Warning This Web page has been archived on the Web.

Archived Content

Information identified as archived on the Web is for reference, research or recordkeeping purposes. It has not been altered or updated after the date of archiving. Web pages that are archived on the Web are not subject to the Government of Canada Web Standards, as per the Policy on Communications and Federal Identity.

Skip booklet index and go to page content

Wavyrayed Lampmussel

II. Recovery

Recovery Goal

The long-term goal of this recovery strategy is to prevent the extirpation of the Wavyrayed Lampmussel in Canada and to promote the downlisting or delisting 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.

Morris et al. (2005) recommend that recovery of the Wavyrayed Lampmussel be assessed using a hierarchical approach where recovery at the species level is dependent upon achieving desired goals at the population and individual levels. They have identified 6 extant and 4 extirpated population units and suggest that these units should form the basis for any evaluation of species recovery.

Recovery Objectives (5 year)

  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.

Approaches to Meeting Recovery Objectives

The approaches to recovery have been organized into four distinct groups – research and monitoring, management, stewardship and awareness. Successful recovery across the range of the Wavyrayed Lampmussel will require consideration of all approaches from all categories. Approaches have been prioritized in a relative sense only as the OFMRT feels that all approaches would assist in meeting the recovery objectives.  Recovery actions that consider multiple approaches will likely have a greater chance of achieving the recovery goals. A narrative has been included after each table where appropriate.

1) Research and Monitoring Approaches

PriorityNumberObjective AddressedBroad Approach/ StrategySpecific StepsAnticipated EffectThreat Addressed
Urgent1-11, 3Surveys – Ausable R., Grand R., Thames R.Conduct further surveys to determine the extent and abundance of the Ausable R., Grand R. and Thames R.  populations. Will identify distribution, density and assist with identification of Critical Habitat. 
Urgent1-21i, 3Surveys – Maitland R.Intensive surveys to quantify distribution and abundance of this newly discovered population.

Will characterize these populations and determine their status.

Will assist with identification of Critical Habitat.

Urgent1-33Research – Critical HabitatDetermine the habitat requirements of all life stages of the Wavyrayed Lampmussel.Will define Critical Habitat for the Wavyrayed Lampmussel.All threats.
Urgent1-43Surveys - Habitat Map areas of suitable habitat.Will assist with identification of Critical Habitat. 
Urgent1-53Research – Cross-basin habitat comparisonDetermine critical conditions for Wavyrayed Lampmussel survival by cross-basin comparisons of populations which are stable (e.g., Grand R.) with those that are declining (e.g., Thames R., Ausable R.).Will assist with determination of critical conditions necessary for recovery in all habitats.All threats.
Urgent1-61Research – host fishInvestigate other host fish species for the Wavyrayed Lampmussel.Identify other host species.Disruption of Host Fish Relationship.
Urgent1-72, 4Surveys – host fishDetermine the distribution and abundance of the identified host species.Determine if Wavyrayed Lampmussels are limited by host availability. Assist in identifying Critical Habitat.Disruption of Host Fish Relationship.
Urgent1-84Monitoring - populationsEstablish routine surveys to monitor changes in the distribution and abundance of all populations Will provide trend through time data for tracking recovery progress. 
Urgent1-94Monitoring - habitatEstablish monitoring stations to track changes in Wavyrayed Lampmussel habitatWill identify habitat trends.  
Urgent1-105Monitoring - exoticsMonitor reservoirs for establishment of zebra mussels. Will provide early warning of threat to populations and habitat.Exotics.
Urgent1-115Barrier analysis

Assess the distribution of in- stream barriers in all basins.

Determine their impact and the feasibility of barrier removal or mitigation where appropriate.

Will determine if dams impact population distributions.Impound-ments.
Urgent1-125Toxicity testingDetermine  glochidial sensitivity to environmental contaminants Will identify threats and potential limiting factors.Water quality – contaminants and nutrients.
Urgent1-136Population augmentationExamine the feasibility of translocations and re-introductions.Will determine if small populations can be augmented or if the species can be reintroduced in historical range. 
Urgent1-146Research – conservation genetics

Compare genetic variation in Canadian range with

variation across entire North American range.

Will assist in determining appropriateness of population augmentation and selecting source population if action is warranted. 
Necessary1-156Research – propagation guidelinesDevelop genetically sound propagation guidelines for freshwater mussels.Will give an estimation of the number of individuals required to maintain or reintroduce 95% of the known genetic variability in propagated populations. 
Necessary1-166Research - phylogeneticsDetermine if different observed lure morphologies are monophyletic.Will resolve taxonomic uncertainty and ensure correct management of unique taxonomic units. 

