Georgia’s Misunderstood Mollusks

Emily Ferrall is a seasonal staff member working with DNR’s Nongame Conservation section.

The Nongame Conservation section sure knows how to keep busy! I have spent many hours over the past few months sampling rare species with DNR biologists. This means I get to help with everything imaginable—from gopher tortoise sampling to monitoring bat populations. Although it is hard to pick a favorite, sampling freshwater mussels is at the top of my list!

Growing up, I couldn’t have told you much about mussels besides the fact that people eat them. Even in college I didn’t learn very much about this group of animals, so my time spent sampling them this summer was eye-opening. A few facts about mussels: Freshwater mussels have a unique life cycle in that their larvae (glochidia) require a fish host. Once the glochidia develop, they drop off of the fish’s gills and settle into the river bottom to live out their life. Mussels are filter feeders and collect their nutrients from microscopic bacteria and algae in the surrounding water. Unfortunately, many mussel species are at risk due to habitat loss and pollution. This has led to many mussel species becoming extinct or listed as endangered.

To monitor these imperiled species, DNR conducts annual freshwater mussel stream surveys across the state. I assisted DNR biologists by donning my wetsuit and getting my head in the water. We feel around for the mussels in the stream bottom and conduct visual surveys to locate them. We collect the mussels and identify them by species and sex—as well as checking to see if the females are brooding (with glochidia). Each mussel receives a unique plastic, alphanumeric tag used to identify it in the future. This allows us to track the survival, growth and reproduction of individual mussels over time as we recapture them.

Identifying and tagging mussels. Jason Wisniewski, DNR.

During this past survey we found many Shinyrayed Pocketbooks, which is listed as endangered under the US Endangered Species Act. Finding a healthy population of this species is a big deal because few populations still exist.

Shinyrayed Pocketbook. Jason Wisniewski, DNR.

Surveying for mussels has been a very thrilling experience for me, and it is rewarding work. More charismatic aquatic species such as fish and turtles often receive more attention, but I encourage you to think of these little guys too! Mussels are a phenomenal group of animals that need our help.