Did you know that shipwrecks are great places for corals to grow?

When a ship sinks to the bottom of the ocean, corals can attach to the wreckage and thrive. That’s one of the things researchers aboard the Ronald H. Brown were looking for when the NOAA ship started its cruise around the Gulf of Mexico in October.

Sponsored by NOAA and the Bureau of Ocean Energy Management, Regulation and Enforcement, scientists have been using a remotely operated vehicle–basically an underwater robot–to explore deep-sea coral habitats in the Gulf of Mexico during several cruises in the past few years.

This cruise was different, though: in the aftermath of the Deepwater BP oil spill, the researchers were also collecting data about potential impacts from the oil. Nearly all the corals they saw were unchanged from previous observations. But on November 3, they saw something different: seven miles from the site of the wellhead, they observed dead and dying corals 1,400 meters below the water’s surface. Closer inspection revealed that a large portion of two coral colonies–one hard coral and one soft coral–were covered in a brown material, and some had tissue that was falling off.

“These observations capture our concern for impacts to marine life in places in the Gulf that are not easily seen,” said Dr. Jane Lubchenco, NOAA administrator. “This is precisely why we continue to actively monitor and evaluate the impact of the spill in the Gulf.”

Sediment and coral samples were brought to the surface to be tested. Natural Resource Damage Assessment scientists will analyze the samples to see if the substance covering them is oil and–if it is oil–if the oil is from the BP spill. The scientists will return to the area in December for more research, using a Navy vehicle that can pilot to depths of almost 15,000 feet.

Learn more about the Ronald H. Brown’s expeditions in the Gulf.