Updated: March 2018
The narwhal is a medium-sized toothed whale that belongs to the family Monodontidae. The only other member of this family is the beluga. Narwhals have stout, torpedo-shaped bodies with a low dorsal ridge in place of a dorsal fin, and a concave-shaped tail fin. They lack the extremely flexible neck and well-defined beak of their closest relative, the beluga. Like the beluga, the narwhal has short paddle-shaped front flippers. At birth, narwhals are grey to greyish-blue in colour. They become darker and more mottled as they grow older, with white patches developing from their abdomen to up over their backs. Adult narwhals are usually light grey in colour, with a mottled pattern of darker markings over a lighter background. Very old narwhal become almost completely white. Male narwhals develop a tusk, which is a modified canine tooth that grows out the left side of the jaw, twisting anti-clockwise to form a spiral. Occasionally male narwhals have two tusks, and a small percentage of females also have a tusk.
There are several stocks of narwhal. The largest inhabit Arctic Canada during the summer, where narwhal number at least 100,000 animals. At least 20,000 inhabit northwest Greenland and over 6,000 occur in East Greenland at the same time of year.
Narwhals are found in Arctic waters, in areas that are seasonally ice-covered. They are found in the northern waters of Canada, Greenland, Norway and Russia (see map: solid=summer, hatched=winter).
Hunted for food and tusks throughout their range. Past commercial harvesting in some areas.
International management regime under the Joint Commission for the Conservation and Management of Narwhal and Beluga (JCNB) and NAMMCO. In West Greenland, hunting quotas have been introduced, and present harvests are within sustainable limits.
Latin: Monodon monoceros
Greenlandic: Qilalugaq qernertaq
The English name “narwhal” is derived from the Old Norwegian word nar which means ‘corpse’, perhaps in reference to the animal’s grey colour, thought to resemble that of a drowned sailor (Heide-Jørgensen and Laidre 2006).
Adult male narwhals reach lengths of up to 460 cm and weights of 1645 kg, while females are smaller at up to 400 cm and 900 kg. The tusk of a male narwhal can exceed 2 m in length
One calf every 3 years. Sexual maturity between about 9 yrs
The narwhal spend their entire lives in cold Arctic waters. They are almost always associated with sea ice, except during late summer in some areas
Narwhals feed primarily on fish and squid, particularly polar cod (Boreogadus saida), Arctic cod (Arctogadus glacialis), Greenland halibut (Reinhardtius hippoglossoides) and squid of genus Gonatus
Narwhal can live for up to 100 years
The narwhal is a medium-sized toothed whale that belongs to the family Monodontidae. The only other member of this family is the beluga. Narwhals have stout, torpedo-shaped bodies with a low dorsal ridge in place of a dorsal fin, and a concave-shaped tail fin. They lack the extremely flexible neck and well-defined beak of their closest relative, the beluga. Like the beluga, the narwhal has short paddle-shaped front flippers.
At birth, narwhals are grey to greyish-blue in colour. They become darker and more mottled as they grow older, with white patches developing from their abdomen to up over their backs. Adult narwhals are usually light grey in colour, with a mottled pattern of darker markings over a lighter background. Very old narwhal become almost completely white.
Male narwhals develop a tusk, which is a modified canine tooth that grows out the left side of the jaw, twisting anti-clockwise to form a spiral. Occasionally male narwhals have two tusks, and a small percentage of females also have a tusk.
Watch a video discussing the possible functions of the narwhal's tusk
The narwhal is a medium-sized toothed whale, with males reaching a maximum length of about 460 cm and a maximum weight of 1645 kg, and females 400 cm and 900 kg (NAMMCO 2013, Garde et al. 2007). Narwhals are very long-lived animals: recent research looking at chemical changes in the eye lens has demonstrated that narwhal can live for over 100 years (Garde et al. 2007), making the narwhal the longest-lived of the toothed whales and one of the longest lived of all mammals.
The narwhal reaches sexual maturity between the ages of 7 and 9. They mate from late May to early June, and calves are born about a year later, during the time the animals are migrating towards their summering areas. On average narwhal have a single calf every 3 years throughout their lifetime (NAMMCO 2013, Garde et al. 2007).
The Unicorn of the sea
The most distinguishing feature of the narwhal is the male’s long tusk, which has led them to be called the “unicorn of the sea”. The tusk is actually a modified canine tooth. Usually only one tusk erupts from the left side of the upper jaw, but a small percentage of male narwhal have a tusk on both sides of the jaw. Other than the single tusk, narwhals are toothless. The tusk is spiral in form, almost always in an anti-clockwise direction. In some narwhal the tusk may exceed 2 m in length (NAMMCO 2013, Garde et al. 2007).
Narwhal feed primarily on fish and squid throughout their range. Both the diet and the intensity of feeding vary seasonally.
During the summer, narwhal apparently feed very little; hence the stomachs of narwhal harvested at this time of year are usually empty. They begin to feed more heavily in the fall during migration and especially during the winter at their deep-water wintering grounds. In Baffin Bay, the winter diet is dominated by the Greenland halibut (Reinhardtius hippoglossoides) (Laidre and Heide-Jørgensen 2005b). To access this bottom-dwelling species, narwhals must make repeated dives to depths of between 800 and 1600 m, each dive taking up to 25 minutes, with about half of that spent near the bottom (Laidre et al. 2003, 2004). Arctic cod (Arctogadus glacialis), polar cod (Boreogadus saida), and squid of the genus Gonatus also form an important part of the winter diet, and may be available in mid-water in areas too deep for narwhals to reach the bottom (Laidre et al. 2003, 2004, Laidre and Heide-Jørgensen 2005b). During the spring, as narwhals follow the retreating ice edge, polar and Arctic cod become more important in the diet (Laidre et al. 2004).
Like all toothed whales, narwhals use echolocation to find prey. This is particularly important for a species that does most of its feeding in very deep waters during the long nights of the Arctic winter. A recent study in which a camera was attached to free ranging narwhals demonstrated that narwhal spend a high proportion of their time upside down while diving and swimming at the sea bottom (Dietz et al. 2007). This may allow them to better project their echolocation clicks to locate prey, and perhaps also to protect their lower jaw and tusk from contact with the bottom.
