However, the scientists restrain their optimism about nature's resiliency with the glaring blemishes out there.

    It's been nearly a year since BP's Gulf of Mexico oil spill began last April, triggering one of the world's worst environmental disasters. Nearly 5 million barrels of oil leaked from the ruptured Deepwater Horizon well during the months-long catastrophe.

    BP said last November that the disaster cost it nearly 40 billion U.S. dollars, according to a Guardian report.

    According to a BP survey of researchers, over three dozen scientists grade the Gulf's big picture health a 68 on average, using a 1-to-100 scale.

    That's just a few points below the 71 the same researchers gave last summer when asked what grade they would give the ecosystem before the spill. And it's an improvement from the 65 given back in October after months of the oil spill.(本文由在线英语听力室整理编辑)