| Freshwater mussels are among the most imperiled groups of freshwater in North America. Nearly 70 percent of the mussels endemic to North America are listed by federal or state entities as either threatened or endangered. Freshwater mussels in Nebraska follow the same trend. The plain pocketbook mussel (Lampsilis cardium) is a Tier I threatened species in Nebraska. This study visited 45 historic L. cardium sites and 10 additional sites to determine the current distribution of this mussel species. Additionally, a variety of biotic and abiotic factors were collected at each site to identifiy correlations with changes in distribution. Factors investigated include ammonia, phosphate, nitrate, fluoride, water temperature, turbidity, stream depth, stream width, and stream flow. Fish host presence and cattle presence were also recorded at each site to determine if any association existed with the distribution of L. cardium. L. cardium was found at 37.8 percent of the sites historically known to harbor populations in Nebraska. Pearson pairwise correlation analysis identified dissolved oxygen as having a significant positive correlation and stream width as having a significant negative correlation to the current distribution of live L. cardium. Niether fish host presence nor cattle presence appear to be reducing L. cardium populations. The data support that L. cardium distribution in Nebraska is significantly reduced. This work also includes a teaching exercise designed for instructors of college-level biology classes. The objectives of this exercise are to allow students to use the scientific method through data collection and analysis, and to expose students to an organism not often used in the classroom. |
