Sewage is tourism’s dirty little secret. Our investigator had to swim through a lot of it to make this video showing how it affects coral reefs.

The first segment was taken near the Chankanaab Dolphin attraction on Cozumel, Mexico. The second was by Dolphin Discovery on Isla Mujeres, Mexico. The third was taken by the Grand Cayman Turtle Farm at Boatswain’s Beach.