Global Range: (<100 square km (less than about 40 square miles)) Range is currently thought to be restricted to the Petite Rivière watershed of southwestern Nova Scotia, with reproduction occurring primarily within the approximately 16 square kilometers (combined area) of Minamkeak, Milipsigate, and Hebb lakes (DFO 2009). The species is enturely land-locked in these three semi-natural lakes (DFO 2006). Formerly the species occurred in the Tusket and Annis rivers in southwestern Nova Scotia; no sighting of this species have been made there since 1982 (Bradford et al. 2004, DFO 2009).

endemic to a single state or province

Canada

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

Length: 40 cm

• Freshwater
• Marine

Habitat Type: Freshwater

Comments: Habitat includes lakes, small to large rivers (often in current), estuaries, and nearshore coastal waters. Spawning has never been observed in the wild, and spawning locations are unknown (DFO 2009).

Non-Migrant: Yes. At least some populations of this species do not make significant seasonal migrations. Juvenile dispersal is not considered a migration.

Locally Migrant: Yes. At least some populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).

Locally Migrant: No. No populations of this species make annual migrations of over 200 km.

Atlantic whitefish may occur as either anadromous or freshwater resident populations. This species was apparently anadromous in the Tusket River system; historical data indicate that gravid nadromous Atlantic whitefish ascended the Tusket River during late September to November (DFO 2009) and returned to sea between mid-February to late March.

Comments: Yarmouth Harbor specimens contained amphipods, small periwinkles, and marine worms. This fish presumably eats aquatic insect larvae and other invertebrates in Millipsigate Lake (Scott and Crossman 1973).

Note: For many non-migratory species, occurrences are roughly equivalent to populations.

Estimated Number of Occurrences: 1 - 5

Comments: This species is represented by a just a few extant occurrences (subpopulations).

Unknown

Comments: Total adult population size is unknown but abundance appears to be low (DFO 2009).

A small school of juveniles (age 0+) was observed in the littoral zone of Hebb Lake in late June 2000; These were the first observations of juvenile Atlantic whitefish in the wild (Hasselman et al. 2005). The maximum age for individuals in the existing wild population is estimated to be 4-5 years; age at first maturity is 2 years (DFO 2009).

• Needs updating

Rounded Global Status Rank: G1 - Critically Imperiled

Reasons: Restricted to three lakes in southern Nova Scotia; population size is unknown; extirpated from Tusket watershed apparently due to a combination of habitat loss and degradation from river acidification (acid rain), ineffective fish passage around dams, introduction of exotic species, and unregulated fishing; increase in non-native smallmouth bass population in the Petite Rivière watershed is an immediate concern.

Canada

Rounded National Status Rank: N1 - Critically Imperiled

Global Short Term Trend: Decline of 10-30%

Comments: This species "continues to decline..." (DFO 2006).

Global Long Term Trend: Decline of 30-70%

Comments: Probable extirpation of Atlantic whitefish from the Tusket watershed was attributed to a combination of habitat loss and degradation from river acidification (acid rain), ineffective fish passage around dams, introduction of exotic species, and unregulated fishing.(DFO 2009).

"There are no indications that current human activities within the Petite Rivière drainage pose a threat to the survival of Atlantic whitefish" (DFO 2004). "There is no certainty that the impact of harm from current human activities will remain low once smallmouth bass have become established in the Petite Rivière drainage" (DFO 2004). Smallmouth bass have been in Minamkeak Lake for several years, and young smallmouth bass recently have been found in Milipsigate Lake (DFO 2010).

"Current potential sources of direct mortality for Atlantic whitefish include: bycatch in recreational angling and other fisheries, entrainment of fish into water intakes, and removals or mortality from sampling for scientific purposes. Current indirect sources of mortality and impacts to habitat currently include: fluctuations in lake levels from municipal water drawdown or irrigation; acidification from acid run-off or acid rain; activities causing increased siltation, eutrophication, or substrate alteration; and barriers to fish passage. Unauthorized introduction and spread of non-native fish species (e.g., smallmouth bass, chain pickerel) may pose competitive, disruptive, or predation risks for Atlantic whitefish." Source: DFO (2009).

Restoration Potential: ...the potential for survival of this population may be higher if fish passage and anadromy is an option within the Petite Riviére, and abundance of smallmouth bass within Minamkeak, Milipsigate, and Hebb lakes is managed. The overall survival and recovery of Atlantic whitefish requires enabling anadromy and range extension outside the Petite Rivière lakes. The recovery of Atlantic whitefish is considered to be both biologically and technically feasible. However, the time to recovery will be dependent both upon the current status of the remaining population and the timing/extent of human intervention. Source: DFO (2009).

Stewardship Overview: Recovery strategy was described by DFO (2006).

Comments: Described as distinct from C. CLUPEAFORMIS in 1967. Mitochondrial DNA and isozyme electrophoretic analyses indicate that C. HUNTSMANI is genetically highly distinct from other coregonines (Bernatchez et al. 1991). Former specific name, CANADENSIS, is nomenclaturally preoccupied (Scott 1987, Robins et al. 1991).