Macroinvertebrate Species Richness and Density Between Modified and Relatively Natural Segments of the Minnesota River

Location

CSU Ballroom

Start Date

20-4-2015 10:00 AM

End Date

20-4-2015 11:30 AM

Student's Major

Biological Sciences

Student's College

Science, Engineering and Technology

Mentor's Name

Shannon Fisher

Mentor's Email Address

shannon.fisher@mnsu.edu

Mentor's Department

Water Resources Center

Mentor's College

Science, Engineering and Technology

Second Mentor's Name

Nathan Lederman

Second Mentor's Department

Biological Sciences

Second Mentor's College

Science, Engineering and Technology

Description

Aquatic macroinvertebrates are sensitive to changing environments and can have cascading effects on trophic levels. Habitat alterations to accommodate barge traffic, such as dredging and channelization, likely influence macroinvertebrate community structure, and subsequently a range of potential ecological interactions. Understanding baseline differences between highly modified and relatively natural segments of the Minnesota River has become a higher priority as existing challenges intensify (e.g., changing hydrologic patterns) and new threats emerge (e.g., invasive species). Therefore, we assessed aquatic macroinvertebrate species richness and density between the lower modified section and the more natural mid-portion of the Minnesota River. Macroinvertebrates were collected with sled nets and light traps from May until August of 2014. Based on disturbance levels that influence the homogeneity of habitats available, we hypothesized that the substantially modified portion of the Minnesota River would have high densities, but from few species, whereas, the more natural areas would have lower densities, but greater species richness. Although we compared a modified riverine segment with an unmodified segment, we must acknowledge that the modified segments were in the lower portion of the basin and the unmodified segments were in the middle portion of the system. Therefore, we also considered the natural changes that occur along the longitudinal gradient. Results were largely as we anticipated; however, we now put our findings into perspective with the challenges and threats facing the Minnesota River.

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Apr 20th, 10:00 AM Apr 20th, 11:30 AM

Macroinvertebrate Species Richness and Density Between Modified and Relatively Natural Segments of the Minnesota River

CSU Ballroom

Aquatic macroinvertebrates are sensitive to changing environments and can have cascading effects on trophic levels. Habitat alterations to accommodate barge traffic, such as dredging and channelization, likely influence macroinvertebrate community structure, and subsequently a range of potential ecological interactions. Understanding baseline differences between highly modified and relatively natural segments of the Minnesota River has become a higher priority as existing challenges intensify (e.g., changing hydrologic patterns) and new threats emerge (e.g., invasive species). Therefore, we assessed aquatic macroinvertebrate species richness and density between the lower modified section and the more natural mid-portion of the Minnesota River. Macroinvertebrates were collected with sled nets and light traps from May until August of 2014. Based on disturbance levels that influence the homogeneity of habitats available, we hypothesized that the substantially modified portion of the Minnesota River would have high densities, but from few species, whereas, the more natural areas would have lower densities, but greater species richness. Although we compared a modified riverine segment with an unmodified segment, we must acknowledge that the modified segments were in the lower portion of the basin and the unmodified segments were in the middle portion of the system. Therefore, we also considered the natural changes that occur along the longitudinal gradient. Results were largely as we anticipated; however, we now put our findings into perspective with the challenges and threats facing the Minnesota River.

Recommended Citation

Dahmes, Alexandra. "Macroinvertebrate Species Richness and Density Between Modified and Relatively Natural Segments of the Minnesota River." Undergraduate Research Symposium, Mankato, MN, April 20, 2015.
https://cornerstone.lib.mnsu.edu/urs/2015/poster_session_A/27