Narwhal (Monodon monoceros) Northern Hudson Bay subpopulation Baffin Bay subpopulation: COSEWIC assessment and status report 2024

Official title: COSEWIC assessment and status report on the Narwhal (Monodon monoceros) Northern Hudson Bay subpopulation Baffin Bay subpopulation in Canada

Not at risk

2024

COSEWIC assessment summary

Assessment summary - May 2024

Common name: Narwhal - Northern Hudson Bay subpopulation and Baffin Bay subpopulation

Scientific name: Monodon monoceros

Status: Not At Risk

Reason for designation: The overall population of this Arctic, ice-loving toothed whale is large (>161,100 total, 93,500 mature individuals) and, although there is uncertainty about population structure, stock numbers, and trends, there is no evidence for a decreasing trend in abundance. Current levels of hunting are thought to be sustainable. Abundance may have declined in some areas coincident with increased shipping, but these likely reflect a redistribution of animals rather than a decline in abundance. Threats anticipated to increase in future include noise pollution from ship traffic and ice-breaking, and climate change. These could present challenges if this species is not closely monitored.

Occurrence: Nunavut, Arctic Ocean, Quebec (Nunavik), Newfoundland and Labrador (Labrador), Atlantic Ocean (Baffin Bay, Davis Strait, Labrador Sea)

Status history: COSEWIC: Designated Not at Risk in April 1986 and in April 1987. Status re-examined and designated Special Concern in November 2004. Status re-examined and designated Not at Risk in May 2024.

COSEWIC executive summary

Narwhal

Monodon monoceros

Northern Hudson Bay subpopulation

Baffin Bay subpopulation

Wildlife species description and significance

The Narwhal (Monodon monoceros) is a medium-sized toothed whale that lacks a dorsal fin. It is the only species in its genus and an upper-level predator in the Arctic food chain. Males can grow to approximately 5.4 m (approximately 1,935 kg) and females to approximately 4.9 m (approximately 1,552 kg). Adults have only two teeth. In most males, the right tooth remains encased in the skull and the left erupts to form a spiral tusk extending straight forward over 3 m. In most females, both teeth remain embedded.

The Narwhal is important to the subsistence economy and culture of Inuit in the eastern Canadian Arctic and Greenland. It is hunted by Inuit mainly for its skin and blubber (together called maqtaaq), meat, and ivory. The ivory is traded, while the maqtaaq is consumed locally and can be shared between communities.

Distribution

Narwhal occurs in Canadian Arctic waters (Northern Hudson Bay and Baffin Bay) and off East Greenland. In Canada, Narwhal comprise a single designable unit (DU), divided into a Northern Hudson Bay (NHB) subpopulation and a Baffin Bay (BB) subpopulation. Northern Hudson Bay Narwhal summer in northwest Hudson Bay and winter in eastern Hudson Strait. Baffin Bay Narwhal summer in the waters of West Greenland and the Canadian High Arctic, and winter in the pack ice of Baffin Bay and Davis Strait.

Habitat

In summer, Narwhal frequent coastal areas that offer deep water and shelter from wind. During the fall migration and while wintering in the pack ice, it prefers the continental slope, where depths range from 1,000 to 1,500 m. The presence of open cracks and leads in fast ice and the density of broken pack ice also appears to influence habitat selection.

Biology

Females are estimated to mature between age 8 and 9 years, males between 12 and 20 years. Females produce their first young at 9 to 12 years. Mating is estimated to peak in mid-April, and most new calves are observed in July and August after a gestation period of 14 to 15 months. While more frequent reproduction is possible, mature females produce a single calf approximately every three years on average until the age of 60. Longevity may be up to 101 years.

Narwhal generally travel in groups in summer but gather in concentrations of many hundreds of animals during migrations in the spring and fall. Their diving ability enables them to travel long distances under water. They eat a variety of fishes and invertebrates but specialize in deep-water foraging. Little is known about the species’ physiological requirements or its ability to adapt to environmental change or shifts in prey availability.

Population sizes and trends

The total abundance of Narwhal estimated from systematic aerial surveys is 161,100 (rounded to the nearest 100) individuals, approximately 90% of the global total. The trend is uncertain but is considered to be stable or possibly increasing. Assuming that 58% of the population is comprised of mature individuals, as reported by Taylor et al. (2007), the estimated total number of mature individuals is 93,500 Narwhal (rounded to the nearest 100). The Northern Hudson Bay subpopulation is estimated at 19,200 (11,200 mature individuals) animals and is considered stable, or increasing slowly, based on the most recent survey estimates and trend analysis. The Baffin Bay subpopulation is estimated to number 141,900 (82,300 mature individuals) animals.

Several management stocks have been identified within the Baffin Bay subpopulation based on summering areas, and most are considered to be increasing or stable. Movement of Narwhal among summering areas within the range of the Baffin Bay population adds uncertainty to this trend assessment.

Threats and limiting factors

Narwhal populations in Canada may be threatened by pollution (underwater noise), climate change, hunting, industrial activities such as shipping of iron ore, commercial fishing, environmental contaminants, and tourism. These whales may also be limited by their relatively narrow habitat and feeding niches. Effects of climate change on Narwhal are uncertain, as is the species’ capacity to adapt. The effects of the other factors are mitigated by its deep-water habits and widespread geographical distribution, much of which is outside normal hunting areas in offshore pack ice and in isolated areas of the Arctic. This remote distribution protects many Narwhal from hunters as well as isolated oil spills or other events. However, increases in ship traffic have eroded this protection over the past decade, and shipping is expected to increase over the next decade. Increasing ship traffic has been correlated with large shifts in Narwhal summer distribution, but its effects on population mortality are uncertain. Hunting probably represents the most consistent threat to Narwhal populations in Canada, but co-management with implementation of quotas and non-quota limitations is in place. The direct and indirect effects of climate change are increasing. A recent significant decline in Narwhal use of Eclipse Sound has raised concerns about the cumulative effects of development activities and climatic stressors on that stock, but these shifts appear to be offset by an increase in Narwhal use of Admiralty Inlet.

Protection, status and ranks

Protection for the Narwhal in Canada is limited to measures that manage the hunt, live capture, and movement of Narwhal products. Hunting is co-managed in their respective regions by the Nunavut Wildlife Management Board (NWMB) and Nunavik Marine Region Wildlife Board (NMRWB), in collaboration with Fisheries and Oceans Canada (DFO). Only Inuit are authorized to hunt Narwhal, and limits are placed on the number of animals each community can land. Although the Narwhal was assessed as Special Concern by the Committee on the Status of Wildlife in Canada (COSEWIC) in 2004, a Species At Risk Act (SARA) listing decision on that assessment has not been made. COSEWIC most recently assessed this species as Not at Risk in May 2024. The species is listed in Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). Canada cooperates with Greenland in the conservation of shared Narwhal populations through participation in the Joint Commission on the Conservation and Management of Narwhal and Beluga (JCNB) and serves as an observer on the North Atlantic Marine Mammal Conservation Organization’s (NAMMCO) Joint Working Group.

Technical summary

Monodon monoceros

Narwhal

Narval

Indigenous Names: Allanguaq (with black and white dots), tuugaalik (with tusk), qirniqtaq qilalugaq (black whale), (qilalugaq tuugaalik (whale with tusk), Inuktitut),

Range of occurrence in Canada (province/territory/ocean): Nunavut, Arctic Ocean, Quebec (Nunavik), Newfoundland and Labrador (Labrador), Atlantic Ocean (Baffin Bay, Davis Strait, Labrador Sea)

Demographic information

Generation time (average age of parents in the population)

33 years (Garde et al. 2015)

Is there an [observed, inferred, or projected] continuing decline in number of mature individuals?

No

Estimated percent of continuing decline in total number of mature individuals within [5 years or 2 generations]

No continuing decline. NA

[Observed, estimated, inferred, or suspected] percent [reduction or increase] in total number of mature individuals over the last [10 years, or 3 generations].

Baffin Bay subpopulation: Changes in estimates have increased over time likely due to improved survey coverage. Population suspected to be stable (NAMMCO 2018).

N Hudson Bay subpopulation: 54% increase in total population from 2011 to 2018 (7 years or approximately 1/4 of a generation) but difference in survey estimates not statistically significant at p < 0.05 level

[Projected or suspected] percent [reduction or increase] in total number of mature individuals over the next [10 years, or 3 generations].

Unknown

Observed, estimated, inferred, or suspected] percent [reduction or increase] in total number of mature individuals over any [10 years, or 3 generations] period, over a time period including both the past and the future.

Unknown

Are the causes of the decline a. clearly reversible and b. understood and c. ceased?

1. NA
2. NA
3. NA

Are there extreme fluctuations in number of mature individuals?

Unknown

Extent and occupancy information

Estimated extent of occurrence (EOO)

Exceeds thresholds with EOO of 3,090,852 km² [minimum convex polygon],

2,588,009 km² [within Canada's jurisdiction]

Index of area of occupancy (IAO)

(Always report 2x2 grid value).

Exceeds thresholds:

IAO (2 km x 2 km): 266,628 grids = 1,066,512 km²

Is the population “severely fragmented” that is, is >50% of its total area of occupancy in habitat patches that are (a) smaller than would be required to support a viable population, and (b) separated from other habitat patches by a distance larger than the species can be expected to disperse?

1. No
2. No

Number of “locations” (use plausible range to reflect uncertainty if appropriate)

Unknown, likely many

Is there an [observed, inferred, or projected] decline in extent of occurrence?

No

Is there an [observed, inferred, or projected] decline in index of area of occupancy?

No

Is there an [observed, inferred, or projected] decline in number of subpopulations?

No

Is there an [observed, inferred, or projected] decline in number of “locations”?

Unknown

Is there an [observed, inferred, or projected] decline in [area, extent and/or quality] of habitat?

Yes, inferred/projected decline in habitat quality with sea-ice loss and increased shipping

Are there extreme fluctuations in number of subpopulations?

No

Are there extreme fluctuations in number of “locations”?

No

Are there extreme fluctuations in extent of occurrence?

No

Are there extreme fluctuations in index of area of occupancy?

No

Number of mature individuals (in each subpopulation)

Subpopulations (stocks) (give plausible ranges)

Baffin Bay subpopulation²:

Total abundance (CV)[number mature animals³]

Somerset Island

49,768 (CV=0.20)² [28,865]

Jones Sound

12,694 (CV=0.33) [7,362]

Smith Sound

16,360 (CV=0.65) [9,489]

Admiralty Inlet

35,043 (CV=0.42) [20,325]

Eclipse Sound

10,489 (CV=0.24) [6,084]

Eastern Baffin Island

17,555 (CV=0.35) [10,182]

BB subpopulation Total:

141,909 (CV=.16) [82,307]

NHB subpopulation Total⁴:

19,232 (CV=0.28) [11,155]

Total both subpopulations:

161,141 (CV=0.14) [93,462]

Total Mature Individuals

93,462

Quantitative analysis

Is the probability of extinction in the wild at least [20% within 20 years or 5 generations, or 10% within 100 years]?

Unknown; analysis not conducted

Threats (direct, from highest impact to least, as per IUCN Threats Calculator)

Was a threats calculator completed for this species? Yes. (Appendix 2)

Overall threat impact is Medium. Key threats were identified as:

1. Pollution (IUCN 9)-Medium
2. Climate Change and Severe Weather (IUCN 11) – Medium-Low
3. Biological Resource Use (IUCN 5) – Low
4. Transportation and Service Corridors (IUCN 4) – Negligible
5. Invasive and Other Problematic Species and Genes (IUCN) – Negligible
6. Energy Production and Mining (IUCN 3) – Negligible
7. Human Intrusions and Disturbance(IUCN 6) – Unknown
8. Natural System Modifications (IUCN 7) – Unknown

Additional relevant limiting factors:

1. Predation by Killer whales is considered to be a limiting factor

Rescue effect (from outside Canada)

Status of outside population(s) most likely to provide immigrants to Canada.

Two stocks are considered part of the Baffin Bay subpopulation outside of Canada: Inglefield Bredning and Melville Bay in Greenland. Both stocks appear stable although there are concerns (NAMMCO 2018).

Is immigration known or possible?

Unknown but possible

Would immigrants be adapted to survive in Canada?

Yes

Is there sufficient habitat for immigrants in Canada?

Depending on cause of extirpation

Are conditions deteriorating in Canada?

Yes

Are conditions for the source population deteriorating?

Likely

Is the Canadian population considered to be a sink?

No

Is rescue from outside populations likely?

No

Data sensitive species

Is this a data sensitive species?

No

Status history

COSEWIC: Designated Not at Risk in April 1986 and in April 1987. Status re-examined and designated Special Concern in November 2004. Status re-examined and designated Not at Risk in May 2024.

Status and reasons for designation

Status: Not At Risk

Alpha-numeric codes: Not applicable.

Reason for designation: The overall population of this Arctic, ice-loving toothed whale is large (>161,100 total, 93,500 mature individuals) and, although there is uncertainty about population structure, stock numbers, and trends, there is no evidence for a decreasing trend in abundance. Current levels of hunting are thought to be sustainable. Abundance may have declined in some areas coincident with increased shipping, but these likely reflect a redistribution of animals rather than a decline in abundance. Threats anticipated to increase in future include noise pollution from ship traffic and ice-breaking, and climate change. These could present challenges if this species is not closely monitored.

Applicability of criteria

Criterion A (Decline in total number of mature individuals):

Not applicable. No evidence of decline in the total number of mature individuals.

Criterion B (Small distribution range and decline or fluctuation):

Not applicable. EOO of 2,588,009 km² and IAO of 1,066,512 km² (within Canadian jurisdiction) exceed thresholds for Threatened.

Criterion C (Small and declining number of mature individuals):

Not applicable. The number of mature of individuals is 93,462, which exceeds the threshold for Threatened, and there is no evidence for a continuing decline.

Criterion D (Very small or restricted population):

Not applicable. The number of mature individuals is 93,462, which exceeds the threshold for Threatened.

Criterion E (Quantitative analysis):

Not applicable. Analysis not conducted.

Preface

Narwhal was designated Not at Risk in Canada by COSEWIC in April 1986 (Campbell et al. 1986) and April 1987 (Strong 1987, 1988). The species’ status was re-examined, and designated Special Concern in November 2004 based on an updated status report (COSEWIC 2004). The two populations, Northern Hudson Bay and Baffin Bay, were presented to COSEWIC as potentially separate designatable units in 2004. However, following COSEWIC practice at that time, they were amalgamated after both were assessed as Special Concern.

Since the last assessment there is new information available to reassess status of Narwhal in Canada. New population estimates are available including the first aerial survey of the entire Baffin Bay subpopulation. New information about threats, particularly with respect to climate change and coincident anthropogenic impacts are also available, including valuable Aboriginal Traditional Knowledge (ATK) recording changes in summer distributions and Killer Whale (Orcinus orca) abundance and distribution. New information on Narwhal aging has improved estimates of reproductive and survival rates, understanding of reproductive senescence, and other aspects of the species’ life-history.

New protected areas have also been put in place within the range of Narwhal in Canada since the last status update, including Tallurutiup Imanga National Marine Conservation Area (TI NMCA) in Lancaster Sound, which has been reserved pending establishment, and Tuvaijuittuq Marine Protected Area (MPA) of northern Ellesmere Island, which is under interim protection while the feasibility of longer-term protection is assessed.

COSEWIC history

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. On June 5, 2003, the Species at Risk Act (SARA) was proclaimed. SARA establishes COSEWIC as an advisory body ensuring that species will continue to be assessed under a rigorous and independent scientific process.

COSEWIC mandate

The Committee on the Status of Endangered Wildlife in Canada (COSEWIC) assesses the national status of wild species, subspecies, varieties, or other designatable units that are considered to be at risk in Canada. Designations are made on native species for the following taxonomic groups: mammals, birds, reptiles, amphibians, fishes, arthropods, molluscs, vascular plants, mosses, and lichens.

COSEWIC membership

COSEWIC comprises members from each provincial and territorial government wildlife agency, four federal entities (Canadian Wildlife Service, Parks Canada Agency, Department of Fisheries and Oceans, and the Federal Biodiversity Information Partnership, chaired by the Canadian Museum of Nature), three non-government science members and the co-chairs of the species specialist subcommittees and the Aboriginal Traditional Knowledge subcommittee. The Committee meets to consider status reports on candidate species.

Definitions

(2024)

Wildlife species

A species, subspecies, variety, or geographically or genetically distinct population of animal, plant or other organism, other than a bacterium or virus, that is wild by nature and is either native to Canada or has extended its range into Canada without human intervention and has been present in Canada for at least 50 years.

Extinct (X)

A wildlife species that no longer exists.

Extirpated (XT)

A wildlife species no longer existing in the wild in Canada, but occurring elsewhere.

Endangered (E)

A wildlife species facing imminent extirpation or extinction.

