The Hickorynut

The Issue

The Hickorynut (Obovaria olivaria) is a species of freshwater mussel that calls the Ottawa River home. It lives on the sandy bottom of deeper stretches of the river and is more likely to be found in areas where its host fish, the Lake Sturgeon is present. The larval form of the Hickorynut (called glochidia) attach to the gills of the Lake Sturgeon where they feed and grow until they are mature enough to detach and live in the river.

Due to a combination of threats including the invasive Zebra Mussel, as well as declining levels of the Lake Sturgeon, declines in Hickorynut distribution and populations have been seen across its North American range. As of August 16, 2019 the priority of the Hickorynut as an endangered species in Canada has increased. It is now listed on Schedule 1 of the Species at Risk Act, meaning it receives federal and legal protections under the act.

How Are We Helping?

In collaboration with the Canadian Museum of Nature researcher and freshwater mussel expert, Dr. André Martel, Ottawa Riverkeeper is working on a project to help protect the Hickorynut. The goal of this initiative is to promote the conservation and recovery efforts for the Hickorynut in the Ottawa River, through outreach in communities where populations of the mussel are found, as well as by conducting survey dives to establish where population “hotspots” can be found.

Boat Wash Pledge

As part of our ongoing project to help conserve and protect the endangered Hickorynut mussel, Ottawa Riverkeeper is asking those of our followers who partake in recreational boating to sign our Boat Wash Pledge to help prevent the spread of aquatic invasive species, notably the zebra mussel.

What are zebra mussels and how are they related to Hickorynut?

Zebra mussels are a small, invasive species of freshwater mussels found throughout the Great Lakes, Lake St. Clair and the Mississippi River watershed, including our own Ottawa River watershed. Originally from Southeastern Europe, the zebra mussel was introduced to North America via ballast water. These mussels pose a number of harmful effects to local waterways and are of particular concern to Hickorynut populations. Zebra mussels are known to attach themselves to the larger Hickorynut impeding them from feeding, breathing and reproducing. Larval zebra mussels are transparent, microscopic and can survive up to 7 days out of water. As they can be nearly impossible to detect with the naked eye, thorough boat washing is key to preventing their spread.    

Zebra mussels aren’t the only species that can find their way onto boats and into bilge water. Many other invasive species, including aquatic plants like Eurasian milfoil, can also be transported in this way. A thorough wash goes a long way to help reduce the inadvertent spread of many invasive species.

Recommended Boat Washing Procedure

To help limit the spread of the zebra mussels and other invasive species, follow these guidelines for washing your boat when moving it from one water body to another:

  1. Remove debris (e.g. wood, algae, plant material, etc.) and dispose of in a trash bin away from a watercourse.
  2. Get rid of bilge water and water in other on vessel containers (e.g. buckets, fish tanks) *Preferably remove bilge water at the same time you remove your boat from the river/lake
  3. Clean using a pressure washer (2600 psi) with warm water (50º C). Alternatively, use a brush, warm water and vinegar (remember to disinfect and rinse the brush after each wash). Don’t forget to clean your anchor as well!

Sign Ottawa Riverkeeper’s Boat Wash Pledge!

I pledge to assist in Ottawa Riverkeeper’s efforts to minimize the spread of invasive species by washing my boat whenever I move it more than 30 m from a water course.
  • Signing the pledge will add you to our newsletter list. You can unsubscribe at any time.