" We’ve had to change our ideas because there seems to be no quiet areas in the St. Johns River."

The last few miles of the St. Johns River might look mostly calm and peaceful, but if you’re a dolphin, forget that: It can be a noisy, chaotic place and communicating there might be like trying to hold an intimate chat during the recent Red Hot Chili Peppers concert.

There’s a natural background hum of snapping shrimp, like rain on a tin roof, and a wide range of fish vocalizations — yes, fish can be noisy. Then there are the dolphins, with their whistles and the buzzing of their sonar-like echolocations.

That’s to be expected. But then add in the noises of a river busy with work and play. How, a team University of North Florida researchers wondered, would that man-made noise affect the 300-bottlenose dolphins who call the river home?

Read more at the Florida Times-Union.