For British Petroleum (BP) the Deepwater Horizon disaster is the story that never ends. After four years, tens of billions of dollars in damages and criminal charges against some individuals, the news just keeps getting worse.

The latest news comes from Penn State University biology professor Charles Fisher and associates. They report in the online Early Edition of the journal Proceedings of the National Academy of Sciences that coral communities in the Gulf of Mexico are showing signs of damage from Deepwater Horizon much further away from the source than originally thought.

“The footprint of the impact of the spill on coral communities is both deeper and wider than previous data indicated. This study very clearly shows that multiple coral communities, up to 22 kilometers from the spill site and at depths over 1800 meters, were impacted by the spill,” said Fisher in a statement.

The impact though likely isn’t on coral exclusively. Coral are simply an indicator of how wide spread the damage is. The oil from the original spill has largely dissipated, however coral retain chemical records in their skeletal structures.

“One of the keys to coral’s usefulness as an indicator species is that the coral skeleton retains evidence of the damage long after the oil that caused the damage is gone,” said Fisher.

Using coral directly impacted by the spill as a fingerprint, Fisher and his colleagues began looking for other coral beds in the surrounding area. Coral are sparse in the deep water of the Gulf, generally they tend to be in shallower water, closer to the coastline.

The researchers used data from the Bureau of Ocean Energy Management to identify 488 potential coral habitats in a 40 km radius of the spill site. Using an autonomous underwater vehicle (AUV), they then began to explore potential sites for coral colonies.

“With the cameras on board the ROV we were able to collect beautiful, high-resolution images of the corals. When we compared these images with our example of known oil damage, all the signs were present providing clear evidence in two of the newly discovered coral communities of the impact of the Deepwater Horizon oil spill,” said Fisher.

This could mean more still more bad news for BP and fishing communities around the Gulf of Mexico. A separate study, published in February of this year, showed that even small amounts of oil could cause serious and spontaneous heart failure in otherwise healthy fish such as tuna.