There have been some attempts to determine the importance of narwhals as predators, by modelling how much fish they consume. Laidre et al. (2004) used a bioenergetic model to estimate the biomass of Greenland halibut needed to sustain narwhals during the five months that they spend on their wintering grounds. Any energy budget model requires certain assumptions to be made, as not all the needed information is available. The authors developed what they termed a “minimum realistic” model with results that compared well with a similar model developed for beluga whale (Welch et al. 1993 in Laidre et al. 2004). Estimates were made for varying levels of Greenland halibut in the narwhal diet: 25%, 50% and 75%. Assuming a diet comprised of 50% Greenland halibut, the 32,000 narwhals in the southern overwintering area would eat approximately 576 t per day, or about 86,000 t of Greenland Halibut for the five-month winter period (DFO 2014). The area classified as the northern over-wintering ground supports a larger number of whales (approx. 45,000) and was estimated to require 700 t per day with a mean consumption over five months of 110,700 t (95% CI of 53,000 t – 310,300 t)(DFO 2014, DFO 2007). This amount is, however, larger than the estimated biomass of Greenland halibut in that area, suggesting that narwhal in this area make greater use of other prey species.
Underwater video of narwhals swimming
Narwhals show sexual dimorphism, with several differences between males and females. Adult male narwhal are on average longer and heavier than females, reaching a maximum length of about 460 cm and a maximum weight of 1645 kg. Adult females have a maximum length of 400 cm and weight of 900 kg (NAMMCO 2013, Garde et al. 2007).
The other obvious difference between the sexes is the presence of the tusk in males. While a small percentage of females may also have a tusk (roughly 6% of tusked narwhals in the Canadian Inuit harvest were females (Petersen et al. 2012), it is a feature found in all adult males. The tusk is actually a modified canine tooth, and is in fact the only tooth these whales possess. Usually only one tusk erupts from the left side of the upper jaw, but in a small percentage of male narwhals a second tusk erupts from the right side of the jaw. The tusk is spiral, almost always in an anti-clockwise direction (NAMMCO 2013, Garde et al. 2007).
Recently Nweeia et al. (2014) suggested that the tusk may have another function altogether: as a sensory organ. The tusk is innervated and small channels in the tusk put the inner, pulpy core of the tusk in contact with the marine environment. A tusked (usually male) narwhal may therefore be able to directly sense changes in the marine environment, such as variations in salinity and temperature, through its tusk. This may aid in navigation and in avoiding being caught in rapidly freezing seas. Nevertheless it is difficult to explain why only male narwhals would have evolved or retained this capability.
PREDATION AND OTHER NATURAL THREATS TO THE POPULATION
Apart from man, the main predator of narwhal is the killer whale. Narwhal react to the presence of killer whales by moving close to land or sea ice, and forming tight groups. They may move into very shallow water and even occasionally become beached (Laidre et al. 2006).
Because of their association with heavy ice cover, narwhals are vulnerable to becoming trapped in ice if high winds move ice around or the temperature drops suddenly. Narwhals require leads or open areas in the ice to breathe, since they are unable to open or maintain a breathing hole through thick ice. A cetacean entrapment in ice is called a savsaat in Inuktitut, and is a relatively common if unpredictable occurrence. Such entrapments may be a major source of natural mortality for narwhal (Heide-Jørgensen et al. 2002). Many of these events probably go undetected, especially if they are small and in a remote location.
A savsaat in 2008 in Eclipse Sound saw at least 629 narwhals entrapped. Six hundred and twenty-nine narwhal were harvested from the savsaat, but more animals may have drowned (DFO 2008). Such a large entrapment of animals is rare in Nunavut, having been recorded only once before in the previous century (Heide-Jørgensen et al. 2002).
Watch a video of killer whales attacking a pod of narwhals
Distribution and Habitat
The narwhal is one of three species of whales (along with beluga and bowhead whales) that spend their entire lives in cold Arctic waters. They are perhaps the most “Arctic” of whales, being found exclusively in areas of the Arctic that are seasonally covered by land-fast or pack ice. They can be found further north and in areas that are inaccessible to other Arctic whale species. They are almost always associated with sea ice, except during late summer in some areas.
During the fall, winter and early spring the narwhal lives in dense pack ice, using leads and polynyas (open water areas within pack ice) to breathe. In the spring, narwhals follow the receding ice pack and spend the summer usually in shallower waters closer to land, often within fjords or close to glacier fronts.
Much has been learned about the physical and seasonal habitat of narwhal through the application of satellite-linked tags. In such studies, narwhal are captured in nets and the tags are attached either to the tusk (in male narwhal) or by bolts through the dorsal ridge. The tags transmit data when the narwhal surfaces. Along with location, tags can collect data on diving and the time spent at specific depth intervals. To date tagging studies have been conducted on almost all summer aggregations of narwhal in Canada and Greenland (Heide-Jørgensen et al. 2013b) and at Svalbard (Lydersen et al. 2007). Read more in Section 11: Research in NAMMCO member countries.
Narwhal begin migrating as early as late March or early April, following the receding ice pack into areas inaccessible in the winter. At this time of year they can be found at ice edges in the Canadian Eastern Arctic, West and East Greenland and Svalbard. Narwhal tend to spend more time near the surface and travel farther each day during the spring (Laidre et al. 2004).
During the summer narwhal can be found closer to land and in shallower water than at other times of the year (Laidre et al. 2004, Heide-Jørgensen et al. 2013ab). They move into areas of the Canadian Eastern Arctic, West and East Greenland, and Svalbard that are covered by landfast ice and inaccessible at other times of the year. During this period narwhal often congregate in fiords and at glacier fronts, and form larger groups than in other periods, up to several hundred animals.
