March 13, 2019
RSGAL Student @ SEFS Capstone Presentations – March 14
Please support Erin by attending the SEFS Capstones Poster Session on Thursday, March 14th 2-4 in Anderson Hall 207.
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Sonar mapping of Higgins eye pearlymussel habitat
Freshwater mussels are one of the most at-risk taxonomic groups in North America with about twenty percent of species and subspecies listed as endangered. Populations are thought to be declining due to habitat loss brought on by invasive species such as the zebra mussel (Dreissena polymorpha), water pollution, and the construction of dams, which prevent the passage of the host fish necessary for mussel reproduction. Freshwater mussels provide vital ecosystem services by acting as biomonitors of stream health, improving water clarity by filter feeding, and providing microhabitats for other freshwater organisms. The focal species of my study is the federally endangered Higgins eye pearlymussel (Lampsilis higginsii) which are found in the Mississippi River and nine of its tributaries, including the Wapsipinicon River. The Wapsipinicon is valuable habitat for Higgins eye due to its lack of zebra mussels, but several dams, now up for removal, have restricted the species to just a few sections of the river. This study compares microhabitat factors and hydraulic parameters at sites with and without Higgins eye pearlymussel populations in five sections of the Wapsipinicon River to determine the habitat requirements of the species. Using GIS, a habitat suitability index and mapped potential reintroduction areas in parts of the river that will become accessible following dam removal were created. Although the data are limited, there is some indication that Higgins eye prefer sandy substrate at river bottom elevations around 231 meters. All of the sites have significant areas that match this description and could provide habitat for Higgins eye in the future, but more data are necessary to select specific sites and confirm this conclusion. If these inaccessible areas are found to support Higgins eye populations we can encourage dam removals and improve our understanding of a struggling and under researched species.
