More than just a meal: Ontario’s freshwater mussels
When people in Ontario hear the word “mussels” they normally think about the tasty ocean mussels smothered in butter and garlic that they have as a meal every so often. What Ontarians often don’t realize, however, is that their province is actually the national hotspot for freshwater mussels. While these native species may not be as appealing to eat as their marine relatives, they are a critically important component of our aquatic ecosystems that are often overlooked in lakes, rivers, wetlands and ponds. Ontario is home to 41 of Canada’s 55 native freshwater mussel species with southwestern Ontario being the country’s most diverse mussel area.
Freshwater mussels may not look like much at first glance but they are so much more than just brown rocks! Ontario’s mussel species all have a complex parasitic lifestyle that requires the baby mussels to spend time on a host species. In all but one instance this host is a fish species, with the exception of one mussel species that uses the Mudpuppy Salamander as a host. The fish species used as a host varies between the mussel species. Baby mussels are called glochidia and look just like the adults with two distinct valves forming their shell. The female mussels have to make sure their babies come in contact with the right host fish species in order for the glochidia to develop. Some female mussels use lures (parts of their tissue that have developed to look like the prey of the host fish) and some have even developed ways to go fishing! Check out the video links below to see some of these unbelievable mussel mamas (and don’t worry, I promise the fish are okay!). Mussels are not only unique, they are also important for filtering water, cycling nutrients and providing homes/food for other animals.
With a bit of a background on Ontario’s freshwater mussels, you may understand why someone would want to work with these special animals and that is what I do. I am an Aquatic Science Technician with Fisheries and Oceans Canada (DFO). The work of the crew I am a part of focuses entirely on freshwater mussels in Ontario and specifically on the species at risk (SAR) that we have here. Formal surveys of freshwater mussels, including long-term monitoring, did not start until the 1990s. This was spurred by the steep decline in our native populations after the introduction of the invasive Zebra and Quagga mussels. Monitoring efforts began in order to determine how our native species were faring under the burden of these invasive and competitive species. Not only do Ontario’s species have to battle threats from invasive species but also in the form of habitat loss and water quality degradation.
My team of fellow mussel lovers works to locate unknown mussel populations throughout Ontario and monitor populations of SAR over time. Our work is concentrated primarily in three species rich rivers in Ontario: the Grand, Thames and Sydenham rivers. The results of our surveys go directly towards assessing and protecting Canada’s freshwater mussel species under the federal legislation of the Species at Risk Act (SARA). Whether snorkeling for mussels in Lake St. Clair or flooding your waders in the Grand River, working with these cuties is never boring (yes, despite the fact that my grandmother doesn’t believe me, mussels are cute!).
If you are interested in learningmore about mussels in your nearby rivers or your cottage’s lake, considering downloading the free mussel app called “Clam Counter” (available for Android and Apple phones) developed by the Toronto Zoo and Fisheries and Oceans Canada to start on your mussel journey! The app has information on all of Canada’s mussel species and includes a key to help with mussel identification, including species lists that are narrowed based on your location. You can even report a mussel finding to help discover and protect our mussels!
Juvenile mussels under a microscope: https://www.youtube.com/watch?v=HA2qP9Qvf4U
Female lure (Lampsilis fasciola): https://www.youtube.com/watch?v=z4G2umYDk70
Host capture (Epioblasma torulosa rangiana): https://www.youtube.com/watch?v=VDEOOWi5wcc
Host capture (Epioblasma triquetra): https://www.youtube.com/watch?v=-1YcaIN8cRs