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Distribution, exploitation and population status of white whales (Delphinapterus leucas) and narwhals (Monodon monoceros) in West Greenland
Abstract
Historic and present distribution of narwhals (Monodon monoceros) and white whales (Delphinapterus leucas) in West Greenland is reviewed. The distribution of white whales changed early in this century. They initially disappeared from Nuuk District and later, during the 1920s, from Maniitsoq District. Southwest Greenland (south of 65°N) is no longer a part of the winter or spring distribution of Baffin Bay white whales. Possible reasons for this change are discussed. No large-scale changes in distribution of narwhals have been detected. The major products from narwhals and white whales traded in Greenland are mattak (= whale skin) and narwhal tusks. The mean yield of mattak per whale is estimated to be about 67 and 133 kg per white whale in the municipalities of Upernavik and Qeqertarsuaq, respectively, and 89 kg per narwhal in the municipality of Avanersuaq. Annual reported catches were approximately 900 white whales and 300 narwhals in West Greenland during 1970-1980. After 1980 the catch reporting system became less reliable and it had virtually collapsed by 1991. However, some statistics of catches during the 1980s are reliable, some are available from other sources and others can be calculated from purchases of mattak. The estimated catches of white whales during the 1980s indicate one of two scenarios: either I) the population estimates from 1981 seriously underestimated the actual population size, or 2) the population has been declining during the 1980s. For narwhals the catches are smaller and the population estimates higher, albeit subject to large variability.
... The detection period of beluga whale clicks during fall 2013 was very short and suggests a southward migration through Baffin Bay. Beluga whales from the Canadian High Arctic are known to migrate south along the northwestern Greenland coast through Baffin Bay in September-November (Doidge and Finley 1993;Heide-Jørgensen 1994). Previous studies have revealed that a large number of tagged beluga whales actually overwinter in the North Water Polynya (northwest Baffin Bay and Smith Sound) (Heide-Jørgensen et al. 2003c;Richard et al. 2001). ...
Offshore Exploration and Production (E&P) activities, such as seismic surveys and drilling, generate sound that can affect marine mammals in different ways. These effects range from permanent or temporary auditory impacts to disturbance or behavioral changes, and communication masking. Depending on the intensity and duration of these effects, and without implementation of appropriate mitigation measures, this can result in population-level consequences. The overarching objective of this study was to advance the protection of marine mammals during the implementation of E&P activities through the following themes: (1) enhancement of the state of knowledge of risk management, (2) efficacy of mitigation, (3) advanced monitoring technology, (4) implementation of advanced industry monitoring and mitigation measures and (5) measurement of heretofore unassessed E&P activities. In this study several marine mammal monitoring and mitigation programs associated with E&P projects are presented to further advance these themes. Topics being addressed include the use of autonomous camera systems for aerial monitoring of a narwhal population, long-term photo-identification studies of western gray whales to better understand site fidelity to their summer feeding grounds, mitigation of gray whales’ behavioral responses to a seismic survey near these feeding grounds and use of Passive Acoustic Monitoring to characterize seismic pulses and drilling activity as well as marine mammal presence in remote arctic areas. A synthesis of the main findings is provided that includes identification of future research needs. Conclusions and specific recommendations are made that will contribute to our ability to assess and mitigate risks of E&P sound to marine mammals.
... The long reaction distance (>11 km), and presumably even longer detection distance, of narwhals agrees with the lack of sightings of narwhals by marine mammal observers onboard seismic vessels conducting industrial-scale exploratory surveys (Lang and Mactavish, 2011;Vanman and Durinck, 2012;Frouin-Mouy et al., 2017). Narwhals are also considered very skittish and hard to approach by many Inuit hunters, and hunting and harpooning them from silently moving kayaks is the preferred hunting method in many areas of Greenland (Heide-Jørgensen, 1994). Based on a propagation model, Schack and Haapaniemi (2017) estimated that belugas, a close relative of narwhals, could potentially detect ship noise (container vessel and icebreaker) up to a distance of 50 km during the ice-covered season and at even longer distances in open water. ...
