COSEWIC assessment and update status report on the Athabasca Thrift, ssp. interior in Canada
Table of Contents
Assessment and Update Status Report
Armeria Maritima ssp. Interior
Committee on the Status
of Endangered Wildlife
Comité sur la situation
des espèces en péril
COSEWIC status reports are working documents used in assigning the status of wildlife species suspected of being at risk. This report may be cited as follows:
Please note: Persons wishing to cite data in the report should refer to the report (and cite the author(s)); persons wishing to cite the COSEWIC status will refer to the assessment (and cite COSEWIC). A production note will be provided if additional information on the status report history is required.
COSEWIC 2002. COSEWIC assessment and update status report on the Athabasca thrift Armeria maritima ssp. interior in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. vi + 12 pp.
(Species at Risk Status Reports)
Argus. G.W. 1999. Update COSEWIC status report on the Athabasca thrift Armeria maritima ssp. interior in Canada in COSEWIC assessment and update status report on the Athabasca thrift Armeria maritima ssp. interior in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. 1-12 pp.
Argus. G.W. 1981. COSEWIC status report on the Athabasca thrift Armeria maritima subsp. Interior in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. 26 pp.
For additional copies contact:
c/o Canadian Wildlife Service
Également disponible en français sous le titre Évaluation et Rapport du COSEPAC sur la situation de l’arméria de l’Athabasca (Armeria maritima ssp. interior) au Canada – Mise à jour
Athabasca thrift -- Illustration courtesy of the Canadian Museum of Nature.
© Her Majesty the Queen in Right of Canada 2003
Catalogue No.: CW69-14/344-2003E-PDF
Assessment Summary – May 2002
Armeria Maritima Ssp. Interior
Reason for designation:
A Canadian endemic occurring sparsely within a unique sand dune ecosystem of limited geographical extent supporting at least 10 endemic plant species with various threats indicated.
Designated Threatened in April 1981. Status re-examined and downlisted to Special Concern in April 1999. Status re-examined and confirmed Special Concern in May 2002. Last assessment was based on an existing status report.
Armeria Maritima Ssp. Interior
Athabasca thrift is a perennial herb with a taproot and a branched woody base from which arise one to several rosettes of flat linear leaves. An erect flowering stem, to 25 cm in height, develops from the centre of each rosette. The small pink flowers are borne in a dense, nearly spherical head. The flowers are subtended by two sets of scarious bracts; the calyx tube is hairless and distinctly lobed.
This subspecies of a wide-ranging species is known only from the south shore of Lake Athabasca, Saskatchewan, where it occurs in the three large dune fields: (1) the William River Dunes located between Ennuyeuse Cr. and the William River, (2) the Thomson Bay Dunes located between William River and Cantara Lake, and (3) the MacFarlane River Dunes, located just west of the MacFarlane River and in the smaller dunes at Archibald Lake.
Athabasca thrift is restricted to dune slacks and gravel barrens.
Little is known about the specific biology of this subspecies. Seedlings become established both on gravel pavements and on moist to wet dune slacks. Plants growing in dune slacks are young, vigorous plants that eventually become covered by the shifting sand. Old plants are found only on the relatively stable gravel pavements.
Population Sizes and Trends
The population of this subspecies is very small, but its exact size and trends cannot be estimated without quantitative data. This subspecies occurs only as small populations or as occasional individuals. Its main habitats, which are gravel pavements, are themselves relatively uncommon and the vegetation on them is very sparse. Species growing on these gravel pavements, therefore, are among the least common species in the Athabasca sand dunes. This subspecies is thought to be one of the most uncommon of the endemics in the sand dunes. There are only eighteen herbarium collections of this taxon.
Limiting Factors and Threats
All-terrain vehicle use for recreational activities has been identified as a threat to the sand dunes and their endemics. Other potential threats may arise from future pressures for mining exploration. Increased visitor use may pose some threats, although such recreational activities, especially from canoeists may be restricted to areas of water access.
Special Significance of the Species
The subspecies is mainly notable for its restricted range as a Canadian endemic.
Existing Protection or Other Status Designations
The main protection of this subspecies comes from its occurrence in the Athabasca Sand Dunes Wilderness Provincial Park.