They return to wintering areas begins in late September or later, depending on when the sea ice begins to form. Fall movements are often quite rapid although narwhal may occupy other coastal areas that remain ice-free for periods at this time of year (Heide-Jørgensen et al. 2013ab). They reach their wintering grounds by November or early December.
In the winter, narwhal occupy areas covered with heavy pack ice over water up to 2000 m in depth. In Baffin Bay they spend the winter in areas with as little as 0.5% open water (Laidre and Heide-Jørgensen 2005a).
The general pattern of seasonal habitat use is similar for all populations that have been tracked so far. During the winter narwhal occupy areas covered with heavy pack ice over water up to 2000 m in depth. In Baffin Bay they spend the winter in areas with as little as 0.5% open water (Laidre and Heide-Jørgensen 2005a), diving repeatedly to depths of up to 1600 m to feed on fish at or near the sea bottom. Narwhal are physiologically adapted for long dives, having a very high ratio of slow oxidative to fast twitch muscle fibres, and by having the highest levels of myoglobin recorded in any marine mammal, giving them exceptional oxygen storage capacity (Williams et al. 2011). They can dive aerobically for up to 24 minutes, giving them the ability to feed at great depths and move up to 1.4 km between breathing holes.
A “stock” of animals is a term often used in wildlife management. The stock is the basic unit of management, mainly because it describes a group of animals that is reproductively and often physically isolated from other groups. Animals in a stock generally share similar life history characteristics, such as age of sexual maturity, rate of breeding etc. Most importantly, animals within a stock mate and breed primarily with other members of that stock.
It is important to try to determine whether narwhal are all members of one stock, or if there are different stocks, for a number of reasons. Narwhal are hunted throughout Nunavut in Canada, and in Greenland. In order to set appropriate harvest levels, managers need to know if narwhals are being taken from one or more stocks, and which stocks those are. It is also important to know if there are different stocks in order to make good population estimates.
Stock identity is determined in various ways: through analyzing the genetic makeup of individuals, tagging studies, studies of stable isotope ratios, use of traditional ecological knowledge, and studies of morphology.
In general, narwhal appear to have low genetic diversity and there is little differentiation among stocks (NAMMCO 2013). There are two possible reasons for this: either a “bottleneck”, or population restriction, occurred in the population at some ancient date, or there is currently a high rate of gene flow between areas. Either or both explanations could be correct.
Despite this overall low genetic diversity, genetic studies have found that narwhals in East Greenland are highly distinct from other groups (NAMMCO 2013). Within west Greenland, far northern (Uummannaaq) narwhals are different than those found further south. Differences are also seen between Baffin Bay, Northern Hudson Bay and East Greenland populations (Petersen et al. 2011, NAMMCO 2013), and less distinct differences between narwhal that summer in Jones Sound and the Somerset Island area (Petersen et al. 2011).
Similar results were found using stable isotope analysis of carbon and nitrogen from skin samples. A clear difference was seen between northern Hudson Bay, East Greenland, and all other stocks (Watt et al. 2012b).
East Greenland narwhals are also distinct in their cranial morphology (Wiig et al. 2012a), however, no differences were seen between West Greenland and Canadian narwhals.
Another method which has been used to try to identify stocks is analysis of organochlorine (OC) contaminant levels in narwhal tissues. Differences in contaminant levels can be caused by differences in feeding, which may depend on prey selection, feeding patterns in summering/wintering areas or on migration routes, and on the feeding behaviour of the individual. In a 2003 study, narwhals sampled from Repulse Bay could be distinguished from all other narwhals studied. Apart from that group, it was not possible to clearly distinguish other stocks using this method (de Marche and Stern 2003).
Tagging studies have been done in a number of locations throughout the narwhal’s range. These studies suggest interannual site fidelity, which means that narwhals generally return to the same summering and wintering areas year after year. There are exceptions, however: one narwhal tagged in Admiralty Inlet wintered in Northern Foxe basin rather than Davis Strait (Watt et al. 2012a, NAMMCO 2013), and one whale tagged in northern Greenland migrated to Somerset Island in the summer (Heide-Jørgensen et al. 2013).
Most narwhal stocks from northern Canada and West Greenland mix in the winter in Baffin Bay/ Davis Strait (Heide-Jørgensen et al. 2013). Mating, however, occurs during the spring migrations to the summering areas, which maintains summer stock identity (NAMMCO 2013).
The “summering aggregations” (areas where narwhals are found in the summer) currently provide the basis for the determination of management stocks, mainly because 1) narwhal stocks tend to be geographically isolated during the summer and 2) because it is during the summer and at these locations that narwhals are usually hunted. Overall, the current thinking is that there are seven stocks in Canada, two in West Greenland, two in East Greenland, and one in Svalbard-Northwest Russia (NAMMCO 2018).
Svalbard and Northwest Russian Arctic
There is very little information on the narwhals that inhabit this area. Generally narwhals were historically sighted and sometimes caught by Norwegian sealers and whalers in the area between East Greenland, Svalbard, the New Siberian Islands and Novaya Zemlya (Gjertz 1991, Lydersen et al. 2007). Narwhals are most frequently observed in the northwest and northeast parts of the Svalbard archipelago, but this probably reflects the numbers of observers rather than the number of animals. Generally narwhals in this area appear to be widely dispersed and do not form large predictable aggregations as they do in other areas. The wintering area of Northeast Atlantic narwhals is not known, but it is likely that they overwinter within the extensive pack ice in this area. Farther east, sightings of narwhal are very rare or non-existent.
During the summer narwhal are found along the East Greenland coast with concentrations found in Scoresby Sound (Ittoqqortormiit), Tasiilaq, and Kangerlussuaq (Heide-Jørgensen et al. 2010, NAMMCO 2017). Narwhal have a scattered distribution along the coast and periodically occupy many fjords in the area. Although narwhals in East Greenland are currently recognised as a single stock (NAMMCO 2018), the NAMMCO-JCNB Joint Working Group (see “Management”) agreed to recognise three separate “management units” in order to avoid local depletions: Tasiilaq, Kangerlussuaq, and Ittoqqortormiit.