Threatened (T)

A wildlife species likely to become endangered if limiting factors are not reversed.

Special concern (SC)
(Note: Formerly described as “Vulnerable” from 1990 to 1999, or “Rare” prior to 1990.)

A wildlife species that may become a threatened or an endangered species because of a combination of biological characteristics and identified threats.

Not at risk (NAR)
(Note: Formerly described as “Not In Any Category”, or “No Designation Required.”)

A wildlife species that has been evaluated and found to be not at risk of extinction given the current circumstances.

Data deficient (DD)
(Note: Formerly described as “Indeterminate” from 1994 to 1999 or “ISIBD” [insufficient scientific information on which to base a designation] prior to 1994. Definition of the [DD] category revised in 2006.)

A category that applies when the available information is insufficient (a) to resolve a species’ eligibility for assessment or (b) to permit an assessment of the species’ risk of extinction.

*   Formerly described as “Vulnerable” from 1990 to 1999, or “Rare” prior to 1990.

**  Formerly described as “Not In Any Category”, or “No Designation Required.”

*** Formerly described as “Indeterminate” from 1994 to 1999 or “ISIBD” (insufficient scientific information on which to base a designation) prior to 1994. Definition of the (DD) category revised in 2006.

Wildlife species description and significance

Name and classification

Scientific: Monodon monoceros Linnaeus 1758

English: Narwhal

French: Narval

Inuktitut: Allanguaq (with black and white dots), tuugaalik (with tusk), qirniqtaq qilalugaq (black whale), (qilalugaq tuugaalik (whale with tusk).

Classification:

Class:

Mammalia (Linnaeus, 1758 - mammals), Order: Artiodactyla (whales, dolphins, even-toed ungulates), Infraorder: Cetacea (Brisson, 1762 - cetaceans, whales), Parvorder: Odontoceti (Flower, 1867 - toothed whales), Family: Monodontidae (Grey, 1821 - white whales).

Narwhal (Monodon monoceros, Linnaeus 1758) is a well-established species and one of two species in the monophyletic family Monodontidae, the other being Beluga (Delphinapterus leucas). Molecular evidence suggests the two species diverged 5 to 6 million years ago (Steenman et al. 2009; Louis et al. 2020; Westbury et al. 2019). There are reports of rare hybrids between Narwhal and beluga (N=3 with one skull collected: Heide-Jørgensen and Reeves 1993; Heide-Jørgensen and Laidre 2006; Skovrind et al. 2019; Vicari et al. 2022).

Morphological description

The Narwhal is a medium-sized toothed whale known for the presence of an elongated tooth (tusk) that erupts from the upper jaw of males. It lacks a dorsal fin but has a low dorsal ridge and unique convex-shaped tail flukes (Fontanella et al. 2011). Adult males can grow to 5.40 m (approximately 1,935 kg) and females to 4.94 m (approximately 1,552 kg) in length (mass)(Weaver and Walker 1988; Roberge and Dunn 1990)). Adult males tend to be 10% to 20% longer than females, not including the tusk, and can be considerably heavier (Naughton 2012). Newborn calves are typically about 1.60 m long (Hay 1984; Neve 1995).

Colouration changes during the lifetime of a Narwhal. Individuals are born an uneven grey or bluish grey, becoming uniform black or bluish black after weaning (Arvy 1978; Reeves and Tracey 1980). As the animal matures, it becomes mottled with white streaks and patches on a dark background. The white patches develop and spread over the entire ventral surface and onto the flanks as an animal ages. Very old animals, particularly males, become almost entirely white (Reeves and Tracey 1980).

Narwhal have two teeth (incisors) which are embedded horizontally in the maxillary bones on the right and left sides of the upper jaw (Eales 1950). In adult males, the upper left tooth emerges from above the lip to form a long straight tusk which can be up to 3 m in length (Dow and Hollenberg 1977; Reeves and Tracey 1980). Rarely, females with a single tusk, males without a tusk, and males and females with two tusks occur (Hay and Sergeant 1976; Reeves and Tracey 1980; Reeves and Mitchell 1981; Petersen et al. 2012; Garde and Heide-Jørgensen 2022). Narwhal also have vestigial teeth with no apparent functional characteristics (Nweeia et al. 2012).

Population spatial structure and variability

Three Narwhal populations have been described in the Global Review of the Conservation Status of Monodontid Stocks (Hobbs et al. 2019). The populations identified are Eastern Greenland, Northern Hudson Bay, and Baffin Bay (Figure 1, 2). Only the Northern Hudson Bay (NHB) and Baffin Bay (BB) populations occur in Canadian waters. The latter were proposed as designatable units, but this proposal was not accepted by COSEWIC (DU; see Designatable units). Genetic analysis of population structure in Narwhal and studies of genetic diversity have all observed low levels of variability (Palsbøll et al.1997; Postma 2017; Westbury et al. 2019; Louis et al. 2020). Despite limited geographical structuring of clades, significant genetic differentiation between the East Greenland population and the other two populations has been reported for both mitochondrial (Palsbøll et al. 1997) and nuclear markers (Petersen et al. 2011). Cranial differences detected between East and West Greenland samples (Wiig et al. 2012) and the geographical pattern of pollution accumulation also suggest differences between east and west Greenland Narwhal (Dietz et al. 2004). East Greenland Narwhal are believed to spend the winter between eastern Greenland and Svalbard, Norway (Dietz et al. 1994; Heide-Jørgensen et al. 2020). There is no evidence that the range of these whales overlaps with that of other Narwhal in Hudson Bay or Baffin Bay (including west Greenland).

The DU structure (see Designatable units) is based on a number of lines of evidence including ATK, specifically from communities that harvest both populations (for example, Iglulik and Sanirajak; White 2012), lack of summering and wintering distribution overlap from satellite telemetry (Westdal et al. 2010; Watt et al. 2012a, 2017; Heide-Jørgensen et al. 2013b; NAMMCO 2018; Hobbs et al. 2019), and biochemical tracers (de March and Stern 2003; Watt et al. 2013). Significant genetic differentiation was estimated from mitochondrial sequencing, despite a lack of fixed differences (de March et al. 2003), and from neutral nuclear microsatellite markers (de March et al. 2003; Petersen et al. 2011). Sequencing of whole mitochondrial genomes did not reveal fixed genetic differences (Postma 2017; Louis et al. 2020), which suggests that the division was established relatively recently or that there is some degree of contemporary gene flow.

Figure 1. Global range of Narwhal showing summer and winter distributions of the Baffin Bay (BB), Eastern Greenland (EG), and Northern Hudson Bay NHB) populations (modified from NAMMCO 2018 and Hobbs et al. 2019 based on references cited in text).

The Northern Hudson Bay subpopulation is considered to be a single management stock; however, within the Baffin Bay subpopulation, six additional Canadian stocks have been delineated for management purposes, primarily on the basis of summering aggregations (DFO 2015; NAMMCO 2018; Hobbs et al. 2019): East Baffin Island, Eclipse Sound, Admiralty Inlet, Somerset Island, Jones Sound, and Smith Sound. There is ongoing research to understand these stocks, and additional data may or may not support all of them. For example, Charry et al. (2020) used a quantitative clustering approach to assess the management of BB Narwhal stocks and did not find support for the hypothesized division of Jones Sound and Smith Sound stocks. Additionally, Inuit have identified the potential for multiple units within the East Baffin Island summer stock, as well as a distinct group of whales summering in Creswell Bay (GN 2012b; DFO 2016; NWMB 2016). In addition, Parry Channel has been noted as a potential stock (Richard 2010a). However, some movement does occur between these areas (Watt et al. 2012a; Golder 2019, 2020a; DFO 2020a). Inuit hunters from communities where multiple stocks are observed have noted physical and behavioural differences (Nweeia et al. 2009, 2017; GN 2012b; NWMB 2016; Nweeia 2020). Two different types of male Narwhal—one that is relatively large and dark with a long tusk and another that is smaller and lighter in colour with a smaller and more twisted tusk have been reported by hunters in Qikiqtarjuaq, Clyde River, and Resolute Bay (Remnant and Thomas 1992; Oolayou 2016a). The Qikiqtaaluk Wildlife Board (QWB) and some communities have disputed the delineation of some stocks such as Eclipse Sound and Admiralty Inlet, pointing out that some animals regularly move between these areas (and also between Admiralty Inlet and Somerset Island) (GN 2012b; NTI 2012; DFO 2016; NWMB 2016; Oolayou 2016a, b; QWB 2022)., Hunters report that Narwhal in Jones Sound are more likely to seek deep water when threatened than those in Eclipse Sound (Reeves 1992a). Where samples are available, genetics research has not provided clear differentiation among these Baffin Bay stocks (de March et al. 2001, 2003; Petersen et al. 2011; Louis et al. 2020) although fatty acid and trace element analyses has recently provided information for differentiating stocks that are presumably feeding in different areas during summer months (Watt et al. 2019d).

Designatable units

COSEWIC recognizes a Designatable Unit (DU) if it has attributes that make it both discrete and evolutionarily significant.

Discreteness

Support for discreteness can come from either (1) evidence of heritable traits or markers that distinguish DUs, or (2) a natural geographic disjunction.

D1. Evidence of heritable traits or markers that clearly distinguish the putative DU from other DUs (for example, evidence from genetic markers or heritable morphology, behaviour, life history, phenology, migration routes, vocal dialects), indicating limited transmission of this heritable information with other DUs.

Evidence to support two DUs based on heritable traits or markers is hampered by historical genetic bottlenecks in the Narwhal which have reduced genetic diversity and power to detect regional differences (Palsbøll et al. 1997; de March et al. 2003; Postma 2017). Genome and mitogenome reconstructions of effective population size and female effective population size, respectively, suggest a long-term low effective population size followed by a recent expansion (Westbury et al. 2019; Louis et al. 2020). Using mitogenome data, researchers did not observe a deep phylogenetic separation observed between the putative NHB and BB designatable units (Postma 2017; Louis et al. 2020). However, this is not surprising, considering that divergence likely occurred after the last glaciation.

Genetic support for the presence of two DUs has been gathered from studies that observed significant differences in mitochondrial haplotype frequencies and nuclear microsatellite markers (de March et al. 2003; Petersen et al. 2011). Mitochondrial DNA is passed from mothers to offspring and has been used to infer maternal fidelity to sites in numerous species (for example, Hartl and Clark 1997). Mitochondrial control region haplotypes for 350 Narwhal (61 from NHB) were analyzed, and significant differences in the fixation index (F_ST), which is a measure of population differentiation due to genetic structure, were observed in 8 of 10 comparisons between BB summer stocks and NHB samples (F_ST range 0.05 to 0.26) (de March et al. 2003), which is indicative of moderate to very great differentiation (Hartl and Clark 1997).

Nuclear DNA markers (microsatellites) are neutral markers that are commonly used for population genetic studies. Two studies have looked at the population genetics of Narwhal in Canada (de March et al. 2003; Petersen et al. 2011). Petersen et al. (2011) conducted a study on population genetic structure which examined 877 Narwhal samples (46 from NHB). A Bayesian analysis was conducted to determine the number of genetic clusters without sampling location data, but it failed to resolve population structure at any level. However, a significant difference was observed between the BB and NHB Narwhal (pairwise F_ST of 0.011). This level of F_ST differentiation could be considered weak (Petersen et al. 2011). However, it is not uncommon to obtain low F_ST values when nuclear markers are used in comparison to mitochondrial markers due to the mode of inheritance and the mutation rate (Prugnolle and de Meeus 2002). Furthermore, this pattern of contrasting nuclear and mitochondrial results is typical of species with male-mediated gene flow and high natal fidelity. Although contemporary gene flow may be suggested by these results, Petersen et al. (2011) indicate that the relative population sizes (BB is estimated to be approximately eight times larger than NHB), the presumed recent geographical separation (post-glaciation), and long generation time may make it difficult to differentiate the two groups using neutral genetic markers. Evidence to support two DUs based on heritable traits can also come from non-genetic lines of evidence such as morphology, life history, or behaviour in cases where there is thought to be an underlying genetic or cultural component. In several cetacean species, vocal repertoires can be used to identify unique groups (for example, Payne and Guinee 1983); however, there are currently no such data for Narwhal. There is some evidence for fidelity to migratory routes between summer and wintering areas (Westdal et al. 2010; Heide-Jørgensen et al. 2013b), although most tagged individual whales only provide data for one transit from summer area to winter areas, and only a relatively small portion of each of the total subpopulations has carried satellite tags (N=9 for NHB Narwhal). Summering areas are well established and may suggest discrete units; the mechanism that maintains them has not yet been established but could be genetic or cultural. Certainly, Aboriginal traditional knowledge has established that Narwhal summering areas in NHB and the central Canadian Arctic are distinct from one another (Stewart 2001; GN 2012b; White 2012). Inuit recognize differences between whales from different areas (Nweeia et al. 2009, 2017; Nweeia 2020), but these differences have been described both between the subpopulations and also within a subpopulation. For example, hunters in Foxe Basin prefer to hunt animals from the Somerset Island stock (Baffin Bay subpopulation) as they are larger than those from Northern Hudson Bay (GN 2012b). Hunters also recognize movements between Canadian and Greenland waters, as they see whales that have scars from Greenland harpoons (GN 2012b; DFO 2016; NWMB 2016). These animals are larger, darker, and have thicker tusks that spiral less, and they are also harder to hunt than whales that summer in Canada (GN 2012b).

Summer Narwhal ranges and migration routes as described by ATK and scientific information show little overlap between the two subpopulations Although only a small proportion of the total population has been tracked, the general pattern is that during winter, animals from Northern Hudson Bay overwinter in deep waters of Davis Strait where it connects to the Hudson Strait, while the Baffin Bay animals occupy deeper waters covered by mobile ice in Davis Strait and Baffin Bay (Figure 3, NAMMCO 2018; Hobbs et al. 2019). Spring migration towards the summering areas is thought to occur during or near the March-May breeding season (Best and Fisher 1974; Hay 1984). There is some suggestion, based on observations of calves (Cosens and Dueck 1990), that the breeding season may be broader or vary among years and sites. However, peak observations of calves occur in July and August (Mansfield et al. 1975; Hay 1984; Hay and Mansfield 1989), so it is likely that migration routes and timing would isolate these two subpopulations during the critical time periods for genetic mixing.

Although feeding strategies may or may not be evidence of a heritable trait, they can be interpreted as evidence of discreteness without the ultimate cause of the differences being known. There is evidence from stable isotope signatures (Watt et al. 2013) and contaminant levels (de March and Stern 2003), which differ significantly, that Narwhal feed in different areas throughout the year. This could be due to animals using different and separate areas for foraging or different foraging strategies. Watt et al. (2013) found that NHB Narwhal were foraging more in benthic environments, which is consistent with a diet sourced from shallower waters, compared to BB Narwhal. This suggests that, in addition to occupying different ranges, animals from the two subpopulations likely also differ in their feeding habitats and prey (Watt et al. 2013). However, there is some uncertainty regarding the timing of sampling, tissue turnover rates and the long-term stability of these patterns. Dietz et al. (2021) used tusks and stable isotopes to infer diet and observed plasticity in feeding ecology, which they ascribed to climate-induced changes in the ecosystem.

D2. Natural (that is, not the product of human disturbance) geographic disjunction between putative DUs such that transmission of information (for example, individuals, seeds, gametes) between these "range portions" has been severely limited for an extended time and is not likely in the foreseeable future. “Extended time” is intended to mean that sufficient time has passed that either natural selection or genetic drift are likely to have produced discrete units, given the specific biology of the taxon.

There is some suggestion that Narwhal occurring in Northern Hudson Bay/ Foxe Basin/ Davis Strait do not overlap in range with those occurring in Baffin Bay / central Canadian Arctic (Richard 1991). However, Narwhal from the central Canadian Arctic do move through Fury and Hecla Strait (Stewart et al. 1995; DFO 2011; GN 2012b; Watt et al. 2012a), which is close to the summer range of the NHB subpopulation. Harvesters in Iglulik (Igloolik) and Sanirajak (Hall Beach) have noted that the Somerset Island summer stock (BB subpopulation) and the Northern Hudson Bay subpopulation both occur in Foxe Basin but do not mix (GN 2012b). In addition, the winter range for the NHB subpopulation is poorly defined and there may be winter or spring overlap, thus there is insufficient support for the two DUs based on the evidence of natural geographic disjunction.

Significance

The significance of units that have been identified as discrete should be based on one or a combination of the following criteria: 1) evidence that the DU has been on an independent evolutionary trajectory for an evolutionarily significant time and 2) evidence that the putative DU possesses heritable traits that if lost cannot be reconstituted.

S1. Direct evidence or strong inference that the putative DU has been on an independent evolutionary trajectory for an evolutionarily significant period, usually intraspecific phylogenetic divergence indicating origins in separate Pleistocene refugia.

