Pollution from feedlots, fertilizers and waste water combined with warmer water temperatures to lower the levels of dissolved oxygen in streams. These changes created conditions more suitable for bullheads and other fish than for species such as the blacknose shiner. Many fish species disappeared from many streams, but the blacknose shiner seems to be the species most affected by these changes. Any stream that still harbors this species does so because of good watershed management practices, whether by intent or by accident. Shiners are a group of minnows that usually have metallic silver or gold sides.
Minnow species are notorious for being difficult to identify.
There are more than 100 species of shiners in North America, but the blacknose shiner is one species that is quite easy to identify with a little experience. A black stripe extends from the tail to the nose, passing through the eye but not extending onto the chin or lips. This black stripe is formed from distinctive crescent-shaped markings on the scale margins. The eyes are large, but the mouth is small, and the upper jaw does not extend to the front of the eye. The back is pale yellow, and the sides are silvery.