Introduction to Mussels - Lunch and Learn at LGROW

Michigan Mussels

Experts from Native Edge, LLC, visiting LGROW to teach LGROW staff, partners, a few GVSU students, and others about freshwater mussels. In the past we have often looked to macro-invertebrates to gauge stream health, now we know that mussels will tell us too! Mussels are very sensitive to pollution and cannot be out of water for more than a minute or so. The presence of certain species of mussel can be great indicators of stream health, since they cannot live in highly degraded habitat, they also make fantastic bio-indicators because they generally stay in the same area which makes it very easy for scientists to monitor their populations.

Mussels are known as "ecosystem engineers", they actually clean the water that they live in by filter feeding - similar to a cleaner fish. They create nutrients for other species and provide structural habitat by stabilizing the stream bed. Mussels are also a food source for other animals such as muskrats and birds. 

We learned about the external anatomy of the freshwater mussel, as well as some key identifying factors for certain species. You can view the information packet here. The video below shows a mussel using a fish lure to attract a Bass and then the mussel releases the fertilized eggs into the fishes gills (this does not negatively affect the fish!).

ALL native mussels in Michigan are protected - if you ever see someone taking mussels PLEASE report them to your local police department or MDEQ. There are 45 extant native mussel species in Michigan, 13 of those are classified as endangered, 6 as threatened, 13 special concern, and 13 common species. In addition there are two known non-native/invasive mussel species in Michigan - the Zebra Mussel (Dreissena polymorpha) and the Quagga mussel (Dreissena rostiformis). 

invasives.jpg

Threats to Freshwater Mussels

  • Impoundments (dams, fishladders, etc.)
  • Land use practices (logging, mining, farm animals, mowing, etc.
  • Channelization and dredging
  • Pollutants (especially heavy metals)
  • Invasive species
  • Loss of hosts
  • Climate change
Rachel FrantzGRWW