As the separation between the two subpopulations has presumably occurred since the last glaciation when Narwhal populations expanded (Westbury et al. 2019; Louis et al. 2020) and levels of differentiation are significant but low (de March et al. 2003, Petersen et al. 2011; but see Louis et al. 2020), there is insufficient evolutionary time to satisfy criterion 1.

S2. Direct evidence or strong inference that can be used to infer that the putative DU possesses adaptive, heritable traits, that cannot be practically reconstituted if lost.

There are several lines of evidence that provide support for the significance of the putative DUs under criterion 2

1. Cetaceans are well known to have lineages with distinct genetic or cultural traits that use specific habitats or feeding strategies (for example, Killer Whale, Orcinus orca), but these have not been established in Narwhal
2. Inuit who live in Iglulik where the two putative DUs overlap in summer have observed two types of Narwhal, but there is conflicting ATK. White (2012) stated that Inuit observe a smaller northern type and a larger southern type, whereas ATK reported in GN (2012b) indicates that the northern animals are larger than those from the NHB DU. There is also contrasting information in different sources regarding the presence of both DUs in this area: ATK reported in GN (2012b) indicates that animals from Northern Hudson Bay do not move far up the coast towards Sanirajak, whereas DFO (2011) reports that Iglulik HTO members see NHB Narwhal as far north as Iglulik. Inuit have also identified putative groups of Narwhal in other regions (that is, a potential High Arctic stock in Parry Channel, a distinct group of Narwhal that summers in Creswell Bay) and additional sub-structuring within recognized summer stocks (for example, East Baffin Island) (GN 2012b; White 2012; DFO 2016; NWMB 2016). However, additional information is needed to be able to evaluate them using the COSEWIC framework
3. Narwhal in the NHB DU migrate along a unique route that is the farthest south of all stocks (Hobbs et al. 2019). Range-edge populations are likely to be found in areas where local adaptations to the unique conditions can become fixed and are not overwhelmed by gene flow from the core of the range. However, telemetry data related to NHB migration are limited (N=9) and information on discreteness of the spring information for all Narwhal is limited

The evidence presented was not sufficient to support the creation of two DUs. Therefore, the default for a single DU for Narwhal in Canada was retained.

Special significance

Narwhal have special significance for northern Indigenous people in Canada and Greenland. For Inuit, the species is a source of cultural connection, food, and economic opportunity (Brody 1976; Reeves 1992a, 1992b, 1993a; Remnant and Thomas 1992; Thomsen 1993; Reeves and Heide-Jørgensen 1994; Stewart et al. 1995; Gonzalez 2001; Richard 2001; DFO 2016; Reeves and Lee 2020). Narwhal are hunted mainly for their skin and blubber (known variously as maqtaaq, maktaaq, and muktaaq) and for their ivory. The meat may be taken and mostly used to feed dogs (Reeves 1992a, 1992b, 1993a, 1993b; Stewart et al. 1995; Gonzalez 2001; Richard 2001; DFO 2016; NWMB 2016). Maqtaaq is a highly valued food that provides protein, has high caloric value, and is rich in vitamin C, zinc, retinol, and other essential nutrients (Geraci and Smith 1979; Kinloch et al. 1992; Wagemann et al. 1996). It is consumed locally or traded/sold with Inuit in other communities (Reeves 1993a, b; NWMB 2016; BIMC 2017a). Narwhal tusks are sold nationally and internationally, and this provides incentive to selectively harvest large males (Reeves 1992a, 1992b; Gonzalez 2001; Reeves and Lee 2020).

Narwhal are one of three ice-adapted whales in the Arctic along with Beluga and Bowhead (Balaena mysticetus) whales. Their reliance on ice and their specialized feeding may place them at particular risk from the effects of climate change (Laidre et al. 2008). Since these are large, near-apex predators in the Arctic ecosystem, fluctuations in their populations could have significant impacts on their prey and predators, although these interactions are not well studied.

Ecologically, the Narwhal is important as a key link in the Arctic food chain between fish, such as Arctic Cod (Boreogadus saida) and Greenland Halibut (Reinhardtius hippoglossoides), and humans and Killer Whales. It is also ecologically significant for its ability to inhabit frigid Arctic waters and dive to great depths. It is the only Arctic ice-adapted whale that does not have a circumpolar distribution. It is a key species that uses Lancaster Sound, the site of the Tallurutiup Imanga National Marine Conservation Area (NMCA). It attracts avid public interest because of its remote habit and its unique spiral tusk, which is used for carvings and other handicrafts.

Distribution

Global range

Narwhal inhabit Arctic waters from the western edge of the Canadian Arctic Archipelago east through the Greenland Sea to Severnaya Zemlya in the eastern Laptev Sea (Figure 1). They occur north to at least 82°N but are seldom seen south of 61°N (Richard 2014). Occasional vagrants have been reported in the Beaufort Sea (Reeves and Tracey 1980; Reeves et al. 2014) and south to the St. Lawrence River (Chung 2018; GREMM 2022) in Canadian waters, as well as south to Great Britain and Germany in European waters (Reeves and Tracey 1980; Haelters et al. 2018). This distribution appears to be unchanged from historical reports.

Canadian range

In Canada, Narwhal primarily use the waters of Baffin Bay, Davis Strait, the central Canadian Arctic, Northern Hudson Bay, Foxe Basin, and Hudson Strait (Figures 2 and 3). Most of these animals winter in Baffin Bay and Davis Strait, between Canada and Greenland, and migrate into Canadian waters for the summer months. Roughly 90% of the total global population summers in Canadian waters. The current Canadian distribution is likely similar to the post-Pleistocene distribution, although Inuit report that Narwhal are expanding their summer range into the central Canadian Arctic (George 2012).

Narwhal summer distribution is influenced by the extent of land-fast ice and the progression of sea-ice break-up; however, there is an added element of uncertainty due to the presence of Killer Whales (Higgins 1968; W. Angalik, pers. comm. in Stewart et al. 1991). However, summer aggregations are known and predictable and form the basis of the stock structure (see Population Spatial Structure).

Narwhal that comprise the NHB subpopulation summer in the waters surrounding Southampton Island, with the largest aggregations in Repulse Bay, Frozen Strait, western Foxe Channel and Lyon Inlet (Richard 1991, 2010b; Gaston and Ouellet 1997; DFO 1998a; Gonzalez 2001; Asselin et al. 2012; Watt et al. 2020). Whales from this subpopulation also summer, typically in smaller numbers, in Wager Bay or Duke of York Bay, and periodically occur farther south to Whale Cove (see also DFO unpubl. data; J. Young, DFO Iqaluit, pers. comm. 2019, 2020). These animals winter in Hudson Strait and the adjacent waters of Davis Strait (Westdal et al. 2010; Elliot et al. 2013).

Most animals that winter in Baffin Bay will migrate into Lancaster Sound to reach summering areas in Barrow Strait, Peel Sound, Prince Regent Inlet, Admiralty Inlet and the Eclipse Sound area (Read and Stephansson 1976; Richard et al. 1994; NAMMCO 2018). The remainder of the Baffin Bay animals summer in the fjords along eastern Baffin Island or at Melville Bay and Inglefield Bredning in West Greenland (Born 1986, Born et al. 1994; Heide-Jørgensen 1994; Bröker et al. 2019). An animal that summered in Admiralty Inlet in 2009 wintered in northern Foxe Basin (Watt et al. 2012a). Much less is known about Narwhal that winter in Pikialasorsuaq (North Water Polynya, called Sarvarjuaq in Inuktitut), which has open water year-round (Finley and Renaud 1980; Richard et al. 1994); however, they are thought to summer in Jones and Smith sounds.

Extent of occurrence and area of occupancy

The extent of occurrence (EOO) for Narwhal in Canada is approximately 2,588,009 km². This far exceeds criteria thresholds. Index of area of occupancy (IAO) is approximately 266,628 2 km x 2 km grid cells = 1,066,512 km² within Canada. The EOO for the Baffin Bay and Northern Hudson Bay subpopulations is approximately 2,640,813 km² and 450,039 km², respectively. The IAOs for the Baffin Bay and Northern Hudson Bay subpopulations are approximately 892,660 km² and 173,852 km², respectively, which exceed criteria thresholds.

Search effort

The Canadian range has been developed from extensive ATK observations (Remnant and Thomas 1992; Stewart et al. 1995; Gonzalez 2001; DFO 2011, 2016; Furgal and Laing 2012; GN 2012a, b; White 2012; Oolayou 2016a, b, c; QIA 2019, 2021); harvest data (Watt and Hall 2018; Watt et al. 2019a; DFO unpubl. data); aerial surveys over the summer range of the NHB population in 2008, 2011 and 2018 (Richard 2010b; Asselin et al. 2012; Watt et al. 2020) and the BB subpopulation in 2013 (Doniol-Valcroze et al. 2015; Charry et al. 2020), as well as the winter range of the BB in the North Water Polynya (Heide-Jørgensen et al. 2013c); and targeted satellite telemetry studies which have informed our knowledge of both the summer and winter distributions of both subpopulations (Dietz et al. 2001, 2008; Heide-Jørgensen et al. 2002, 2003, 2013 b; Westdal et al. 2010; Richard et al. 2014; DFO 2020a; Golder 2019, 2020a). The extent of the summer western distribution edge in the central Canadian Arctic is uncertain, so a combination of ice metrics and community observations were used to delineate that boundary (Figure 2). In the south, the range was extended to encompass eastern Coronation Gulf because Narwhal have been reported and taken at Cambridge Bay (George 2012). In the Parry Channel and Queen Elizabeth Islands, the map uses the area defined with the 30-year median for fractured ice in mid-August (CIS 2013). Since Narwhal tagged near Somerset Island did not start to migrate to the wintering area until mid-September (Heide-Jørgensen et al. 2003), they could presumably utilize this area. The August 2018 observation in Archer Fiord of 26 Narwhal including a juvenile (Carlyle et al. 2021; Florko et al. 2021) provides support for the proposal to extend the species’ northern range to include Archer Fiord, Lady Franklin Bay, and Hall Basin as per COSEWIC (2004). The winter range for the Baffin Bay subpopulation was based on satellite telemetry (Heide-Jørgensen et al. 2013b; NAMMCO 2018; DFO 2020a) plus a polygon representing the North Water Polynya that follows the outline of Pikialasorsuaq (Pikialasorsuaq (North Water Polynya)). The summer area of the Northern Hudson Bay subpopulation was defined using ATK (for example, Gonzalez 2001) and aerial survey information (Watt et al. 2020), while the winter distribution is based on satellite telemetry (Westdal et al. 2010) and aerial surveys (Elliot et al. 2013).

Figure 2. Distribution of Narwhal in Canada and adjacent waters (modified from NAMMCO 2018 and Hobbs et al. 2019 based on references cited in text). The two populations are Northern Hudson Bay (in shades of red) and Baffin Bay (in shades of blue). Recognized stocks within the Baffin Bay population are Admiralty Inlet (AI), Eastern Baffin Island (EB), Eclipse Sound (ES), Jones Sound (JS), Southampton Island (SI), Smith Sound (SS), Inglefield Bredning (IB), and Melville Bay (MB). The exclusive economic zone (EEZ) boundary for Canada is designated in green.

Habitat

Habitat requirements

Narwhal inhabit a vast area where direct observation is challenging during most of the year. However, ATK and satellite telemetry have revealed several aspects of their habitat requirements, and when this is information is coupled with diet reconstruction, some habitat requirements can be inferred. For much of the year, Narwhal are associated with sea-ice cover (Reeves and Tracy 1980; Laidre et al. 2004, 2008). They are highly specialized for living in heavy ice cover, and these adaptations allow them to access prey in deep waters when predators are absent (Reeves and Tracy 1980; Laidre et al. 2004, 2008; Laidre and Heide Jørgensen 2005; Naughton 2012). Ice also provides a refuge from predation by Killer Whales, which leave the Central Arctic coincident with the formation of annual ice (Matthews et al. 2011).

In summer, Narwhal show a preference for deep waters (Finley 1976; Kingsley et al. 1994; Richard et al. 1994; NPC 2000; GN 2012a; Watt et al. 2017). This manifests in a use of deep areas (> 500 m) in the centre of Eclipse Sound and Prince Regent Inlet (Richard et al. 1994; Watt et al. 2017) and east of Hudson Strait (Watt et al. 2017) in winter, and also the use of fiords with steep bathymetry and deep waters in summer (Kingsley et al. 1994; Richard et al. 1994). Telemetry data show that the whales make numerous dives while in these deep waters, which suggests that they are feeding on benthic organisms. Summer use of shallower water is thought to be for calving, in some areas, or as a response to or refuge from Killer Whale predation (GN 2012b). The summer affinity of Narwhal for glacial fronts formed by high inputs of fresh meltwater, such as occur in Melville Bay of West Greenland (Laidre et al. 2016), has not been reported from Canadian waters although similar habitats may exist.

Narwhal use a variety of habitats both offshore and along the coast while migrating between summer and winter areas (Riewe 1992; Dietz et al. 2001; Shuert et al. 2023). In winter, they show a preference for continental slope areas, where depths range from 1,000 to 1,500 m and upwellings may increase biological productivity (Dietz and Heide-Jørgensen 1995; Dietz et al. 2001; Watt et al. 2017). Wintering habitat is thought to be determined by prey distribution and modified by ice cover (Koski and Davis 1994; Kenyon et al. 2018). In Baffin Bay, both sexes selected bathymetric areas that corresponded to higher densities of Greenland Halibut, and this relationship has held across years of differing mobile pack ice structure (Kenyon et al. 2018).

Habitat trends

The Narwhal is an ice-adapted species, so changes in ice regime have the potential to significantly affect their populations (Vibe 1967). Genomic work has revealed that past habitat extent coincided with major changes in effective population size, the most recent of which was an increase when the amount of suitable habitat expanded following the last glaciation (Westbury et al. 2019; Louis et al. 2020).

Trends in sea ice

Changes in sea ice are the most documented change in habitat affecting the Narwhal. Within the species’ range these include loss of sea-ice extent (for example, Stroeve and Notz 2018), longer open-water periods (Laidre et al. 2018), and changes in ice flow patterns (Howell and Brady 2019). These results largely agree with observations from holders of ATK in Canada and Greenland (Laidler 2006; Dale 2009; Nielsen 2009; Nweeia et al. 2009; 2017; GN 2012b; DFO 2016; NWMB 2016; Oolayou 2016a, b, c; Nweeia 2020). Narwhal may be at particular risk from these changes given their specialization for life in ice-covered habitats and their limited genetic diversity, which may reduce their evolutionary potential for effective adaptation (Laidre and Heide-Jørgensen 2005; Laidre et al. 2008; Williams et al. 2011, 2017; Pagano and Williams 2021).

Changes in the patterns of sea-ice formation have also been suggested as a risk factor for Narwhal due to increased risk of entrapment (GN 2012b; Laidre et al. 2012; NWMB 2016; Nweeia et al. 2017; Watt et al. 2019e; Nweeia 2020). There have been changes in the timing of freeze-up throughout the Narwhal range which has affected the timing of migration, indicating that the cues that trigger migration in Narwhal may no longer match the timing of ice formation every year (Laidre et al. 2012; Shuert et al. 2022).

Trends in habitat productivity

Coincident with changes in sea-ice coverage, there have been changes in the productivity of Baffin Bay. Although there are no studies linking changes in ocean productivity with Narwhal, there is the potential for these changes to have a significant impact. The North Water Polynya (Pikialasorsuaq), for example, has seen a reduction in productivity due to increased freshwater inputs and mixing (Bergeron and Tremblay 2014). Other areas may see increased productivity because of a longer ice-free period (Steiner et al. 2015).

Biology

Life cycle and reproduction

Vital rates for Narwhal are uncertain due to the difficulties associated with accurate age estimation. Narwhal dentition is not well suited for age determination as growth layers in the embedded tusks of both sexes are difficult to read and subject to resorption that limits the record to about 15 years. The larger erupted male tusk provides a more complete record, but to view the growth layers it must be sectioned medially along the whole of its length—a difficult and expensive process (Watt et al. 2019a). Garde et al. (2012) regressed counts of the growth layers in erupted Greenland Narwhal tusks against aspartic acid L/D isomer ratios in the animal’s eye lens nuclei to estimate the rate of aspartic acid racemization. This rate and data from reproductive organs and body length were then used to assess life-history parameters (Garde et al. 2015). For West Greenland Narwhal, age at sexual maturity was estimated to be 8 to 9 years for females and 12 to 20 years for males; first parturition 9 to 12 years first pregnancy 12.1 years oldest pregnant female at 67.9 years; maximum life span at about 100 years; and pregnancy rate at 0.38. Hay (1984) reported similar pregnancy rates (0.30 to 0.38) from Pond Inlet Narwhal. Generation time was estimated at 33 years (Garde et al. 2015).

