Date of Award

Summer 6-7-2019

Degree Type

Thesis

Degree Name

Master of Science in Biology degree

Department

Department of Biology

First Advisor

Krebs, Robert

Second Advisor

Dr. Bernard Walton

Third Advisor

Dr. Emily Rauschert

Abstract

Inspiration for the Clean Water Act (1972), the Cuyahoga River has been one of the most protected rivers in the country since the 1970s. Water quality is now within acceptable limits outlined by the Ohio Environmental Protection Agency, shoreline integrity has improved, and sediments mostly test free from toxins and heavy metals. With recovery, various faunal communities, such as freshwater mussels (family Unionidae), are expected to re-establish; no previous surveys of the Cuyahoga focus on this issue. To better understand whether mussel populations recovered as water quality improved within the Cuyahoga Watershed, surveys were completed by two-person teams for one hour each. Sites were selected to compare either with earlier surveys in the 1990s within the Upper Cuyahoga or with possible dam removal sites within the Middle and Lower regions of the River. Site choice depended upon access. Surveys of in 2012 were consistent with trends observed in the 1990s in species richness and population size within the upper portions of the Cuyahoga. However, when resurveyed in 2016 at the same sites, both abundance and species richness declined even in generalist species, as live individuals counted declined from 389 to 111. Species richness declined from the original eight species to four found in the 2012 survey. No previous work existed to provide comparison to our 2015 survey of 20 sites. In all, only 37 live individuals, representing three species, were located. One live individual was located within the Lower Cuyahoga in 2016, after teams surveyed 15 sites, representing a significant decline in v abundance and diversity as the Cuyahoga flows from Geauga County, Ohio to the Cuyahoga Valley National Park and into Lake Erie. The loss of freshwater mussels is a complex problem resulting from the building and release of impoundments, pollution, and flow dynamics, challenging the ability to isolate a single cause. Removal of dams has increased complexity of this problem in the lower portions of the river. As continued decline is expected, further work must be completed to understand how to restore this imperiled fauna.

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