After a week of scouring along the Iowa River, researchers and volunteers from the Iowa Department of Natural Resources made promising findings regarding Iowa River’s mussel population, a critical indicator of the waterway’s aquatic health.
The experts found 20 different species during the 2014 Mussel Blitz, an annual research project to assess the health and diversity of Iowa’s mussels. Among them was the Higgins’ eye pearlymussel, an endangered species which was reintroduced to the river in 2003 by stocking fish with young specimens, at the time just the size of a grain of salt. Researchers found six adult Higgins’ eyes in the Iowa River during the Mussel Blitz, indicating that the species was able to mature in the waterway.
While mussels thrived in Iowa waterways for centuries, most have faced heavy setbacks due to damming, fluctuations in water levels and chemicals in the water. 43% of North America’s 300 mussel species are in danger of extinction, including 78 endangered or threatened species in the Midwest.
Since their primary threats are sedimentation and pollutants, mussels are important to Iowa’s waterways as indicators of aquatic health. Reproducing populations of mussels indicate good water quality and wildlife diversity, and mussels help purify the aquatic system by acting as natural filters. They’re also an important food source for otters, herons and some fish.