Narwhal are seasonal breeders (Best and Fisher 1974; Hay 1984; Hay and Mansfield 1989). The females are polyoestrous and experience up to four consecutive ovulations during the breeding season (Hay 1984). Conception occurs between 20 March and 19 May, peaking in mid-April (Hay 1984). The gestation period has been estimated at between 14 (Best and Fisher 1974) and 15.3 months (Hay 1984). Neonates are typically about 160 cm long and weigh about 80 kg (Hay 1984; Neve 1995). Most calves are born in July and August (Mansfield et al. 1975; Hay 1984; Hay and Mansfield 1989). However, the presence of newborn Narwhal in Lancaster Sound on 27 May, and regularly thereafter during the spring of 1986 (Cosens and Dueck 1990), suggested that the breeding and calving periods are either broader than reported or vary significantly between years and/or sites. Some Inuit have also said that Narwhal can have calves at any time of the year, or at minimum, throughout the entire spring and summer seasons (DFO 2016; GN 2012b; Oolayou 2016a, b; Nweeia 2020). Important calving areas for the Baffin Bay DU, as identified by Inuit, include Milne Inlet and Tremblay Sound (Eclipse Sound region), Admiralty Inlet, Sam Ford Fiord, and other fiords north and south of Clyde River (East Baffin), Home Bay (East Baffin), and near Bathurst Island (Somerset Island summer stock) (GN 2012a, b; Oolayou 2016a, b, c; QIA 2019, 2021). However, while certain areas of importance are identified, Inuit have observed that Narwhal will calve anywhere within their summer range (DFO 2016; GN 2012b). Narwhal in the NHB DU often calve at the head of Lyon Inlet (GN 2012b).

Mature females produce a calf about once every three years on average (Hay and Mansfield 1989; Kingsley 1989) (note that some Inuit indicate a four-year calving interval, Oolayou 2016b). Nursing duration can range from about2 to 6 years (Zhao et al. 2021). Modelling performed by Ellis et al. (2018), which used ovarian activity data from across the lifespan of west Greenland Narwhal (Garde et al. 2015), showed that a significant (p < 0.001) proportion of females in this population live beyond their reproductive lifespan, with the proportion ranging from 0.19 for a shrinking population, to 0.24 for a stable population, and 0.29 for a growing population. The presence of older females may increase the fitness of other group members (for example, through transmission of knowledge) as has been observed in other cetaceans (for example, Killer Whales, Brent et al. 2015).

The rate of population increase for West Greenland Narwhal was estimated at 2.6% based on a population projection matrix parameterized with the data on age structure and fertility rates (Garde et al. 2015). The age distribution and survival rate estimates included both natural and hunting mortality; it was not possible to partition the two. Given the Narwhal’s low reproductive rate and longevity, survival rates close to 99% may be required to prevent population declines (Garde et al. 2015). Some hunters have observed that Narwhal have a faster reproductive system than Beluga Whales, because Narwhal populations increase at a faster rate (NWMB 2016).

There has been some disagreement between biologists and Inuit with respect to the reproductive rate of the Narwhal (Remnant and Thomas 1992; Stewart et al. 1995; Gonzalez 2001). Scientific reproductive rates are based on examination of the ovaries and uterus. The presence of two foetal age classes in summer indicates that the gestation period is greater than 12 months and that Narwhal cannot breed annually. However, on average 20% of females may calve every two years (Hay 1984). Inuit observation of females accompanied by more than one calf, sometimes by a neonate and a yearling or two-year-old suggest a shorter birth interval (Remnant and Thomas 1992; Thomsen 1993; Stewart et al. 1995). Research to determine the relatedness of individuals in these cases may help to understand these observations.

Removal by humans is a consistent cause of direct mortality. Increasing ship traffic has been correlated with large changes in habitat use by Narwhal, but its effects on population mortality are uncertain. The rate of mortality from predation by Killer Whale and Polar Bear (Ursus maritimus) are uncertain but could be significant (see Lefort et al. 2020a re Killer Whale predation), and may vary significantly depending on the annual presence of Killer Whales and ice. Large-scale mortality due to entrapment by ice can occur but is unpredictable. Rates of disease mortality are unknown.

Physiology and adaptability

Little is known about the physiological requirements of Narwhal or of the species’ ability to adapt to environmental changes. Adaptations for maneuverability and heat retention in Arctic waters, such as thick blubber and lack of a dorsal fin (Werth and Ford 2012), may make it difficult for them to dissipate excess body heat in response to rising sea temperatures, causing physiological stress (Chambault et al. 2020). In Scoresby Sound, East Greenland, Narwhal preferentially selected cold feeding areas, in summer and winter, with temperatures ranging from 0.6 to 1.5°C at depths of 300 to 850 m (Heide-Jørgensen et al. 2020; Tervo et al. 2021a). It is not known whether this narrow niche is because prey are concentrated and easier to catch at these low temperatures or due to limitations in the whale’s thermoregulation.

For Narwhal, an adaptation for prolonged deep dives, includes a high proportion of slow twitch muscle, which favours endurance rather than speed (Pagano and Williams 2021). This may leave Narwhal vulnerable to predation and competition in a warming ocean. The metabolic demands of diving to avoid a perceived threat (for example, Killer Whale, ships, seismic pulses, hunters) can be 1.9 times greater than for foraging dives (Williams et al. 2020). If the whales are unable to make the physiological adjustments needed for long dives or they are unable to make energy-saving prolonged glide descents, then this could result in a 2.0- to 2.2-fold increase in the energetic cost of diving (Williams et al. 2022). This can rapidly deplete tissue oxygen stores and lead to a prolonged period of post-escape recovery (Williams et al. 2017). This mismatch will become increasingly important as the duration and frequency of anthropogenic and other threats increase (Williams et al. 2020). Monitoring for changes in diving behaviour and related energy expenditure may be important for assessing the impacts of stressors such as climate change (Tervo et al. 2021a) and noise disturbance (Williams et al. 2022; Tervo et al. 2023).

Low genetic diversity at the genetic markers examined to date (Palsbøll et al. 1996; de March et al. 2003; Postma 2017; Westbury et al. 2019) suggests that there may be limited capacity to adapt evolutionarily to a radical environmental change or disease threat. However, Narwhal may possess phenotypic and/or behavioural plasticity in addition to benefiting from cultural transmission of information that facilitates adaptation to environmental changes. This is supported by stable isotopic signatures in tusks of northwest Greenland Narwhal that demonstrate surprising plasticity in their feeding ecology (Dietz et al. 2021).

Narwhal, like all cetaceans, depend on sound for numerous life-history functions including navigation, prey capture, and social interactions (Southall et al. 2019). It is a vocal species that produces a variety of sounds including pulsed calls, clicks, and whistles (Ford and Fisher 1978; Marcoux et al. 2011a, b, 2016). Vocal sequences, an indication of signal complexity in communication, have recently been described in Narwhal (Walmsley et al. 2020), including distinctive calls hypothesized to maintain contact between mother and calf (Ames et al. 2021). The Narwhal click is a highly directional biosonar signal with intensities of up to 222 dB re 1 μPa (Koblitz et al. 2016). The ability of Narwhal to avoid areas where anthropogenic noise sources mask their communication and acoustic orientation may be limited by their habitat specialization and site fidelity (Koblitz et al. 2016). Inuit have an extensive understanding of Narwhal sensitivity to noise, and traditional rules were established to avoid disturbance at calving areas (QIA 2019, 2021).

Sources of stress identified by Inuit for Narwhal include Killer Whale predation, underwater noise from shipping and industrial development, overpopulation, entrapments, climate change, and research activities (GN 2012b; NTI 2012; DFO 2016; Oolayou 2016b; NWMB 2016; QIA 2019, 2021). When they are stressed, Narwhal show elevated levels of cortisol hormone (Watt et al. 2021). Cortisol levels in blubber from whales summering in the northern Baffin Island area that were harvested for subsistence were significantly lower (0.81 ± 0.45 ng/g [±SE]) prior to the increase in vessel traffic to Milne Inlet for the Mary River Project (2000 to 2006) than following the increase (2013 to 2019; 1.81 ± 0.48 ng/g [±SE]), and much higher during a winter entrapment event (2015; 10.52 ± 0.59 ng/g [±SE]). Further monitoring is needed to understand which stressors are contributing to the hormonal response and what the implications could be for individual fitness and the population over time (Watt et al. 2021).

Dispersal and migration

Narwhal display a pronounced seasonal migratory cycle, the timing of which can vary depending upon ice conditions. They generally travel in groups of less than 25 animals which are dispersed during localized movements in summer (Marcoux et al. 2009), but gather into concentrations of many hundreds of animals during directed migrations in the spring and fall (Koski and Davis 1994; Richard et al. 1994). Most migratory movements occur at the surface and their swimming speed averages 5.0 km/h whether they are travelling horizontally or diving vertically (Heide-Jørgensen et al. 2001).

There is good agreement between scientific sources (for example, Richard et al. 1994; Dietz et al. 2001, 2008; Heide-Jørgensen et al. 2002, 2003, 2013b; Westdal 2008; Westdal et al. 2010; Watt et al. 2012a) and ATK sources (for example, Remnant and Thomas 1992; Stewart et al. 1995; Furgal and Laing 2012; GN 2012b; White 2012; NWMB 2016; Oolayou 2016a, b, c; QIA 2019, 2021) on the general timing and progression of migration in the two populations.

Satellite-tagging data from the NHB Narwhal subpopulation (Westdal 2008; Westdal et al. 2010) support observations made during aerial surveys (Richard 1991; Koski and Davis 1994; Watt et al. 2020) and from ATK (Gonzalez 2001; Westdal et al. 2010; GN 2012b). Narwhal tagged in Lyon Inlet (2005) and Repulse Bay (2006) remained in their summering habitat until late October, migrated eastward via Frozen Strait and Hudson Strait in November and early December to winter in an area east of Hudson Strait, and returned westward via Hudson Strait in June (Westdal 2008; Westdal et al. 2010). Naujaat (formerly Repulse Bay) hunters see them at the floe edge in late June (Gonzalez 2001). Narwhal from this population are not known to move north of Lyon Inlet (Richard 1991; Gonzalez 2001; GN 2012b); those in northern Foxe Basin are considered part of the BB subpopulation (Doniol-Valcroze et al. 2015).

Narwhal from the BB subpopulation move northward along the ice edge offshore of the east coast of Baffin Island in April and May (Remnant and Thomas 1992; Stewart et al. 1995; Stewart 2001; Heide-Jørgensen et al. 2003; Nweeia et al. 2009, 2017; GN 2012b; Watt et al. 2012a; DFO 2016; Oolayou 2016a; Nweeia 2020; QIA 2021). They then move westward into the sounds of eastern Baffin Island and into Lancaster Sound and adjoining waters as the ice permits, following cracks and leads, typically during June and July, to reach their summering habitats in the Eclipse Sound area, Admiralty Inlet, Prince Regent Sound, Barrow Strait, and Peel Sound (NWMB 2016; QIA 2019, 2021). Some animals travel south out of Prince Regent Inlet through Fury and Hecla Strait and into northern Foxe Basin (Brody 1976; Stewart et al. 1995; GN 2012a; Watt et al. 2012a; Golder 2020a). When land-fast ice begins to form, typically in September or October, the whales begin to move out of these summering areas adjoining Lancaster Sound and the sounds of eastern Baffin Island (GN 2012b; Oolayou 2016a, b, c). Some animals continue eastward from Lancaster Sound and move offshore from southeastern Devon Island towards Baffin Bay (Koski and Davis 1994). Most Narwhal move eastward out of the Central Arctic through Lancaster Sound or Eclipse Sound and then south along the east coast of Baffin Island, visiting many of the fiords on their way to wintering areas in southern Baffin Bay and northern Davis Strait (Dietz et al. 2001, 2008; Heide-Jørgensen et al. 2002, 2003, 2013b; Watt et al. 2012a, 2017).

Interspecific interactions

Predation

Killer Whales are widely acknowledged as a predator of Narwhal in Canadian waters (Reeves and Mitchell 1988; Gonzalez 2001; Laidre et al. 2006; Higdon 2007; Ferguson et al. 2012; GN 2012b; Higdon et al. 2012; NTI 2012; DFO 2016; Oolayou 2016c; QWB 2016; Nweeia et al. 2017; Lefort et al. 2020a; Nweeia 2020; QIA 2021), but overall predation rates are not well known. A bioenergetics model estimated that in the northern Baffin Island region, Killer Whales could consume 1,290 ± 214 Narwhal per year (Lefort et al. 2020a). Killer Whale occurrence is increasing in the region (Higdon and Ferguson 2009; DFO 2011; Higdon et al. 2012, 2014; NWMB 2016; Oolayou 2016c; QWB 2016; Lefort et al. 2020b; Nweeia 2020), and predation pressure on Narwhal could be similarly increasing (GN 2012b; QIA 2021).

In addition to causing direct mortality, Killer Whale presence drives Narwhal behavioural responses. Narwhal will flee and hide in pack ice (when available) or in shallow nearshore waters in the presence of Killer Whales (Reeves and Mitchell 1988; Gonzalez 2001; Laidre et al. 2006; Higdon 2007; Ferguson et al. 2012; Higdon et al. 2012; Westdal et al. 2013; NWMB 2016; Breed et al. 2017). This behaviour is well known to Inuit and is called ‘aarlirijuk’ (“fear of killer whales”) in the south Baffin dialect of Inuktitut (NWMB 2000). They breathe quietly to avoid detection and stop vocalizing instantly when Killer Whales approach (Ford 1987). Their fear is such that they will ignore humans (Gonzalez 2001; Westdal et al. 2013). In 1999, Killer Whales drove large numbers of Narwhal into shallow waters near Naujaat (Repulse Bay) (Gonzalez 2001), resulting in an unusually large harvest by Inuit. Breed et al. (2017) synchronously tracked Killer Whale and Narwhal movements via satellite telemetry in Admiralty Inlet. A switching-state space model and a series of mixed effects models showed that Killer Whale presence had a strong effect on Narwhal behaviour and distribution. When Killer Whales were within about 100 km, satellite-tagged Narwhal moved closer to shore and altered their movement patterns. Furthermore, these effects persisted for the entire 10-day period that the Killer Whales were present (Breed et al. 2017). Important Narwhal summering areas (inlets, fiords) provide refuge from Killer Whales, and their presence influences Narwhal movements, behaviour, stress levels, and migration timing (GN 2012a, b; NTI 2012; NWMB 2016; Oolayou 2016c; QIA 2019, 2021; Nweeia 2020). These non-lethal antipredator responses, such as fleeing and cessation of feeding, carry energetic and missed opportunity costs (Miller et al. 2022). Inuit hunters have also reported seeing more Narwhal with injuries from Killer Whale attacks in recent years than previously (GN 2012b; Oolayou 2016c). Synergistic effects are also possible, as increased Killer Whale presence may lead to Narwhal staying on their summering grounds longer in the fall, increasing the risk of entrapment (Oolayou 2016b, c). The long-term effects of increasing Killer Whale presence on Narwhal mortality, distribution, and behaviour are unknown.

Polar Bears can kill Narwhal calves (Kingsley 1990), prey upon stranded Narwhal (Smith and Sjare 1990), and scavenge carcasses from Inuit subsistence hunts (Galicia et al. 2015, 2016). Hunters have described parallel claw scars from unsuccessful bear attacks on the backs, sides, and tails of Narwhal (Kingsley 1990; Stewart et al. 1995). While predation rates appear to be low, hunters in some communities are also seeing an increase in Narwhal with scars from Polar Bears (Oolayou 2016c). Greenland Shark (Somniosus microcephalus) scavenge dead Narwhal, but it is not known whether they also actively prey on them (Beck and Mansfield 1969; Stewart et al. 1995). Atlantic Walrus (Odobenus rosmarus rosmarus) have also been found eating dead Narwhal (Gray 1929).

Diseases and parasites

Little is known of the diseases of Narwhal and their response to pathogens (Murray et al. 1995; Nielsen et al. 2000). However, there is general concern for Arctic species in relation to climate change and increased exposure from southern species that are moving northward (Bradley et al. 2005; Burek et al. 2008; Davidson et al. 2011; Sanderson and Alexander 2020). Antibody surveys of Narwhal have revealed exposure to Brucella spp. (5 in 77 tested: Nielsen et al. 2001a). A Narwhal infected with an alphaherpes virus was captured live during tagging in Tremblay Sound (north Baffin) (Nielsen et al. 2023). The prevalence and health impacts of this virus in Narwhal are unknown. In surveys of Narwhal in the Canadian Arctic, no animals tested positive for Influenza A (Nielsen et al. 2001b) or morbillivirus (Nielsen et al. 2000). These, or viruses in the same family, have caused mortality in other cetaceans which may be expanding into the Arctic, and lack of antibodies may suggest Narwhal are naive hosts and at greater risk (Nielsen et al. 2004). Inuit have observed that Narwhal blubber more frequently has yellow, unhealthy-appearing sections than in the past, although the reasons for this are not known (GN 2012a).