Summary of Status Report
Athabasca thrift is one of ten endemic vascular plants known from the Lake Athabasca sand dune region of northwestern Saskatchewan. It is one of the most uncommon endemics in the Athabasca sand dunes. Its habitat is localized and fragile. Although the Athabasca sand dunes enjoy Provincial Wilderness Park protection there is reason to believe that pressures from mining and tourism will require continued vigilance.
COSEWIC Mandate, Membership and Definitions
The Committee on the Status of Endangered Wildlife in Canada (COSEWIC) determines the national status of wild species, subspecies, varieties, and nationally significant populations that are considered to be at risk in Canada. Designations are made on all native species for the following taxonomic groups: mammals, birds, reptiles, amphibians, fish, lepidopterans, molluscs, vascular plants, lichens, and mosses.
COSEWIC comprises representatives from each provincial and territorial government wildlife agency, four federal agencies (Canadian Wildlife Service, Parks Canada Agency, Department of Fisheries and Oceans, and the Federal Biosystematic Partnership), three nonjurisdictional members and the co-chairs of the species specialist groups. The committee meets to consider status reports on candidate species.
- Any indigenous species, subspecies, variety, or geographically defined population of wild fauna and flora.
- Extinct (X)
- A species that no longer exists.
- Extirpated (XT)
- A species no longer existing in the wild in Canada, but occurring elsewhere.
- Endangered (E)
- A species facing imminent extirpation or extinction.
- Threatened (T)
- A species likely to become endangered if limiting factors are not reversed.
- Special Concern (SC)*
- A species of special concern because of characteristics that make it particularly sensitive to human activities or natural events.
- Not at Risk (NAR)**
- A species that has been evaluated and found to be not at risk.
- Data Deficient (DD)***
- A species for which there is insufficient scientific information to support status designation.
The Committee on the Status of Endangered Wildlife in Canada (COSEWIC) was created in 1977 as a result of a recommendation at the Federal-Provincial Wildlife Conference held in 1976. It arose from the need for a single, official, scientifically sound, national listing of wildlife species at risk. In 1978, COSEWIC designated its first species and produced its first list of Canadian species at risk. Species designated at meetings of the full committee are added to the list.
The Canadian Wildlife Service, Environment Canada, provides full administrative and financial support to the COSEWIC Secretariat.
Lists of Figures
- Figure 1: Athabasca Thrift
- Figure 2: Map of the Lake Athabasca sand dunes and the limits of the Lake Athabasca Sand Dunes Wilderness Provincial Park
- Figure 3: Map of the distribution of Armeria maritima subsp. interior
COSEWIC Status Report
Armeria maritima ssp. interior
Athabasca thrift is a perennial herb with a tap root and a branched woody base from which arise one to several rosettes of flat linear leaves. An erect flowering stem, to 25 cm in height, develops from the centre of each rosette. The small pink flowers are borne in a dense, nearly spherical head. The flowers are subtended by two sets of scarious bracts; the calyx tube is hairless and distinctly lobed.
Courtesy of Canadian Museum of Nature.
This subspecies is a Canadian endemic of the Athabasca Sand Dunes.
This taxon is known only from the south shore of Lake Athabasca, Saskatchewan, where it occurs in the three large dune fields: (1) the William River Dunes located between Ennuyeuse Cr. and the William River, (2) the Thomson Bay Dunes located between William River and Cantara Lake, and (3) the MacFarlane River Dunes, located just west of the MacFarlane River and in the smaller dunes at Archibald Lake (Figure 3).
Based on Argus, 1981 and recent herbarium specimens.
Armeria maritima subsp. interior occurs primarily on gravel pavements within areas of active sand dunes. These gravel pavements originated through aeolian action on a sandy gravel till. As the sand was winnowed out of the till the surface became covered by a single layer of stones, a lag concentrate, that reduced erosion of sand from the till (Raup & Argus 1982). In time, the pavement stones were eroded sand polished by wind-blown sand into two- or three-faced ventifacts. This habitat is variously described on herbarium labels as gravel barrens, sandy-gravel barrens, or sandy till plains covered with ventifact gravel. This taxon is also known to grow in moist interdunal depressions; both west and east of the William River and south of Yakow Lake (herbarium specimens, Purdy 1995). Its cespitose growth form, however, does not adapt it to withstand burial by sand. As the dune slack is invaded by moving sand these plants will be buried. These populations, therefore, are relatively ephemeral but they may play an important role in survival of the subspecies as sources of seed.
