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Wavyrayed Lampmussel

Habitat Description

The Wavyrayed Lampmussel is typically found in clear, hydrologically stable rivers and streams. Clarke (1981) and Cummings and Mayer (1992) reported the species from gravel or sandy bottoms of riffle-areas in medium sized streams. Strayer (1983) reported the Wavyrayed Lampmussel in Michigan from medium-sized and large streams characterized by low gradients, clear waters, steady flows and substrates of sand and gravel.  Dennis (1984) examined the habitat preferences of 72 species in the Tennessee River basin and reported L. fasciola from small (2nd to 4th order creeks) and medium (5th to 7th order) sized streams. Dennis (1984) reported that the most productive habitat consisted of stable substrates with a mixture of fine particles, gravel and rocks. Within Ontario waters it is usually found in clean sand or gravel substrates in shallow (< 1m) riffle areas. In the Great Lakes it has been found along shallow wave-washed shoals (Metcalfe-Smith and McGoldrick 2003).

Currently Occupied Habitat:

Geospatial Description:

Habitat in need of conservation for the Wavyrayed Lampmussel has been geospatially located using the methods developed by McGoldrick et al. (in press) (Figure 5 - 8) who recommend using the Ontario Ministry of Natural Resource’s Aquatic Landscape Inventory Software (ALIS version 1) (Stanfield and Kuyvenhoven 2005) as the base unit for definition of important habitat within riverine systems.  The ALIS system employs a valley classification approach to define river segments with similar habitat and continuity on the basis of hydrography, surficial geology, slope, position, upstream drainage area, climate, landcover and the presence of instream barriers. For Great Lakes populations where ALIS segments can not be employed, McGoldrick et al. (in press) recommend using a 5km buffer around known species occurrences. The 5km buffer was selected in light of the spatial extent of historic sampling within Lake St. Clair.  Within all identified river segments the width of the habitat zone in need of protection is defined as the area from the mid-channel point to bankfull width on both the left and right banks.

Currently occupied habitat for the Wavyrayed Lampmussel can be summarized as:

  • A 60 km stretch of the Grand River between Inverhaugh and Cambridge (Metcalfe-Smith and McGoldrick 2003).
  • 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 Middle Thames (T. Morris, Fisheries and Oceans Canada, Burlington, unpublished data).
  • The lower reaches of the Middle, Little and South Maitland Rivers and the 45 km section of the main branch of the Maitland River from Wingham to the confluence with the South Maitland.
  • The lower section of the Little Ausable River and a 12 km stretch of the main channel of the Ausable River upstream of Nairn (Metcalfe-Smith et al. 1999).
  • A 12km2 region of the St Clair delta (Zanatta et al. 2002).

Functional Description:

Within the area defined under Geospatial Description only areas meeting the characteristics described below are deemed to represent habitat in need of conservation:

  • permanently wetted and
  • of a stream order greater than 2 (riverine populations only) and
  • having clean sand/gravel substrates sometimes stabilized by larger material (rubble, boulder or bedrock) and
  • riffle/run habitat (riverine populations only) or
  • shallow sand flats (Great Lakes populations) and
  • providing access to suitable host specimens during the period of female gravidity (June 1 – October 15).

Activities Likely to Impact Currently Occupied Habitat

            The currently occupied habitat of the Wavyrayed Lampmussel could be negatively affected by a variety of activities.  Direct destruction of habitat could result from in-stream activities such as dredging, road crossings and pipeline crossings or the construction of dams.  Currently occupied habitat could also be negatively affected by any land-based activities that affect water quality or quantity.  Such activities would include (but are not limited to) the input of nutrients, sediment and toxic substances through improperly treated storm water, cultivation of riparian lands, unfettered access of livestock to the river, channelization and drainage works, water taking, aggregate extraction, and the release of improperly treated sewage. 

            McGoldrick et al. (in press) have earlier identified a number of threshold values which can be used to gage the likelihood that an activity will negatively impact or destroy currently occupied habitat. Any activity that results in an exceedance of the threshold values in Table 4 should be considered likely to destroy currently occupied habitat.

Table 4: Threshold values for determining the likelihood that an activity will negatively impact currently occupied habitat.
unionized ammonia0.21 mg/L
total ammonia1.7 mg/L
copper4.7 µg/L
total phosphorus0.05 mg/L
nitrate-nitrite ratio2.0 mg/L
turbidity8 JTU
potassium6 mg/L

When dealing with freshwater mussels it is necessary to consider not only the physical and chemical components of habitat but also the biological. Any activity which disrupts the connectivity between Wavyrayed Lampmussel populations and their host species (see section on Life Cycle and Reproduction) may result in the destruction of currently occupied habitat. Activities which may disrupt the mussel-host relationship include, but are not limited to, damming, dewatering and sport or commercial harvest.  Note that activities occurring outside the currently occupied habitat zone may affect the host population within the zone (e.g., downstream damming activites may prevent the movement of fish into the currently occupied habitat zone during the period of mussel reproduction (June 1 – October 15)). Any activity that impacts a host population within an area of currently occupied habitat should be evaluated to ensure that the reproductive cycle is not disrupted.