Narwhal are hosts to several endo- and ectoparasites. Five species of endoparasites have been found in the middle ear sinuses (n=1) digestive tract (n=3) and lungs (n=1) of Narwhal (Hay and Mansfield 1989). Two species of ectoparasites, including whale lice (Cyanus spp.), infest the skin fold at the base of the tusk and any wounds on the body (Porsild 1922; Hay and Mansfield 1989).

Nutrition and interspecific interactions

Niche modelling using stable isotopes shows that there are significant differences in dietary niche among Narwhal from Baffin Bay, Northern Hudson Bay, and East Greenland (Watt et al. 2013). Differences in dive behaviour among animals from these locations paralleled their diet differences (Watt et al. 2015). Dentine isotope profiles indicate sex differences and individual variability in resource use among Narwhal (Zhao et al. 2022).

Stomach content analyses show that Baffin Bay Narwhal eat a variety of fishes and invertebrates, with their primary prey items being Greenland Halibut, Arctic Cod, Polar Cod (Arctogadus glacialis), and Boreoatlantic Armhook Squid (Gonatus fabricii) (Finley and Gibb 1982; Hay and Mansfield 1989; Laidre and Heide-Jørgensen 2005). Inuit hunters have made similar observations about prey species composition and have also found Greenland Cod (Gadus ogac) and Arctic Char (Salvelinus alpinus) in Narwhal stomachs (Remnant and Thomas 1992; Thomsen 1993; Stewart et al. 1995; GN 2012a, b; NTI 2012; NWMB 2016; Oolayou 2016c). The composition of their diet varies with season and location, likely because of dietary preferences and the seasonal or geographical availability of prey species (Neve 1995; GN 2012b; NTI 2012; NWMB 2016). Based on their buzz patterns, which mark the final phase of potential prey capture (Blackwell et al. 2018), and the relatively smooth swimming patterns that follow, Narwhal foraging for squid may ingest them by buccal suction (Ngô et al. 2021).

Narwhal in Northern Hudson Bay were found to have stable isotope values which points to primarily benthic foraging (for example, for shrimps), which is concordant with the relatively shallow habitat they occupy (Watt et al. 2013). Inuit in Naujaat have observed a number of prey items, with Arctic Cod as a primary food source and other species like shrimp, clams and smaller fish also being consumed (Gonzalez 2001; GN 2012b). Stable isotopes from soft tissues reveal seasonal variation in the Northern Hudson Bay Narwhal diet (Watt and Ferguson 2015), while stable isotopes and mercury from tusks provide evidence of long-term (1962 to 2010) variation in the diet of Narwhal from Northwest Greenland (Dietz et al. 2021).

Little is known about the interactions between Narwhal and other species in relation to food and habitat. Their preference for deep-water habitat effectively separates them from Beluga Whales for much of the summer. Narwhal do participate with seabirds, Belugas, Harp Seals (Pagophilus groenlandicus) in mass aggregations feeding on Arctic Cod; the whales occasionally drive the cod into shallow water in late summer (Finley and Gibb 1982; Welch et al. 1993).

Narwhal feed heavily on cod and Greenland Halibut but the extent of their dependence on these species as a food source is unknown. Watt et al. (2013) suggest that the Baffin Bay population feeds heavily on fewer species at generally higher trophic levels (for example, Greenland Halibut) than the other populations. This narrow niche may indicate that intraspecific competition was not strong enough to cause resource limitation. Differing niches Narwhal from the three areas (Watt et al. 2013) and the temporal plasticity of feeding ecology by individuals (Dietz et al. 2021) suggest that Narwhal may be able to expand their dietary niche in the face of a changing climate and environment. Differences in foraging ecology between the sexes may be population-specific and driven by intra- and interspecific competition (Louis et al. 2021).

Population sizes and trends

Sampling effort and methods

Population sizes of the two Canadian Narwhal subpopulations and the different “summer stocks,” as defined by DFO for management purposes (Richard 2010a, b; DFO 2015, 2020a), are estimated using aerial surveys, with 1 to 5 estimates available for the different management areas. Higdon and Ferguson (2017) compiled a database of 22 records for Narwhal aerial surveys conducted between 1975 and 2013, based on peer-reviewed scientific publications and government technical reports where the primary goal was abundance estimation. All recent surveys correct for availability and perception bias and represent the most comprehensive estimates available to date; however, differences in survey and analysis methods and changes to survey coverage preclude rigorous assessment of trends. There is also extensive ATK on Narwhal abundance and changes in abundance over time (for example, GN 2012b; NTI 2012; NWMB 2016; Oolayou 2016a, b, c; QIA 2019, 2021; Nweeia 2020). Inuit have expressed concerns that factors such as increasing Killer Whale presence, which alters Narwhal behaviour and movements, are not adequately considered in survey-based estimates (NWMB 2016; QWB 2016; Nweeia 2020).

Abundance

The most recent estimate of global Narwhal abundance, from NAMMCO (2018), is 172,297 individuals, for 10 of the 12 stocks they recognized (no data are available for the Northeast Greenland and Svalbard-Northwest Russian Arctic units) (also see Hobbs et al. 2019; Reeves and Lee 2020). This includes the 7 Canadian summer stocks considered by DFO, which constitute the majority (ca. 90%) of the global population. All 10 survey-based estimates were corrected for both perception and availability bias. Assuming that mature animals comprise 58% of the population (Taylor et al. 2007), this would result in a global population size of 99,932 mature adults (excluding the two global stocks not surveyed).

Northern Hudson Bay subpopulation

Narwhal in Northern Hudson Bay, which are managed as a single stock by DFO, were last surveyed in 2018, with a fully corrected estimate of 19,232 (CV = 0.278, 95% CI = 11,257 to 32,856; Watt et al. 2020; see Table 1) (13,655 adults). Narwhal abundance in this area has increased since the 1980s, but appears to be leveling off (Biddlecombe and Watt 2022).

^a An August 2016 aerial photographic survey of the Eclipse Sound summer stock was conducted, with a fully corrected estimate of 12,039 individuals (CV = 0.23, 95% CI = 7,768 to 18,660) (Marcoux et al. 2019). The Admiralty Inlet aggregation was not surveyed concurrently. Industry-sponsored surveys in 2019, 2020 and 2021 documented continued (and significant) declines in Narwhal abundance in Eclipse Sound, and the Admiralty Inlet abundance estimate in 2021 was statistically higher than in previous years (Golder 2020b, 2021; BIMC 2022). Industry-sponsored surveys in 2022 recorded an increase in Narwhal abundance in Eclipse Sound compared to 2021 and previous estimates, but numbers were still significantly lower than estimates from 2016 and earlier (WSP 2023).

^b The DU total for Baffin Bay excludes two stocks (Inglefield Bredning, Melville Bay) that summer in West Greenland waters. When these two summer stocks are included, the total DU population = 172,297 whales.

Baffin Bay population

A large-scale comprehensive survey of Baffin Bay Narwhal abundance was conducted in 2013, when all six of the population’s summer aggregation areas were surveyed (DFO 2015; Doniol-Valcroze et al. 2015). The number of animals per stock ranged from approximately 10,500 (Eclipse Sound) to almost 50,000 (Somerset Island), with a total for the Baffin Bay subpopulation (Canadian portion only) of about 142,000 (95% CI=104,700 to 192,300) individuals (Table 1) (or just over 82,000 adults, assuming 58% are mature, Taylor et al. 2007). This is higher than previous estimates (see review in DFO 2013), but survey coverage was also greater and it is difficult to determine trends (see below and Appendix 1). DFO conducted another survey of Eclipse Sound in 2016 (Marcoux et al. 2019), and industry-sponsored surveys were conducted in both the Eclipse Sound and Admiralty Inlet stock aggregation areas every year from 2019 to 2022 (Table 2)(Golder 2020b, 2021, 2022; WSP 2023) (see below re trends). Inuit representatives from Pond Inlet and Arctic Bay have suggested to DFO that Narwhal are numerous in both areas, and more so in Admiralty Inlet (White 2012, and see below re diverging trends). Narwhal from the eastern Baffin Island component (that is, stock) of the Baffin Bay population are particularly abundant in Home Bay during the open-water season (GN 2012a, b; White 2012; Oolayou 2016a).

Fluctuations and trends

Good estimates of Baffin Bay and Hudson Bay Narwhal abundance before commercial whaling cannot be generated from historical harvest data (Mitchell and Reeves 1981; Reeves 1992a; Stewart 2008). The first surveys for Narwhal were flown in the mid-1970s in Admiralty Inlet (Fallis et al. 1983), and surveys for other stocks started later (1980s for the Eclipse Sound and Somerset Islands components of the Baffin Bay population and the Northern Hudson Bay population, see Table 1, also Higdon and Ferguson 2017). The East Baffin Island stock (Baffin Bay subpopulation) has only been surveyed twice, and not until the early 2000s; the Smith Sound and Jones Sound components were first surveyed in 2013 and only one estimate is available (Table 1). Given the relatively short survey history, it is not possible to assess trends over three generations (approx. 99 years). NAMMCO (2018) (also see Hobbs et al. 2019) summarized possible trends for each stock using available information and these are reproduced in Table 1. Appendix 1 presents a more detailed description of the survey data and ATK, indicating population trends for the different stocks. Overall, Narwhal abundance in Canada seems to be stable; however, considerable uncertainty exists for some stocks, and a possible increase for the Somerset Island stock.

Rescue effect

There may be a possibility of rescue for Narwhal in Canada from the Inglefield Bredning and or Melville Bay stocks that summer in West Greenland but winter in the same areas of Baffin Bay. However, given that these stocks are relatively small and subject to the same threats as Canadian Narwhal, there is little likelihood of a rescue effect. There is no evidence of movements from East Greenland (which is a separate population) further east into Canadian waters (Heide-Jørgensen et al. 2015).

Threats and limiting factors

Narwhal populations in Canada may be threatened by human activities such as hunting, commercial shipping related to non-renewable resource development, tourism, renewable resource exports, fisheries, and environmental contaminants. Some of these activities are being facilitated by climate change. The effects of some of these threats are mitigated by the species’ deep-water habits and its widespread geographical distribution. For example, there are areas of offshore pack ice and other areas of the Arctic that are not accessible to hunters or commercial shipping. This may change over the next decade in response to planned increases in ship traffic via Hudson Strait and Baffin Bay-Eclipse Sound (related to mining and access to non-renewable resources), and through the eastern Canadian Arctic, which will be facilitated by climate change. The question of whether Narwhal that summer in isolated areas can serve as a reserve for those in more accessible areas, where they are more vulnerable to extirpation, remains unanswered. Narwhal are not seen as direct competitors with humans for resources, or as a physical threat.

Threats

Narwhal are vulnerable to the cumulative effects of various threats, especially hunting, shipping, and climate change. These are listed below in order of decreasing severity, following the IUCN-CMP (International Union for Conservation of Nature – Conservation Measures Partnership) unified threats classification system (based on Salafsky et al. 2008). The overall threat impact is Medium for each subpopulation (see Appendix 2 for details).

1. Pollution (IUCN 9)-medium
2. Climate Change and Severe Weather (IUCN 11) – Medium-Low
3. Biological Resource Use (IUCN 5) – Low
4. Transportation and Service Corridors (IUCN 4) – Negligible
5. Invasive and Other Problematic Species and Genes (IUCN 8) – Negligible
6. Energy Production and Mining (IUCN 3) – Negligible
7. Human Intrusions and Disturbance(IUCN 6) – Unknown
8. Natural System Modifications (IUCN 7) – Unknown

Additional relevant limiting factors:

1. Killer Whales are considered to be a limiting factor

IUCN 9, pollution (medium)

Air-borne pollutants (IUCN 9.5) (low)

Elevated concentrations of cadmium and mercury have been found in the tissues of Narwhal taken in Canada and Greenland (Wagemann et al. 1983, 1996, 1998; Hansen et al. 1990). These metals accumulate in soft tissue as the animal grows, but the lack of age data and small sample sizes make it difficult to identify trends in their accumulation over time and space. Taking into account these limitations, the tissue concentrations of cadmium in Narwhal taken at Pond Inlet do not appear to have changed over the period 1978 to 1979 to 1992 to 1994; however, total mercury concentrations in the muscle, liver, and kidney may have increased (Wagemann et al. 1996). The effects of age and dietary differences and the contribution of anthropogenic mercury could not be quantified. Sonne et al. (2013) found liver and kidney lesions in Narwhal in northwest Greenland, and suggested mercury contamination may have been a contributing factor, particularly for the renal lesions. Concern has been raised about the potential for kidney damage in Narwhal from elevated cadmium levels and about the risk to human health from consuming maqtaaq and meat containing elevated mercury concentrations (Wagemann et al. 1996; 1998).

Mercury deposition in the dentine layers of 10 Narwhal tusks from Northwest Greenland increased log-linearly from 1962 to 2010 (Dietz et al. 2021). An unexpected rise in these levels in recent years may have been caused by increased mercury emissions and/or greater bioavailability in a warmer, ice-free Arctic.

In 1982 to 1983, Narwhal blubber and liver samples collected at Pond Inlet were analyzed for organochlorine pesticides (DDT, chlordane, polychlorinated camphenes [PCCs], dieldrin, hexachlorocyclohexanes [∑HCH], mirex), polychlorinated biphenyl congeners (PCBs), and chlorobenzenes (∑CBz) (Muir et al. 1992). Their mean ∑PCB concentrations were 6- to 15- fold lower than in dolphins from the Canadian East Coast and Belugas from the St. Lawrence River estuary, respectively, while PCC levels were 4- to 2- fold lower, and ∑HCH, dieldrin and ∑CBz differed by less than 2-fold. The pattern of these contaminants in their tissues suggests that Narwhal are exposed to proportionally more volatile compounds, likely due to long-range transport, and may have less capacity to metabolize some of these compounds relative to odontocetes living closer to sources of these contaminants. No temporal trends have been identified in the accumulation of organochlorine contaminants in Narwhal.

Excess energy (IUCN 9.6) (medium)

Noise pollution (IUCN 9.6.3)

Potential noise impacts on marine mammals include disturbance, masking, and acoustic injury (Southall et al. 2019). With the exception of loud noises generated seasonally by sea ice, Arctic waters have much less ambient noise and are generally much quieter than other waters (Halliday et al. 2020). The ability to hear and produce sounds effectively is crucial for Narwhal, which may be particularly sensitive to noise (GN 2012b; NTI 2012; Heide-Jørgensen et al. 2013a; DFO 2016, 2019e; NWMB 2016; QWB 2016; QIA 2019, 2021; Tervo et al. 2023) and react to icebreaking vessels at distances where the received sound levels are low (Finley et al. 1990; Cosens and Dueck 1993; Finley and Greene 1993). Narwhal in East Greenland responded to disturbances from ship noise and airgun pulses at distances greater than 40 km from the sound source (Tervo et al. 2021b, 2023). Normal diving and foraging behaviour decreased by 50% to 75% at distances where received sound levels from the ships alone or from the ships and concurrent airgun seismic pulses were below background noise (Tervo et al. 2023). Hauser et al. (2018) assessed the vulnerability of 80 subpopulations of seven Arctic marine mammal species to vessel traffic during the ice-free season, and reported that Narwhal were the most vulnerable to vessel impacts due to their high exposure and sensitivity. Arctic regions with geographic bottlenecks, such as the eastern Canadian Arctic, were characterized as contributing to a level of vulnerability that is two to three times higher than more remote regions, as these pinch points (for example, Lancaster Sound, Hudson Strait) are obligatory pathways for both shipping traffic and migratory marine mammals (Hauser et al. 2018). Narwhal communication signals and shipping noise overlap between 300 Hz and 10 kHz (DFO 2019e), which means vessel noise can potentially mask Narwhal vocalizations, including mother–calf communication (Ames et al. 2021). Based on studies of the closely related Beluga Whale, Narwhal may compensate for noise-related masking by changing their call frequency, or reducing their calling rate, which could impact communication efficiency (Lesage et al. 1999; Halliday et al. 2019). Narwhal may also be affected by noise from the construction of ports and small craft harbours, particularly noise generated by pile driving and other activities.