There is no information on changes in quality or loss of this habitat but it is evidently very fragile. When the area was first visited in 1962 (Argus unpubl.) tracks of a light aircraft, which landed on an area of gravel pavement some 10 or more years earlier, were still very evident. Disturbance of the gravel veneer could increase the rate of surface erosion.
All populations of this subspecies occur within the Athabasca Sand Dunes Wilderness Provincial Park.
Seedlings of Armeria maritima subsp. interior become established both on gravel pavements and on moist to wet dune slacks (Raup & Argus 1982, Purdy 1995). Because of its cespitose growth form large, old plants are found only on the relatively stable gravel pavements. Plants growing in dune slacks are young, vigorous plants (Purdy 1995), but these plants, inasmuch as they lack the capacity to grow up through sand, eventually will be buried by moving dunes. Further research on the biology of this endemic is needed.
Population Sizes and Trends
This subspecies occurs only as small populations or as occasional individuals. Gravel pavements, the main habitats, are themselves relatively uncommon and the vegetation on them is very sparse. Species growing on these gravel pavements, therefore, are among the least common species in the Athabasca sand dunes. This subspecies is thought to be one of the most uncommon of the endemics in the Athabasca sand dunes (Harms pers. comm.). There are eighteen herbarium collections of this taxon (Harms et al. 1992); of these, sixteen in Ottawa herbaria (National Herbarium of Canada or the Department of Agriculture Herbarium) were reexamined. The population of this subspecies is very small but its exact size and trends cannot be estimated without quantitative data. There is no evidence, however, to suggest that its numbers have diminished in recent years.
Limiting Factors and Threats
Armeria maritima subsp. interior is limited by its small population size and restricted habitat.
Roads -- When the 1981 COSEWIC report was written (Argus 1981), the proposed construction of a road from Cluff Lake to the south shore of Lake Athabasca would have opened the Athabasca dunes to human activity. The need for this road is likely to be replaced by a road from Points North to Black Lake. The Cluff Lake Road seems no longer to be an important limiting factor (Bihun pers. comm.).
Visitors -- Tourists visiting the park and pleasure seekers from Uranium City, particularly those using ATVs, can have great impact on the sand dune ecosystem. At present there are about 200 people living in Uranium City. Feasibility studies are being done to evaluate the possibility of opening a gold mine in the Uranium City area (Bihun pers. comm.). The possibility of ATV traffic on the dunes, despite being banned from the park, is real. The regulations pertaining to the use of the park may be well-intentioned but are they enforceable? It is not known how easily the regulations can be changed to include such multiple use.
Tourism is increasing in the Lake Athabasca area. At present, the most important activity is fishing boat traffic from Ft. McMurray, Alberta; but few fishermen seem to venture onto the dunes. Ecotourism, however, is becoming attractive in northern Saskatchewan. Canoe trips on the Fond du Lac River to the sand dunes are becoming more common (a lecture on such a trip was presented to the Canadian Recreational Canoeing Association, Merrickville, Ontario, on 27 Nov. 1997). There are regulations designating camping sites and activities on the dunes. Because the dunes are not routinely monitored by Ministry personnel, the effectiveness of these regulations is unknown (Bihun pers. comm., Rogers pers. comm.).
Mining -- Mining exploration is permitted up to the edge of the park. In the west, the edge of the park is the western edge of the William River dune field and in the east the MacFarlane River. Presently there is no buffer zone around the park (Bihun pers. comm., Rogers pers. comm.). The boundaries of the dune region, when it was designated a Protected Area, included a buffer zone. When the area became a Provincial Wilderness Park, however, the buffer zone was removed. If the area and its endemic flora are to be adequately protected a buffer zone must be reestablished.
Geophysical surveys, presumably for uranium ore bodies, were done in the region in 1997-1998. If and when mining becomes economically viable, mining could take place right up to the edge of the open dunes (Bihun pers. comm.). The impact on the dune habitat and its endemic flora from both mining activities themselves and the greatly increased recreational use of the dunes would be very great.
