(Another reason rocks are important from the Missouri Division of Geology and Land Survey.)

Limestone is important to fish and aquatic life

Wild rainbow trout photo from geologist Boot Pierce

Missouri’s geology consists of an abundant amount limestone. This underlying bedrock and highly weathered karst landscape has produced some of the largest springs and best trout stream habitat in the Midwest.

An especially wonderful characteristic of limestone chemistry is its ability to buffer acids, including acidic rainwater. This is important to fish and aquatic life because it helps protect against rapid changes in pH. As rainwater infiltrates into the ground and becomes groundwater, the limestone and slightly acidic rainwater react. The result is decreased water acidity while at the same time the dissolving away of small amounts of limestone, thus creating a karst landscape and springs for which the Ozarks are famous.

In addition to the benefits of the buffered water, the springs and spring creeks below them have a much more consistent year-round water temperature. This constant temperature allows for a steady growing cycle for trout food sources such as macro invertebrates and other smaller fish.

Yelton Spring photo by Boot Pierce

See photos from Trout Season opening day at Bennett Spring, Roaring River and Montauk state parks.

Like this? There’s more Missouri geology weekly at:
http://blogs.mo.gov/geology/