IUCN 11, climate change and severe weather (medium -low)

Habitat shifting and alteration (IUCN 11.1)

Reduction in sea-ice cover and duration have been documented for all areas within the range occupied by Narwhal (Laidre et al. 2015). There is significant concern about the effects that climate change will have on Narwhal populations, and several papers have suggested that they are very sensitive to climate related changes in sea-ice cover (Laidre et al. 2008; Kovacs et al. 2011; Chambault et al. 2020, 2022). Inuit have observed significant changes in the Arctic climate, especially sea ice changes, including earlier break-up in spring and later freeze-up in fall and a reduction in land-fast ice (DFO 2011, 2016; GN 2012b; NWMB 2016; Oolayou 2016a, b, c; Nweeia et al. 2017; Nweeia 2020). Thinning ice could be a factor in changes to Narwhal distribution, since Inuit have reported that Narwhal remain longer near their communities before they start migrating to their wintering areas (Oolayou 2016a). Satellite-tracking data from the Canadian Arctic provide evidence, for the past 21 years, of a 10-day per decade delay in autumn migration timing, with males moving out first and females (potentially with dependent young) departing later (Shuert et al. 2023). However, there is also uncertainty regarding how Narwhal may adapt to changing conditions, with some research suggesting that there is more flexibility in their diet than previously thought (Watt et al. 2013). Climate change has the potential to alter the distribution, duration, and quality of seasonal ice cover in the Arctic and thereby change the distribution and density of ice-associated prey species (Tynan and DeMaster 1997). Sea ice plays an important role in the distribution of predators of Narwhal, causing Killer Whales to avoid entering certain areas (Higdon and Ferguson 2009) and to leave as ice forms in the autumn (Matthews et al. 2011). Reductions in ice coverage or duration will make Narwhal more vulnerable to predation by Killer Whales (Higdon and Ferguson 2009) and to harvest (Nielson 2009). Changes in sea-ice formation may lead to an increased frequency of entrapments (Laidre et al. 2012).

Warming of Arctic waters due to loss of ice and increased solar radiation has a number of implications for Narwhal. There is concern regarding changes to major ocean currents (Hu et al. 2020), and associated changes in the distribution of competitor species (see IUCN 8.1 Invasive non-native/alien species/diseases). Borealization is making Arctic waters more hospitable to temperate species of competitors, as has been observed in fish species (Fossheim et al. 2015). Warmer waters may also result in higher energetic costs for species like Narwhal, which are adapted to cold waters (Williams et al. 2011, 2020; Pagano and Williams 2021). Ice may provide these whales with a refuge from storms (Kovacs et al. 2011; IUCN 11.4 Storms and flooding). In mid-east and southeast Greenland, rising sea temperatures have been correlated with the lowest abundance of Narwhal (Chambault et al. 2020, 2022).

Increased atmospheric CO₂ levels and warming waters are causing a number of other impacts that may threaten Narwhal (IUCN 11.5 Other impacts). Increasing CO₂ levels are correlated with increased ocean acidification (Terhaar et al. 2020). Acidification may affect prey species with mineralized exoskeletons such as diatoms),with cascading ecological effects (Moore et al. 2014). Acidification also is known to increase sound propagation (Ilyina et al. 2010), thereby magnifying the impact of other threats related to climate change that increase underwater noise levels (See 3.1 Oil and Gas drilling and 4.3 Shipping lanes).

IUCN 5, biological resource use (bb=low, nhb=negligible)

Fishing and harvesting aquatic resources (IUCN 5.4)

Hunting

Hunting activities probably represent the most consistent limiting factor or threat to Narwhal populations in Canada. Inuit residents of 13 communities hunt animals from the Baffin Bay sub population, while Hudson Bay Narwhal are hunted mainly by residents of Naujaat (formerly Repulse Bay) and sometimes by residents of 8 or 9 other communities (Table 3, Figure 3). Because of their seasonal movements, most of the Narwhal stocks in Canadian waters can be vulnerable to hunting in more than one area each year (Watt et al. 2019b, c). Fishing for a Narwhal calf or a Narwhal accompanied by a calf is prohibited under the Marine Mammal Regulations of the Fisheries Act.

^a Data reported are from the most recent available DFO statistics (J. Young, DFO, pers. comm. 2022), with the exception of the 1998 to 2000 Baffin Bay totals and the 1999 Hudson Bay total, which were revised upward from the DFO 2020 data, based on hunter catch reports to the Nunavut Wildlife Harvest Study (Priest and Usher 2004) that were higher during the DFO harvest year than those reported by DFO. There are also minor differences in the totals for some years based on DFO revisions since the previous COSEWIC (2004) update.

^b Quota totals for Baffin Bay in 2001, 2004, and 2006, and for Hudson Bay in 1998 to 2006 follow the current DFO statistics (J. Young, DFO, pers. comm. 2022), which have been revised since around 2006.

^c The 2020 Hudson Bay total does not include 33 Kivalliq Wildlife Board reserve tags that were used in Naujaat (Repulse Bay).

Figure 3. Annual quotas and landed catches in Canadian waters of Narwhal from the Baffin Bay and Hudson Bay populations from 1977 through 2020 (See Table 3 for data and sources). Quotas include limits placed on landed catches by regulatory bodies and by community-based management. Unused tags that can be carried over to the next year are included in the totals but reserve tags are not.

The actual number of Narwhal killed during these hunts is higher than the number landed; however, this number is not known because few data were collected on the number of animals that were killed and lost. These losses vary depending upon the location, weather, hunter experience, and type of hunt (for example, floe edge, ice crack, open water).

Richard (2008) calculated an overall struck and lost estimate based on data from Arctic Bay, Pond Inlet, Kugaaruk and Qikiqtarjuaq from 1999 to 2004, which yielded a correction factor of 1.29 (SD 0.16). Using the same approach, Watt and Hall (2015) calculated an overall struck and lost estimate based on data from Arctic Bay, Pond Inlet, and Kugaaruk from 2005 to 2010, which yielded a correction factor of 1.23 (SD 0.21). Overall, current catch levels appear sustainable.

Given uncertainties related to reproductive and survival rates, and the species’ vulnerability to unpredictable mass mortality from entrapment in ice, a precautionary hunting rate is thought to be about 2% (DFO 1998a).

The total allowable landed catch (TALC) advice for the six summering stocks in the Baffin Bay population (which assumes that the animals show fidelity to these stocks and is based on the 2013 survey abundance estimates) totals 1,540 Narwhal per year (DFO 2015; Doniol-Valcroze et al. 2015), or about 1.1% of the estimated population. In 1977 to 1998, the annual landed catch averaged 290 whales (CV 0.19) and in 1999 to 2020 this figure increased to 524 (CV 0.36) (DFO unpubl. data; J. Young, pers. comm. 2022) (Table 3; Figure 3). Thus, in the Baffin Bay DU, current catch levels appear sustainable.

The Northern Hudson Bay Narwhal subpopulation is hunted primarily in the Naujaat area, mostly by Inuit from that community (COSEWIC 2004). Current (2022) harvest advice for the Hudson Bay Narwhal Population is based on the 2011 aerial survey abundance estimate of 12,485 animals (DFO 2012; P. Hall, DFO Winnipeg, pers. comm. May 2022). The potential biological removal (PBR) estimate is 201 (1.3%), and the total allowable landed catch (TALC) of 157 is shared between Nunavut (147) and Nunavik (10). Recent harvest levels are somewhat less than this (Table 3; Figure 3).

Narwhal have been caught in fishing nets (Mitchell 1981), but this is rare and currently of lesser concern than the effects of competition for food. The establishment of the Disko Fan, Davis Strait, and Hatton Bay marine conservation areas (DFO 2019b, 2019c, 2019d) which prohibit bottom-contact fishing will help mitigate the effects of these fisheries.

IUCN 4, transportation and service corridors (negligible)

Shipping lanes (IUCN 4.3)

Ship traffic in the Canadian Arctic has nearly tripled over the past decade (Dawson et al. 2020), and vessel traffic, particularly through the Northwest Passage, is expected to continue increasing in response to climatic warming (Smith and Stephenson 2013; Melia et al. 2016; Andrews et al. 2018). Key stressors from interactions with ship traffic can include underwater shipping noise, ice habitat alteration, sediment mobilization, introduction of non-Indigenous species, accidental oil spills, and ship strikes. Their effects on Narwhal distribution and abundance are not well understood. However, elevated levels of cortisol in Narwhal were found to be correlated with the increase in shipping to Milne Inlet for the Mary River Iron Mine Project, which suggests that current levels of shipping are contributing to the stress levels of animals that summer in the northern Baffin Island area (Watt et al. 2021). Inuit have also noted that since the start of mining and shipping activities in Milne Inlet, the condition of marine mammals has declined, and more Narwhal have been observed that would be characterized as “skinny” and lacking blubber relative to normal physical condition(QIA 2021). Inuit consider marine species to be greatly impacted by underwater noise, and Narwhal to be particularly sensitive to disturbances from shipping activity (GN 2012b; NTI 2012; DFO 2016; NWMB 2016; QWB 2016; QIA 2019, 2021). Migratory species like Narwhal are especially vulnerable to shipping given the intersection between industrial shipping and migratory routes (QIA 2021).

Substantial increases in ship traffic are expected over the next decade in connection with mining developments, particularly the Mary River Iron Mine on northern Baffin Island, which has approval to export 18 metric tonnes (Mt) of iron ore to market annually from Steensby Inlet via Foxe Basin and Hudson Strait (BIMC 2012, 2018; NIRB 2012). Once developed, shipping via this “southern” route may continue for at least 21 years, operate year-round and require 102 round trips annually using purpose-built capesize ore carriers (Polar class 4 or 5; 180,000 tonnes deadweight). This shipping will affect Narwhal from Northern Hudson Bay that winter in Hudson Strait (Elliot et al. 2013). It represents a significant increase in shipping disturbances in the wintering habitat of NHB Narwhal, since few vessels currently transit Hudson Strait in winter (for example, ore carriers to and from Deception Bay). Ship traffic through key summering habitat of this population is typically limited to a few community resupply vessels en route to or from Naujaat, and the occasional tourist vessel.

Other shipping to and from Hudson Bay via Hudson Strait may also increase in response to resupply requirements (Andrews et al. 2018; Carter et al. 2019), resumption of regular grain shipments from Churchill (Franz-Warkentin 2019), and tourism (Stewart et al. 2010). Plans to transport oil by rail to Churchill were suspended in 2014 due to safety concerns and political opposition (Jones 2013; McNeill 2014; Hansen 2018), but export bottlenecks have prompted interest in building a pipeline to Churchill (Lambert 2020) or Port Nelson (Polczer 2023), Manitoba. Realization of this plan would increase the risk of oil spills affecting Narwhal in Northern Hudson Bay and Hudson Strait.

Baffinland Iron Mines Corp. is permitted to mine and ship 6 Mt of iron ore annually from the Mary River Iron Mine via its “northern” shipping route (BIMC 2023). In recent years, annual ore shipments have averaged about 5.4 Mt (range 4.7 to 5.9 Mt from 2019 to 2022), with 62 to 81 round-trip voyages (average 72) of ore carriers from the port at Milne Inlet to overseas markets via Eclipse Sound – Pond Inlet - Baffin Bay - Davis Strait – Labrador Sea (BIMC 2023). A proposal to increase mine production to 12 Mt/year (BIMC 2018) underwent regulatory review from 2015 until 2022, but was not approved (BIMC 2023). Approval would have led to an increase in the number of ore carrier transits, a longer shipping season, and increased transits by tugs, icebreakers, and wet/dry resupply vessels (BIMC 2017b; Knight Piésold Consulting 2019; BIMC 2020). Industrial shipping has led to a decrease in Narwhal in the Eclipse Sound area (also see Golder 2020b, 2021) and an associated increase in whales in Admiralty Inlet and along the east coast of Baffin Island (GN 2012b; NTI 2012; DFO 2016; NWMB 2016; Oolayou 2016b; QWB 2016; QIA 2019, 2021). More Narwhal are also being observed by residents of Resolute Bay, a situation that has been attributed to increased shipping in the Northwest Passage and also possibly changes in ice cover and Narwhal population growth (GN 2012b). Increased shipping associated with the operation of the Nanisivik Mine in Admiralty Inlet in the 1970s led to Narwhal displacement during the summer (NTI 2012). This displacement was temporary, as Narwhal returned once the mine was closed (NTI 2012). However, the Mary River project may last decades longer. Impacts from the Mary River Project are different from what Inuit experienced during the operation of the Nanisivik Mine, largely due to the increased volume in vessel traffic (NWMB 2016). Shipping activity has also influenced Narwhal behaviour, and vessel noise is making hunting more difficult. Narwhal are more skittish and harder to herd into shallow water, and hunting is more challenging in the vicinity of concentrated shipping traffic (Oolayou 2016a, b; QIA 2019). Decreased Narwhal abundance in Eclipse Sound has also led to the loss of use of preferred areas for hunting (QIA 2019, 2021).

As ship traffic increases, so too will interactions with Narwhal, particularly in Hudson Strait, Baffin Bay, Pond Inlet, Eclipse Sound, Milne Inlet, and the Northwest Passage. The risk of ship strikes is unknown but presumed to be low. Narwhal should be able to detect approaching vessels well in advance, year-round (Heide-Jørgensen et al. 2021). However, systematic observations from vessels are needed to properly assess this threat.

IUCN 8, invasive and other problematic species and genes (negligible)

Invasive non-native/alien species/diseases (IUCN 8.1)

Increased anthropogenic activity in the North (see IUCN S4) and ecosystem changes related to climate change (IUCN 11) will continue to increase the threat related to invasive species. These invasives could consist of new competitors in the system or novel parasites or diseases. Recent years have seen observations of temperate whale species like Humpback (Megaptera novaeangliae) and Minke (Balaenoptera acutorostrata) in locations where they have not been previously reported (Higdon and Ferguson 2011). Although there has been no research to assess direct competition with Narwhal, the expectation is that greater frequency of occurrence and abundance of temperate species will increase competition and bring the potential for novel disease (for example, Sanderson and Alexander 2020).

‑Hull fouling and large, frequent discharges of ballast water have the potential to introduce non-Indigenous species that affect marine ecology through competition or predation or serve as vectors for novel parasites and/or diseases (Goldsmit et al. 2018, 2019, 2020). Many of the vessels arriving in-ballast have travelled from temperate marine waters of western Europe, typically large ports that are hubs for the spread of invasive species. Mid-ocean exchange and, more recently, treatment technologies are being used to reduce the risk of species introductions. The risks that non-Indigenous and invasive species pose to Narwhal are uncertain, as is the adaptive potential of Narwhal to changes in prey abundance, disease, or parasites.

Problematic native species/diseases (IUCN 8.2)

Modelling studies suggest that Narwhal are susceptible to infection by the SARS-CoV-2 virus and they represent a potential intermediate host for its transmission to humans (Huang et al. 2022). This virus is the causal agent behind the COVID-19 pandemic that spread across the world in 2020. Beluga and other cetaceans were also found to be susceptible to the virus. However, it is unknown what health effects the virus would have on Narwhal or other cetaceans (Damas et al. 2020; Liu et al. 2020; Huang et al. 2022). See also Diseases and Parasites.

IUCN 3, energy production and mining (bb=negligible, nhb= n/a or none)

Oil and gas drilling (IUCN 3.1)

The threat that hydrocarbon exploration and development poses to Narwhal in Canadian waters is low at present, particularly for the NHB population. Under the Canadian Petroleum Resources Act (Order Prohibiting Certain Activities in Arctic Offshore, 2022, P.C. 2022-1317 December 15, 2022) all Canadian Arctic waters are indefinitely off-limits to future offshore oil and gas licensing. This designation is in force until December 31, 2023 (Government of Canada 2022) and is subject to reassessment at 5-year intervals. All exploration licences within the species’ Canadian range have been surrendered, and there are no production licences, but significant discovery licences are still in place in the Arctic Islands of Nunavut (n = 20) and Eastern Arctic Offshore (n =1) (CIRNAC 2019). Future risks from oil and gas exploration and development are considered greater for BB Narwhal than for NHB Narwhal, given the locations of significant discovery licences and the species’ ice entrapment history (Higdon et al. in review). Heide-Jørgensen et al. (2013a) expressed concern that noise from marine seismic surveys related to oil and gas exploration might disrupt the migratory behavior of Narwhal and increase their risk of mass mortality from ice entrapment. Inuit reported a temporary displacement of Narwhal from Admiralty Inlet during summer beginning in the late 1970s, which was assumed to be a result of increased shipping traffic into the Nanisivik Mine. This trend was highlighted by Narwhal entrapments in Foxe Basin in October 1979 and 1980 (NTI 2012). Inuit also report that increasing vessel traffic is a factor in migration delays, and has led to some more recent entrapments (DFO 2016; Oolayou 2016b).

Based on its Strategic Environmental Assessment of Baffin Bay and Davis Strait, the Nunavut Impact Review Board (NIRB 2019) expects that it will take at least a decade to complete the research, planning, and consultation needed to inform reassessment by the Minister to determine if the moratorium should be lifted. Lack of the information needed to properly assess the impacts of seismic exploration, shipping, and oil spills on marine mammals were among the reasons cited for this conclusion (NIRB Recommendations 53, 54, 62). Development of appropriate impact thresholds for noise disturbance and hearing damage to marine mammal species was recommended (Rec. 41) should the moratorium be lifted. It was also recommended that consideration be given to “establishing setbacks or other development restrictions on the proximity of oil and gas development activities, infrastructure and other components (particularly seismic surveying activities) in areas, and during seasons, that are currently closed to fishing in order to protect sensitive benthic areas and Narwhal overwintering habitats” (Rec. 78).

