Viosca Knoll 906 is a deep sea coral reef approximately 1300ft (~400m) below the Gulf of Mexico, home to a thriving Leiopathes (black coral) ecosystem. The number ‘906’ identifies the oil and gas lease block that encompasses area – in this case, ‘906’ reef is situated approximately 20 miles north of the Deepwater Horizon oil rig disaster where 11 workers lost their lives, and thousands of gallons of oil per day is pouring into the Gulf. The New York Times Green blog is reporting on how this reef will act as a before and after ‘litmus test‘ to the disaster – scientists first surveyed this reef back in 2008. The stuff that looks like snow in the video footage is imaginatively known as ‘marine snow’ – particulate matter made up of mucus, algae, sediment and other odds and ends of organic matter, and is a prime food source for Leiopathes corals (unlike their tropical counter-parts which are phototrophic and rely on sunlight, not much light reaches reefs at this depth). If the fall out from the oil spill really does end up reaching the deep sea floor, then these filter feeding corals will be the silent sentinels. And with no obvious end in sight for the leaking oil well, and the spill threatens to head via the loop current towards Florida and beyond….