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COSEWIC Annual Report - 2006

Appendix VII - Detailed COSEWIC Species Assessments, April 2006

Results are grouped by taxon and then by status category. A reason for designation is given for each species. A short history of status designations follows. The range of occurrence in Canada for each species (by province, territory, or ocean) is provided.

Mammals

Ord's Kangaroo Rat

Dipodomys ordii

Endangered

Assessment Criteria A3c; B2ab(iii); C2a(i)

Reason for Designation
km²and only 1000 or fewer individuals are alive at the end of most winters. There is strong evidence for local adaptations of the Canadian population and a rescue effect is extremely unlikely because the nearest population in the United States is 270 km away.

Range AB SK

Status History
Designated Special Concern in April 1995. Status re-examined and designated Endangered in April 2006.

Pacific Water Shrew

Sorex bendirii

Endangered

Assessment Criteria B1ab(i,iii)

Reason for Designation
The habitat of this rare species, confined to the lower Fraser valley region of British Columbia, continues to decline and fragment as a result of development. There is little chance of rescue. It is extremely rare throughout its range.

Range BC

Status History
Designated Threatened in April 1994 and in May 2000. Status re-examined and designated Endangered in April 2006.

Northern Fur Seal

Callorhinus ursinus

Threatened

Assessment Criteria Met criteria for Endangered, A2b; B2ab(v), but designated Threatened, A2b; B2ab(v), because there are still more than 600,000 individuals and the species does not appear to be in imminent danger of extinction.

Reason for Designation
The population that breeds on the Pribilof Islands in the Bering Sea feeds in, and migrates through, British Columbia waters. This population numbered about 629,000 animals in 2004. Although still relatively large, the population, as inferred from pup counts, has declined by 50-60% over three generations (1974-2004). The rate of decline has been particularly rapid since 1998. Trends in counts of adult males from 1974-2004 are confounded by response to the cessation, in 1984, of the selective commercial harvesting of sub-adult males in 1984. These counts have declined rapidly and inexplicably since 1992. The reasons for the population decline are unknown. Entanglement in marine debris, disturbance, pollution, and environmental changes, possibly including a regime shift in the Bering Sea and North Pacific ecosystems, are thought to be contributing factors. Little is known about possible limiting factors in British Columbia and other regions where fur seals forage during their annual migration.

Range BC Pacific Ocean

Status History
Designated Not at Risk in April 1996. Status re-examined and designated Threatened in April 2006.

Atlantic Walrus

Odobenus rosmarus rosmarus

Special Concern

Assessment Criteria not applicable

Reason for Designation
Five populations ranging from Nova Scotia to the high Arctic are recognized for management purposes based on geographical distributions, genetics and lead isotope data. Some of the populations appear to be at greater risk than others due to over-hunting, and may be threatened. However, knowledge about population structure is insufficient to assess them separately. The Nova Scotia-Newfoundland-Gulf of St Lawrence population was hunted to extirpation by the late 18th century. Sporadic recent sightings of individuals and small groups in the Gulf of St Lawrence and off Nova Scotia are not considered evidence of re-establishment. The South and East Hudson Bay population is believed to number in the low hundreds, although population size and structure are poorly known. Observations from the late 1930s to the present suggest that numbers declined significantly, but the rate of decline cannot be quantified and it is not known whether the decline is continuing. The small population size suggests it may be vulnerable to disturbances and small increases in hunting effort. The total size of the Northern Hudson Bay-Davis Strait population could be as small as 4000-6000 individuals. Its ability to sustain minimum current removals is questionable. Some portion of this population is hunted in Greenland waters. The Foxe Basin population was estimated to be 5,500 in 1989. It is unknown if current exploitation rates are sustainable. Hunting is believed to have reduced the Baffin Bay (High Arctic) population to only a few percent of the number present in 1900. Limited information suggests the current population is small and that a portion of it continues to be hunted at unsustainable levels in the North Water area of Canada and northwest Greenland. However, satellite tracking and genetic information suggests that some animals in this population are resident in the Canadian Archipelago (west Jones Sound and Penny Strait / Lancaster Sound) and are not exposed to over-hunting. Better information is needed on population sizes and composition, seasonal movements, vital rates, and hunting mortality. The biggest threat is over-hunting, particularly on populations that inhabit the southern and northern ends of the species' current range. The species is near to qualifying for threatened status and requires an effective plan to manage hunting. No Management Plans are currently in place for the species. Although quotas have been set in few communities, it is not known if they are adequate to prevent over-hunting.

Range NU MB ON QC NB PE NS NL Arctic Ocean

Status History
The Atlantic Walrus in Canada was originally treated by COSEWIC as two separate populations: Eastern Arctic population (Not at Risk in April 1987 and May 2000) and Northwest Atlantic population (Extirpated in April 1987 and May 2000). In April 2006, COSEWIC included both populations in a single designatable unit for Atlantic Walrus in Canada, and the species was designated Special Concern.

Harbour Porpoise -- Northwest Atlantic population

Phocoena phocoena

Special Concern

Assessment Criteria not applicable

Reason for Designation
The species is widely distributed in eastern Canadian marine waters. Surveys of portions of the range (Bay of Fundy/Gulf of Maine and the Gulf of St. Lawrence) during the late 1990s indicated more than 100,000 porpoises. Incidental catch (bycatch) in fishing gear, especially gillnets, is a major source of mortality. Bycatch probably has declined in areas where use of gillnets has decreased. Management measures in the Bay of Fundy and Gulf of Maine have been shown to reduce porpoise bycatch rates in gillnets. However, these measures have not been implemented in much of the species' range, including the Gulf of St. Lawrence and Newfoundland and Labrador, where annual mortality in several gillnet fisheries is still estimated to be in the thousands. There is also some concern that porpoises in the Bay of Fundy and possibly other areas may be excluded from portions of their habitat by acoustic harassment devices associated with aquaculture. Although the population remains abundant, the particular susceptibility of harbour porpoises to bycatch in fishing gear represents an incipient threat. Given that, the lack of good abundance information in some parts of the range and the lack of porpoise bycatch monitoring and mitigation in many of the relevant fisheries are reasons for concern.

Range Atlantic Ocean

Status History
The Northwest Atlantic population was designated Threatened in April 1990 and in April 1991. Status re-examined and designated Special Concern in May 2003 and in April 2006.

