It will take decades to repair the damage from the 2010 BP oil spill to communities of tiny organisms living in and on the soft sediment on the floor of the Gulf of Mexico surrounding the well, according to a new study published on Tuesday.

The study, published in the online scientific journal PLOS One, was conducted by the US National Oceanic and Atmospheric Administration(NOAA), BP and university researchers.

The study found the most damage to the abundance and diversity of tiny animal organisms extends 3 km from the wellhead in all directions, covering a 24-square-km area. Moderate damage was seen up to 20 km to the southwest of the wellhead and 8.5 km to the northeast, covering an area of 148 square km.

"The tremendous biodiversity of meiofauna in the deep-sea area of the Gulf of Mexico we studied has been reduced dramatically," Jeff Baguley, one of the researchers, said in the study, referring to small boneless organisms that range in size from 0.042 to 0.300 mm.

"Nematode worms have become the dominant group at sites we sampled that were impacted by the oil. So though the overall number of meiofauna may not have changed much, it's that we've lost the incredible biodiversity," he said.

It's the first time a study has attempted to outline the breadth of damage to life on the sea floor around the ill-fated well, according to the Times-Picayune. The results will be used as part of the federal effort to determine how much damage has been done to natural resources by the oil, which could lead to BP and others responsible for the accident developing a project to mitigate the damage.

On April 20, 2010, BP's Deepwater Horizon drill platform caught fire and exploded, killing 11 workers and triggering one of the worst environmental disasters in the country's history.