What was done
The authors report that an endangered cold-water coral has been found growing on oil platforms in the North Sea; and they discuss the significance of this finding.

What was learned
The cold-water coral Lophelia pertusa is listed under the Convention on International Trade in Endangered Species and is supposedly susceptible to disturbance from increased sedimentation and from the toxicological effects of drilling discharges (Rogers, 1999).  However, during the summer of 1999 it was found growing on oil rigs in the North Sea - where it has never before been observed - and where it is exposed to "operational discharges, such as oily water, drilling muds and chemicals, and contaminants that may leak from the cuttings piles."  In addition, the coral colonies exhibited growth rates that were greater than what was previously believed possible; and they did so in waters that were sometimes warmer than what was previously believed to be their upper thermal limit.

What it means
Two possibilities come to mind.  Some corals - even those we call endangered - are much more resilient than we have previously believed.  Or, there has been some change in the environment that is enabling corals to overcome what formerly would have been insurmountable challenges to their existence.

Reference
Rogers, A.D.  1999.  The biology of Lophelia pertusa (Linnaeus 1758) and other deep-water reef-forming corals and impacts from human activities.  International Review of Hydrobiology 84: 315-406.