Nuttall's Cottontail nuttallii subspecies

Sylvilagus nuttallii nuttallii

Special Concern

Assessment Criteria not applicable

Reason for Designation
This rabbit was first recorded in Canada about 70 years ago and has since increased its range in the Okanagan, where it may have reached the maximum possible extent of its distribution. Remaining rabbit habitat in the Okanagan is less than 8000 hectares, increasingly fragmented, and continues to be lost to urbanization and agriculture. The total population size, based on available habitat, is probably less than 3500 individuals. Rescue potential from Washington is minimal because of the declining availability of habitat. There are substantial uncertainties about the current area of occupancy, which may have declined over the last few decades as habitat has been lost.

Range BC

Status History
Designated Special Concern in April 1994 and in April 2006.

Common Minke Whale -- North Atlantic subspecies

Balaenoptera acutorostrata acutorostrata

Not at Risk

Assessment Criteria not applicable

Reason for Designation
Calculations by the Species Specialist Subcommittee, based on survey estimates for some areas and informed judgements for others, suggest a total population in the order of 15,000 (6000 West Greenland, 1000 Gulf of St. Lawrence, 3000 Scotian Shelf, probably at least 5000 Newfoundland/Labrador = 15,000). Although the hunt in West Greenland may involve the same stock that occurs in eastern Canadian waters, recent and current removals are likely sustainable, given that the annual catch quota is 175, representing an offtake of ca. 0.01, which does not exceed replacement. Human-caused mortality from other potential threats does not exceed replacement.

Range Atlantic Ocean

Status History
Designated Not at Risk in April 2006.

Common Minke Whale -- North Pacific subspecies

Balaenoptera acutorostrata scammonii

Not at Risk

Assessment Criteria not applicable

Reason for Designation
There is no identifiable threat to the subspecies in the eastern North Pacific (there is no whaling; number of deaths from entanglement in fishing gear and ship strikes is not thought to be high enough to cause concern). There is considerable potential for rescue – mainly from United States waters to the north and south; individuals occurring in inshore waters in Canada could constitute a naturally small population.

Range Pacific Ocean

Status History
Designated Not at Risk in April 2006.

Gaspé Shrew

Sorex gaspensis

Not at Risk

Assessment Criteria not applicable

Reason for Designation
It is highly likely that this shrew is more widespread and abundant than presently believed. Although the occurrence of presumed preferred habitat is restricted and isolated in the landscape, it is not at risk. The species appears to be widespread in talus habitats throughout its range. Recent information questions the taxonomic status of this shrew. Whereas it may well be a subspecies of Sorex dispar, when the original designation was made, it was considered a Canadian endemic species.

Range QC NB NS

Status History
Designated Special Concern in April 1988. Status re-examined and designated Not at Risk in April 2006.

Southern Flying Squirrel -- Great Lakes Plains population

Glaucomysvolans

Not at Risk

Assessment Criteria not applicable

Reason for Designation
Flying squirrels are small inconspicuous nocturnal forest-dwelling rodents with impressive gliding ability. They are difficult to distinguish from the Northern Flying Squirrel. Dedicated sampling programs have generally revealed greater abundance and range than previously assumed. Its known area of occupancy has expanded. Habitat loss through deforestation and fragmentation of remaining forest may lead to extirpation of some local populations in the southern part of its range in Ontario, but does not currently pose a threat to the persistence of this population. The overall trend in habitat availability is stable or positive. Recent research in Ontario has revealed a much wider range of suitable habitat and reported a substantial range expansion. There is little information on this squirrel from Quebec as there have been no directed surveys for this species.

Range ON QC

Status History
Designated Special Concern in April 1988. Split into two populations in April 2006 and the Great Lakes Plains population was designated Not at Risk.

Southern Flying Squirrel -- Atlantic (Nova Scotia) population

Glaucomys volans

Not at Risk

Assessment Criteria not applicable

Reason for Designation
Flying squirrels are small inconspicuous nocturnal forest-dwelling rodents with impressive gliding ability. They are difficult to distinguish from the Northern Flying Squirrel. In Nova Scotia, the southern species was first detected in 1971, and until 2001, was only known from seven sites. New recent research located southern flying squirrels in 32 locations and over a much wider area in the southern part of the province than expected. Like a number of species in Nova Scotia, it is at the north of its range and disjunct. Habitat loss through deforestation and fragmentation of intact forest may lead to extirpation of some local populations, but does not currently pose a threat to the species' persistence and the population appears stable.

Range NS

Status History
Designated Special Concern in April 1988. Split into two populations in April 2006 and the Atlantic (Nova Scotia) population was designated Not at Risk.

 

Birds

Burrowing Owl

Athene cunicularia

Endangered

Assessment Criteria A2bc; C1

Reason for Designation
This grassland owl has suffered significant declines across its North American range; Canadian populations declined 90% in the 1990s and the species is essentially extirpated from British Columbia and Manitoba. This population decline slowed somewhat between 1994 and 2004, but remained at approximately 57%. The true cause or causes of this widespread decline remain unknown.

Range BC AB SK MB

Status History
Designated Threatened in April 1979. Status re-examined and confirmed in April 1991. Status re-examined and designated Endangered in April 1995. Status re-examined and confirmed in May 2000 and in April 2006.

Ivory Gull

Pagophila eburnea

Endangered

Assessment Criteria A2a; C1

Reason for Designation
Aboriginal Traditional Knowledge and intensive breeding colony surveys over the last four years indicate that the Canadian breeding population of this long-lived seabird has declined by 80% over the last 20 years. This bird feeds along ice-edge habitats in the high Arctic and breeds in very remote locations. Threats include contaminants in food chain, continued hunting in Greenland, possible disturbance by mineral exploration at some breeding locations, and degradation of ice-related foraging habitats as a result of climate change.

Range NT NU NL

Status History
Designated Special Concern in April 1979. Status re-examined and confirmed in April 1996 and in November 2001. Status re-examined and designated Endangered in April 2006.

