Keith Crandall : Five years after the Deepwater Horizon rig exploded , we are only beginning to understand its effects on the Gulf . The explosion of a BP oil well in 2010 killed 11 workers and spewed millions of gallons of crude into the Gulf.
Keith Crandall : Five years after the Deepwater Horizon rig exploded , we are only beginning to understand its effects on the Gulf . A crab species may be a key indicator of the impact , he says .