Assessing readiness for introducing mussels to the iconic Cuyahoga River, USA

Few rivers in the United States are more infamous than Ohio’s Cuyahoga River, once characterized as oozing, not flowing, and which became the impetus for the Clean Water Act of 1972 following publicity on a series of fires. While certain indicators, e.g., fish populations and water quality, have signaled improvements to system health, no natural recovery of freshwater mussels has occurred even within extensive protected parklands. Collaborating with multiple stakeholders, pilot projects were completed, first on survival of caged Actinonaias ligamentina (muckets) from a nearby river, and second, on the survival and growth of hatchery-reared 1-year old Lampsilis siliquoidea (fatmuckets) placed in small silos. This second project contrasted success to a control location in the Grand River, Ohio, where mussels are abundant. If sediment did not inundate mussel enclosures, almost all adults survived, and juvenile survival approached 60% with 16% linear growth in a two-month-long period, matching results at a control site. Thus water quality and food resources appeared sufficient. However, sediment was often unstable, sometimes burying caged adult mussels and six of 26 silos, killing all juvenile mussels within. These results demonstrate a need to carefully model the river for stable benthic structure, as visibly good habitat at low water may not equate to habitat stability at higher flows.