The depleted population of belugas ( Delphinapterus leucas ) inhabiting the St Lawrence estuary, Canada, was monitored by periodic photographic aerial surveys. In order to correct counts made on aerial survey film and to obtain an estimate of the true size of the population, the diving behaviour and the visibility from the air of these animals was studied. A Secchi-disk turbidity survey in the belugas’ summer range showed that water clarity varied between 1.5 m and 11.6 m. By studying aerial photographs of sheet-plastic models of belugas that had been sunk to different depths below the surface, we found that models of white adults could be seen down to about the same depth as a Secchi disk, but no deeper. Smaller models of dark-grey juveniles could only be seen down to about 50% of Secchi-disk depth. By observing groups of belugas from a hovering helicopter and recording their disappearances and re-appearances, it was found that they were visible for 44.3% of the time, and that an appropriate correction for single photographs would be to multiply the photographic count by about 222% (SE 20%). For surveys in which there was overlap between adjacent frames, the estimated correction would be 209% (SE 16%). This correction factor was slightly conservative and gave an estimate of the true size of the population, based on a single survey, of 1,202 belugas (SE 189) in 1997. An estimate for 1997 based on smoothing 5 surveys 1988–1997 was 1,238 (SE 119).
{"title":"Visibility of St Lawrence belugas to aerial photography, estimated by direct observation","authors":"M. Kingsley, I. Gauthier","doi":"10.7557/3.2848","DOIUrl":"https://doi.org/10.7557/3.2848","url":null,"abstract":"The depleted population of belugas ( Delphinapterus leucas ) inhabiting the St Lawrence estuary, Canada, was monitored by periodic photographic aerial surveys. In order to correct counts made on aerial survey film and to obtain an estimate of the true size of the population, the diving behaviour and the visibility from the air of these animals was studied. A Secchi-disk turbidity survey in the belugas’ summer range showed that water clarity varied between 1.5 m and 11.6 m. By studying aerial photographs of sheet-plastic models of belugas that had been sunk to different depths below the surface, we found that models of white adults could be seen down to about the same depth as a Secchi disk, but no deeper. Smaller models of dark-grey juveniles could only be seen down to about 50% of Secchi-disk depth. By observing groups of belugas from a hovering helicopter and recording their disappearances and re-appearances, it was found that they were visible for 44.3% of the time, and that an appropriate correction for single photographs would be to multiply the photographic count by about 222% (SE 20%). For surveys in which there was overlap between adjacent frames, the estimated correction would be 209% (SE 16%). This correction factor was slightly conservative and gave an estimate of the true size of the population, based on a single survey, of 1,202 belugas (SE 189) in 1997. An estimate for 1997 based on smoothing 5 surveys 1988–1997 was 1,238 (SE 119).","PeriodicalId":30560,"journal":{"name":"NAMMCO Scientific Publications","volume":"4 1","pages":"259-270"},"PeriodicalIF":0.0,"publicationDate":"2014-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71335501","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Innes, M. Heide-Jørgensen, J. Laake, K. Laidre, H. Cleator, P. Richard, R. Stewart
The summer range of belugas ( Delphinapterus leucas ) and narwhals ( Monodon monoceros ) in Prince Regent Inlet, Barrow Strait and Peel Sound in the Canadian High Arctic was surveyed from 31 July to 3 August 1996 with a visual aerial survey of offshore areas and photographic aerial surveys of concentration areas. The visual survey estimate based on the number of belugas visible to the observers using systematic line transect methods was 10,347 (cv = 0.28). This included corrections for whales that were missed by the observers, observations without distance measurements and an estimate of 1,949 (cv=0.22) belugas from a photographic survey in southern Peel Sound. Using data from belugas tagged with satellite-linked time-depth recorders, the estimate was adjusted for individuals that were diving during the survey which resulted in an estimate of 18,930 belugas (cv = 0.28). Finally, counts of belugas in estuaries, corrected for estuarine surface time, were added to provide a complete estimate of 21,213 belugas (95% CI 10,985 to 32,619). The estimated number of narwhals corrected for sightings that were missed by observers was 16,364 (cv = 0.24). Adjusting this for sightings without distance information and correcting for whales that were submerged produced an estimate of 45,358 narwhals (95% CI 23,397 to 87,932).
