PS 54-202 - Short-term responses of the macroinvertebrate and fish community following restoration of a fourth-order stream

Friday, August 12, 2016
ESA Exhibit Hall, Ft Lauderdale Convention Center
Jennifer M. Clark, Biology Department, Hiram College, Hiram, OH
Background/Question/Methods

Anthropogenic impacts such as logging, agriculture, urbanization, and damming, impair streams and can have negative impacts on the biotic community. In an effort to improve stream health, restoration projects have been implemented across the globe. Prior to being obtained by the college, the Hiram College Eagle Creek restoration site was heavily logged. In addition to other upstream impacts, land use change has caused heavily eroded banks, high turbidity, a sandy benthos, and poor canopy cover to occur within this site. The main goal of the restoration project was to reconnect Eagle Creek with its floodplain and decrease flooding to downstream suburban areas via diversion into a new meander. In an effort to monitor short-term changes in the biotic community, both macroinvertebrate and fish surveys were completed one year prior to restoration (summer 2013) and the year following restoration (summer 2014). Surveys were completed in 10 separate 50-meter stretches including one upstream of the restored section (reference site), three within the restored section, two within the old channel, and three downstream of the restoration site. Within each of the ten sites, macroinvertebrates were collected using D-frame nets in 20 random locations while fishes were collected via two passes of electrofishing.

Results/Conclusions

Overall, there were no significant differences in macroinvertebrate species richness across sampling sites prior to restoration vs. one year post-restoration (year P=0.5071, site P=0.2945). Further, there was no significant difference in macroinvertebrate species richness between the old channel sites (summer 2013) and new channel (summer 2014) (P=0.8796) suggesting that the macroinvertebrate community recovered relatively quickly to restoration practices. Similarly, macroinvertebrate species richness was not significantly different prior to restoration versus post-restoration (P=0.1490) suggesting that the community was either resistant or resilient to upstream restoration. All taxa present prior to restoration were also present post-restoration in each of the ten sites. Index of Biotic Integrity scores for fishes ranged from fair to very good in the old channel (pre-restoration) and improved post-restoration in the new channel with all scoring very good. Scores remained the same at downstream sites ranging from very good to exceptional. Although, scores represent no negative consequences of restoration on the fish community, three sensitive fish species (Northern hog suckers, mottled sculpins, and stonecat madtoms) were not present in the new channel following restoration and declined by more than 50% in downstream sections. Both macroinvertebrate and fish communities will be monitored as part of a long-term study.