Current habitat in the Great Lakes

Figure 5: Currently occupied habitat for the Wavyrayed Lampmussel (Lampsilis fasciola) in the Great Lakes and connecting channels.

Current Habitat ine the Upper Thames and Ausable rivers

Figure 6: Currently occupied habitat for the Wavyrayed Lampmussel (Lampsilis fasciola) in the Upper Thames and Ausable rivers.

Current habitat in the Maitland River

Figure 7: Currently occupied habitat for the Wavyrayed Lampmussel (Lampsilis fasciola) in the Maitland River.

Current habitat in the Upper grand River

Figure 8: Currently occupied habitat for the Wavyrayed Lampmussel (Lampsilis fasciola) in the Upper Grand River.

Historically Occupied Habitat: Historically occupied habitat includes a 40km stretch of the East Sydenham River and a small stretch of the lower Grand River near York. Although the St Clair and Detroit rivers, Lake St Clair (excluding the delta) and the western basin of Lake Erie represent historically occupied habitat they are low priority sites for recovery/re-establishment due to the presence of high abundances of dreissenid mussels.

Critical Habitat: The identification of Critical Habitat 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 although Table 5 outlines activities that would assist with obtaining the required information. The activities listed in Table 5 are not exhaustive but outline the range and scope of actions identified by the OFMRT as necessary to identify Critical Habitat for the Wavyrayed Lampmussel. It is likely that the process of investigating the actions in Table 5 will lead to the discovery of further knowledge gaps that will have to be addressed. Until Critical Habitat can be defined the recovery team has identified the areas listed in the Currently Occupied Habitat section as areas in need of conservation.

Table 5: Schedule of activities to identify Critical Habitat
ActivityApproximate Time Frame1
Conduct mussel population surveys2006-2008
Assess habitat conditions in occupied areas (e.g., flow, substrate, water clarity and quality)2006-2008
Determine any life stage differences in habitat use2007-2009
Survey and map areas of suitable but unused habitat within historical range2008-2010
Assess genetic structure of populations2006-2008
Determine host fish species2006
Conduct host fish population surveys2006-2008
Assess habitat use by host species2006-2008
Determine areas of overlap between mussel and host habitat2009-2010

Habitat Trends: The majority of Lake St. Clair (excluding the delta) the Detroit River and the western basin of Lake Erie are no longer suitable habitat for the Wavyrayed Lampmussel because of the infestation of dreissenid mussels. There is strong evidence that poor water clarity limits the distribution of the Wavyrayed Lampmussel (Metcalfe-Smith & McGoldrick, 2003). High turbidity and suspended solids in the Sydenham and Ausable rivers have rendered large portions of habitat unsuitable. Water clarity in the occupied reaches of the Grand and Maitland Rivers does not seem to be a problem.

Habitat Protection: The federal Species at Risk Act (SARA) was proclaimed in June of 2003. Under SARA there are general prohibitions against killing, harming, taking, possessing, capturing, and collecting the Wavyrayed Lampmussel and against damaging or destroying its residences, as well as prohibitions on the destruction of Critical Habitat. The Fisheries Act represents an important tool for habitat protection and along with other federal environmental legislation is complimentary to the Species at Risk Act. Under the federal Fisheries Act mussels are considered shellfish, falling under the definition of ‘fish’, and their habitat is therefore protected from harmful alteration, disruption or destruction unless authorized by the Minister of Fisheries and Oceans, or his/her delegate. Planning authorities must be consistent with the provincial Policy Statement under Section 3 of Ontario’s Planning Act, which prohibits development and site alteration in the significant habitat of endangered species. The Ontario Lakes and Rivers Improvement Act prohibits the impoundment or diversion of a watercourse if siltation will result while the voluntary Land Stewardship II program of the Ontario Ministry of Agriculture, Food and Rural Affairs is designed to reduce erosion on agricultural lands. Stream-side development in Ontario is managed through floodplain regulations enforced by local conservation authorities. 

A majority of the land adjacent to the rivers where Wavyrayed Lampmussels are found is privately owned, however, the river bottom is generally owned by the Crown. The Municipality of Southwestern Middlesex (formerly Mosa Township) owns a 20 ha section of forest along the reach of the Sydenham River where Wavyrayed Lampmussel shells were found in 1997 (Muriel Andreae, St. Clair Region Conservation Authority, cited in Metcalfe-Smith et al. 2000) and the SCRCA owns approximately 1816 ha of property in the watershed.  The Ausable Bayfield Conservation Authority (ABCA) owns approximately 1830 ha of property split between a number of locations in the Ausable River basin (K. Vader, ABCA, cited in Metcalfe-Smith et al. 2000) and the Maitland Valley Conservation Authority owns 28 properties covering 1800 ha within the Maitland River watershed including one site where the Wavyrayed Lampmussel was found (Wawanosh Conservation Area). Much of the land adjacent to the refuge site identified in the Lake St. Clair delta falls under the jurisdiction of the Walpole Island First Nation (Zanatta et al. 2002).