Nearly all the tar balls filling the beaches of Alabama in the wake of Hurricane Isaac are from the BP Deepwater Horizon oil disaster that started in 2010 and continues to spread its black legacy to the communities and ecosystems, a report released Thursday from Auburn University shows.

The report states: "as TS Lee and Hurricane Isaac have revealed, mobilization and re-deposition of oil onto the beaches continues to be a lasting consequence of the Deepwater Horizon catastrophe."

The research team collected roughly 25 pounds of tar balls and tar mat fragment samples post-Hurricane Isaac from seven locations along the state's coast.

By analyzing the chemical fingerprints of samples of tar balls in 2010 soon after the BP Deepwater Horizon disaster (June 2010), after Tropical Storm Lee (September 2011) and Hurricane Isaac (September 2012), the team found nearly identical make-ups, implicating the BP disaster as the effects of the oil disaster continue to unfold, years later.

Beyond the ugly site of tar balls filling Alabama beaches, the report warns of ecological concerns, saying that they "contain a number of hazardous PAH [polycyclic aromatic hydrocarbons] compounds" at roughly the same concentrations as those from three years ago, and "in fact, some of the PAHs appear to be concentrating within tar mat." The report states that the "ecological implications of this fact remain uncertain."

The report's authors write that "without detailed chemical analysis it is safe to conclude that the fragile, sticky tar balls and oil fragments currently found along Alabama’s shoreline are all Deepwater Horizon-related tar balls and oil fragments. In our opinion, local communities should not be burdened with proving the chemical origin of these tar balls and oil fragments; rather it should be the responsibility of BP to prove an alternative origin for these tar balls if they consider that a possibility."