Narwhals are frequently found north of Scoresby Sound as far north as Nordost Rundingen (82°N; Boertmann and Nielsen 2009 and 2010). Given the long coastline, it is possible that there are several stocks in Northeast Greenland, however there is currently very little (or no) data to determine stock structure (NAMMCO 2018). Narwhals may also occur between Greenland and Svalbard but there is little supporting data.
West Greenland (Inglefield Bredning and Melville Bay stocks)
Narwhal are found off West Greenland at all times of the year, and two stocks occur in summer aggregations at Inglefield Bredning and Melville Bay. During the fall, winter and spring they are found in the ice pack off the West Greenland coast from Smith Sound to just south of Disko Bay (Heide-Jørgensen et al. 2010). While the summering aggregations are considered to be stocks for management purposes, at other times of the year narwhals off West Greenland are likely composed of a mixture of narwhals from several summering areas, including stocks that summer in Canada (Heide-Jørgensen et al. 2012).
There are seven stocks/summer aggregations of narwhal in Canada.
The North Hudson Bay narwhal summer in northwestern Hudson Bay, particularly near Repulse Bay and into Foxe Basin. Tagging studies indicate that this group winters in the pack ice at the eastern end of Hudson Strait (DFO 2010a, Heide-Jørgensen et al. 2012). The Northern Hudson Bay stock can be separated from other Canadian stocks through genetics, contaminant analysis and by the fact that it’s distribution does not overlap with that of any other group of narwhal.
The six other Canadian stocks (Somerset Island, Jones Sound, Smith Sound, Eclipse Sound, Admiralty Inlet, and East Baffin Island) winter in southern Baffin Bay/northern Davis Strait, and have summer concentrations throughout the eastern Canadian Arctic Archipelago. These stocks are considered “shared stocks” with Greenland, as they migrate into Greenlandic waters seasonally. Tagging studies have indicated that there is little mixing between areas during the summer, although it does sometimes occur. The distribution of all these stocks, and the two stocks in West Greenland, overlaps in the winter and not surprisingly they cannot be readily differentiated genetically or by other means. Nevertheless these divisions are useful for management purposes as it allows a stock allocation to hunting areas, which is a more conservative approach than assuming that there is only one “panmictic” stock of narwhals in the area, as the latter approach could result in local depletions if an underlying stock structure existed.
Estimating the abundance of narwhals is difficult due to the remoteness and large size of their distribution area, the mobility of the animals, and their close association with sea ice. Aerial surveys are most commonly used, but the results obtained must be corrected for both whales that are at the surface but missed by observers, plus those that are below the surface out of sight when the survey airplane is overhead. Another problem is that direct comparisons between surveys are not always possible, since surveys rarely have the same timing or cover the same area.
A rough estimate for the total world population is 85,000 – 100,000 animals (White 2012, NAMMCO 2017): A more detailed breakdown of the population status in different areas of the Arctic is given below.
Svalbard-Northwest Russian Arctic
An survey in 2015 resulted in an estimate of 837 narwhals (Vacquié-Garcia et al. 2017), but this is likely a minimum estimate as the survey did not cover all of the area where narwhals may occur. There are no previous abundance estimates to compare with the 2015 estimate to obtain a trend.
The first comprehensive survey, carried out in 2008, resulted in a total corrected abundance estimate of 6,444 (95% CI: 2,504–16,575), of which over half was found in the Scoresby Sound area (Heide-Jørgensen et al. 2010). There were no previous surveys to compare with to obtain a trend, however surveys were flown in 2016 and 2017 and these estimates will be available in the near future.
A first ever survey for narwhals in northeast Greenland was conducted in 2017 and the estimate is expected in the near future.
A survey conducted in 2007 resulted in an estimate of 8,368 (CV = 0.25, CI 5209 to 13,422; corrected for availability and perception; Heide-Jørgensen et al. 2010) narwhals in the Inglefield Bredning stock. Previous surveys have been conducted since 1984 have used different methods and covered different areas, so the abundances are not directly comparable to get a trend (Born et al. 1994; Heide-Jørgensen 2004) but the distribution seen in 2007 was similar to these past surveys (Heide-Jørgensen et al. 2010).
Melville Bay was surveyed in 2014, and the corrected estimate was 3,091 (95% CI 1,228 – 7,783).
The wintering area in eastern Baffin Bay along the West Greenland coast was most recently surveyed in March-April 2012, as part of a long-term series of surveys conducted 7 times since 1981. The survey resulted in a corrected estimate of 18,583 narwhals (95% CI: 7,308–47,254). Aggregations of narwhals were seen clumping at the sea ice edge, probably due to bathymetric features in this area. Numbers here seem to fluctuate from year to year, probably because of annual variations in ice conditions in the area, as well as variations in the timing of seasonal migrations.
This result is a large increase in the abundance from the previous survey in 2006, which was 7,819 narwhals. This is likely because the 2012 survey covered a larger survey area, especially in the north part of the area where 1/3 of all the animals were seen. This area was not previously surveyed.
A comprehensive survey with narwhals as the main target species was carried out in Canadian waters in August 2013. The survey covered all major known summer aggregation areas for Baffin Bay narwhal in Canada, including Peel Sound, Prince Regent Inlet, Admiralty Inlet, Eclipse Sound and the East Baffin Coast. Jones Sound and Smith Sound were surveyed for the first time. This was the largest aerial survey ever carried out in Canada, with three planes and 15 observers taking part over a four week period. It is also the first time that all major narwhal habitat has been surveyed in a single year.
The most recent abundance estimate for this stock from the 2013 survey is 49,768 (CV=0.20; estimate adjusted for perception and availability bias; Doniol-Valcroze et al. 2015). This stock appears to be increasing based on surveys from 1981, 1984, 1996, 2002-2004 and 2013 (NAMMCO 2015, Witting 2016).
The 2013 survey was the only time this stock has been surveyed, and resulted in an abundance estimate of 12,694 (CV = 0.33) narwhals (Doniol-Valcroze et al. 2015). Since this was the only survey it is not possible to determine a trend for this stock.
