On the surface, it's looking good for the recovery of the Gulf of Mexico a year after the BP oil spill.

But what's going on deep down is a cause for concern for scientists even though they say the overall health of the Gulf is nearly back to normal.

Scientists say there are some glaring blemishes that restrain their optimism about nature's resiliency.

More than three dozen scientists grade the Gulf's big picture health a 68 on average. It was 71 before the spill and 65 back in October.

But scientists cite significant declines in key health indicators such as the sea floor, dolphins and oysters. Gulf experts pointed to the mysterious deaths of hundreds of young dolphins and turtles, strangely stained crabs and dead patches on the sea floor.