Vesper Sparrow affinis subspecies

Pooecetes gramineus affinis

Endangered

Assessment Criteria B1ab(i,ii,iii)+2ab(i,ii,iii); C2a(i,ii); D1

Reason for Designation
This songbird, a subspecies of the Vesper Sparrow, is found in Canada only in coastal grasslands in the extreme southwestern corner of British Columbia, where it now breeds only at one site with a population of about 5 pairs. The taxon is declining in the United States as well, where it has a restricted distribution in western Washington and Oregon. Habitat loss is the greatest threat, both through direct destruction of habitat for urban development and through invasion by alien plant species.

Range BC

Status History
Designated Endangered in April 2006.

Golden-winged Warbler

Vermivora chrysoptera

Threatened

Assessment Criteria Met criterion for Endangered, A2be, but designated Threatened because the species is still widespread, shows the ability to maintain small pure populations within the Blue-winged Warbler range, is still expanding in Manitoba, and is thus not in imminent danger of extinction. Criterion met for Threatened: A2be.

Reason for Designation
This small songbird has declined by 79% over the last 10 years according to Breeding Bird Survey data from Canada. The main threat appears to be competition and genetic swamping (hybridization) from the closely-related Blue-winged Warbler, which is spreading north because of habitat change and perhaps climate change.

Range MB ON QC

Status History
Designated Threatened in April 2006.

Northern Saw-whet Owl brooksi subspecies

Aegolius acadicus brooksi

Threatened

Assessment Criteria Met criterion for Endangered, C2a(ii), with its small population and projected habitat loss, but designated as Threatened, C2a(ii), because of the presence of substantial protected areas.

Reason for Designation
This is a distinct subspecies endemic to Canada, with a small world population (ca. 1900 adults) restricted to the Queen Charlotte Islands. It is a forest specialist, preferring older forests with abundant nesting snags and an open understory in a landscape where such resources are continually becoming scarcer due to forest harvest.

Range BC

Status History
Designated Threatened in April 2006.

Louisiana Waterthrush

Seiurus motacilla

Special Concern

Assessment Criteria Met criterion for Threatened, D1, but designated Special Concern because the population in Canada has been stable over the last two decades and rescue effect from the United States is likely.

Reason for Designation
This wood warbler breeds along clear, shaded, coldwater streams in southern Ontario and possibly southwestern Quebec. The Canadian population is small – probably less than 200 pairs – but has been stable over the last two decades and immigration from United States populations probably occurs. Habitat degradation, particularly from ATVs, may be a threat at some sites.

Range ON QC

Status History
Designated Special Concern in April 1991. Status re-examined and confirmed in April 1996 and in April 2006.

McCown's Longspur

Calcarius mccownii

Special Concern

Assessment Criteria not applicable

Reason for Designation
This species has experienced a severe population decline since the late 1960s. This trend appears, however, to have slowed in the past decade. The species is threatened by continuing habitat loss and degradation. It may also risk exposure to pesticides associated with increased breeding in cultivated fields.

Range AB SK

Status History
Designated Special Concern in April 2006.

Rusty Blackbird

Euphagus carolinus

Special Concern

Assessment Criteria not applicable

Reason for Designation
More than 70% of the breeding range of the species is in Canada's boreal forest. The species has experienced a severe decline that appears to be ongoing, albeit at a slower rate. There is no evidence to suggest that this trend will be reversed. Known threats occur primarily on the winter range, and include habitat conversion and blackbird control programs in the United States.

Range YT NT NU BC AB SK MB ON QC NB PE NS NL

Status History
Designated Special Concern in April 2006.

Red-shouldered Hawk

Buteo lineatus

Not at Risk

Assessment Criteria not applicable

Reason for Designation
In Canada, this forest-nesting species has been stable or increasing, depending on the region, over the last 10 to 20 years. The main threat to the species is habitat loss and degradation, which is likely to be most serious in the southern parts of its Canadian range. Populations are stable or increasing in most parts of the United States, so there is also a potential outside source for rescue.

Range ON QC NB

Status History
Designated Special Concern in April 1983. Status re-examined and confirmed in April 1996. Status re-examined and designated Not at Risk in April 2006.

Reptiles

Lake Erie Watersnake

Nerodia sipedon insularum

Endangered

Assessment Criteria B1ab(ii,iii,v)+2ab(ii,iii,v); C2a(i)

Reason for Designation
It has a small population, likely fewer than 1000 adults, confined to four small Canadian islands in western Lake Erie. Threats, which include loss of its shoreline habitats, mortality on roads, and destruction of hibernacula by quarries and construction, are increasing. Although persecution by people may be levelling off, it is still a significant threat to these snakes.

Range ON

Status History
Designated Endangered in April 1991 and in April 2006.

Western Painted Turtle -- Pacific Coast population

Chrysemys picta bellii

Endangered

Assessment Criteria B1ab(i,ii,iii)+2ab(i,ii,iii); C2a(i); D1

Reason for Designation
There are few records from Vancouver Island and the mainland south coast / Fraser River valley, and both regions are undergoing major loss of wetlands and a rapid increase in roads, development, and people. Recent searches of the lower Fraser River valley and of eastern Vancouver Island indicate the subspecies has declined in some of the handful of areas where it was previously observed.

Range BC

Status History
Designated Endangered in April 2006.

Western Painted Turtle -- Intermountain - Rocky Mountain population

Chrysemys picta bellii

Special Concern

Assessment Criteria not applicable

Reason for Designation
The number of turtles is likely small and declining because of extensive loss of wetland habitats and proliferation of roads.

Range BC

Status History
Designated Special Concern in April 2006.

Western Painted Turtle -- Prairie / Western Boreal - Canadian Shield population

Chrysemys picta bellii

Not at Risk

Assessment Criteria not applicable

Reason for Designation
Populations are numerous and widespread and there is an abundance of good habitat, especially in the eastern part of the range (Ontario).

Range AB SK MB ON

Status History
Designated Not at Risk in April 2006.

Amphibians

Long-toed Salamander

Ambystoma macrodactylum

Not at Risk

Assessment Criteria not applicable

Reason for Designation
Despite high rates of habitat loss due to anthropogenic development in British Columbia's Lower Mainland and eastern Vancouver Island regions, which put stress upon native amphibians in general, and previous concerns over the status of Alberta populations, the species remains widespread and abundant throughout the majority of its Canadian range.

Range BC AB

Status History
Designated Not at Risk in April 2006.