An aerial survey conducted in 2013 resulted in an abundance estimate for the Smith Sound stock of 16,360 (CV=0.65) narwhals (Doniol-Valcroze et al. 2015). As this is the only survey of this area, there is not enough information to determine a trend.
The most recent (2013) abundance estimate for this stock was 10,489 with a CV of 0.24 (Doniol-Valcroze et al. 2015). The previous survey in 2004 resulted in an abundance estimate of 20,230 (CV=0.36), and because of the overlapping confidence intervals from the two surveys there is no significant change in abundance. With only two surveys, however, a trend cannot be determined.
The survey in 2013 resulted in an abundance estimate for this stock of 35,043 (CV=0.42; estimate adjusted for perception and availability bias; Doniol-Valcroze et al. 2015). This stock appears to be stable, based on five surveys conducted over the past 30 years (Richard et al. 2010, Asselin and Richard 2011, Witting 2016).
Eastern Baffin Island
The most recent abundance estimate for this stock is 17,555 ± 0.35 (adjusted for availability and perception bias; Doniol-Valcroze et al. 2015). A previous survey in 2003 resulted in an abundance estimate of 10,073 ± 3,487. It is not possible to determine a trend from these data.
North Hudson Bay
The most recent survey for narwhals in northern Hudson Bay was conducted in 2011, and resulted in an estimate of 12,485 narwhals (95% C.I. 7,515 – 20,743) (Asselin et al. 2011).
Svalbard – Northwest Russian Arctic
There is currently very little information about narwhal abundance, distribution, and stock identity in this area, and therefore it is difficult to assess the status of the stock. The experts at the Global Review of Monodontids (GROM) meeting held in 2017 (see box to the right; NAMMCO 2018) gave a moderate level of concern for narwhals in this area, mainly due to the lack of information that is available and the likelihood that there is a low abundance. A survey in 2015 resulted in an estimate of 837 narwhals (Vacquié-Garcia et al. 2017), but this is likely a minimum estimate as the survey did not cover all of the area where narwhals may occur. Narwhals are protected in Svalbard and Russia.
East Greenland and Northeast Greenland
The total abundance for narwhals in East Greenland are presently unknown but likely are fairly low and the catch quotas are presently higher than the recommended takes. A new abundance estimate from a survey conducted in spring/summer 2017 will help clarify the situation in East Greenland.
In 2017, the NAMMCO-JCNB Joint Working Group, and the Global Review of Monodontids (GROM), both recognised that the environment in this area is changing rapidly, including increased sea surface temperatures, rapidly retreating ice cover, and disappearance of tidewater glaciers. These changes may be resulting in poor and reduced narwhal habitat. In addition, tropical species (including humpback whales) have been observed in the area, which is likely causing competition for prey, exposure to novel diseases, etc. With all of the environmental changes occurring, it will be difficult to tease apart these impacts from the hunting pressure in the area.
Reviewing the status of all belugas and narwhals
In March 2017, NAMMCO organised a Global Review of Monodontids (GROM), which discussed the conservation status, threats, and data gaps for all stocks of belugas and narwhals globally. The last review was done almost 20 years ago, and a large amount of new information has become available since then, especially on stock identity, movements, abundance, and threats to the populations. Additionally, there are many new stressors that have emerged in the last 20 years, especially related to climate change.
Stock experts representing Greenland, Canada, Alaska, Russia, the Government of Nunavut, Nunavut Tunngavik, Inc., the Inuvialuit Settlement Area and the Nunavik Wildlife Management Board participated.
The report can be found here and a publication is in preparation for peer review.
Given all of these challenges for narwhals in East Greenland, the GROM (NAMMCO 2018) stated “There is a high level of concern for narwhals in East Greenland due to the lack of data (particularly on stock structure), low abundance, declining trend, likely overharvest, and the numerous climate-related changes in habitat.”
In Northeast Greenland, narwhals are frequently sighted along the coast north of Scoresby Sound. This area is within the Northeast Greenland National Park, and no hunting takes place in marine waters along the Park’s boundary. Although this area has not been previously surveyed for narwhals, a new abundance estimate is expected from aerial surveys conducted in 2017.
The GROM experts had moderate concern for this stock – while the narwhals are protected in this area, there is a lack of information on abundance, distribution, and stock structure, and the climate-related habitat changes being seen just south of this area may have similar effects on narwhals in northeast Greenland in the near future.
The two stocks of narwhals that summer in west Greenland are Inglefield Bredning and Melville Bay.
The Inglefield Bredning stock is apparently depleted from it’s previous abundance, but has been stable since the 1908s (Witting 2016). With the stable abundance and sustainable harvest levels, there is currently low concern for this stock (NAMMCO 2018).
The Melville Bay stock is apparently stable, but the it is a small stock and the current harvest levels exceed the recommendations of the NAMMCO-JCNB Joint Working Group and therefore the GROM expressed high concern for this stock (NAMMCO 2017, 2018).
Narwhals that occur in West Greenland during the fall, winter, and spring are likely from a mix of stocks that include Inglefield Bredning and Melville Bay, but also narwhals that are from the summer aggregations/stocks from Canada (see below).
There are seven stocks of narwhals that summer in Canada, six of which are “shared stocks” with Greenland (i.e., they may migrate into Greenlandic waters and are available to Greenlandic hunters at some point during the year).
The Somerset Island stock is the largest narwhal stock and appears to be increasing. This stock is hunted by multiple communities in Canada and also in Greenland during the migration, but the removals are considered sustainable. Given these factors, there is low concern for this stock (NAMMCO 2018).
The Jones Sound and Smith Sound narwhal stocks are fairly large (about 12,000 and 16,000 respectively), removal numbers are low and sustainable, and there are few habitat concerns. Therefore is low concern for both of these stocks (NAMMCO 2018).
The Admiralty Inlet stock if fairly large and stable, and the hunt is considered sustainable. Although there are habitat concerns related to increasing human activities (including disturbance from freighters, cruise ships and supply vessels) in their summer habitat, the GROM had low concern due to the size and sustainability of the hunts (NAMMCO 2018).