1-1 & 1-2: Additional surveys are required to confirm the complete extent of Wavyrayed Lampmussel distributions in the Ausable, Grand and Thames Rivers. Particular areas in need of additional survey work have been identified under Knowledge Gaps in the Background section. A thorough understanding of all current and historic distributions is a necessity for determination of Critical Habitat as indicated by the schedule of activities in Table 4. In the case of the newly discovered Maitland River population, additional surveys will need to be more exhaustive than in the other drainages.

1-3 – 1-5: Critical Habitat is a cornerstone concept of SARA and represents one of the best tools for preserving the Wavyrayed Lampmussel. Given the present knowledge of the species it is not possible to identify Critical Habitat at this time however the activities identified in items 1-3 to 1-5, and those in Table 4, will begin to fill the gaps and allow for a description of Critical Habitat. Additional data collected in conjunction with the populations surveys will assist with determining habitat requirements while surveys to map areas which possess the identified habitat requirements will assist with identifying areas of Critical Habitat.

1-6 & 1-7: The obligate parasitic larval stage of the Wavyrayed Lampmussel represents a potential bottleneck in its lifecycle.  Research and recovery actions focusing on the pre or post encystment period may prove unproductive if the presence of a host fish is the limiting step. In order to determine if these species are host limited it is necessary to first confirm the host species and then to confirm that the distributions of the mussel and its host overlap in time and space in a manner that will permit successful encystment. The identification of high host specificity in some mussel species requires that hosts be identified for local populations whenever possible.  Efforts should be directed towards confirming that species identified as hosts for American populations also function as hosts in Canada.

            Once the Canadian hosts have been confirmed it is necessary to ensure that host species distributions overlap with Wavyrayed Lampmussel distributions. Since the adult mussels are essentially sessile this can be accomplished by confirming that members of the hosts species occur in reaches with mature female mussels at times when the female mussels possess mature glochidia.

1-8 – 1-10: A network of detailed, permanent monitoring stations should be established throughout the present and historic ranges of the Wavyrayed Lampmussel. Monitoring sites should be established in a manner so as to permit:

  • Quantitative tracking of changes in mussel abundance or demographics (size distribution, age structure etc.) or that of their hosts.
  • Detailed analyses of habitat use and the ability to track changes in use or availability.
  • The ability to detect the presence of exotic species (i.e. zebra mussels). Reservoirs represent the likely seed locations for zebra mussels in the inland rivers.. Monitoring sites should be established within or close to these reservoirs to permit the early detection of zebra mussels in the event that they invade these systems.  Monitoring of exotics in the Lake St. Clair delta will likely be conducted in close association with the managed refuge sites.

Monitoring stations established to benefit Wavyrayed Lampmussels will provide the opportunity to collect data on the distribution, demographics, habitat and hosts of all mussel species and will be incorporated into the recovery plans for other mussel SAR.

1-11: An assessment of instream barriers should be conducted for all watersheds where the Wavyrayed Lampmussel is known to exist. Barriers should be mapped and their effects on local habitat conditions (e.g., flow, temperature, substrate stability and composition) should be assessed to determine if they are impacting Wavyrayed Lampmussel habitat. While instream barriers have been largely cited as having a detrimental effect on mussels through temperature and hydraulic changes as well as restricting host distributions, anecdotal evidence indicates that small barriers on the Sydenham River may be providing habitat for hosts of the Wavyrayed Lampmussel (pers. comm., M. Andreae, SCRCA, October 2003).

1-13 – 1-16: Additional surveys and monitoring may reveal that some populations are not likely to persist without active intervention. In some cases these populations may benefit from supplementation with individuals from nearby stable locations or through stocking with artificially reared juveniles.  Research into the feasibility of population augmentation should begin immediately to prepare for this possibility and should be directed towards:

  • Identifying genetically suitable stocks for source populations.
  • Establishing laboratory rearing procedures. U.S. groups have had great success in producing juvenile Wavyrayed Lampmussels in captivity and successfully rearing them to reproductive maturity (Hanlon 2000). Consultation with these groups will likely contribute to the development of successful protocols in Canada.
  • Evaluating methods to maximize survival of transplanted individuals.