Fishes

Atlantic Salmon -- Lake Ontario population

Salmo salar

Extirpated

Assessment Criteria not applicable

Reason for Designation
Once a prolific species throughout the Lake Ontario watershed, there has been no record of a wild Atlantic salmon since 1898. The Lake Ontario Atlantic salmon was extinguished through habitat destruction and through over-exploitation by a food and commercial fishery. Attempts to re-establish Atlantic salmon through stocking have failed, and the original strain is no longer available.

Range ON

Status History
Last reported in 1898. Designated Extirpated in April 2006.

Atlantic Salmon -- Inner Bay of Fundy populations

Salmo salar

Endangered

Assessment Criteria A2bc; C2a(i,ii); D1

Reason for Designation
These salmon represent a unique Canadian endemic; their entire biological distribution exists within Canada. Adult numbers are estimated to have declined by more than 95% in 30 years, and most rivers no longer have either adults or juveniles. In 2003, fewer than 100 adults are estimated to have returned to the 32 rivers known to have historically contained the species. There is no likelihood of rescue, as neighbouring regions harbour severely depressed, genetically dissimilar populations. The reasons for the collapse in adult abundances are not well understood. Reduced survival from smolt to adulthood in marine waters is thought to be a key factor. There are many possible causes of this increased mortality, including ecological community shifts; ecological / genetic interactions with farmed and hatchery Atlantic salmon; environmental shifts; and fisheries (illegal or incidental catch). Threats to the species in the freshwater environment are thought to be historical and contemporary in nature. Historical threats include loss and degradation of habitat (attributable to the construction of barriers to migration and logging); contemporary threats may include interbreeding with escaped farmed fish and environmental change (warmer temperatures, contaminants).

Range NB NS Atlantic Ocean

Status History
Designated Endangered in May 2001 and in April 2006.

Speckled Dace

Rhinichthys osculus

Endangered

Assessment Criteria B1+2ab(iii)

Reason for Designation
The species is restricted to the Kettle River mainstem and two main tributaries in southcentral British Columbia where it appears to be limited by the availability of suitable habitat. As this population is isolated above Cascade Falls, it cannot be rescued from downstream United States populations. The Kettle River is a flow-sensitive system that appears to be experiencing increasing frequency of drought conditions. The species is threatened by these reduced water flows and projected increasing water demands.

Range BC

Status History
Designated Special Concern in April 1980. Status re-examined and designated Endangered in November 2002 and in April 2006.

White Shark -- Atlantic population

Carcharodon carcharias

Endangered

Assessment Criteria A2b

Reason for Designation
The species is globally distributed in sub-tropical and temperate waters, but absent from cold polar waters; hence Atlantic and Pacific populations in Canada are isolated from each other and are considered separate designatable units. This very large apex predator is rare in most parts of its range, but particularly so in Canadian waters, which represent the northern fringe of its distribution. There are only 32 records over 132 years for Atlantic Canada. No abundance trend information is available for Atlantic Canada. Numbers have been estimated to have declined by about 80% over 14 years (less than one generation) in areas of the Northwest Atlantic Ocean outside of Canadian waters. The species is highly mobile, and individuals in Atlantic Canada are likely seasonal migrants belonging to a widespread Northwest Atlantic population; hence the status of the Atlantic Canadian population is considered to be the same as that of the broader population. Additional considerations include the long generation time (~23 years) and low reproductive rates (estimated gestation is 14 months and average fecundity is 7 live-born young) of this species, which limit its ability to withstand losses from increase in mortality rates. Bycatch in the pelagic long line fishery is considered to be the primary cause of increased mortality.

Range Atlantic Ocean

Status History
Designated Endangered in April 2006.

Carmine Shiner

Notropis percobromus

Threatened

Assessment Criteria D2

Reason for Designation
This freshwater fish species occurs in an extremely restricted area of Manitoba. The major threat to the species is the alteration in water flow as a result of stream regulation.

Range MB

Status History
Designated Special Concern in April 1994. Status re-examined and designated Threatened in November 2001 and in April 2006.

Chinook Salmon -- Okanagan population

Oncorhynchus tshawytscha

Threatened

Assessment Criteria Met criteria for Endangered, D1, but designated Threatened because of the rescue effect. Met criteria for Threatened: D1+2.

Reason for Designation
The Chinook salmon (Okanagan population) are the only remaining Columbia Basin population of Chinook salmon in Canada, and are geographically, reproductively and genetically distinct from all other Canadian Chinook salmon populations. They consist of anadromous salmon that migrate to and from the Pacific Ocean through the Columbia River, and also individuals that remain in Osoyoos Lake. The Chinook salmon (Okanagan population) was once large enough to support an important food and trade fishery prior to settlement by non-native people. The population used to occupy the area from Osoyoos Lake to Okanagan Lake, but McIntyre Dam has limited access to only the area below the dam and in Osoyoos Lake. As well as this habitat loss, the population was depleted by historic overfishing in the Columbia River and juvenile and adult mortality due to dams downstream on the Columbia River. Fisheries exploitation in the ocean, deterioration in the quality of the remaining Canadian habitat, and new predators and competitors such as non-native fishes also contributed to the current depleted state of the population. Genetic data show evidence of successful reproduction and maturation by individuals in this population, but also that this small population has genetic diversity similar to much larger populations in adjacent areas of the Columbia River basin, and is closely related to those populations. The genetic data, as well as the presence of fish of hatchery origin in the Canadian portion of the Okanagan River indicate that it is very likely that fish from elsewhere in the upper Columbia River basin have contributed reproductively to the population. With spawning numbers as low as 50 adults, the population is at risk of extinction from habitat loss, exploitation and stochastic factors, but may also be subject to rescue from populations in adjacent areas of the Columbia River basin.

Range BC Pacific Ocean

Status History
Designated Endangered in an emergency assessment in May 2005. Status re-examined and designated Threatened in April 2006.

