In the first birthing season for dolphins after the spill, dead baby dolphins washed up along Mississippi and Alabama shorelines at about 10 times the normal number.[211] [dead link] A peer-reviewed NOAA/BP study disclosed that nearly half the bottlenose dolphins tested in mid-2011 in Barataria Bay, a heavily oiled area, were in “guarded or worse” condition, "including 17 percent that were not expected to survive". BP officials deny that the disease conditions are related to the spill, saying that dolphin deaths actually began being reported before the BP oil spill.[198][212][213] By 2013, over 650 dolphins had been found stranded in the oil spill area, a four-fold increase over the historical average.[214] The National Wildlife Federation (NWF) reports that sea turtles, mostly endangered Kemp’s ridley sea turtles, have been stranding at a high rate.