2) Management Approaches

PriorityNumberObjective AddressedBroad Approach/ StrategySpecific StepsAnticipated EffectThreat Addressed
URGENT2-11, 2Capacity BuildingPromote and enhance expertise in freshwater mussel identification/ biology and provide for the transfer of knowledge.Will ensure correct identification of mussel species at risk, sound experimental design and maximize efficiency.All threats.
URGENT2-25, 7Cooperation –  ecosystem recovery strategiesWork with existing ecosystem recovery teams to implement recovery action plans.Ensure a seamless implementation of all recovery actions.All threats.
URGENT2-35Fish Management PlanEncourage the development of management plans for host fish species.Will assist with ensuring that host fish abundance and distributions do not limit recovery of the Wavyrayed Lampmussel.Disruption of Host Fish Relationship.
URGENT2-45Exotic Species Management PlanDevelop an implementation plan to respond to the identification of exotic species invasion of Wavyrayed Lampmussel habitatWill ensure a  timely and coordinated response to the invasion of exotic species (e.g., zebra mussels)Exotics.
URGENT2-55DrainageWork with drainage supervisors, engineers and contractors to limit the effects of drainage activities on Wavyrayed Lampmussel habitat.Will mitigate harmful effects of drainage activities.Siltation/ Suspended solids.
URGENT2-65Wastewater Treatment Plants and Stormwater Management FacilitiesIdentify potential problem areas and encourage upgrading where appropriate.Will improve water quality by reducing nutrient and suspended solid inputs from urban centres. Siltation/ Suspended solids; Water quality – contaminants and nutrients.
URGENT2-75Water Supply ManagementEnsure that flow requirements of the Wavyrayed Lampmussel are considered in management of flow regimes.Will help ensure that minimum baseflow conditions are maintained for the Wavyrayed Lampmussel.Urbanization
NECESSARY2-85Municipal PlanningEncourage municipal planning authorities to consider Recovery Goals in official plans.Will provide further protection for the Wavyrayed Lampmussel and ensure that future development does not degrade important habitat.Urbanization; Water quality.
Benneficial2-95Policy and LegislationEncourage and support the development and implementation of legislation and policies at all levels of government that will protect existing populations and enhance recovery. Will ensure a coordinated approach to species protection. All threats.

2-1: The current capacity within southern Ontario to perform the necessary survey and monitoring work is insufficient. Knowledge of freshwater mussel identification, distribution, life history and genetics is limited to a small number of individuals from a limited number of government and academic institutions with the retirement of several key researchers expected prior to the 5-year re-evaluation period for this strategy. A concerted effort must be made to increase this capacity by:

  • Training personnel in the identification of all mussel species with emphasis on the rare species.
  • Producing a field guide to the mussels of Ontario.
  • Encouraging graduate and post-graduate research aimed at fulfilling the needs identified under Research and Monitoring.

2-2:  Many of the threats to the Wavyrayed Lampmussel can be classified as widespread and chronic (See Threats section) and represent general ecosystem threats affecting numerous other aquatic species. Efforts to remediate these threats will benefit many species in addition to the Wavyrayed Lampmussel and should be implemented in close connection with the aquatic ecosystem recovery teams for the Thames, Grand  and Sydenham rivers (see section entitled Activities already completed or underway) to eliminate duplication of efforts and ensure that undertaken activities are not detrimental to other species.   


2-3: The host fish for the Wavyrayed Lampmussel may have to be afforded some degree of protection beyond those of the Ontario Fishery Regulations if the species is to recover. The likely host species, smallmouth bass, is a popular sport-fish species and subject to intense angling pressure throughout the distribution of the Wavyrayed Lampmussel.  Since the smallmouth bass is not listed by COSEWIC this species receives no direct protection under SARA although the potential role of hosts as residences for larval mussels may trigger future protection under the act. It will be necessary to develop a formal management plan for the smallmouth bass and any species identified as a host for the Wavyrayed Lampmussel to ensure that host populations remain healthy and do not hinder recovery of the mussels.

2-4: In the event that the routine monitoring programs (1-10) detect the presence of zebra mussels or other exotic species within the range of the Wavyrayed Lampmussel, a coordinated plan should be developed to ensure a quick response. The plan should include an assessment of potential risks and proposed actions (e.g., eradication of exotics, relocation of native mussels or shell cleaning).

2-5: Drainage development and maintenance activities that mitigate existing threats and prevent the continued degradation of aquatic habitat within the range of the Wavyrayed Lampmussel should be supported and promoted.

2-7:  The Wavyrayed Lampmussel is a species adapted to hydrologically stable flow regimes and does not possess any of the shell modifications typical of species adapted to high shear environments (Watters 1994).  The species has also been identified by Tetzloff (2001) as one of the most susceptible species to low dissolved oxygen conditions which may be associated with toxic events or reductions in flow conditions (Johnson et al. 2001). Careful consideration must be paid to the management of flow regimes in rivers with Wavyrayed Lampmussels to ensure that flow conditions remain within preferred levels for this species.