1996年7月31日至8月3日，对加拿大北极高纬度摄摄王湾、巴罗海峡和皮尔湾的白鲸和独角鲸的夏季活动范围进行了调查，对近海地区进行了目视空中调查，并对集中地区进行了摄影空中调查。利用系统样线法对观测者可见的白鲸数量的目视调查估计为10,347 (cv = 0.28)。这包括对观测者错过的鲸鱼的修正，没有距离测量的观察，以及在皮尔湾南部的摄影调查中估计的1,949头白鲸(cv=0.22)。使用带有卫星连接时间深度记录器的白鲸数据，对调查期间潜水的个体进行了调整，结果估计有18,930只白鲸(cv = 0.28)。最后，根据河口水面时间进行校正后，河口白鲸的数量增加，从而提供了21,213头白鲸的完整估计(95% CI 10,985至32,619)。据估计，被观测者错过的独角鲸校正后的数量为16,364 (cv = 0.24)。在没有距离信息的情况下进行调整，并对淹没在水下的鲸鱼进行校正，估计有45358头独角鲸(95% CI 23397至87932)。
{"title":"Surveys of belugas and narwhals in the Canadian High Arctic in 1996","authors":"S. Innes, M. Heide-Jørgensen, J. Laake, K. Laidre, H. Cleator, P. Richard, R. Stewart","doi":"10.7557/3.2843","DOIUrl":"https://doi.org/10.7557/3.2843","url":null,"abstract":"The summer range of belugas ( Delphinapterus leucas ) and narwhals ( Monodon monoceros ) in Prince Regent Inlet, Barrow Strait and Peel Sound in the Canadian High Arctic was surveyed from 31 July to 3 August 1996 with a visual aerial survey of offshore areas and photographic aerial surveys of concentration areas. The visual survey estimate based on the number of belugas visible to the observers using systematic line transect methods was 10,347 (cv = 0.28). This included corrections for whales that were missed by the observers, observations without distance measurements and an estimate of 1,949 (cv=0.22) belugas from a photographic survey in southern Peel Sound. Using data from belugas tagged with satellite-linked time-depth recorders, the estimate was adjusted for individuals that were diving during the survey which resulted in an estimate of 18,930 belugas (cv = 0.28). Finally, counts of belugas in estuaries, corrected for estuarine surface time, were added to provide a complete estimate of 21,213 belugas (95% CI 10,985 to 32,619). The estimated number of narwhals corrected for sightings that were missed by observers was 16,364 (cv = 0.24). Adjusting this for sightings without distance information and correcting for whales that were submerged produced an estimate of 45,358 narwhals (95% CI 23,397 to 87,932).","PeriodicalId":30560,"journal":{"name":"NAMMCO Scientific Publications","volume":"16 1","pages":"169-190"},"PeriodicalIF":0.0,"publicationDate":"2014-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71335290","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper reviews published information on the white whale or beluga ( Delphinapterus leucas ) inhabiting the Barents, Kara and Laptev seas. Some data obtained during multi-year aerial reconnaissance of sea ice in the Russian Arctic are also included. Ice conditions, considered one of the major factors affecting distribution of belugas, are described. The number of belugas inhabiting the Russian Arctic is unknown. Based on analysis of published and unpublished information we believe that the primary summer habitats of belugas in the Western Russian Arctic lie in the area of Frants-Josef Land, in the Kara Sea and in the western Laptev Sea. Apparently most belugas winter in the Barents Sea. Although it has been suggested that a considerable number of animals winter in the Kara Sea, there is no direct evidence for this. Apparent migrations of animals are regularly observed at several sites: the straits of the Novaya Zemlya Archipelago, the waters north of the archipelago, and Vilkitskiy Strait between the Kara and Laptev seas. Calving and mating take place in summer, and the beluga mother feeds a calf for at least a year. Females mature earlier than males, and about 30% of mature females in a population are barren. Sex ratio is apparently close to 1:1. The diet of the beluga in the region includes fish and crustaceans and shows considerable spatial and temporal variations. However, polar cod ( Boreogadus saida ) is the main prey most of the year, and whitefish ( Coregonidae ) contribute in coastal waters in summer. Usually belugas form groups of up to 10 related individuals of different ages, while large aggregations are common during seasonal migrations or in areas with abundant and easily available food. Beluga whaling in Russia has a history of several centuries. The highest catches were taken in the 1950s and 1960s, when about 1,500 animals were caught annually in the Western Russian Arctic. In the 1990s, few belugas were harvested in the Russian Arctic. In 1999 commercial whaling of belugas in Russia was banned. Belugas can be caught only for research, cultural and educational purposes and for the subsistence needs of local people. With the absence of significant whaling, anthropogenic pollution seems to be the major threat for the species.