One of the last pristine marine soundscapes, the Arctic, is exposed to increasing anthropogenic activities due to climate-induced decrease in sea ice coverage. In this study, we combined movement and behavioral data from animal-borne tags in a controlled sound exposure study to describe the reactions of narwhals, Monodon monoceros , to airgun pulses and ship noise. Sixteen narwhals were live captured and instrumented with satellite tags and Acousonde acoustic-behavioral recorders, and 11 of them were exposed to airgun pulses and vessel sounds. The sound exposure levels (SELs) of pulses from a small airgun (3.4 L) used in 2017 and a larger one (17.0 L) used in 2018 were measured using drifting recorders. The experiment was divided into trials with airgun and ship-noise exposure, intertrials with only ship-noise, and pre- and postexposure periods. Both trials and intertrials lasted ∼4 h on average per individual. Depending on the location of the whales, the number of separate exposures ranged between one and eight trials or intertrials. Received pulse SELs dropped below 130 dB re 1 μPa ² s by 2.5 km for the small airgun and 4–9 km for the larger airgun, and background noise levels were reached at distances of ∼3 and 8–10.5 km, respectively, for the small and big airguns. Avoidance reactions of the whales could be detected at distances >5 km in 2017 and >11 km in 2018 when in line of sight of the seismic vessel. Meanwhile, a ∼30% increase in horizontal travel speed could be detected up to 2 h before the seismic vessel was in line of sight. Applying line of sight as the criterion for exposure thus excludes some potential pre-response effects, and our estimates of effects must therefore be considered conservative. The whales reacted by changing their swimming speed and direction at distances between 5 and 24 km depending on topographical surroundings where the exposure occurred. The propensity of the whales to move towards the shore increased with increasing exposure (i.e., shorter distance to vessels) and was highest with the large airgun used in 2018, where the whales moved towards the shore at distances of 10–15 km. No long-term effects of the response study could be detected.
... Until the early 1920s, there was another aggregation of belugas that lived most of the fall, winter and early summer in the fjords of Southwest Greenland. The belugas of Southwest Greenland were driven to extinction by unsustainable hunting (Heide-Jørgensen, 1994). ...
Environmental change and increasing levels of human activity are threats to marine mammals in the Arctic. Identifying marine mammal hotspots and areas of high species richness are essential to help guide management and conservation efforts. Herein, space use based on biotelemetric tracking devices deployed on 13 species (ringed seal Pusa hispida , bearded seal Erignathus barbatus , harbour seal Phoca vitulina , walrus Odobenus rosmarus , harp seal Pagophilus groenlandicus , hooded seal Cystophora cristata , polar bear Ursus maritimus , bowhead whale Balaena mysticetus , narwhal Monodon monoceros , white whale Delphinapterus leucas , blue whale Balaenoptera musculus , fin whale Balaenoptera physalus and humpback whale Megaptera novaeangliae ; total = 585 individuals) in the Greenland and northern Barents Seas between 2005 and 2018 is reported. Getis-Ord G i * hotspots were calculated for each species as well as all species combined, and areas of high species richness were identified for summer/autumn (Jun-Dec), winter/spring (Jan-May) and the entire year. The marginal ice zone (MIZ) of the Greenland Sea and northern Barents Sea, the waters surrounding the Svalbard Archipelago and a few Northeast Greenland coastal sites were identified as key marine mammal hotspots and areas of high species richness in this region. Individual hotspots identified areas important for most of the tagged animals, such as common resting, nursing, moulting and foraging areas. Location hotspots identified areas heavily used by segments of the tagged populations, including denning areas for polar bears and foraging areas. The hotspots identified herein are also important habitats for seabirds and fishes, and thus conservation and management measures targeting these regions would benefit multiple groups of Arctic animals.
... Some populations of the two species were reduced by commercial hunting for oil, meat, and skins and in the case of narwhals, the valuable tusk (Mitchell and Reeves, 1981;Reeves and Heide-Jørgensen, 1994;Heide-Jørgensen, 1994). Belugas in some areas were culled to reduce perceived competition with fisheries (Reeves and Mitchell 1984). ...
The monodontids—narwhals, Monodon monoceros, and belugas, Delphinapterus leucas—are found in much of the Arctic and in some subarctic areas. They are hunted by indigenous subsistence users. In the past, some populations were substantially reduced by commercial hunting and culling; more recently, some populations have declined due to uncontrolled subsistence hunting and environmental degradation. Monodontids are impacted increasingly by human activities in the Arctic including ship and boat traffic, industrial development, icebreaking, seismic surveys, competition with fisheries, and alteration of habitat due to climate change. Since comprehensive reviews in the 1990’s, substantial new information has become available on both species and on changes to their habitat as a result of human activities and climate change. Thus NAMMCO and partners undertook an updated review in 2017. The review recognized 21 extant beluga stocks, 1 extirpated beluga stock, and 12 stocks of narwhals. The available information on each stock regarding population size, depletion level, current and past removals, and
trends in abundance was reviewed to determine status. Concern was expressed where
the lack of information prevented reliable assessment, removals were thought to be un-
sustainable, or the population was deemed at risk of declining even without direct removals by hunting. Beluga stocks of greatest concern are the small stocks in Ungava Bay (possibly extirpated), Cook Inlet (ca 300), St. Lawrence Estuary (ca 900), and Cum-
berland Sound (ca 1,100), and the stocks with uncertainty in Eastern Hudson Bay and the Barents-Kara-Laptev Seas. Narwhal stocks of greatest concern are those in Melville Bay and East Greenland.