3) Stewardship Approaches

PriorityNumberObjective AddressedBroad Approach/ StrategySpecific StepsAnticipated EffectThreat Addressed
URGENT3-15Riparian buffersEstablish riparian buffer zones in areas of high erosion potential by encouraging naturalization or planting of native species.Will improve water quality by reducing bank erosion, sedimentation and overland run-off. Siltation/ suspended solids; water quality-contaminants and nutrients.
URGENT3-25Tile drainageWork with landowners to mitigate the effects of tile drainage. Will reduce nutrient and sediment inputs.Siltation/ suspended solids; water quality-contaminants and nutrients.
NECESSARY3-35Soil TestingEncourage soil testing to determine fertilizer application rates.Will reduce nutrient inputs to the river.Water quality-contaminants and nutrients.
NECESSARY3-45Livestock accessLimit livestock access to rivers. Will improve habitat quality by reducing nutrient inputs, bank erosion, and physical disturbance.Siltation/ suspended solids; water quality-contaminants and nutrients.

The activities characterized in this section, and represented by the sample of activities above, embody sound agricultural practices that when implemented will benefit both the terrestrial and aquatic ecosystems. These activities can generally be referred to as “best management practices”. In the three watersheds with aquatic ecosystem recovery strategies (Sydenham, Thames, Ausable) as well as the two watersheds with other recovery plans (Grand, Lake St. Clair) it will be important for members of the OFMRT to interact closely with members of these teams when carrying out recovery actions for the Wavyrayed Lampmussel. Many of the ecosystem teams will have established stewardship liaisons and have activities already underway which will mesh nicely with the actions required to benefit the Wavyrayed Lampmussel.

4) Awareness Approaches

PriorityNumberObjective AddressedBroad Approach / StrategySpecific StepsAnticipated EffectThreat Addressed
URGENT4-15, 7Recreational Angler OutreachIncrease awareness within the angling community about the role of the smallmouth bass as a host for the Wavyrayed Lampmussel.  Will reduce the impact of angling on host fish species.Host fish disruption; recreational activity.
URGENT4-25Exotic speciesIncrease public awareness of the potential impacts of transporting/ releasing exotic species.Will reduce the risk of zebra mussels becoming established in the reservoirs.Exotics.
NECESSARY4-31, 7Field guideDevelop a field guide to the freshwater mussels of Southern Ontario.Will assist with identification of species at risk and the transfer of knowledge.All threats.
NECESSARY4-41, 7Mussel identification workshopCoordinate a 2 day workshop covering topics of mussel biology, ecology and the identification of all freshwater mussel species found in southern Ontario.Will assist with identification of species at risk and the transfer of knowledge.All threats.
NECESSARY4-57Public OutreachEncourage public support and participation by developing awareness materials and programs.Will increase public awareness of the importance of species at risk.All threats.

4-1: The likely host of the Wavyrayed Lampmussel, the smallmouth bass, is a popular sport-fish in southern Ontario and necessitates a thorough outreach program with the sport-fish industry.  Outreach activities should be directed at ensuring a non-destructive sport-fishery directed at locations and times when smallmouth bass are unlikely to be harbouring Wavyrayed Lampmussel glochidia.

4-3 & 4-4: Increasing basic mussel knowledge and identification skills was identified as a key Management objective (2-1) and can be assisted through the development of the Awareness materials identified here including the development of a mussel field guide for Ontario and a hands-on workshop for interested government, agency, NGO and individuals.   

4-5: Increased public knowledge and understanding of the Wavyrayed Lampmussel will play a key role in the recovery of this, and other, endangered mussels. The role that freshwater mussels play within the aquatic ecosystem and their role as indicators of habitat degradation and human health hazards must be conveyed to all stakeholder groups. Outreach programs should be developed for landowners, interest groups, schools and any interested parties.

Potential Impacts of Recovery Strategy on Other Species/Ecological Processes:

The Wavyrayed Lampmussel is a sensitive species, particularly to issues of water clarity and quality. For this reason, we expect that efforts made to improve conditions for the Wavyrayed Lampmussel will benefit most other aquatic species. A few opportunistic species that can readily adapt to degraded conditions (e.g., Pyganodon grandis or Pimephales promelas) may see a decline in numbers/range as a result of rehabilitative efforts. These changes should not be viewed in a negative light but rather as a resetting of the aquatic community to pre-disturbance conditions.