Other mining-related activities in the sand dunes include the collecting of seed for mine tailing reclamation. In order to stabilize extensive tailings resulting from the extraction of heavy oils from the Athabasca tar sands, SYNCRUD of Ft. McMurray, Alberta, is investigating the use of sand dune endemics (Purdy 1995, Bihun pers. comm.). Two firms, one from Alberta and one from Saskatchewan have already applied for and collected seeds from the park (Purdy pers. comm.). Such activities in the sand dunes are incompatible with the protection of the habitat of endemic species.
The Athabasca sand dunes are not as remote and isolated as they once were. Pressures from mining, tourism, recreational use, and other commercial activities are rapidly increasing and likely to do so in the future. The protection of the unique endemic flora of the region will require the establishment of an adequate buffer zone around the park, enforceable regulations to limit access to its most sensitive regions, and adequate monitoring of the region by provincial conservation officers.
Special Significance of the Species
This subspecies is of interest because is an endemic that has evolved during the late Pleistocene glacial age somewhere in northwestern Canada or even locally along the south shore of Lake Athabasca subsequent to deglaciation. A variety of cultivars of this species are sold by nurseries because of the ease of their cultivation and use as an ornamental in rock gardens.
Existing Protection or Other Status
Armeria maritima subsp. interior was designated a threatened species by COSEWIC in 1981. In 1992 the sand dune region on the south shore of Lake Athabasca was officially designated the Athabasca Sand Dunes Wilderness Provincial Park (Anon 1997). The 1925 square kilometre park extends about 100 km along the south shore of the lake from just west of Ennuyeuse Creek to just east of the MacFarlane River and 20-30 km south of the lakeshore (Figure 2). The park has been zoned into three regions. The greatest protection is given to William River dune field (west of the William R.), lesser protection is given to dune fields in other areas. All regions have restrictions on camping, the number of individuals using a campsite, the use of open fires, collecting plants or ventifacts, and hiking on desert pavements (gravel pavements).
Summary of Status Report
Athabasca thrift (Armeria maritima subsp. interior) is one of ten endemic vascular plants known to occur in the Lake Athabasca sand dune region of northwestern Saskatchewan. It was assigned a status of threatened by COSEWIC in 1981 because of its rarity and specialized habitat that were then threatened by an all-weather road from Cluff Lake to the south shore of Lake Athabasca. It is one of the most uncommon endemics in the Athabasca sand dunes. Its habitat is localized and fragile. Although the Athabasca sand dunes enjoy Provincial Wilderness Park protection there is reason to believe that pressures from mining and tourism will require continued vigilance.
Armeria maritima ssp. interior
Extent and Area Information
- limited threats from visitor use of the park, especially through ATV activity
Rescue Effect (immigration from an outside source): none (endemic)
George Bihun, Conservation Officer, Saskatchewan Environment and Resources Management, Stony Rapids, Saskatchewan, provided important insights based on his personal experience in the Athabasca sand dunes and specific comments on limiting factors.
C.C. Chinnappa, University of Calgary, Calgary, Alberta, provided an update on current botanical activities in the Athabasca sand dunes.
Vemon L. Harms, University of Saskatchewan, Saskatoon, Saskatchewan, provided very useful information on species status in the Athabasca sand dunes.
Sheila Lamont, Botanist, Saskatchewan Conservation Data Centre, Regina, Saskatchewan, put me into contact with knowledgeable individuals.
Bret G. Purdy, Inter-Theme Research Coordinator, Sustainable Forest Management Network, University of Alberta, Edmonton, provided me with information on current research and economic activities in the Athabasca sand dunes.
Kay Rogers, Ottawa, Ontario, visitor to the Athabasca Sand Dune region in 1997.
Earl Wiltse, Provincial Endangered Wildlife Specialist, Saskatchewan Environment and Resource Management, Regina, Saskatchewan, provided names of knowledgeable individuals.
Funding for this status report was provided by the Canadian Wildlife Service, Environment Canada.
Abouguendia, Z.M. (ed.). 1981. Athabasca Sand Dunes in Saskatchewan. Mackenzie River Basin Study Report Supplement 7. Mackenzie River Basin Committee.
Abouguendia, Z.M., R.C. Goodwin, V.L. Harms, J.H. Hudson, J.S. Rowe, and R. Wright. 1981. Plant Ecology and Taxonomy, pp. 155-199, in: Abouguendia, Z.M. (ed.). 1981, Athabasca Sand Dunes in Saskatchewan. Mackenzie River Basin Study Report Supplement 7. Mackenzie River Basin Committee.