Shortfin Mako -- Atlantic population

Isurus oxyrinchus

Threatened

Assessment Criteria A2b

Reason for Designation
As a large (maximum length 4.2 m), relatively late-maturing (7-8 yrs) pelagic shark, the species has life-history characteristics making it particularly susceptible to increased mortality from all sources, including human activities. The species is circumglobal in temperate and tropical waters. Individuals found in Atlantic Canada are considered part of a larger North Atlantic population. There does not appear to be any reason to assume that the Canadian Atlantic "population" is demographically or genetically independent from the larger Atlantic population, so the status of the species in Atlantic Canada should reflect the status throughout the North Atlantic. Although there is no decline in an indicator of status for the portion of the species that is in Atlantic Canada, two analyses suggest recent declines in the North Atlantic as a whole (40% 1986-2001; 50% 1971-2003). The main causes of the species' decline (mortality due to bycatch in longline and other fisheries) are understood and potentially reversible, but these sources of mortality have not been adequately reduced.

Range Atlantic Ocean

Status History
Designated Threatened in April 2006.

American Eel

Anguilla rostrata

Special Concern

Assessment Criteria not applicable

Reason for Designation
Indicators of the status of the total Canadian component of this species are not available. Indices of abundance in the Upper St. Lawrence River and Lake Ontario have declined by approximately 99% since the 1970s. The only other data series of comparable length (no long term indices are available for Scotia/Fundy, Newfoundland, and Labrador) are from the lower St. Lawrence River and Gulf of St. Lawrence, where four out of five time series declined. Because the eel is panmictic, i.e. all spawners form a single breeding unit, recruitment of eels to Canadian waters would be affected by the status of the species in the United States as well as in Canada. Prior to these declines, eels reared in Canada comprised a substantial portion of the breeding population of the species. The collapse of the Lake Ontario-Upper St. Lawrence component may have significantly affected total reproductive output, but time series of elver abundance, although relatively short, do not show evidence of an ongoing decline. Recent data suggest that declines may have ceased in some areas, however, numbers in Lake Ontario and the Upper St. Lawrence remain drastically lower than former levels, and the positive trends in some indicators for the Gulf of St. Lawrence are too short to provide strong evidence that this component is increasing. Possible causes of the observed decline, including habitat alteration, dams, fishery harvest, oscillations in ocean conditions, acid rain, and contaminants, may continue to impede recovery.

Range ON QC NB PE NS NL Atlantic Ocean

Status History
Designated Special Concern in April 2006.

Blue Shark -- Atlantic population

Prionace glauca

Special Concern

Assessment Criteria not applicable

Reason for Designation
This species is a relatively productive shark (maximum age 16-20 years, mature at 4-6 years, generation time 8 years, 25-50 pups every two years) but as an elasmobranch, populations are susceptible to increased mortality from all sources including from human activities. The species is considered to have a single highly migratory population in the North Atlantic, of which a portion is present in Canadian waters seasonally. The abundance index which is considered to best represent the whole population has declined 60% 1986-2000 but another index shows no long-term trend for the whole population 1971-2003. Indices of abundance in and near the Canadian waters show variable trends from no decline to 60% decline from the 1980s to early 2000s. There is evidence for a decline in mean length in longline fisheries in Canadian waters 1986-2003. The primary threat is bycatch in pelagic longline fisheries; although the threat is understood and is reversible, it is not being effectively reduced through management. Assessing the impact of bycatch on the population would benefit from better information on proportion of individuals discarded which survive. It appears that recent fishery removals from the North Atlantic have been several tens of thousands of tons annually. Estimated Canadian removals, a small proportion of the total, have been declining since the early 1990s and recently have averaged around 600 t/yr.

Range Atlantic Ocean

Status History
Designated Special Concern in April 2006.

Deepwater Sculpin -- Great Lakes - Western St. Lawrence populations

Myoxocephalus thompsonii

Special Concern

Assessment Criteria not applicable

Reason for Designation
This species occurs in the deeper parts of 10 coldwater lakes, including lakes Superior, Huron and Ontario, in Ontario and Quebec. Previously thought to be exterminated in Lake Ontario, it now appears to be reestablished in that lake, albeit in small numbers. Populations have been exterminated in 2 lakes in Quebec due to eutrophication of these lakes, and may be in decline in Lake Huron, possibly in relation to the introduction of zebra mussel.

Range ON QC

Status History
The "Great Lakes - Western St. Lawrence populations" unit (which includes the former "Great Lakes populations" unit, designated Threatened in April 1987) was designated Special Concern in April 2006.

River Redhorse

Moxostoma carinatum

Special Concern

Assessment Criteria not applicable

Reason for Designation
This freshwater fish species occurs in Ontario and Quebec and although it has been collected at new locations in both provinces, sometimes in large numbers, this is thought to reflect the use of more effective sampling techniques such as boat electrofishing. It has likely disappeared historically from the Ausable, Châteauguay and Yamaska rivers, since the use of boat electrofishing has failed to collect it recently. Threats to the species include habitat degradation (pollution, siltation), stream regulation that affects water flow (dams) and habitat fragmentation (dams). The Canadian range is highly fragmented and rescue effect is improbable because of the precarious conservation status in adjoining US States.

Range ON QC

Status History
Designated Special Concern in April 1983. Status re-examined and confirmed in April 1987 and in April 2006.

Deepwater Sculpin -- Western populations

Myoxocephalus thompsonii

Not at Risk

Assessment Criteria not applicable

Reason for Designation
This species is widely distributed in western Canada where it is found in the deepest parts of at least 52 coldwater lakes in northwestern Ontario, Manitoba, Saskatchewan, Alberta and the Northwest Territories. There is no evidence to indicate population declines, or of any threats that would convey a degree of risk to these populations.

Range NT AB SK MB ON

Status History
Designated Not at Risk in April 2006.

Blue Shark -- Pacific population

Prionace glauca

Data Deficient

Assessment Criteria not applicable

Reason for Designation
The species is apparently present regularly in Canada's Pacific waters, probably as part of a wider North Pacific population. Catch information and data from the International Pacific Halibut Commission longline survey (1998-2004) suggest the species is widespread on the continental shelf with a concentration at the shelf break. It has also been taken, at times in large numbers, in oceanic waters. No information is available to assess status in Canada, as there have been few records in existing surveys. Pacific-wide indices are of low reliability because of historical misidentification issues, but one recent assessment from United States National Marine Fisheries Service suggests that fishing mortality on this species in the North Pacific is well below the level of maximum sustainable yield. Level of fishery removals (bycatch) in the Canadian Pacific are low, of the order of 20-40 t/yr.

