Future of Freshwater Mussel Populations		Printable Version (PDF)
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Contents What Is a Mussel? Mussel Differences Reproduction Ecology and Benefits Mussels' Future

Propagation of Carolina Heelsplitter (Lasmigona decorata), YouTube

“Since 1900, 123 freshwater animal species have been recorded as extinct in North America” (Ricciardi and Rasmussen 1220). That statistic represents an alarm for the future populations of freshwater mussels. Many action plans are in place to assist with assessing and promoting mussel populations. Scientists have successful laboratory propagation techniques for restoring some species’ populations. While other agencies are tackling the habitat loss, water pollution control and monitoring, and ecosystem improvement, human residents are taking more of an interest and demanding conservation. One way to accomplish that is to undergo natural restoration of impaired systems (Strayer et al 436). Of course, it will take years to generate more recruitment of mussels.

Boating sign at Lough Neagh in County Antrim, Northern Ireland

Additionally, recreational boating has undergone changes needed to prevent the spread of invasive species (Johnson et al 1789). The longevity, sedentary nature, and sensitivity of mussels to environmental changes makes them uniquely suited for long-term monitoring and for assessing the stability and health of waterbodies. Conservation of freshwater mussels will benefit from a better understanding of the biology of each species, and from population studies that determine age and size distribution, population density, condition, and habitat at multiple spatial scales. Modifications need to be implemented universally, so the declining mussel populations have more than a chance at the future. “The numbers of imperiled mussels in the United States and Canada portend a trajectory toward an extinction crisis that, unless dampened by prompt conservation action, may result in the complete loss of some genera and severe impoverishment of the richest freshwater mussel fauna in the world,” (Williams et al 22).   

International Union for Conservation of Nature Deputy Director General Bill Jackson discusses freshwater conservation, YouTube

What will the future hold for mussels? Only time will tell…in the meantime, keep filtering mussels!

List of Visuals

1. Freshwater pearl mussel , Swedish "Flodpärlmussla," from the river Navarån Västernorrland, Sweden.
   http://commons.wikimedia.org/wiki/File:Group_of_Margaritifera_margaritifera.jpg
   Wikimedia Commons

2. A dorsal view of a bivalve shell, drawn by Muriel Gottrop in May 2005.
   http://commons.wikimedia.org/wiki/File:Valve-DorsalView.png
   Wikipedia, the Free Encyclopedia

3. Water Flow in a Eulamellibranch bivalve (clam; phylum Mollusca)
   http://www.biology.ualberta.ca/courses.hp/zool250/animations/Clam.swf
   Heather Kroening/A. Richard Palmer/Bio-DiTRL, © 2000

4. Marine blue mussel, Mytilus edulis, showing some of the inner anatomy. The white posterior adductor muscle is visible in the upper image, and has been cut in the lower image to allow the valves to open fully.
   http://en.wikipedia.org/wiki/File:Miesmuscheln-2.jpg
   Wikipedia, the Free Encyclopedia

5. Larva of bivalve; North-West Black Sea, coastal waters, at a depth of 0.5 meters.
   http://commons.wikimedia.org/wiki/File:Bivalvia_gen._sp.,_larva_1.jpg
   Wikimedia Commons

6. Footage of the Wavy-rayed lampmussel (Lampsilis fasciola) from the Little Tennessee River in western North Carolina.
   http://www.youtube.com/watch?v=CnTpMbpqbLc&feature=related
   College of Veterinary Medicine, North Carolina State University/YouTube

7. An Eastern lampmussel (Lampsilis radiata), found along the Atlantic Slope, pulses its lure upon detection of passing shadows. Its fleshy, exposed mantle may contribute to this hyper-sensitivity to light and shadow.
   http://www.youtube.com/watch?v=sVvI_eOTt2g
   Aquatic Epidemiology and Conservation Laboratory/YouTube

8. This is a time lapse of a glochidium becoming encysted on a fish fin. Glochidia are larval freshwater (unionid) mussels. These animals must spend this portion of their life cycle attached to a freshwater fish.
   http://www.youtube.com/watch?v=6TZYF-7-Guk
   Galvez Laboratory, Louisiana State University/YouTube

9. Life history of freshwater mussels. The bottom photo shows the fish "lure" displayed by a gravid female mussel to attract a host fish (Lampsilis reeveiana; photo courtesy of Chris Barnhart, Southwestern Missouri State College, Missouri). The lure of the female Higgins' eye pearlymussel is similar.
   http://www.fws.gov/midwest/mussel/images/mct_2002_figure5.html
   US Fish & Wildlife Service/YouTube

10. Nick Rowse, a biologist with the U.S. Fish and Wildlife Service, searched the bottom of the Lower St. Croix River for zebra mussels, a small, prolific, non-native clam that's a mortal threat to the river's many native mussels.
    Knight-Ridder/Tribune News Service (2000), taken from ProQuest's eLibrary
    

11. A short video clip from the 3rd Annual Mussel Festival held in Bath County, Virginia, to educate landowners and the public about the importance of these animals to rivers and streams.
    http://www.youtube.com/watch?v=URHTrAAkpr0&feature=related
    Virginia Department of Game and Inland Fisheries/YouTube

12. Zebra mussels also cover individual mussels; this fat mucket (Lampsilis siliquoidea) was removed from the bottom sediment by divers. All exposed areas were covered by zebra mussels.
    http://www.fws.gov/midwest/mussel/images/zebra_mussels_on_native_mussel.html
    US Fish & Wildlife Service

13. Clammers standing atop a mound of mussels killed to make mother-of-pearl buttons, circa 1911
    http://www.fws.gov/midwest/mussel/images/clammers.html
    US Fish & Wildlife Service

14. Propagation of Carolina Heelsplitter (Lasmigona decorata)
    http://www.youtube.com/watch?v=kG7-76N_p6A&feature=related
    Aquatic Epidemiology and Conservation Laboratory, North Carolina State University/YouTube

15. Zebra mussels sign, County Antrim, Northern Ireland. The non-native zebra mussel first appeared in Lough Neagh in 2005. The sign is beside the Sixmilewater close to where it enters Lough Neagh.
    http://commons.wikimedia.org/wiki/File:Zebra_mussels_sign,_Antrim_-_geograph.org.uk_-_1625378.jpg
    Wikipedia, the Free Encyclopedia

16. International Union for Conservation of Nature (IUCN) Deputy Director General Bill Jackson talks about today's water challenges and explains how IUCN is working to make sure that there is enough water in the world for nature and for people.
    http://www.youtube.com/watch?v=2H9Vp8qr20Q
    International Union for Conservation of Nature/YouTube

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