Greenland has established Narwhal protection zones to avoid or limit the exposure of Narwhal in West Greenland waters to seismic testing when they are on their summering or wintering habitats as well as during migration(Kyhn et al. 2011). When exposed to seismic airgun pulses and ship noise, Narwhal (n=11) in Scoresby Sound in East Greenland reacted by changing their swimming speed and direction (Heide-Jørgensen et al. 2021). When the larger airgun was used (17.0 L, which is relatively small compared to those used for seismic studies), received pulse sound exposure levels (SELs) dropped below 130 dB re 1 mPa² s by 4 to 9 km and background noise levels were reached at a distance of 8 to 10.5 km. Avoidance reactions of the whales could be detected at a distance greater than11 km in 2018 when in line of sight of the seismic vessel, and increases in horizontal travel speed of about 30% could be detected up to 2 hours before the seismic vessel was in line of sight. The closer the vessel approached, the more likely Narwhal were to move towards and stay near the shore in comparison with normal behaviour. When the large airgun was used, shoreward movements began when the source was 10 to 15 km away. When the whales were near shore or in a cul-de-sac, they generally increased their travel speed, except when in the presence of airgun pulses in the cul-de-sac, at which point they significantly decreased their travel speed.

Mining and quarrying (IUCN 3.2)

Threats to Narwhal from mineral exploration and development have increased since the 2004 COSEWIC assessment, for both Canadian Narwhal populations. This trend will continue if the Mary River Iron Mine project proceeds as planned (BIMC 2018), or if other mineral deposits are developed. The existing mines are situated inland from coasts that are visited by the BB Narwhal (Mary River Iron Mine) and the NHB Narwhal (Raglan Mine, Canadian Nickel Mine, Meadowbank Gold Mine, Meliadine Gold Mine). This limits direct effects from the mine itself, but these projects require construction of ports, and shipping activity. Mining-associated shipping is widely recognized by Inuit as a disruption to Narwhal movements and behaviour and on hunter success (GN 2012b; NTI 2012; NWMB 2016; QIA 2019, 2021). Threats from ship noise, habitat disruption, introduction of non-Indigenous species, and oil pollution are discussed in other sections. Any offshore mining development would require the establishment of a new regulatory framework (Hanna et al. 2018).

IUCN 7, natural system modifications (unknown)

Other ecosystem modifications (IUCN 7.3)

Fragmentation of sea ice by icebreaking ships could have ecological consequences for both Canadian Narwhal populations. It might, for example, affect Narwhal distribution and abundance along the shipping routes by influencing migration timing and habitat use (GN 2012b; NTI 2012; NWMB 2016; QIA 2019, 2021). It could also increase access for Killer Whales and allow them to prey upon Narwhal (Higdon and Ferguson 2009; Lefort et al. 2020a), and it could lead to entrapments of Narwhal by sea ice (Higdon et al. in review; NTI 2012; Heide-Jørgensen et al. 2013a). Icebreaking is currently being used by the Mary River Iron Mine during the spring and fall shoulder seasons to enable vessel access to and from Milne Inlet and markets in Europe and Asia via Eclipse Sound, Pond Inlet, and Baffin Bay. The NHB Narwhal are exposed to icebreaking vessels that transit Hudson Strait en route to and from the Raglan and Canadian Nickel mines and their markets. The number of icebreaker transits via Hudson Strait is currently low but will increase sharply in 2024 if the Mary River Iron Mine begins ore exports from Steensby Inlet (BIMC 2018).

Turbot (Greenland Halibut) is a key prey species for Narwhal, and fishing for this fish species occurs in Canadian and Greenland waters, in Baffin Bay and Davis Strait. Research and monitoring in Greenland have shown that Greenland Halibut stocks are declining and the size of landed halibut is decreasing.

Interest in developing inshore fisheries has prompted exploratory fisheries in waters such as Sam Ford (Kangiqtualuk Uqquqti), Kingnelling, Makiak, Coronation and Kangert fjords, Eclipse Sound, and Scott Inlet (DFO 2020b; see also CBC 2017). The availability of halibut may also be reduced by commercial fishing for Pink Shrimp (Pandalus borealis), which are prey for halibut (DFO 2018). The effects of these fisheries on wintering Narwhal are unknown.

IUCN 6, natural system modifications (unknown)

Recreational activities

Private pleasure craft are identified by Inuit as a bigger concern than cruise ships. Private vessels are largely unregulated and Inuit have observed them going into places where they should not go. Zoning for Tallurutiup Imanga NMCA should address some management concerns, etc.

Floe edge tourism has a small footprint (tent camps, snowmobile travel, no permanent infrastructure).

Inuit have identified research activities as causing stress.

Number of locations

The number of geographically or ecologically distinct areas in which a single threatening event could rapidly affect all individuals present cannot reasonably be determined for either Canadian Narwhal population but likely exceeds ten.

Protection, status, and ranks

Legal protection and status

Protection for Narwhal within Canada is limited to measures that manage hunting and live capture, as well as the movement of Narwhal products. The species is not listed under the Species at Risk Act (S.C. 2002, c. 29). As yet, there are no Arctic marine parks or protected areas that protect Narwhal in Canadian waters from hunting or shipping. However, some protection is afforded to Narwhal habitat such as within the newly approved Tallurutiup Imanga National Marine Conservation Area, which will eventually be established and protected under the Canada National Marine Conservation Areas Act.

International trade in Narwhal products is regulated by a number of laws and conventions. These include the Marine Mammal Protection Act in the United States; the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), which is embodied in Canada’s Wild Animal and Plant Protection and Regulation of International and Interprovincial Trade Act (WAPPRITA; S.C. 1992, c. 52); and Council Regulation EC 338/97 in the European Union (see Shadbolt et al. 2015 for summary).

Canadian harvest quotas and protection

Narwhal hunting in Canada is co-managed by Fisheries and Oceans Canada (DFO), the regional authority (the Nunavut Wildlife Management Board [NWMB] in Nunavut or the Nunavik Marine Regional Wildlife Board in Nunavik [NMRWB]), the Regional Wildlife Organizations (RWOs), and the local Hunters and Trappers Organizations (HTOs) or equivalents (Reeves and Lee 2020). DFO can provide advice to the Board(s) and hunting communities on sustainable hunting levels, but total allowable harvests and non-quota limitations are set following the land claim decision-making process. The DFO Minister either accepts, rejects, or varies the Board`s decision (Richard and Pike 1993; DFO 1998a, 1998b).

Hunting regulations are implemented by DFO under the Fisheries Act and the Marine Mammal Regulations. Under the regulations, only Inuit can hunt Narwhal and a quota (number of animals that can be harvested) is granted to each community. An Integrated Fisheries Management Plan (IFMP) was developed through Nunavut’s co-management system in consultation with Nunavut Tunngavik Incorporated (NTI), the Government of Nunavut (GN), Regional Wildlife Organizations (RWOs), hunter and trapper organizations (HTOs), and Narwhal hunters (DFO 2014a). This plan was approved through the Nunavut Agreement NWMB-DFO minister decision-making process in 2012 and implemented in 2013.

The Ending the Captivity of Whales and Dolphins Act (S.C 2019, c. 11), which was passed on June 21, 2019, ends the holding of cetaceans in human care. Although no Narwhal are currently held in captivity, this Act will prevent future live captures of Narwhal except as authorized for scientific research or for the animal’s health or welfare.

International trade and cooperation

The regulation of international trade in Narwhal products began in 1972, when the U.S. Marine Mammal Protection Act banned the importation of marine mammal products, including Narwhal ivory, into the United States (Reeves 1992a, 1992b; Reeves and Lee 2020). Narwhal tusks are only allowed to enter the USA for non-commercial purposes (for example, scientific research, pre-MMPA acquisitions); however, recent smuggling operations indicate that demand still exists (Shadbolt et al. 2015; Reeves and Lee 2020). Exports (and re-exports) of Narwhal products require a CITES permit (or re-export certificate) and a non-detriment finding (NDF) from the source country (Reeves and Lee 2020). In Canada, export permits are administered by DFO, which manages Narwhal under the Fisheries Act. The current Standing NDF for Canadian Narwhal is supported by 15 peer-reviewed reports published by the Canadian Science Advisory Secretariat (CSAS) from 2008 to 2018 (see Reeves and Lee 2020). CITES is embodied in the Wild Animal and Plant Protection and Regulation of International and Interprovincial Trade Act (WAPPRITAE) (Lien 1999).

The Narwhal is also listed under Appendix II of the Convention on the Conservation of Migratory Species of Wild Animals (CMS or Bonn Convention), which promotes international cooperation in the management of migratory species.

Canada cooperates with Greenland in the conservation of shared Narwhal populations through participation in the Canada/Greenland Joint Commission on Conservation and Management of Narwhal and Beluga (JCNB), a bilateral body established in 1989 to provide management advice on shared stocks. Canada is also an active “observer” at meetings of the North Atlantic Marine Mammal Commission (NAMMCO), a marine mammal management organization established in 1992 by several Nordic countries, of which the Greenland Home Rule government is a member.

Non-legal status and ranks

In 2017, the International Union for Conservation of Nature (IUCN) reassessed the global population status of the Narwhal as “Least Concern” (Lowry et al. 2017).

NatureServe lists the species’ global status as G4 (Apparently Secure; last reviewed 4 April 2016), its national status in Canada as N3B (Vulnerable, increased level of risk, new interpretation of same information, Breeding), its Eastern Arctic Ocean rank as S3B (Vulnerable, Breeding), and its national status in the United States as NU (Unrankable).

Habitat protection and ownership

Tallurutiup Imanga National Marine Conservation Area (TINMCA) includes important Narwhal habitat and migratory routes in Lancaster Sound and adjacent areas. The NMCA is to be established under the Canada National Marine Conservation Areas Act. One of its objectives is the protection and conservation of species at risk, including Narwhal. However, it is not yet clear what protection the NMCA will afford Narwhal.

Four national parks of Canada under the jurisdiction of the Parks Canada Agency include coastal waters that may afford Narwhal some protection from disturbance and development but not from Inuit harvesting. Auyuittuq on southeastern Baffin Island, Qausuittuq on northern Bathurst Island, and Quttinirpaaq on northern Ellesmere Island all protect inlets or fiords within the range of the BB Narwhal population. Ukkusiksalik National Park, which includes Wager Bay, is used by NHB Narwhal.

Five national wildlife areas (NWA) under the jurisdiction of the Canadian Wildlife Service afford BB Narwhal protection under the Canada Wildlife Act and its Wildlife Area Regulations. Their primary purpose is to protect and conserve wildlife and their habitat. Like the parks, they do not prevent Inuit from harvesting Narwhal. These NWAs include Akpait and Qaqulluit southeast of Qikiqtarjuak, Nanuit Itillinga along the east and west coasts of Bathurst Island at either end of Polar Bear Pass, Ninginganiq in the Isabella Bay area of eastern Baffin Island, and Nirjutiqarvik around Coburg Island.

Three migratory bird sanctuaries (MBS) under the jurisdiction of the Canadian Wildlife Service which are protected from disturbance under the Migratory Birds Convention Act and its Migratory Bird Sanctuary Regulations may include small areas of coastal marine habitat used by Narwhal. The Prince Leopold Island MBS north of Southampton Island, Seymour Island MBS north of Bathurst Island, and Maud Gulf (Ahiak) MBS along the mainland coast of the Queen Maud Gulf may afford some protection for BB Narwhal. The East Bay (Qaqsauqtuuq) MBS on Southampton Island may do the same for NHB Narwhal.

Since the last Narwhal update, Fisheries and Oceans Canada (DFO) has created three new marine conservation areas (CA), all of which prohibit bottom-contact fishing activities and are located in areas with sensitive marine corals and Narwhal wintering habitat. The Disko Fan CA (DFO 2019b) and Davis Strait CA (DFO 2019c) provide protection for Greenland Halibut and are used in winter by BB Narwhal, and the Hatton Bay CA (DFO 2019d) does the same for NHB Narwhal (see also DFO 2007).

DFO has also established the Tuvaijuittuq Marine Protected Area (MPA), which protects a large area of marine habitat around northern Ellesmere Island, some of it adjoining marine habitat in Quttinirpaaq National Park. Under this interim designation made by Ministerial Order under the Oceans Act, new or additional human activities are prohibited in the MPA for up to five years (from August 2019), with some exceptions, such as the exercise of Inuit rights respecting wildlife harvesting as provided for under the Nunavut Agreement; marine scientific research consistent with the conservation objectives of the MPA; safety, security and emergency activities; and certain activities carried out by a foreign national, entity, ship or state.

The Quebec Minister of Environment and the Fight against Climate Change has proposed the establishment of biodiversity reserves (BR) along the southern coast of Hudson Strait (Fjord-Tursukattaq BR, Kangiqsujuaq BR) and the west coast of Ungava Bay (Quaqtaq-Kangirsuk BR). These habitats may provide limited protection for NHB Narwhal during migration.

Some of these protected areas are peripheral to the Canadian distribution of Narwhal but may not be in the future as climate change alters the ice regime and seasonal access. In future, the Tuvaijuittuq marine habitat of Quttinirpaaq National Park may play a greater role in protection of BB Narwhal, as may the waters of Qausuittuq National Park and the Queen Maud Gulf (Ahiak) Migratory Bird Sanctuary.

Acknowledgements and authorities contacted

Acknowledgements

Funding for the preparation of this report was provided by Environment and Climate Change Canada. The authorities listed below provided valuable data and/or advice.

Authorities contacted

• Robertson, M. Canadian Wildlife Service, Yellowknife, NT
• Pirie-Dominix, L. Canadian Wildlife Service, Iqaluit, NU
• Boyne, A. Candadian Wildlife Service, Dartmouth, NS
• Hagesteijn, M. Canadian Wildlife Service, NL
• Picard, K. Canadian Wildlife Service, Quebec City, QC
• McCarney, P., Laing, R., Dicker, J. Research at Nunatsiavut Government, Nain, NL
• Anderson, R. Research Scientist, Canadian Museum of Nature, Ottawa, ON
• Kling, A. Senior Science Advisor, Fisheries and Oceans Canada, Ottawa, ON
• Sheppard, P. Species and Conservation Management, Ecosystem Scientist, Vancouver, BC
• Labbe, A. Fisheries and Oceans Canada, Ottawa, ON
• Marcoux, M. Fisheries and Oceans Canada
• Watt, C. Fisheries and Oceans Canada
• Mahy, M. Parks Canada, Iqaluit, NU
• Elverum, C. Parks Canada, Sirmilik, NU
• Mercier, F. Parks Canada
• McDonald, R. Senior Environmental Advisor, National Defence, Ottawa, ON
• Humber, J. Ecosystem Management Ecologist, Department of Wildlife and Conservation, Corner Brook, NL
• Moores, S. Senior Manager, Endangered Species and Biodiversity, Department of Wildlife and Conservation, Corner Brook, NL
• Carriere, S. Biologist, Wildlife Division, Department of Environment and Natural Resources, Yellowknife, NT
• Fournier, B. GIS and Wildlife Data Specialist, Government of NT, Yellowknife, NT
• Larter, N. Manager, Wildlife Research and Monitoring, Department of Environment and Natural Resources, Fort Simpson, NT
• Mallory, C. High Arctic Biologist, Department of Environment, Government of Nunavut, Igulik, NU
• Gauthier, I. Biologist, provincial coordinator of threatened or vulnerable wildlife species, Direction générale de la gestion de la faune et des habitats, Ministère des Forêts, de la Faune et des Parcs (Quebec Department of Forests, Wildlife and Parks)
• Fraser, D. Victoria, BC
• Moores, A. Professor, Simon Fraser University, Burnaby, BC
• Laurendeau, C. Centre de données sur le patrimoine naturel du Québec, Direction de l'expertise sur la faune et ses habitats, Ministère des Ressources naturelles et de la Faune du Québec (Quebec Department of Natural Resources and Wildlife), Quebec City, QC
• Durocher, A. Atlantic Canada Conservation Data Centre, NL Wildlife Division, Endangered Species and Biodiversity Section, Corner Brook, NL
• Environment and Natural Resources, Conservation Data Centre, Government of the Northwest Territories, Yellowknife, NT
• Way-Nee, E. Fisheries Resource Coordinator. Fisheries Joint Management Committee, Inuvik, NT
• Smart, M., and Brunelle, J. Hunting, Fishing, and Trapping Coordinating Committee, Montreal, QC
• Palliser, T., and Basterfield, M. Nunavik Marine Region Wildlife Board, Inukjuak, QC
• Arok, J. Nunavut Wildlife Management Board, Iqaluit, NU
• Snook, J., and Taylor, C. Torngat Joint Fisheries Board, Happy Valley-Goose Bay, NL
• Wilson, K., and Thompson, A. Wildlife Management Advisory Council: North Slope, Whitehorse, YT
• Brooks, M. Arctic Oil and Gas Senior Specialist, WWF-Canada
• Carlyle, C. MSc Student, Fisheries and Oceans Canada, Freshwater Institute, Winnipeg, MB
• Dionne, F.A. Coordinator, Aboriginal Fisheries, Fisheries and Oceans Canada
• Ferguson, S. Fisheries and Oceans Canada, Winnipeg, MB
• Hall, P., and Young, J. Fisheries and Oceans Canada, Winnipeg, MB
• Hobbs, R., and Guldborg Hansen, R. NAMMCO
• Treble, M. Fisheries and Oceans Canada, Winnipeg, MB

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Personal communications

Bychok, A. April 2022. Senior Fisheries Management Biologist, Fisheries and Oceans Canada.