Range Pacific Ocean

Status History
Species considered in April 2006 and placed in the Data Deficient category.

Darktail Lamprey

Lethenteron alaskense

Data Deficient

Assessment Criteria not applicable

Reason for Designation
This freshwater fish is the only representative of its species in the western Arctic aquatic ecozone. Too little of its biology and actual distribution is known for an assessment to be made.

Range NT

Status History
Species considered in April 1990 and in April 2006 and placed in the Data Deficient category.

White Shark -- Pacific population

Carcharodon carcharias

Data Deficient

Assessment Criteria not applicable

Reason for Designation
The species is globally distributed in sub-tropical and temperate waters, but absent from cold polar waters; hence Atlantic and Pacific populations in Canada are isolated from each other and are considered separate designatable units. This very large apex predator is rare in most parts of its range, but particularly so in Canadian waters, which represent the northern fringe of its distribution. There are only 13 records over 43 years for the Pacific coast of Canada. No abundance trend information is available for Pacific Canadian waters, or for adjacent waters in the United States that would permit a status designation.

Range Pacific Ocean

Status History
Species considered in April 2006 and placed in the Data Deficient category.

Arthropods

Aweme Borer

Papaipema aweme

Endangered

Assessment Criteria D1

Reason for Designation
Prior to the collection of one specimen in Ontario in 2005, this moth was last collected 70 years earlier. It is known from only five localities globally, three of which are in Canada. Although the species is poorly known, it is apparently restricted to a rare, fragmented and threatened habitat. Repeated collecting at all of the historic locations has not resulted in relocation of the species, and intensive collecting in the vicinity of the recent record has not yielded any additional specimens.

Range ON

Status History
Designated Endangered in April 2006.

Eastern Persius Duskywing

Erynnis persius persius

Endangered

Assessment Criteria B1ab(iii)+2ab(iii); C2a(i); D1

Reason for Designation
This lupine-feeding butterfly has been confirmed from only two sites in Canada. It inhabits oak savannahs in southern Ontario, a habitat that has undergone substantial declines and alterations. Larval host plant populations have been greatly reduced. There have been no confirmed records of this butterfly for 18 years, but unconfirmed sight records suggest that the species might still exist in Canada.

Range ON

Status History
Designated Endangered in April 2006.

Five-spotted Bogus Yucca Moth

Prodoxus quinquepunctellus

Endangered

Assessment Criteria B1ac(iv)+2ac(iv)

Reason for Designation
This highly specialized moth exists in Canada as a single population that occurs in a very small, restricted area, isolated from the main range of the species in the United States. The moth is entirely dependent on the obligate mutualistic relationship between its host plant (Soapweed), and the plant's pollinator (Yucca Moth), both of which are at a high level of risk. It is threatened by the high level of wild ungulate herbivory, which in some years greatly reduces recruitment of the moth, its host plant and the host plant pollinator, and by off-road vehicles that destroy the host plant.

Range AB

Status History
Designated Endangered in April 2006.

Gold-edged Gem

Schinia avemensis

Endangered

Assessment Criteria B2ab(iii)

Reason for Designation
This moth is a habitat specialist that needs active dunes or blow-outs with populations of its sole larval host plant. It is known from only two small populations in Canada and two in the United States. Large-scale decline in active dune habitat over the past 100 years has likely resulted in a corresponding reduction in the moth. Only very small, scattered, isolated patches of suitable habitat, totaling approximately 6 km², remain. They are threatened by habitat loss in the form of stabilization of active dunes by both native and introduced vegetation and by overgrazing of its larval host plant, which severely impacts small, isolated populations of the moth. The closest population of the moth in the United States is about 1200 km to the south in Colorado, so immigration of individuals into the Canadian population is not possible.

Range AB SK MB

Status History
Designated Endangered in April 2006.

Half-moon Hairstreak

Satyrium semiluna

Endangered

Assessment Criteria B1ab(iii,v)+2ab(iii,v)

Reason for Designation
The butterfly occurs as disjunct populations in two small, restricted areas at the northern extreme of the species' range. The species' population has likely declined in the past as a result of habitat loss. Both populations continue to be threatened by habitat loss and degradation. In British Columbia the species occurs in an area under severe pressure for development. In both Alberta and British Columbia, invasive weeds also pose a serious threat.

Range BC AB

Status History
Designated Endangered in April 2006.

Non-pollinating Yucca Moth

Tegeticula corruptrix

Endangered

Assessment Criteria B1ac(iv)+2ac(iv)

Reason for Designation
This highly specialized moth exists in Canada as a single viable population that occurs in a very small, restricted area, isolated from the main range of the species in the United States. A second isolated population is on the verge of disappearing or has already been lost. The moth is entirely dependent on the obligate mutualistic relationship between its host plant (Soapweed), which is Threatened, and the plant's pollinator (Yucca Moth), which is Endangered. It is threatened by the high level of wild ungulate herbivory, which in some years greatly reduces recruitment of the moth, its host plant and the host plant pollinator, and by off-road vehicles that destroy the host plant.

Range AB

Status History
Designated Endangered in April 2006.

Sonora Skipper

Polites sonora

Special Concern

Assessment Criteria not applicable

Reason for Designation
This skipper occurs in some moist grassy openings in a forested landscape. It is known from only six locations in a small, restricted area of Canada where its distribution is very patchy and it does not occupy all apparently suitable available habitats. The ability of Canadian populations to benefit from immigration from other Canadian populations or from populations in adjacent Washington State is likely limited at best. The skipper is threatened by intensive grazing and habitat loss due to natural habitat change and road construction. However, it shows some ability to make use of some man-made habitats, such as grassy roadside areas, agricultural meadows and small clearcuts, but only if these habitats are moist or mesic.

Range BC

Status History
Designated Special Concern in April 2006.

Molluscs

Blue-grey Taildropper Slug

Prophysaon coeruleum

Endangered

Assessment Criteria B1ab(iii)+2ab(iii)

Reason for Designation
This species has a very small extent of occurrence (~ 150 km²) and area of occupancy (< 5 km²), and a continuing decline is projected in quality of habitat. It is found in remnant patches of older forest with a deciduous component. It is currently known from only 5 locations on southern Vancouver Island. Threats at these locations include heavy recreational use and the impacts of introduced plants and animals, including introduced invasive slugs and snails.

