Student Resource Pages - What Killed Freddy the Fish?

Cover-Freddie the Fish

When detectives discovered the lifeless body of Freddy, the bass, they searched for other dead fish in the area. Often, where there’s one, investigators find others. And they did.

Jackson Bend Fish Kill

A "fish kill" happens when a bunch of fish die at the same time.
Fish kill at Jackson Bend, Lake Granberry, 2003, Used with permission, photo by Gary Turner of Brazos River Authority

Detectives now had an official "fish kill" on their hands.

Greg Conley, a Pollution Biologist with the TPWD Kills and Spills Team (K.A.S.T.) specializes in solving "fish kills" so he took over Freddy's case.

Mr. Conley solved the mystery: Freddy and his friends died of nonpoint source pollution. Lime in the soil from construction sites had been carried by run-off to the stream where the fish lived.

Lime? But, but…isn't that a harmless little green fruit? Well, yes. But it's also a white powder put into the soil to make dirt stronger so houses won't budge after they're built.

Here's what Mr. Conley believes happened:

A crazy storm came, creating run-off from a place where they were preparing the dirt to build new houses. They have to make the dirt ready before they build on top of it to help prevent erosion. Remember what erosion is?

Oh, what a mess that storm made!

From these construction sites, the rain washed lots of dirt away into storm drains. Have you ever noticed those places in

Storm Drain

Storm Drain

the street where all the extra water goes? Well, we call those storm drains and all that water heads straight to our creeks and streams. Clean, gross, yucky, trashy…all that water goes directly into creeks and streams.

So right into the storm drains went all that muddy water from the construction site…goosh….moosh…sloosh…then right into the creeks and streams went all that muddy water from the construction site... goosh….moosh…sloosh…

But plain old muddy water didn't kill Freddy and his friends. Nope. Remember, how that dirt also had white powder in it called "lime?" Well, when run-off brought the dirt with the lime into the stream that's what killed Freddy and the others.

Muddy Water

Muddy, Turbulent Water

Whooooosh....that lime-laden water rushed straight at them! They had no idea danger headed their way. No one could warn them, "Hey you guys get outta there! There's nonpoint source pollution coming at you! Swim! Quickly!"

The lime changed something in the water called "pH." It made the "pH" go too high, too fast, and the fishes' bodies just couldn't handle it. When "pH" in the water changes way too quickly it kills fish. Freddy and the other bass died, creating a mystery for us to solve.

But now we know what killed Freddy the Fish. Freddy and his friends died of nonpoint source pollution.

Dangerous for Fish =>