The Eclipse Sound stock appears to be stable at around 10,000 narwhals (although there is considerable uncertainty around the abundance estimate) and removals are considered sustainable. A major and growing concern is ship traffic related to the Baffinland-Mary River iron mine and tourism. Overall, the Eclipse Sound stock of narwhals is of moderate concern (NAMMCO 2018).
The Eastern Baffin Island stock is fairly large and removals relatively low, however there is moderate concern for the stock. These concerns relate mainly to the lack of data on movements and stock structure, and the possibility several stocks, rather than only one, inhabit the region in summer (NAMMCO 2018).
The Northern Hudson Bay stock of narwhals is separated from the other stocks in both summer and winter. This is the only narwhal stock in Canada that is not shared with Greenland. This is a fairly large stock of around 12,500 animals and the current level of hunting removals is considered sustainable. Although the loss of sea ice and concomitant increases in shipping and other industrial activities are of concern, overall concern for this stock is low (NAMMCO 2018).
Narwhals inhabit the waters of two NAMMCO member states: Norway and Greenland.
Norway does not presently permit the harvest of narwhals in its territory.
Some West Greenland narwhals may travel to Canadian waters, therefore management is a shared responsibility between Greenland and Canada. Greenland and Canada have established a bilateral management body, the Canada/Greenland Joint Commission on the Conservation and Management of Narwhal and Beluga (JCNB). The JCNB has a Scientific Working Group which meets jointly with the NAMMCO Scientific Committee Working Group on the Population Status of Narwhal and Beluga in the North Atlantic. This scientific body provides advice at the request of the JCNB and NAMMCO, pertaining to such issues as stock delineation, total allowable catches and threats to beluga and narwhal populations. The JCNB Commission meets periodically to receive this advice and provide management advice to Canada and Greenland.
SCIENCE-BASED MANAGEMENT GIVES RESULTS
There was concern in the past that West Greenland narwhals were declining in numbers due to overharvesting. This concern was based on an apparent decline in summer numbers at Inglefield Bredning in between 1986 and 2002, and a decline in the numbers seen in winter index surveys conducted in the 1980’s and 1990’s in Disko Bay (NAMMCO 2006, NAMMCO 2010). However, more recent surveys (Heide-Jørgensen et al. 2010) do not suggest that numbers are in decline, and that other factors such as methodological differences between surveys and annual fluctuations in numbers due to ice conditions may have contributed to the previous apparent decline. In 2012, both the JCNB and the NAMMCO Scientific Committees used recent abundance estimates and other information to conclude that quotas and takes from the summer aggregations at Inglefield Bredning and Melville Bay are sustainable (NAMMCO 2013). It was recommended that, in order to have a 70% probability of population increase, narwhal catches should total no higher than 310 per year in West Greenland. The Greenland Home Rule Government accepted this advice and has limited harvests in West Greenland to the recommended levels by introducing seasonal quotas in all areas. The fall and winter harvests at Uummannaq and Disko Bay are likely supplied by both Greenlandic and Canadian summer aggregations, and present quotas and takes are considered sustainable (NAMMCO 2013).
Quotas for narwhals were introduced in 2004 for West Greenland, and in 2008 for East Greenland (Nielsen and Meilby 2013). A license for the species and period is required in order to hunt narwhal, in addition to a hunting permit. There is no narwhal hunting permitted in the national park in northeastern Greenland. The Ministry of Fisheries, Hunting and Agriculture is responsible for regulating narwhal whaling in Greenland. Regulations govern the seasons in which narwhals can be hunted and the weapons and equipment that may be used. Successful whale hunts must be reported to municipal authorities to facilitate monitoring of the harvest. Compliance with quotas and other regulations is monitored by wildlife officers at the local level.
Catch allocation model
Managing a shared stock between two countries can be challenging, especially when that stock of animals migrates. The main problem is how to identify which stock the hunters are taking in various areas in different seasons. The NAMMCO-JCNB Joint Scientific Working Group have developed a model that allows managers to assign catches from the narwhal metapopulation that is shared by Canada and Greenland to the appropriate summering aggregation, by different hunting grounds and seasons. The model includes all information that is available on narwhal movements including telemetry data, all abundance estimates, seasonal occurrence and historical catch data (see examples of the types of information used below). This model is a good example of how two countries can work together to solve a tricky management problem.
Management in Canada
Canada sets harvest levels for narwhals using a “Precautionary Approach Framework” (DFO 2008), which takes a conservative approach to management. As part of this approach, the Potential Biological Removal (PBR) method is used to determine the Total Allowable Harvest. This method was developed in the United States for the regulation of human-induced mortality on marine mammals, and produces a single threshold value for removals from a population, which allows depleted stocks to grow and other stocks to maintain their numbers.
The method produces a total allowable landed catch (TALC) for a narwhal stock, which takes into account whales that are struck and lost by hunters. Hunt loss corrections are derived from annual reports of landed and lost whales from communities under Community Based Management (DFO 2008).
For Baffin communities, present harvests are well below the recommended TALCs (DFO 2012c).
Narwhals have long been a staple food resource for indigenous peoples throughout the Arctic, and continue to be an important part of northern diets today. The skin and attached subcutaneous fat was and is considered a delicacy called muktuk (various spellings and pronunciations, including maktaaq and mattak). The meat varied in quality depending on the cut and was eaten raw, dried or cooked, or used as dog food.
Sometimes the meat and muktuk were aged and prepared in specific ways to make traditional delicacies. The flippers, organs and intestines were also used as food. The skin from the top part of the whale was cut and prepared to make rope, and the tendons were used to make sinew for sewing. The blubber was rendered to oil and used in traditional lamps (qulliq) as a source of light and heat. Even the bones were used as a food source, construction material and for carving. While many of these uses have been replaced by modern materials, narwhal muktuk and meat are still an important part of the diet in some areas of Arctic Canada and Greenland.
