OUTDOOR CORNER: HOW TO LOOK FOR THE SMALL SIGNS OF A HEALTHY STREAM

Have you ever seen an old outer space movie? Some of the aliens depicted in some of these old films look just like some aquatic insects found in streams.

I bet there are a lot of people that don't realize that certain insects that they see flying around (such as dragonflies or mayflies) spent most of their lives as a nymph or larva in a nearby lake or stream.

These insects start out as "babies" in water but they go through metamorphosis and change into adults that fly. These insects support most of the food chain in an aquatic system. Fish, crayfish, amphibians and turtles feed on aquatic insects. Some aquatic insects feed on aquatic vegetation and organic matter.

There are also some aquatic insects (like dragonflies) that are predators, which eat fish and other insects. These insects not only keep our waters clean by eating matter from the bottom of the stream but they also are a major food source for other animals.

Small streams are usually the easiest place to find these insects. Aquatic insects congregate in the riffles of a stream. They can also be found under rocks and near vegetation. A 3'x3' net is very effective at collecting insects. One person will hold the net in the riffle, making sure it is on the stream bottom. The other person will "dance" upstream until they have disturbed the substrate to dislodge insects and washed them into the net.

Then pick the net up take it to shore and look at all of the bugaboos. There are a lot of small streams around Cape Girardeau where these insects can be found.

After you look at the insects please put them back into the stream; remember that they support many other animals. Aquatic insects are not only important to the food chain but they are also indicators of pollution. There are some insects (midges, rat tail flies) that are tolerant to pollutants and there are some insects (mayflies, stone flies, caddisflies) that are intolerant to pollution. Biologists go to streams and look for aquatic insects so they can determine the health of the stream.

If they find insects that are intolerant to pollution, the stream is usually healthy. If they don't find intolerant insects, the stream is usually unhealthy. If the stream is unhealthy, the biologist will then take a close look at the stream to find out why. If the stream is in good condition, the biologist will try to make sure that it stays that way.

There aren't enough biologists to look at all the streams around the state, but the public can help. Stream Teams are volunteers that monitor streams. They look for aquatic insects and help measure dissolved oxygen, pH, and other parameters. With help like this we can ensure that Missouri's streams will stay healthy.

Aquatic insects are very important for streams and the other organisms that live in streams. The environmental health of Missouri is important because it directly effects the quality of life of humans. Missouri's waters are a major component of the environmental health in Missouri.

For more information about aquatic insects or Stream Teams contact the Missouri Department of Conservation in Cape Girardeau at (573) 290-5730.

Christopher J. Kennedy is a fisheries management specialist with the Missouri Department of Conservation.