Anon. 1997. Athabasca Sand Dunes. Provincial Wilderness Park. Saskatchewan Provincial Parks Department. Brochure available from Saskatchewan Environment and Resources Management, Stony Rapids, Sask. SOJ 2RO
Argus, G.W. and Steele, J.W. 1979. A reevaluation of the taxonomy of Salix tyrrellii, a sand dune endemic. Systematic Botany 4: 163-177.
Argus, G.W. 1981. Status report on the Athabasca thrift, Armeria maritima ssp. interior in Canada. Committee on the Status of Endangered Wildlife in Canada, Ottawa.
Argus, G.W. 1997. Infrageneric classification of Salix L. in the New World. Systematic Botany Monographs. 52: 1-121.
Harms, V.L., P.A. Ryan, and J.A. Haraldson. 1992. The Rare and Endangered Native Vascular Plants of Saskatchewan. The Saskatchewan Rare Plants Database and Summary Sheets of the Candidate Rare Species. W.P. Fraser Herbarium, University of Saskatchewan, Saskatoon, Sask. 1144 pp.
Lawrence, G.H.M. 1947. The genus Armeria in North America. American Midland Naturalist 37: 757-779.
MacDonald, S.E., C.C. Chinnappa, D.M. Reid, and B.G. Purdy. 1994. Population differentiation of the Stellaria longipes complex within Saskatchewan's Athabasca sand dunes. Can. J. Bot. 65: 1726-1732.
Porsild, A.E. 1955. The vascular plants of the western Canadian Arctic Archipelago. National Museum of Canada, Bulletin 135.
Purdy, B.G., Bayer, R.J., and MacDonald, S.E. 1994. Genetic variation, breeding system evolution and conservation of the narrow sand dune endemic Stellaria arenicola and the widespread S. longipes (Caryophyllaceae). American Journal of Botany 81: 904-911.
Purdy, B.G. 1995. Genetic variation in endemic plants of the Athabasca sand dunes: origin, evolution, and implications for conservation. PhD. Thesis, University of Alberta, Edmonton, AB. [A shortened version of this thesis appears as an undated report prepared for the Endangered Species Recovery Fund, World Wildlife Fund Canada and the Saskatchewan Department of Parks and Renewable Resources.]
Purdy, B.G. and Bayer, R.J. 1995a. Genetic diversity in the tetraploid sand dune endemic Deschampsia mackenzieana and its widespread diploid progenitor D. cespitosa (Poaceae). American Journal of Botany 82: 121-130.
Purdy, B.G. and Bayer, R.J. 1995b. Allozyme variation in the Athabasca sand dune endemic, Salix silicicola, and the closely related widespread species, S. alaxensis. Systematic Botany 20: 179-190.
Raup, H.M. 1936. Phytogeographical studies in the Athabasca-Great Slave Lake region. Journal of the Arnold Arboretum 17: 180-315.
Raup, H.M. and Argus, G.W. 1982. The Lake Athabasca sand dunes of northern Saskatchewan and Alberta, Canada. I. The land and vegetation. National Museums of Canada, Publications in Botany 12.
George W. Argus received a PhD in Biology from Harvard University in 1961. He worked as a professor at the University of Saskatchewan from 1961-1969 and a curator at the Canadian Museum of Nature from 1972-1995. He retired in 1995 as Curator Emeritus. He is a specialist in the systematics of the genus Salix (willow) and has written monographs and floristic treatments on the genus. In 1973 he initiated and directed the Rare and Endangered Plants Project which published on rare plants in Canada, including Rare vascular plants in Canada - Our natural heritage. In the past he has served as scientific authority for flora to the Convention on International Trade in Endangered Species and as a member of various conservation committees. Currently he is a member of the editorial committee of the Flora of North America and is writing a monograph on the systematics of New World Salix. His research in systematics has been recognized by the Gleason Award from the New York Botanical Garden and his conservation-related work received the Lawson Medal from the Canadian Botanical Association.
Personal communications with:
Bihun, G. Personal communication on 5 Nov. 1997, e-mail dated 3 Feb. 1998, 20 Sept. 1998.
Harms, V.L. Letter dated 3 July 1997.
Purdy, B.G. E-mail message dated 5 Jan. 1998.
Rogers, K. Personal communication 10 Sept. 1998.
- Date Modified: