Ongoing litigation and political wrangling over the Deepwater Horizon accident have generated considerable speculation about the size of the potential financial penalties facing BP, how much money will go to the Gulf Coast states and how the states will spend the money. Lost in all that is a more fundamental question: What impact did the spill actually have on the Gulf Coast environment?

Immediately following the accident in 2010, many predicted it would have severe and long-lasting consequences—for the Gulf of Mexico and far beyond. CNN reported that “there will be tar balls all the way up the East Coast, all the way to Europe.” CBS News predicted “a permanent end” to the Gulf’s seafood industry. Advocacy groups predicted the spill could have “generational” impacts on Gulf shrimp and that Gulf Coast tourism could suffer “up to $23 billion of losses” and take years to recover.

None of those things happened.

Last year, for example, recreational fishermen caught more pounds of fish than in nearly 30 years, according to data from the National Oceanic and Atmospheric Administration.  The oil didn’t make it to Tampa—let alone the beaches of Normandy. Gulf shrimp landings didn’t take “generations” to rebound. They quickly returned to pre-spill levels. And crowds have flocked to the Gulf, setting tourism records every year since the spill.

Make no mistake: The Deepwater Horizon accident was a tragedy. Eleven people lost their lives. Birds, fish and other wildlife perished. And with a camera trained 24/7 on the wellhead, a sense of alarm was understandable while the well was flowing.

But today, it’s worth examining what is currently known about the spill’s actual impact based on the environmental data that is now available. This includes studies conducted as part of the Natural Resource Damage Assessment (NRDA)—the process for determining what harm has been done to natural resources. The Deepwater Horizon NRDA is the most extensive and expensive environmental assessment ever conducted, spanning four years so far and costing BP a billion dollars and counting.

Although the NRDA is not finished, the evidence to date shows the Gulf environment is rebounding and that most of the environmental impact was of short duration and in a limited geographic area.

How did the Gulf defy so many dire predictions? There were four factors.

The first was the Gulf’s inherent resilience. Natural oil seeps release up to the equivalent of nearly six Exxon Valdez spills in the Gulf each year, and microbes in the Gulf have adapted over time to feast on oil. Several studies have shown that these voracious microbes consumed a significant amount of oil after the spill.

Another factor was the spill’s location. The spill occurred in deep water—5,000 feet below the surface—and more than 40 miles from shore in a temperate climate. That allowed a lot of oil to dissolve, evaporate, deteriorate or be physically removed before it reached land.