Historically, the catch of narwhals or other large animal was divided and shared among participating hunters and their extended families according to complex traditional rules (Inuktitut ningiqtuq, Greenlandic ningerpoq) that helped to ensure that the entire camp or community received a portion of the catch (Wenzel 1995). More recently, the regulation of narwhal hunting and changing hunting methods and equipment have led to changes in the sharing system (Sejersen 2001). In Greenland particularly, part of the catch is sold in the open-air markets (Greenlandic Kalaalimineerniarfik, Danish brædtet) present in every village and town. This provides a welcome source of income for hunters. Commercial sale of beluga products is not widespread in Nunavut, although this is starting to change.
Hunting occurs during the open water season from boats, and also from the floe edge during the fall, winter and spring. The timing of the hunt depends on the weather, the nature of the ice, and the movements of the narwhals. The timing of each of these depends on location. For example, Arctic Bay generally has a shorter hunting period (June–September) than Pangnirtung, which may run from March to November (Heide-Jørgensen et al. 2013b).
In West Greenland, in the Upernavik, Uummanaaq and Disko Bay areas, hunting occurs generally during the fall and winter (NAMMCO 2013). In the far north of West Greenland, hunters from Qaanaaq sometimes see narwhals in the Smith Sound area in winter and spring (January–June), however, most hunting takes place between May and September with peaks in the months of July and August (Heide-Jørgensen et al. 2013b).
In East Greenland, the majority of the harvest occurs during the summer months (Heide-Jørgensen and Laidre 2009). As with other stocks, the timing of the hunt depends on the movement of the narwhals.
The following descriptions of hunting methods in Canada and Greenland were taken from the NAMMCO Expert Group Meeting to Assess the Hunting Methods for Small Cetaceans, held in 2011 (NAMMCO 2012).
In West Greenland and Canada, narwhals are hunted during the spring, summer and fall from small boats, or at the ice edge or at ice cracks. In some areas of West Greenland, the kayak is still used for hunting. In this type of hunting, the animal is approached quietly by one or two kayaks, and the hunger uses a hand-held harpoon with a detachable head (Greenlandic: tuukaak). The harpoon head is attached by a line to a float (Greenlandic: quataq) and then to a drag or brake (Greenlandic:miutak) which slows the wounded animal. The hunter then shoots the whal with a high-powered rifle when it resurfaces.
Similar hunting methods are used from small motor boats and from the ice in Greenland and Canada. Ideally, the whale is harpooned first to secure it; it is thereafter despatched using a rifle. In some cases, the harpoon strike alone is sufficient to kill the animal. In other cases, the narwhal is shot first to wound it and slow it down so it can be secured using a harpoon and line.
In the far north of Greenland, nets are sometimes used to capture narwhal, particularly during the dark season and in very heavy ice. The narwhal swims into the net, becomes entangled and will drown if it cannot surface. If they remain alive, they are shot be the hunter when the net is checked.
Recent Harvests in Greenland
Catches of narwhals in West Greenland from 1993-2017. Between 1993-2016 the catches are corrected for under-reporting detected from purchases of mattak (low option), for periods without catch records (medium option) and from rates of killed-but-lost whales (high option). From Garde and Heide-Jørgensen (NAMMCO/SC/-JCNB/SWG/2017-JWG/07) presented at the NAMMCO-JCNB Joint Working Group (contact the NAMMCO Secretariat). The 2017 catches are not corrected. The catches from Uummannaq and Disko Bay are from a mix of stocks (see “Management”).
DIRECT AND INDIRECT IMPACTS OF CLIMATE CHANGE
One concern of changing sea ice cover is that loss of sea ice, particularly during the summer, may increase the access of killer whales to narwhals, thus increasing predation. Access to narwhals by man is also changing with changes in sea ice concentration and extent. In Smith Sound, climate change may have decreased spring and summer ice cover, which has enabled people in north Greenland to access the area and increase their catches (Nielsen 2009). The presence of open water is an important influence on the narwhal hunt, with the majority (72%) of the hunt in Nunavut taking place during the summer months (July 25th–October 1) (White 2012). Narwhals have also recently been moving further west in the Canadian Arctic, perhaps due to changes in sea ice cover, and been sighted and hunted near communities in the Central Canadian Arctic where they have been seldom seen before (White 2012).
Increasing industrial development in the Arctic, especially increased ship traffic, could also pose a threat to narwhal populations. Narwhals can detect the noise made by large icebreakers from at least 25 to 30 km away (Cosens and Dueck 1993). Other studies have found narwhals reacting to such noise at distances from 40–60 km (Finlay et al. 1990, Cosens and Dueck 1988). Communities close to shipping routes in the NW Passage, Arctic Bay and Pond Inlet, report fewer narwhals in their areas than there has been in the past, and some hunters attribute this to increased ship traffic (White 2012). This is a concern as ship traffic is expected to increase as sea ice cover decreases with global warming.
Prior to 1996, there had been very little fishing in NAFO Division 0A, the waters on the Canadian side of Baffin Bay. Since 1998, the Greenland halibut fishery in this area has expanded. Currently, both otter trawls and gillnets are used in this fishery. As the fishery expanded, concerns were raised by both DFO and the Nunavut Wildlife Management Board that narwhals could be affected by removal of their primary prey species on their overwintering grounds, damage to bottom habitat by trawling, and entanglement of whales in lost gillnets.
In order to mitigate these concerns, a number of measures were introduced. For example, an end date of Nov. 10 was established for the gill net season, in an effort to reduce the risk of gear loss due to late season ice conditions. This date may be changed in response to seasonal conditions. As well, starting in 2007, the southeast part of NAFO area 0A was closed to Greenland halibut fishing in order to protect this important food source for overwintering narwhals.
OIL AND GAS EXPLORATION
Better drilling technology and a warming climate have increased interest in northern areas previously inaccessible to oil and gas exploration. It has been estimated that more than 20 million barrels of undiscovered oil and still greater quantities of natural gas might exist on the continental shelf of East and West Greenland, with still more in the Canadian Arctic Archipelago (Gautier et al. 2009). Seismic exploration, which involves the discharge of airguns that create very loud low-frequency sounds underwater, have been conducted off West Greenland since 2007, and is expected to begin soon off East Greenland. Recently, Heide Jørgensen et al.(2013c) reviewed the potential effects of these activities on narwhals and other Arctic marine mammals.