Hall, P. April 2022. Fisheries Management Coordinator, Fisheries and Oceans Canada, Fisheries Management Program.

Pattimore, J. 1986. Formerly Harvest Coordinator, Baffin Region Inuit Association, Iqaluit, Nunavut. X0A 0H0.

Young, J. 2019-2020. Fisheries Management Technician, Fisheries and Oceans Canada.

Biographical summary of report writer(s)

D. Bruce Stewart (MSc), Head of Arctic Biological Consultants, has studied aquatic ecosystems throughout northern Canada since 1976. He has conducted many aquatic field studies in Arctic Canada and worked with Inuit on the land studying Arctic Char, and in the communities compiling traditional knowledge of marine mammals. Bruce has provided expert advice on aquatic resources, species at risk, invasive species, parks initiatives, and resource developments to governments, Inuit and First Nations organizations, co-management and assessment boards, and environmental NGOs. Over the past decade he has advised the Qikiqtani Inuit Association on the environmental review of the Mary River Iron Mine Project on Baffin Island, and the Kivalliq Inuit Association on environmental reviews of the Meliadine Gold and Kiggavik Uranium projects. Bruce authored or co-authored COSEWIC update status report on the Atlantic Walrus (2006, 2017), Narwhal (2004), and Bearded Seal (2007), and the report on designatable units for Beluga Whales (2016), and has written over 120 publications, reports and articles. Recent works include a catch history for Beluga in Cumberland Sound, reports on the state of circumpolar walrus populations and on Atlantic Walrus in Northern Hudson Bay, and a series of papers on managing marine invasive species risk in Arctic Canada.

Jeff W. Higdon is an independent wildlife biologist based in Winnipeg, MB. His PhD is from the University of Manitoba, where he carried out research on the biogeography and conservation of world pinnipeds. He has conducted extensive field research on Narwhals and other Arctic marine mammals, including photo-identification, biopsy sampling, live-capture and tagging, hunt sampling, and hunt monitoring. Other research projects have involved collecting and interpreting Aboriginal traditional knowledge, historical research on marine mammal hunting, and assessments of potential environmental impacts to marine biota from proposed development projects and Arctic shipping. He has co-authored COSEWIC update status reports on the Atlantic Walrus and Ringed Seal and the report on designatable units for Beluga Whales, and has written over 60 peer-reviewed scientific papers, book chapters and technical reports. Current research activities include developing community-based monitoring programs, risk assessments, industrial development project reviews, and protected areas planning, for clients in Government, Inuit and First Nations organizations, as well as environmental non-government organizations.

Stephen D. Petersen (MSc, PhD, Assiniboine Park Zoo, Winnipeg, MB) has been a wildlife biologist for more than 20 years. He has been the Director of Conservation and Research for Assiniboine Park Zoo (APZ) for the last 10 years. He also is the chair of the International Polar Bear Conservation Centre Advisory Board, co-chair of the Terrestrial Mammal Specialist Sub-Committee of COSEWIC, and co-chair of the Field Techniques Subcommittee of the AZA Polar Bear Research Council. The APZ Conservation and Research Department runs active field and zoo-based programs from the labs and offices at the Leatherdale International Polar Bear Conservation Centre. His department has a strong focus on the ecology, behaviour, and genetics of Arctic marine mammals and they have been conducting research in Churchill for almost a decade. Stephen has a PhD from Trent University (Ontario), an MSc from Acadia University (Nova Scotia) and a BSc from the University of Alberta (Alberta). Stephen is also adjunct professor at both University of Winnipeg and University of Manitoba.

Collections examined

No collections were examined for the preparation of this report.

Appendix 1. Indications of population trends

Based on a trend analysis performed using four surveys conducted over the past 30 years, the Somerset Island stock in the Baffin Bay population may be increasing (see also NAMMCO 2015; Witting et al. 2019). The Admiralty Inlet stock has been surveyed 5 times over the past 30 years, and results indicate no significant change in population size over this time (NAMMCO 2018; Witting et al. 2019). With regard to the Eclipse Sound summering aggregation, NAMMCO (2018) (and Hobbs et al. 2019) considered the stock to be possibly stable, but noted that a trend could not be established as only two comprehensive surveys were available. Another survey has since been done (in 2016, see Marcoux et al. 2019), with results similar to the 2013 survey, and no evidence for declines in the short term. However, given the uncertainty around movements between summering aggregations (Watt et al. 2012; NAMMCO 2018; Hobbs et al. 2019), and the lack of concurrent surveys of both Eclipse Sound and Admiralty Inlet, the trend is reported here (Table 1) as unknown. Only two surveys (2003, 2013) are available for the Eastern Baffin Island stock, so trend analysis is not possible. NAMMCO (2018) considered this stock to be possibly stable. As noted above, no trends can be established for the Smith Sound and Jones Sound components, as only one survey estimate is available.

There is some ATK available on trends in Baffin Bay stocks. In the 1990s Inuit noticed little change in the number of Narwhal in some areas used by the Somerset Island stock (Remnant and Thomas 1992; Stewart et al. 1995; also see Furgal and Laing 2012). Some hunters in the early 1990s reported that Narwhal numbers had increased around Iglulik (Foxe Basin) (Remnant and Thomas 1992). More recently, Inuit representatives from Resolute reported that hunters are seeing fewer Narwhal in Creswell Bay than in the past (White 2012), although more of these whales are being seen in the Resolute Bay area than previously, possibly due to decreases in ice cover, increased shipping in the Northwest Passage, or an increasing population (GN 2012b). Narwhal have recently become more abundant near the community of Kugaaruk (NTI 2012). Recent appearances of Narwhals near Cambridge Bay have been attributed by Inuit to the presence of Killer Whales (NTI 2012). Grise Fiord residents have also seen record numbers of Narwhal in the community more recently (GN 2012b; NTI 2012), and there has been an increase in Narwhal abundance in Smith Sound with declines in ice cover (Nweeia 2020). Inuit in Jones Sound have observed an increased presence of Narwhal during the summer, especially females with calves and younger sub-adult animals (NTI 2012).

In the early 1990s, the Narwhal population in Admiralty Inlet was reported as stable (Remnant and Thomas 1992; Furgal and Laing 2012), and Inuit representatives have more recently reported that numbers are now increasing in this area (DFO 2016; GN 2012b; White 2012; NWMB 2016). The increase in Narwhal abundance in Admiralty Inlet has continued as numbers have declined in Eclipse Sound (Oolayou 2016b; QWB 2016; QIA 2019, 2021). The Eclipse Sound stock was reported by hunters to be stable or decreasing in past decades (Remnant and Thomas 1992). Most interviewees (21/35) thought that the population size had not changed, while a minority (5/35) thought that Narwhal were less common than in the 1960s, possibly because of increased hunting pressure and/or increased noise from boats and snowmobiles (Remnant and Thomas 1992; Furgal and Laing 2012). Representatives from both Pond Inlet and Arctic Bay have reported that Narwhal numbers have declined in recent years in Eclipse Sound, potentially as a result of increased ship traffic and noise (also see below) (GN 2012b; White 2012; DFO 2016; NWMB 2016; Oolayou 2016b; QWB 2016; QIA 2019, 2021).

The majority of hunters interviewed by Remnant and Thomas (1992) believed the East Baffin Island stock to be increasing since the 1960s and 1970s (also see Furgal and Laing 2012). Some hunters thought this increase was due to increased shipping activity in other areas and changing sea-ice conditions, while others thought that there was a population increase due to improved management and treatment of the animals (Remnant and Thomas 1992). Community representatives from Qikiqtarjuaq noted that many yearlings and calves have been observed recently in that area as overall numbers have increased (GN 2012b; White 2012; Oolayou 2016c). Overall, there is no ATK information to suggest a decline in abundance of the Baffin Bay population of Narwhal, and local changes in abundance may reflect changes in distribution due to changes in sea-ice conditions, Killer Whale presence, and increased shipping traffic in other areas, and not numbers (Remnant and Thomas 1992; Stewart et al. 1995; GN 2012b; Furgal and Laing 2012; White 2012; DFO 2016; NWMB 2016; Oolayou 2016b; QWB 2016; QIA 2019, 2021). Inuit generally report that Narwhal populations are stable or increasing, but there is annual variability in abundance and distribution (Nweeia 2020).

The 2020 estimate for the combined Admiralty Inlet and Eclipse Sound stock aggregation areas was 36,044 (CV = 0.12, 95% CI = 28,267 to 45,961) calculated from industry-sponsored surveys (Golder 2021), which is not significantly different from the 2019 estimate of 38,677 (CV = 0.11, 95% CI = 31,155 to 48,015) (Golder 2020b, industry-sponsored surveys) or the 2013 estimate of 45,532 (CV = 0.33, 95% CI = 22,440 to 92,384) (Doniol-Valcroze et al. 2015, DFO surveys) for both summer aggregation areas combined (Table 2). For the Admiralty Inlet stock area alone, the 2020 estimate (31,026 Narwhal, CV = 0.14, 95% CI = 23,406 to 41,126; Golder 2021) was not significantly different than survey estimates in 2019 (28,746 Narwhal, CV = 0.15; 95% CI = 21,545 to 38,354; Golder 2020b) or 2013 (35,043 Narwhal, CV = 0.42; 95% CI = 14,188 to 86,553; Doniol-Valcroze et al. 2015). For the Eclipse Sound stock, however, the 2020 estimate was 5,018 animals (CV = 0.03, 95% CI = 4,736 to 5,317) (Golder 2021), a significant decline from previous surveys that estimated a population of 9,931 (CV = 0.05, 95% CI = 9,009 to 10,946) in 2019 (Golder 2020b), 12,039 (CV = 0.23, 95% CI = 7,768 to 18,660) in 2016 (Marcoux et al. 2019), and 10,489 (CV = 0.24, 95% CI = 6,342 to 17,347) in 2013 (Doniol-Valcroze et al. 2015). Aerial surveys in 2021 documented a continued significant decline in Eclipse Sound Narwhal abundance, to 2,595 animals (CV = 0.33, 95% CI = 1,369 to 4,919 (BIMC 2022). The 2021 surveys of Admiralty Inlet estimated a total population of 72,582 (CV = 0.09, 95% CI = 61,333 to 85,895), a statistically significant increase over past years (BIMC 2022). The combined estimate for both areas (75,177 Narwhal, CV = 0.08, 95% CI = 63,795 to 88,590) was also higher than previous estimates for both summer stock areas combined (BIMC 2022). Potential causes for the decline in Narwhal abundance in Eclipse Sound, and increases in whales in other areas like Admiralty Inlet (displacement), include disturbances from shipping and other industrial activities in addition to small craft harbour construction in Pond Inlet and an increase in Killer Whale presence (GN 2012b; DFO 2016; NWMB 2016; Oolayou 2016b; QWB 2016; QIA 2019, 2021; Nweeia 2020). Industry-sponsored surveys of both aggregation areas were again conducted in 2022 (WSP 2023). These surveys documented an increase in Eclipse Sound abundance to 4,592 Narwhal (CV = 0.10, 95% CI 3,754 to 5,617) (WSP 2023) compared to 2021, but this is still significantly lower than the population size prior to increases in shipping. The 2022 surveys of Admiralty Inlet estimated a population abundance of 43,042 Narwhal (CV = 0.15, 95% CI 32,218 to 57,502), which is similar to estimates from DFO surveys in 2013 and industry-sponsored surveys in 2020; this figure is higher than the 2019 estimate from industry-sponsored surveys, and lower than that estimated from industry surveys in 2021 (WSP 2023). In 2023, the aerial survey abundance estimate for Eclipse Sound was 10,492 (95% CI=9,578 to 11,494) Narwhal, which is not significantly different from the 2013, 2016, or 2019 estimates. In Admiralty Inlet, the abundance estimate was 30,212 (95% CI=22,559 to 40,467) Narwhal, for a combined estimate of 40,706 (95% CI=32,711 to 50,655) animals (WSP 2024).

Surveys of the Northern Hudson Bay population were conducted in the 1980s, 2000, 2011, and most recently in 2018 (Higdon and Ferguson 2017; NAMMCO 2018; Watt et al. 2020; Biddlecombe and Watt 2022). The earlier surveys were conducted at different spatial scales using different data collection (visual, photographic) and analysis (corrections for perception and availability bias or not) methods (NAMMCO 2018). The 2011 visual survey data were re-analyzed using the methods of the visual surveys in 1982 and 2000 to allow comparison; the results showed a significant increase in population size over time (Asselin et al. 2012). NAMMCO (2018) considered the population to be “likely stable” (Table 1); however, there was uncertainty about the trend so another survey was needed to corroborate the high abundance estimate obtained in 2011 (Asselin et al. 2012). There is some ATK available for Narwhal population trends in Northern Hudson Bay, but the information is equivocal. Hunters and elders at a late-2000 workshop thought that numbers were not decreasing in the area (Gonzalez 2001), but a decade later the population appeared to be decreasing (Westdal et al. 2010). While the mean abundance estimate was higher in 2018 than in 2011, the difference was not statistically significant, and further analysis is needed to assess trends (Watt et al. 2020).

Appendix 2. Threat calculator results for the Narwhal, Monodon monoceros (Northern Hudson Bay subpopulation and Baffin Bay subpopulation)

Threats assessment worksheet - Northern Hudson Bay subpopulation

Species or ecosystem scientific name: Northern Hudson Bay subpopulation - Monodon monoceros - Narwhal

Date: 10/31/2023

Assessor(s): Jeff Higdon (writer), Bruce Stewart (writer), Stephen Petersen (writer), John Ford (MMSSC), Hal Whitehead (MMSSC), Dwayne Lepinski (facilitator), Shannan May-McNally (DFO), Kyle Ritchie (NWMB), Steve Ferguson (MMSSC), Mike Hammill (MMSSC), Rob Stewart (MMSSC), Marie Auger-Méthé (MMSSC), Katie Kowarski (MMSSC), Kristin Westdal (Oceans North), Marianne Marcoux (DFO), Josh Jones and Eva Hidalgo Pla (Scripps), Christine Lacho (), Karen Timm (COSEWIC)

References: 6-month COSEWIC report + draft calculator provided by report writers

Assigned overall threat impact: C = Medium

Overall threat comments: Gen time = 33 years, therefore timeframe for severity and timing = 99 years. 54% increase total pop 2011 to 2018 but not stat. sign; population stable; approximately 11,200 matures; single management "stock". Figures 2 and 3 shows distribution of 2 DUs.

Classification of Threats adopted from IUCN-CMP, Salafsky et al. (2008).

Threats assessment worksheet - Baffin Bay subpopulation

Species or ecosystem scientific name: Baffin Bay subpopulation - Monodon monoceros - Narwhal

Date: 10/31/2023

Assessor(s): Jeff Higdon (writer), Bruce Stewart (writer), Stephen Petersen (writer), John Ford (MMSSC), Hal Whitehead (MMSSC), Dwayne Lepinski (facilitator), Shannan May-McNally (DFO), Kyle Ritchie (NWMB), Steve Ferguson (MMSSC), Mike Hammill (MMSSC), Rob Stewart (MMSSC), Marie Auger-Méthé (MMSSC), Katie Kowarski (MMSSC), Kristin Westdal (Oceans North), Marianne Marcoux (DFO), Josh Jones and Eva Hidalgo Pla (Scripps), Christine Lacho (), Karen Timm (COSEWIC)

References: 6-month COSEWIC report + draft calculator provided by report writers

 

Assigned overall threat impact: C = Medium

Overall threat comments: Gen time = 33 years, therefore timeframe for severity and timing = 99 years. Several "stocks" (n=6 management stocks), most considered increasing or stable. Population (approximately 93,500 matures) suspected to be stable. Some Canadian animals subject to hunting in Greenland. Figures 2 and 3 show distribution of 2 subpopulations

Classification of Threats adopted from IUCN-CMP, Salafsky et al. (2008).