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Recovery Strategy for the Wavyrayed Lampmussel (Lampsilis fasciola) in Canada (Final)


Executive Summary

The Wavyrayed Lampmussel (Lampsilis fasciola, Rafinesque 1820) is a small sexually dimorphic mussel recognized by its yellow or yellowish-green rounded shell. The shell is characterized by numerous thin wavy green rays that may be narrow and individual or coalesced into wider rays in some specimens. Regardless of size, the rays are always wavy with multiple interruptions giving rise to the common name of this mussel. The species is typically found in small to medium, clear, hydrologically stable rivers where it inhabits clean sand/gravel substrates in and around shallow riffle areas.

The Wavyrayed Lampmussel is considered globally secure (G4). It is nationally secure within the United States (N4) although it is declining throughout its range, particularly in the north where it is considered endangered in Illinois, threatened in Michigan and New York and of special concern in Indiana. This species is considered imperiled (N1) in Canada where it is listed as Endangered by COSEWIC. The Canadian distribution is restricted to Ontario where it was likely always a rare species. The historical Canadian range included western Lake Erie, Lake St. Clair, and the Maitland, Ausable, St. Clair, Sydenham, Thames, Detroit and Grand Rivers, however current distributions are limited to a small portion of the Lake St. Clair delta and the Ausable, Grand, Thames and Maitland rivers with only the Grand, Thames, and Maitland populations believed to be healthy.

Threats to the Wavyrayed Lampmussel are many and varied. The main reason for the declines in lake populations, and the major current threat to the Lake St. Clair population, is the presence of the exotic zebra mussel (Dreissena polymorpha). Zebra mussels attach to the shells of native mussels and act to inhibit feeding, respiration, excretion and locomotion. Riverine populations of Wavyrayed Lampmussel are subject to different threats than lake populations with the primary threats being declining water quality and the loss of habitat. Most of the watersheds where Wavyrayed Lampmussels are still found are predominantly agricultural with high nutrient and sediment inputs to the watercourse from the adjacent terrestrial lands. The obligate parasitic nature of the reproductive cycle of the Wavyrayed Lampmussel necessitates a consideration of threats to the host fish species as well as the direct threats to the mussel.

The long-term goal of this recovery strategy is to prevent the extirpation of the Wavyrayed Lampmussel in Canada and to promote the recovery of this species by:

  1. protecting existing populations to prevent further declines,
  2. restoring degraded populations to healthy self-sustaining levels by improving the extent and quality of habitat and
  3. re-introducing the Wavyrayed Lampmussel into areas where it formerly existed where feasible.

The following specific short term objectives have been identified to assist with meeting the long term goal:

  1. Determine extent, abundance and population demographics of existing populations.
  2. Determine/confirm fish hosts, their distributions and abundances.
  3. Define key habitat requirements to identify Critical Habitat.
  4. Establish a long-term monitoring program for Wavyrayed Lampmussels, their habitat and that of their hosts.
  5. Identify threats, evaluate their relative impacts and implement remedial actions to reduce their effects.
  6. Examine the feasibility of relocations, reintroductions and artificial propagation.
  7. Increase awareness of the significance of the Wavyrayed Lampmussel and its status as a Canadian Species at Risk.

The Recovery Team has identified a variety of approaches that are necessary to ensure that the objectives are met. These approaches have been organized into four categories: Research and Monitoring, Management, Stewardship and Awareness.

This Recovery Strategy represents one piece of a multi-faceted approach to ensure the preservation of this endangered mussel. The needs of the Wavyrayed Lampmussel have been directly considered in the development of aquatic ecosystem recovery strategies for the Sydenham River, the Ausable River and the Thames River and the goals, objectives and approaches outlined in these ecosystem strategies will therefore benefit the Wavyrayed Lampmussel. Although not directly considered in the Grand River Fish Recovery Strategy or the Walpole Island Ecosystem Recovery Strategy, the Recovery Team feels that the actions proposed by these ecosystem oriented teams will likely benefit the Wavyrayed Lampmussel through overall improvement of aquatic habitat. In addition to these recovery planning efforts a number of ongoing research programs will assist with achieving the goals outlined in this strategy. A team at the University of Guelph has established a research facility to investigate potential host species for the Wavyrayed Lampmussel and other mussel species at risk while a laboratory at the University of Toronto/Royal Ontario Museum has recently begun to examine the conservation genetics of mussel species at risk with a focus on the Wavyrayed Lampmussel. Researchers from the Fisheries and Oceans Canada and the National Water Research Institute of Environment Canada are conducting ongoing surveys for mussel species at risk in southwestern Ontario and examining the feasibility of establishing managed refuge sites in the St. Clair delta region.

The specification of Critical Habitat is a crucial component to the recovery of endangered species under the Species at Risk Act and requires a thorough knowledge of the species needs during all life stages as well as an understanding of the distribution, quantity, and quality of habitat across the range of the species. At present, this information is not available for the Wavyrayed Lampmussel; therefore, the Ontario Freshwater Mussel Recovery Team has identified a series of tasks that will assist with collecting the information required to characterize Critical Habitat for the species. Until Critical Habitat can be identified the Recovery Team has identified habitats in need of protection that include:

  • 60 km of the upper Grand River between Inverhaugh and Cambridge,
  • a 30 km section of the North Thames River above London including Medway and Fish creeks. A 25 km section of the Middle Thames River from London to Dorchester as well as the lower reaches of the Middle Thames from Thamesford to its confluence with the South Thames
  • a 45 km stretch of the Maitland River from the confluence with the South Maitland River upstream to Wingham, the lower reaches of the South Maitland, Middle Maitland and Little Maitland Rivers,
  • the lower section of the Little Ausable River, a 12km stretch of the main channel of the Ausable River upstream of Nairn and
  • a 12 km² region of the St. Clair delta.

The Ontario Freshwater Mussel Recovery Team feels that the approaches outlined in this strategy to achieve recovery of the Wavyrayed Lampmussel are best accomplished through cooperation with existing ecosystem recovery teams. In watersheds with these teams, implementation of recovery actions should be coordinated to ensure that activities are beneficial to all species at risk and to eliminate the possible duplication of efforts. Where ecosystem teams are absent, Recovery Implementation Groups (RIGs) may be struck to facilitate the carrying out of recovery actions. Evaluation of the success of recovery actions will be achieved primarily through the routine monitoring programs established to track changes in population demographics and habitat, however, RIGs will also incorporate specific milestones into Recovery Action Plans. The entire Recovery Strategy will be reassessed after 5 years to evaluate the progress towards achieving the goals and objectives and to incorporate new information.