100 metres (330 feet) of depth, along the continental slope.

The relatively shallow waters near the coasts are teeming with coral.

“It is such a huge amount of fertilizer and it is a terrible location,” said Ali Al-sawalmih, director of the Marine Science Station at the University of Jordan.

Adapted to warm water conditions, scientists have hoped the Red Sea might serve as a refuge for corals as climate change further warms the world’s oceans - making any potential impact even more significant.

The conflict in the area further complicates any cleanup and would dissuade salvage ships from entering the high risk waters, shipping industry sources said.

So far, it is not clear who has insured the Belize-registered Rubymar and would therefore pay for any remediation. It is not known how the fertiliser was stored and how secure it would be from reaching the water. And so far, any damage has yet to be reported.

But the sinking has the potential to be the worst environmental catastrophe the region has experienced in more than a decade, Sawalmih said.

An overload of fertilisers can stimulate excessive growth of algae, using up so much oxygen that regular marine life cannot survive. This creates dead zones where nothing lives.

Fertilizers often also contain traces of harmful chemicals which are toxic to marine life.

“Fishing communities along Yemen’s Red Sea coast in Hodeidah and Taiz will be impacted by the contamination,” said Mohammed al-basha with U.S. analytics company Navanti Group. This could lead to lower catches and damage to livelihoods.

The sinking of the Rubymar represents one of the few times in recent years a vessel has sunk with vast quantities of fertiliser on board, and perhaps the only sinking in a sensitive coral ecosystem.

Earlier this year, a Germanflagged vessel carrying 1,000 tonnes of nitrogen fertiliser struck a bridge and sank along the Danube River border between Serbia and Croatia.