The warnings are clear.They want you to be aware.
Fortunately there are also people out there who are working on keeping the beaches clean. All day long they go up and back collecting whatever may be polluted with the tar balls from the Deep Water Horizon oil spill.
That's a piece of a bag of chips or whatever that the gull has picked up and is carrying back to land. That's why they remind all of us that the pollution that you and I carelessly throw out the window of the car can be just as deadly as the disasters that strike.