Range BC

Status History
Designated Endangered in April 2006.

Mapleleaf Mussel -- Saskatchewan - Nelson population

Quadrula quadrula

Endangered

Assessment Criteria B2ab(i,ii,iii,iv)

Reason for Designation
Small area of occupancy; all localities but one are in one system, the Red Assiniboine drainage, and a major event could extirpate the population; no evidence for recruitment (few small individuals); numerous threats including degrading water quality from agriculture, domestic waste, commercial and industrial activities.

Range MB

Status History
Designated Endangered in April 2006.

Rainbow Mussel

Villosa iris

Endangered

Assessment Criteria B2ab(i,ii,iii,iv)

Reason for Designation
This attractive yellowish green to brown mussel with green rays is widely distributed in southern Ontario but has been lost from Lake Erie and the Detroit and Niagara rivers and much of Lake St. Clair due to zebra mussel infestations. It still occurs in small numbers in several watersheds but the area of occupancy and the quality and extent of habitat are declining, with concern that increasing industrial agricultural and intensive livestock activities will impact the largest population in the Maitland River.

Range ON

Status History
Designated Endangered in April 2006.

Mapleleaf Mussel -- Great Lakes - Western St. Lawrence population

Quadrula quadrula

Threatened

Assessment Criteria Met criteria for Endangered, B2ab(i,ii,iii,iv), but designated Threatened because populations are stable or perhaps increasing in most existing locations. Criteria met for Threatened: B1ab(i,ii,iii,iv)+2ab(i,ii,iii,iv).

Reason for Designation
This heavy shelled mussel that is shaped like a maple leaf, has a very small area of occupancy in watersheds dominated by agriculture with past and continuing declines due to habitat loss and degradation. Although the mussel has been lost from the Great Lakes and connecting channels due to zebra mussels, the numbers of mature individuals appear to be very large in two of the watersheds and three of five watersheds have recovery teams in place for aquatic species at risk. Zebra mussels continue to be a potential threat in watersheds that have numerous impoundments.

Range ON

Status History
Designated Threatened in April 2006.

Vascular Plants

American Columbo

Frasera caroliniensis

Endangered

Assessment Criteria B1ab(ii,iii,iv,v)+2ab(ii,iii,iv,v); C2a(i)

Reason for Designation
A long-lived perennial with 11 to 12 extant Canadian populations. These are fragmented and restricted geographically to a highly agricultural and urbanized region that is subject to continuing habitat loss and degradation. Populations consist primarily of vegetative rosettes with only a few flowering plants produced in a given year. The spread of invasive plants within its habitat is a major threat to the persistence of the species. Further losses of populations due to site development are anticipated.

Range ON

Status History
Designated Special Concern in April 1993. Status re-examined and designated Endangered in April 2006.

Brook Spike-primrose

Epilobium torreyi

Endangered

Assessment Criteria D1

Reason for Designation
Although no plants have been seen at the two known sites after intensive directed surveys, there is still the possibility that some seeds may remain in the soil seed bank given the relatively short period of time since the last observation of plants in 1993, or that previously overlooked populations may be found.

Range BC

Status History
Designated Endangered in April 2006.

Cherry Birch

Betula lenta

Endangered

Assessment Criteria A2ac; B1ab(ii,iii,v)+2ab(ii,iii,v); C1+2a(i,ii); D1

Reason for Designation
A widespread deciduous tree of eastern North America that is known from a single small population in Ontario. This population has declined considerably over the past four decades with fewer than 15 trees remaining in the wild. Its habitat is surrounded by residential development and the population is at continued risk from storms, erosion and habitat loss and degradation.

Range ON

Status History
Designated Endangered in April 2006.

Coast Microseris

Microseris bigelovii

Endangered

Assessment Criteria B1ab(ii,iii)+2ab(ii,iii)

Reason for Designation
A small annual herb present in a few fragmented sites within a narrow coastal fringe on southeast Vancouver Island in a densely inhabited urbanized region. Development, recreational activities, site management practices and competition from invasive alien plants continue to impact the species.

Range BC

Status History
Designated Endangered in April 2006.

Contorted-pod Evening-primrose

Camissonia contorta

Endangered

Assessment Criteria B1ab(ii,iii,iv,v)+2ab(ii,iii,iv,v)

Reason for Designation
An annual herb restricted to several dry, open and sandy coastal habitats of very small size. The small fragmented populations are impacted by on-going habitat loss, high recreational use and competition with several invasive exotic plants.

Range BC

Status History
Designated Endangered in April 2006.

Dwarf Woolly-heads -- Southern Mountain population

Psilocarphus brevissimus

Endangered

Assessment Criteria B1ac(iv)+2ac(iv)

Reason for Designation
An annual herb restricted to a very small range and present at only three small sites on private lands within the COSEWIC Southern Mountain Ecological Area of British Columbia. Population size is subject to extreme fluctuations in the number of mature individuals due to variation in precipitation levels and the population is at risk from such factors as increased land development in the region and land use practices.

Range BC

Status History
Designated Endangered in November 2003. Renamed Dwarf Woolly-heads(Southern Mountain population) in April 2006 and designated Endangered.

Rough Agalinis

Agalinis aspera

Endangered

Assessment Criteria B1ab(ii,iii,iv,v)+2ab(ii,iii,iv,v); C2a(i)

Reason for Designation
An herbaceous annual having a restricted geographical range and occupying small prairie remnants mainly along roadsides in southern Manitoba. The few small populations are at risk from such impacts as late season mowing, burning, overgrazing and road expansion.

Range MB

Status History
Designated Endangered in April 2006.

Short-rayed Alkali Aster

Symphyotrichum frondosum

Endangered

Assessment Criteria B1ab(ii,iii,iv,v)+2ab(ii,iii,iv,v)

Reason for Designation
An annual herb of lake shorelines present at only a few remaining sites in restricted habitats. The small populations are subject to disruption from such activities as trampling, beach management, spread of invasive plants and potential development of a major facility at one of the primary sites.

Range BC

Status History
Designated Endangered in April 2006.

Bolander's Quillwort

Isoetes bolanderi

Threatened

Assessment Criteria D2

Reason for Designation
A small aquatic plant currently known in Canada from only one small lake in southwestern Alberta. The population has a large number of plants but is prone to being extirpated by a single, unpredictable event that could affect the entire population in a short period of time. Another population in a nearby lake has already disappeared over the past 50 years.