{"title":"Belugas ( Delphinapterus leucas ) of the Barents, Kara and Laptev seas","authors":"A. Boltunov, S. Belikov","doi":"10.7557/3.2842","DOIUrl":"https://doi.org/10.7557/3.2842","url":null,"abstract":"This paper reviews published information on the white whale or beluga ( Delphinapterus leucas ) inhabiting the Barents, Kara and Laptev seas. Some data obtained during multi-year aerial reconnaissance of sea ice in the Russian Arctic are also included. Ice conditions, considered one of the major factors affecting distribution of belugas, are described. The number of belugas inhabiting the Russian Arctic is unknown. Based on analysis of published and unpublished information we believe that the primary summer habitats of belugas in the Western Russian Arctic lie in the area of Frants-Josef Land, in the Kara Sea and in the western Laptev Sea. Apparently most belugas winter in the Barents Sea. Although it has been suggested that a considerable number of animals winter in the Kara Sea, there is no direct evidence for this. Apparent migrations of animals are regularly observed at several sites: the straits of the Novaya Zemlya Archipelago, the waters north of the archipelago, and Vilkitskiy Strait between the Kara and Laptev seas. Calving and mating take place in summer, and the beluga mother feeds a calf for at least a year. Females mature earlier than males, and about 30% of mature females in a population are barren. Sex ratio is apparently close to 1:1. The diet of the beluga in the region includes fish and crustaceans and shows considerable spatial and temporal variations. However, polar cod ( Boreogadus saida ) is the main prey most of the year, and whitefish ( Coregonidae ) contribute in coastal waters in summer. Usually belugas form groups of up to 10 related individuals of different ages, while large aggregations are common during seasonal migrations or in areas with abundant and easily available food. Beluga whaling in Russia has a history of several centuries. The highest catches were taken in the 1950s and 1960s, when about 1,500 animals were caught annually in the Western Russian Arctic. In the 1990s, few belugas were harvested in the Russian Arctic. In 1999 commercial whaling of belugas in Russia was banned. Belugas can be caught only for research, cultural and educational purposes and for the subsistence needs of local people. With the absence of significant whaling, anthropogenic pollution seems to be the major threat for the species.","PeriodicalId":30560,"journal":{"name":"NAMMCO Scientific Publications","volume":"4 1","pages":"149-168"},"PeriodicalIF":0.0,"publicationDate":"2014-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71335281","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We conducted >236,000 km of aerial surveys and some supplementary studies of belugas ( Delphinapterus leucas ) in the central and eastern Canadian High Arctic in 974-79. Belugas that wintered in the “North Water” in Baffin Bay moved southwest into Lancaster Sound in April and early May. The main westward migration into Lancaster Sound occurred over a 2 to 3 week period during late June to late July. Estuaries along Somerset Island were occupied for <3 weeks from mid-July to mid-August. Little feeding occurred in estuaries. From mid-August until fall migration began in mid-September belugas occupied estuaries and offshore waters in Peel Sound. Fall migration eastward through Lancaster Sound was exclusively along the south coast of Devon Island, highly co-ordinated, and rapid; most of the population passed through the sound in <1 week. The whales then moved north along the east coast of Devon Island; some entered Jones Sound while others crossed directly to SE Ellesmere Island. Most calving occurred in July and early August; calving was not seen in estuaries and probably occurred offshore. Excluding calves, adults and yearlings formed 77% and 8.4%, respectively, of the population. The proportion of calves during mid-August was consistent with a triennial calving cycle. During late summer, belugas fed on coastal concentrations of polar cod ( Boreogadus saida ), under pan ice offshore (probably on cod), and in deep offshore waters. The size of the Canadian High Arctic population in the late 1970s was estimated to be at least 10,250 to 12,000 animals without allowing for animals that may have passed between surveys or that were below the surface at the time of the counts.
