David E. Bowles, Jesse M. Bolli, Myranda K. Clark
Transactions of the Kansas Academy of Science 116 (3-4), 97-112, (1 January 2013) https://doi.org/10.1660/062.116.0301
KEYWORDS: Aquatic invertebrates, water quality, Cub Creek, prairie streams
To address concerns about water quality in Cub Creek, Homestead National Monument of America (HOME), Nebraska, the National Park Service began monitoring aquatic invertebrates annually beginning in 1996. Invertebrates were collected using Hester-Dendy multiplate samplers placed at two sampling sites on Cub Creek. Water quality parameters measured in the creek included temperature, dissolved oxygen, specific conductance, pH, turbidity, nitrate-nitrogen, total phosphorus, and fecal coliform bacteria (Escherichia coli). Most water quality measurements met state standards and were generally consistent and typical for streams of this size in the region, but phosphorus concentrations, turbidity, and fecal coliform bacteria levels greatly exceeded acceptable levels. Similarly, summary data for invertebrate community metrics, including low taxa richness, diversity and evenness, low Ephemeroptera, Plecoptera, Trichoptera (EPT) richness, and high Hilsenhoff Biotic Index (HBI) suggest that Cub Creek is not fully biologically supporting. However, invertebrate metrics generally did not exceed control chart limits based on historical data collected from 1996–2004, showing that since 2005 the metrics have not deviated significantly from their historical baseline. Additionally, Mann-Kendall trend test for each metric for the period 1996–2012 did not show significant trends (P ≥0.05) thus further indicating that stream integrity has not diminished beyond that when monitoring first began. Impacts to water quality in Cub Creek originate upstream of the monument boundaries, making mitigation difficult. Protecting and managing in-stream habitat and riparian zone integrity will aid in maintaining the integrity of Cub Creek flowing through the monument.