Range AB

Status History
Designated Special Concern in April 1995. Status re-examined and designated Threatened in April 2006.

Green-scaled Willow

Salix chlorolepis

Threatened

Assessment Criteria D1

Reason for Designation
An endemic shrub restricted to the serpentine outcrops of Mount Albert in Gaspésie Provincial Park, Quebec. The low numbers of the shrub located on a single mountain top are at risk from stochastic events, potential impact of the exotic tussock moth, and limited impact from hikers along the Appalachian Trail.

Range QC

Status History
Designated Threatened in April 2006.

Smooth Goosefoot

Chenopodium subglabrum

Threatened

Assessment Criteria Met criteria for Endangered, B2b(iii)c(iv), but designated Threatened due to a large number of sites scattered over a large area. Criteria met for Threatened: B2b(iii)c(iv).

Reason for Designation
An herbaceous annual with fluctuating populations of relatively small size. The species is restricted to areas of active sand habitats in southern Alberta, Saskatchewan and Manitoba. Current risks to the species include sand dune stabilization, invasive species, oil and gas development and recreational activities.

Range AB SK MB

Status History
Designated Special Concern in April 1992. Status re-examined and designated Threatened in April 2006.

Dwarf Woolly-heads -- Prairie population

Psilocarphus brevissimus

Special Concern

Assessment Criteria not applicable

Reason for Designation
This population is widely distributed in Saskatchewan and Alberta at more than 40 sites with large among-year fluctuations in numbers of mature individuals and with concerns over potentially significant future impacts. These pertain to potential future development of coal-bed methane gas extraction in a significant part of the range of the population and disruptions from pipeline construction.

Range AB SK

Status History
Designated Special Concern in April 2006.

Serpentine Stitchwort

Minuartia marcescens

Not at Risk

Assessment Criteria not applicable

Reason for Designation
A globally rare perennial herb which is present almost exclusively in Canada in disjunct and fragmented populations found on basic soils over serpentine outcrops at higher elevations. Several large populations occur in protected areas with minimal threats identified for the species.

Range QC NL

Status History
Designated Not at Risk in April 2006.

Mosses

Delicate Luster Moss

Isopterygium tenerum

Not at Risk

Assessment Criteria not applicable

Reason for Designation
This species is a small, shiny light green creeping moss. In Nova Scotia, it is found in the habitat of Coastal Plain species. It grows in a variety of habitats including soil and rocks along the wet margins of lakes and rivers. Although the species has a Canadian distribution restricted to southern Nova Scotia, it is more common and continuously distributed at known locations than previously thought. There are no direct or imminent threats to support an “at-risk” status.

Range NS

Status History
Designated Not at Risk in April 2006.

Lichens

Seaside Centipede Lichen

Heterodermia sitchensis

Endangered

Assessment Criteria D1

Reason for Designation
This is a foliose lichen restricted to shoreline Sitka Spruce trees on the west coast of Vancouver Island. It has been documented from only ten locations in Canada, 11 worldwide. It requires high levels of nitrogen, so is restricted to sites subject to nitrogen enrichment, for example, sea lion haul-out sites and bird nest sites. The species may have poor dispersal abilities. It is highly vulnerable to tsunamis, and intensified winter storm activity associated with global warming.

Range BC

Status History
Designated Endangered in April 1996. Status re-examined and confirmed in May 2000 and in April 2006.

Cryptic Paw

Nephroma occultum

Special Concern

Assessment Criteria not applicable

Reason for Designation
This foliose lichen is endemic to western North America where it is known in Canada from 45 locations, however there are likely more undiscovered locations. The Canadian sites account for more than 50% of the global range with only 5 locations protected from forest harvesting. The species has restricted habitat requirements and grows in mid to lower canopy of old growth coastal and interior humid cedar-hemlock forest. It reproduces only by vegetative propagules with limited dispersal distance. The species is vulnerable to forest harvesting, changes in understory humidity, insect defoliation (hemlock looper), and fire.

Range BC

Status History
Designated Special Concern in April 1995 and in April 2006.

Ghost Antler

Pseudevernia cladonia

Special Concern

Assessment Criteria not applicable

Reason for Designation
The species is a chalky white, finely branched macrolichen occurring on twigs of conifers in cool montane and coastal spruce-fir forests in eastern North America. It is very patchily distributed in New Brunswick and Nova Scotia, probably owing to dispersal limitations, and in southeastern Quebec, it is restricted to scattered mountaintops >800 m in elevation and to the height-of-land along the border with the United States. In its montane locations, the construction of communication towers, alpine ski development, and logging have caused some reductions in the area and quality of habitat. In the Maritimes, some population losses are attributable to logging and housing development. The severity of the threats is offset by the abundance of the species over a broad area and potential discovery of large populations on some mountain tops in Quebec.

Range QC NB NS

Status History
Designated Special Concern in April 2006.

Notes

Lake sturgeon, Acipenser fulvescens: The reassessment of the lake sturgeon that was scheduled for the April 2006 COSEWIC meeting was deferred so that the basis for delineating designatable units could be better documented. An update status report to support COSEWIC's previous assessment from May 2005 is currently not available. COSEWIC will defer forwarding its assessment of lake sturgeon to the Minister of the Environment for consideration for addition to Schedule 1 of the Species at Risk Act until an update status report is approved.

Purple Spikerush, Eleocharis atropurpurea: Report withdrawn for one year to allow inclusion of Aboriginal traditional knowledge information on population occurrence and size.

Sowerby's Beaked Whale, Mesoplodon bidens: Report withdrawn to allow incorporation of information related to perceived threats.

Westslope Cutthroat Trout, Oncorhynchus clarkii lewisi: Report withdrawn to clarify eligibility of populations to be assessed. A status report to support COSEWIC's previous assessment from May 2005 is currently not available. COSEWIC will defer forwarding its assessment of westslope cutthroat trout to the Minister of the Environment for consideration for addition to Schedule 1 of the Species at Risk Act until a status report is approved.

Wood Turtle, Glyptemys insculpta: Report withdrawn to integrate more details on population abundance and decline in the report, and to clarify information on designatable units.