Like all toothed whales, narwhals use their echolocation abilities to find prey, avoid predators and in navigation. Narwhals also use it to find openings in dense pack ice where they can come up to breathe. In addition to echolocation, narwhals have a broad vocal repertoire which they use to stay in touch with other members of their pod. Their Arctic habitat has heretofore been largely unaffected by human-caused sounds, to which they are therefore unaccustomed.
The effects of ship noise, seismic exploration, drilling and other sounds on narwhals have been largely unstudied, but could include short or long term changes in behaviour, such as feeding activities and vocalization. Noise could also induce avoidance responses and changes in migratory timing and routes. Extremely loud sounds, such as those produced by seismic exploration, have the potential to directly damage narwhal hearing if they occur at close range, in addition to masking environmental sounds that may be important to narwhals. Narwhals have been observed to react to vessel noise even at long distance and low sound intensity, generally by leaving the area and reducing their vocalizations.
THE NATURAL RISK OF ENTRAPMENTS MAY BE INCREASED BY SEISMIC ACTIVITIES
Narwhals spend about half the year in their winter feeding areas, in a marine environment covered by dense pack ice. Although narwhals are among the most ice-adapted of whales, they are still subject to occasional entrapments when the ice freezes up or closes around them, leaving them dependent on a small breathing hole and often resulting in their death when the breathing hole closes. The circumstances leading to entrapments are well known to the Inuit inhabitants of Disko Bay in West Greenland, who historically have harvested whales that have become entrapped. However, in recent years, entrapments have occurred in other areas where they have not been frequently observed, leading Heide-Jørgensen et al. (2013c) to speculate that seismic activities in Baffin Bay may have contributed to these events.
In November 2008, over 1,000 narwhals were entrapped in the ice near Pond Inlet, Nunavut, in an area of Lancaster Sound that freezes solid in the winter and is not therefore winter habitat for cetaceans. Previous tagging experiments have demonstrated that most narwhals begin their southward migration from this area by the end of September. However, seismic exploration was occurring in Baffin Bay in September and October of the same year, and it is possible that the noise produced by this activity may have delayed or prevented the narwhals from migrating, and contributed directly to the entrapment. All of these animals eventually died, most of them harvested by local Inuit who knew they would not survive the winter.
Smaller entrapments occurred in Inglefield Bredning in Northwest Greenland in November 2009 and February 2010. Again, this is normally summer habitat for narwhals and they are thought to leave the area well before November. And again, seismic activity in Baffin Bay in September and October 2009 may have delayed or prevented their migration from the area.
While these occurrences do not constitute conclusive proof that seismic activities are affecting the timing of narwhal migrations, they certainly demonstrate the need for caution in pursuing these activities in or close to narwhal habitat. Heide-Jørgense et al. (2013c) conclude that further research on the effects of anthropogenic noise on narwhals and other Arctic marine mammals is urgently needed, and that this research should ideally precede any further such activities in the area.
Watch a video of narwhals swimming into ice and becoming temporarily entrapped
STATUS ACCORDING TO OTHER ORGANISATIONS
Narwhals are currently listed on Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) (as are all species of cetaceans not listed on Appendix I). CITES is a legally-binding multilateral environmental agreement that aims to ensure that international trade does not threaten the survival of species in the wild. Both Denmark (Greenland) and Norway are signatories to the convention. A listing on Appendix II means that an export permit shall only be granted when the Scientific Authority of the State of export has advised that such export will not be detrimental to the survival of the species in the wild.
On the IUCN “Red list” narwhals are listed as Near Threatened in an assessment made in 2008 (Jefferson et al. 2012).
Research on narwhal and other marine mammals is carried out through the Greenland Institute of Natural Resources in Nuuk, Greenland. Research carried out in both east and west Greenland has included the collection and analysis of samples for genetic studies, the application of satellite tags, and abundance surveys. The latter have provided important information on the size of the population of whales wintering off West Greenland, and the trends in abundance over time. Genetic studies are used to try to determine stock structure and relationships, while satellite tagging provides information on stock structure through narwhal movements and habitat use. Another use of satellite tags is to record ocean temperatures and depths, and tags on narwhals have been used for this (see Laidre et al. 2010). Satellite-tagging studies of narwhals in both Canada and Greenland were initiated in 1993, and have been ongoing since then (Heide-Jørgensen et al. 2013b).
Work has also been done in Greenland on ageing methods for narwhals. A new species-specific racemization rate for narwhals has been estimated by regressing aspartic acid D/L ratios in eye lens nuclei against growth layer groups (GLG) in tusks (NAMMCO 2013, Garde et al. 2007). This information is then used to better estimate the age of a narwhal, and so to construct age distribution and estimate life history parameters for stocks.
In 2017, GINR is conducting a large-scale project on narwhal ecology and biology in Scoresby Sound, East Greenland. You can read more about the project, and follow their progress here: https://narwhals2017.com/
In Norway, narwhal research is carried out by the Norwegian Polar Institute in Tromsø, Norway. In one study, several narwhals off Svalbard were fitted with satellite tags in order to record their diving depths and duration of those dives (Lydersen et al. 2007). This research is not ongoing at the present time. Narwhal are fully protected in Norway, and no hunting of them is allowed.
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Witting L 2016. Meta population modelling of narwhals in East Canada and West Greenland. Report submitted as supporting document to the Canada National Marine Mammal Peer Review Committee. Winnipeg, Canada. http://dx.doi.org/10.1101/059691
Links to other websites
[ABA] Arctic Biodiversity Assessment 2013
Canada Department of Fisheries and Oceans
Greenland Institute of Natural Resources
IUCN Red List, narwhal status report
Norwegian Polar Institute
University of Michigan Museum of Zoology: Animal Diversity Web Wikipedia