... Until the early 1920s, there was another aggregation of belugas that lived most of the fall, winter and early summer in the fjords of Southwest Greenland. The belugas of Southwest Greenland were driven to extinction by unsustainable hunting (Heide-Jørgensen, 1994). ...
This article describes the relationship between sea ice and marine mammals around Greenland, the possible effects of climate change and the importance of subsistence hunting in modern Greenland. We also summarize the biology, conservation status and utilization of the polar bear, walrus, seal and whale species of Greenland.
Though narwhal have survived multiple ice ages, including 2.5 Ma and the last interglacial period with warming temperatures, Arctic climate change during the Anthropocene introduces new challenges. Despite their evolutionary connection to Arctic Pleistocene fossils, narwhal archeocete ancestors from the Pliocene ( Bohaskaia monodontoides ) and Miocene ( Denebola and Odobenocetopsidae) inhabited warm waters. Narwhal Arctic adaptation holds valuable insights into unique traits, including thin skin; extreme diving capacity; and a unique straight, spiraled, and sensory tooth organ system. Inaccessible weather, ice conditions, and darkness limit scientific studies, though Inuit knowledge adds valuable observations of narwhal ecology, biology, and behavior. Existing and future studies in myriad fields of physical, chemical, biological, and genetic science, combined and integrated with remote sensing and imaging technologies, will help elucidate narwhal evolution, biology, and adaptation. When integrated with Qaujimajatuqangit, “the Inuit way of knowing,” these studies help describe interesting biologic expressions of the narwhal.
This study presents and evaluates data on recent commercial exchanges in narwhal (Monodon monoceros) products, particularly tusks, from Greenland. No evidence was found of an export trade in narwhal blubber or skin (mattak), but since the mid-1960, mattak has been sold to the Royal Greenland Trade Department (or more recently Royal Greenland Production) for re-sale within Greenland. Since 1977 the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) ha, required documentation for the international trade in narwhal tusk. The Greenland Home Rule Government assumed responsibility for this documentation beginning in 1985. More than 90% of the tusks exported with CITES permits issued by the Home Rule Government have given Denmark as the declared destination. Of the total tusks re-exported from Denmark with CITES documentation between 1985 and 1992, approximately two-thirds had the United Kingdom as the declared destination. The monetary value of an "average" tusk-bearing narwhal to a Greenlandic hunter in 1990 was estimated as 7632 Dkr (1272 US dollars). This estimate includes the tusk (6 kg), mattak (80 kg) and meat (46 kg) that were sold but makes no allowance for the products consumed by the hunter and his family. The cash value of narwhal products has not diminished in spite of high inflation in Greenland since the late l960s.
Understanding the complex dynamics of environmental change in northern latitudes is particularly critical for arctic avian communities, which are integral components that maintain biological connections between the mid-and northern latitudes. We report on studies done in 2010-2015 in Northwest Greenland as part of a larger effort focused on understanding the population dynamics of High Arctic marine bird communities. We use several data sources and analysis techniques, including diet data, stable isotopes, and Bayesian inference, to identify the potential relationships between ecological response of coastal marine birds and rapid environmental change such as increased freshwater runoff from glacier melt, inshore oceanographic change, and cascading trophic perturbations. Our preliminary results indicate that community wide spatial and temporal dynamics of this high Arctic marine bird community are far greater during our study period than was evident in past decades. We also find that the magnitude of change is greater here in the high Arctic (eg., 78 °N) compared to low Arctic coastal marine ecosystems (eg., western Aleutian Islands, 53 °N). In particular, we show that the ecological patterns observed within such widespread arctic species as Dovekie (Alle alle), Thick-billed Murres (Uria lomvia), and Black-legged Kittiwakes (Rissa tridactyla) indicate diets are strongly perturbed from a decade earlier. Moreover, we find that the variance in environmental and ecological parameters is increasing over relatively small temporal and spatial scales. We hypothesize that these fine-scale changes are related to oceanographic and trophic-level responses to increased freshwater injection into coastal waters, in addition to larger scale perturbations possibly related to a cascade of climate-related factors.
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