Threehorn Wartyback

Consultations on listing under the Species at Risk Act

Threehorn Wartyback (Photo credit: Fisheries and Oceans Canada)
Threehorn Wartyback (Photo credit: Fisheries and Oceans Canada)

wartyback-obliquaire-questionnaire.pdf (729 kb, Get Adobe Reader)

One of the purposes of the Species at Risk Act (SARA), proclaimed by the Government of Canada in 2003, is to provide for the legal protection of wildlife species and the conservation of biological diversity.

The Committee on the Status of Endangered Wildlife in Canada (COSEWIC) has the mandate to conduct assessments on the status of wildlife species and categorize them according to their level of risk for extinction (extinct, extirpated, endangered, threatened, or special concern).

The Government of Canada considers scientific evidence, comments received from Canadians during consultations, and potential socio-economic impacts before making a decision whether or not to include the species on the List of Wildlife Species at Risk under SARA.

Recovery planning is undertaken for all listed species, and prohibitions are put in place protecting species assessed as extirpated, endangered or threatened.

As part of the consultation process, the Government of Canada would like to hear your opinions on listing the Threehorn Wartyback as Threatened under the Species at Risk Act, and any comments on the potential positive and negative impacts this listing would have on you, your industry, your community and/or the ecosystem.

The Threehorn Wartyback has recently been assessed as “Threatened” by the Committee on the Status of Endangered Wildlife in Canada. Before deciding whether this species will be protected under the Species at Risk Act, Fisheries and Oceans Canada would like your opinion, comments and suggestions regarding the possible ecological, cultural and economic impacts of listing or not listing it.

Please provide your input by September 15, 2014 using the survey or go to the Species at Risk Public Registry Website.

Threehorn Wartyback

The Threehorn Wartyback is one of Canada’s 54 freshwater mussel species and the only mussel of the genus Obliquaria found in Canada. It is a rare mussel, only found in North America, and it reaches an average length of 4 centimetres. Its thick shell is circular to triangular in shape, with shell colour ranging from green, tan or brown. There is a single row of 2-5 large knobs or “horns” across the tops of both shells. A complete species profile on the Threehorn Wartyback can be found on the Fisheries and Oceans Canada website.

In Canada, the Threehorn Wartyback was historically known only in Ontario, in Lake St. Clair, the Detroit River, western Lake Erie and the Sydenham, Thames and Grand rivers. It is now believed to be lost from the Great Lakes, though small populations remain in the Sydenham, Thames and Grand rivers.

Distribution map of the Threehorn Wartyback in Canada

distribution map

Proposed listing under SARA: Threatened

In 2013, the Threehorn Wartyback was assessed as Threatened by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC). If listed as Threatened under the Species at Risk Act, a recovery strategy and action plan will be developed.

Threats

Remaining Threehorn Wartyback mussels are significantly threatened by pollution related to urban and agricultural activities. Specifically, it is the sediment loading that leads to the clogging of the mussel’s gill structures, while nutrient loading and contaminants degrade water quality and overall habitat. Infestations of aquatic invasive species also remain a threat. Specifically, the Zebra Mussel is largely responsible for the loss of Threehorn Wartyback populations within the Great Lakes and connecting channels. By attaching to the Threehorn Wartyback by the hundreds, Zebra Mussels interfere with the native mussel’s ability to feed, move, breathe and reproduce. The Zebra Mussel continues to similarly threaten the remaining riverine populations of the Threehorn Wartyback. Additionally, Round Gobies are currently impacting native fish communities, including fish hosts that support native mussels. Human recreational activities, such as driving all-terrain vehicles (ATVs) over fragile mussel beds in the Sydenham River, are also another known threat.

Special significance of the species

Freshwater mussels are molluscs, soft-bodied animals without a skeleton (invertebrates) that live on the bottom of streams, rivers, lakes and ponds. They use a muscular foot to burrow and crawl and have a pair of hinged shells.  Mussels are filter feeders -- nature’s water purifiers -- and are food for other wildlife like fishes, otters, mink, muskrats and some birds.  They are also among the most endangered creatures in the world.

Possible management measures

If the Threehorn Wartyback is listed under SARA, Fisheries and Oceans Canada will, in collaboration and consultation with stakeholders and partners, use the best available information to develop a recovery strategy and action plan for the species.

Protection and recovery of species under SARA

If the Threehorn Wartyback is added to the List of Wildlife Species at Risk as Threatened, it will be legally protected under SARA and subject to prohibitions. It will be illegal to kill, harm, harass, capture or take a Threehorn Wartyback, or possess, buy, sell or trade any part of one unless authorized by a permit issued under SARA. It will also be illegal to destroy the critical habitat of the Threehorn Wartyback – the habitat necessary for its survival and recovery – once it is identified in the recovery strategy or action plan.

Questions

  1. Which stakeholder group best represents you or your organization?
    1. Aboriginal
    2. Academic
    3. General public
    4. Government
    5. Industry
    6. Non-profit organization
    7. Small business
    8. Wildlife Management Board
    9. Other? ________________________
  2. Do you think protecting the Threehorn Wartyback under the Species at Risk Act would have economic, environmental, cultural and/or social BENEFITS for your organization?

  3. Do you think protecting the Threehorn Wartyback under the Species at Risk Act would have economic, environmental, cultural and/or social COSTS for your organization?

  4. Should the Government of Canada add the Threehorn Wartyback as Endangered to the List of Wildlife Species at Risk for protection under the Species at Risk Act?

  5. Do you have any other comments about this listing consultation that you would like us to consider?