Actions Already Completed or Underway

Sydenham Recovery Ecosystem Strategy: The Sydenham River Recovery Team was formed in 1999 and charged with developing an ecosystem based recovery strategy for the Sydenham River basin.  The recovery strategy focuses on the 14 aquatic species (5 mussels including the Wavyrayed Lampmussel, 8 fishes, 1 turtle) within the basin that have been listed as endangered, threatened or of special concern by the COSEWIC. The primary objective of the recovery strategy “is to sustain and enhance the native aquatic communities of the Sydenham River through an ecosystem approach that focuses on species at risk” (Dextrase et al. 2003).  The Sydenham River Recovery Team has formed four Recovery Implementation Groups (RIG): management, stewardship, research and monitoring, and community outreach.

ThamesRiver Recovery Ecosystem Strategy: The Thames River Recovery Team has set out to develop an ecosystem based recovery strategy for the Thames River watershed. The stated goal is to develop “a recovery plan that improves the status of all aquatic species at risk in the Thames River through an ecosystem approach that sustains and enhances all native aquatic communities” (Thames River Recovery Team 2003). This recovery strategy addresses 25 COSEWIC listed species including 7 mussels, 12 fishes and 6 reptiles.

AusableRiver Ecosystem Recovery Strategy: The Ausable River Recovery Team is developing an ecosystem Recovery Strategy for the 14 COSEWIC listed aquatic species in the Ausable River basin. This plan covers 4 endangered mussel species including the Wavyrayed Lampmussel. The goal of the strategy is to “prepare a recovery plan (recovery strategy + action plan) that sustains and enhances the native aquatic communities of the Ausable River through an ecosystem approach that focuses on species at risk “ (Ausable River Recovery Team 2003).

Grand River Fish Species at Risk Recovery Strategy: The Grand River Recovery Team has developed a draft recovery strategy for fish species at risk in the Grand River. The goal of this strategy is “to conserve and enhance the native fish community using sound science, community involvement and habitat improvement measures” (Portt et al. 2003). Although the strategy does not directly address the Wavyrayed Lampmussel, “(its) habitat preferences and requirements will be taken into account when assessing management actions targeting fish species at risk. In most cases, it is anticipated that recovery actions benefiting fishes at risk will also benefit these other rare species” (Portt et al. 2003).

WalpoleIslandEcosystem Recovery Strategy: The Walpole Island Ecosystem Recovery Strategy Team was established in 2001 to develop an ecosystem based recovery strategy for the area containing the St. Clair delta with the goal of outlining steps to be taken to maintain or rehabilitate the ecosystem and species at risk (Walpole Island Heritage Centre 2002). Although the strategy is initially focusing on terrestrial ecosystems there are future plans to include aquatic components of the ecosystem. 

Fish Host Identification: A research group led by Dr. G. L. Mackie and Dr. J Ackerman has been established at the University of Guelph to investigate aspects of the reproductive cycle of freshwater mussels (host fish determination, glochidial development, juvenile growth and survival). The group conducts its research at the Hagen Aqua Lab on the grounds of the university in Guelph, Ontario, Canada. This facility has already been used to investigate potential hosts for five species of endangered mussels including the Wavyrayed Lampmussel (McNichols et al. 2005).

Source Protection Planning: A White Paper on Watershed-based Source Protection Planning was released in February 2004 (Ontario Ministry of the Environment 2004). Source Protection Planning will identify potential sources of contamination to the surface water and groundwater, determine how much water is readily available, evaluate where that water is vulnerable to contamination and implement programs to minimize risk of contamination to water quality as well as minimizing threats to water quantity.    

Allowable Harm Analysis: Fisheries and Oceans Canada, in partnership with other interested parties, has initiated an analysis of the potential for Wavyrayed Lampmussel populations to withstand any additional level of human-induced mortality without impeding recovery of the species. This Allowable Harm Analysis (AHA) is being conducted on the population units recommended by Morris et al. (2005) and will assist managers when making decisions regarding development activities within the watersheds occupied by the Wavyrayed Lampmussel.

Recovery Action Plans

One or more action plans relating to this recovery strategy will be produced within 5 years of the strategy being published.


The routine monitoring programs will provide the primary means of evaluating the success of the listed recovery approaches. The monitoring programs will provide trend through time data allowing the tracking of Wavyrayed Lampmussel populations and habitat and will form the basis of an adaptive management program. Recovery Implementation Groups will develop specific goals in the Recovery Action Plans to provide a further basis for evaluating success. The entire Recovery Strategy will be reviewed in 5 years at which time all goals, objectives and approaches will be re-evaluated.