Warnings have been issued that the sinking of the Rubymar, which carried oil and 22,000 tons of fertilizer, could cause ecological damage to the Red Sea and its coral reefs. The British-owned cargo vessel that was attacked by Houthi militants last month sunk on Saturday, after taking on water for days. It is the first vessel to be fully destroyed by the Yemeni rebel group, which has vowed to attack vessels over Israel’s catastrophic war in Gaza. At risk from the toxic substances on the ship are a bustling fishing industry, some of the world’s largest coral reefs and desalination plants supplyi…