{"title":"Distribution and abundance of Canadian High Arctic belugas, 1974-1979","authors":"W. Koski, K. Finley","doi":"10.7557/3.2839","DOIUrl":"https://doi.org/10.7557/3.2839","url":null,"abstract":"We conducted >236,000 km of aerial surveys and some supplementary studies of belugas ( Delphinapterus leucas ) in the central and eastern Canadian High Arctic in 974-79. Belugas that wintered in the “North Water” in Baffin Bay moved southwest into Lancaster Sound in April and early May. The main westward migration into Lancaster Sound occurred over a 2 to 3 week period during late June to late July. Estuaries along Somerset Island were occupied for <3 weeks from mid-July to mid-August. Little feeding occurred in estuaries. From mid-August until fall migration began in mid-September belugas occupied estuaries and offshore waters in Peel Sound. Fall migration eastward through Lancaster Sound was exclusively along the south coast of Devon Island, highly co-ordinated, and rapid; most of the population passed through the sound in <1 week. The whales then moved north along the east coast of Devon Island; some entered Jones Sound while others crossed directly to SE Ellesmere Island. Most calving occurred in July and early August; calving was not seen in estuaries and probably occurred offshore. Excluding calves, adults and yearlings formed 77% and 8.4%, respectively, of the population. The proportion of calves during mid-August was consistent with a triennial calving cycle. During late summer, belugas fed on coastal concentrations of polar cod ( Boreogadus saida ), under pan ice offshore (probably on cod), and in deep offshore waters. The size of the Canadian High Arctic population in the late 1970s was estimated to be at least 10,250 to 12,000 animals without allowing for animals that may have passed between surveys or that were below the surface at the time of the counts.","PeriodicalId":30560,"journal":{"name":"NAMMCO Scientific Publications","volume":"4 1","pages":"87-126"},"PeriodicalIF":0.0,"publicationDate":"2014-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71335223","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Innes, D. Muir, R. Stewart, M. Heide‐Jørgensen, R. Dietz
Belugas ( Delphinapterus leucas ) caught by hunters from various hamlets in the Arctic differed in the concentrations of organochlorine contaminants in their blubber. By applying Canonical Discriminant Analysis (CDA) it was possible to separate all seven sampling locations from each other. Over 90% of the samples could be classified back to their landing location based on the data transformations developed by CDA. This analysis suggested that “stock” or management unit for belugas is best described by the culturally transmitted behaviour of their migration route. The analysis also provides evidence that most belugas caught by hunters from Grise Fiord are not the same as belugas caught while migrating along West Greenland; that some belugas caught in Sanikiluaq are not the same as beluga caught in the Nastapoka River estuary; and that the belugas caught in Kimmirut are not the same as belugas caught in Cumberland Sound. There is a need to redefine the stock descriptions of some belugas in Canada and Greenland.
{"title":"Stock identity of beluga ( Delphinapterus leucas ) in Eastern Canada and West Greenland based on organochlorine contaminants in their blubber","authors":"S. Innes, D. Muir, R. Stewart, M. Heide‐Jørgensen, R. Dietz","doi":"10.7557/3.2837","DOIUrl":"https://doi.org/10.7557/3.2837","url":null,"abstract":"Belugas ( Delphinapterus leucas ) caught by hunters from various hamlets in the Arctic differed in the concentrations of organochlorine contaminants in their blubber. By applying Canonical Discriminant Analysis (CDA) it was possible to separate all seven sampling locations from each other. Over 90% of the samples could be classified back to their landing location based on the data transformations developed by CDA. This analysis suggested that “stock” or management unit for belugas is best described by the culturally transmitted behaviour of their migration route. The analysis also provides evidence that most belugas caught by hunters from Grise Fiord are not the same as belugas caught while migrating along West Greenland; that some belugas caught in Sanikiluaq are not the same as beluga caught in the Nastapoka River estuary; and that the belugas caught in Kimmirut are not the same as belugas caught in Cumberland Sound. There is a need to redefine the stock descriptions of some belugas in Canada and Greenland.","PeriodicalId":30560,"journal":{"name":"NAMMCO Scientific Publications","volume":"4 1","pages":"51-68"},"PeriodicalIF":0.0,"publicationDate":"2014-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71335178","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Information and statistics including trade statistics on catches of white whales or belugas ( Delphinapterus leucas ) in West Greenland since 1862 are presented. The period before 1952 was dominated by large catches south of 66o N that peaked with 1,380 reported kills in 1922. Catch levels in the past five decades are evaluated on the basis of official catch statistics, trade in mattak (whale skin), sampling of jaws and reports from local residents and other observers. Options are given for corrections of catch statistics based upon auxiliary statistics on trade of mattak, catches in previous decades for areas without reporting and on likely levels of loss rates in different hunting operations. The fractions of the reported catches that are caused by ice entrapments of whales are estimated. During 1954-1999 total reported catches ranged from 216 to 1,874 and they peaked around 1970. Correcting for underreporting and killed-but-lost whales increases the catch reports by 42% on average for 1954-1998. If the whales killed in ice entrapments are removed then the corrected catch estimate is on average 28% larger than the reported catches.
{"title":"Catch statistics for belugas in West Greenland 1862 to 1999","authors":"M. Heide‐Jørgensen, A. Rosing-Asvid","doi":"10.7557/3.2840","DOIUrl":"https://doi.org/10.7557/3.2840","url":null,"abstract":"Information and statistics including trade statistics on catches of white whales or belugas ( Delphinapterus leucas ) in West Greenland since 1862 are presented. The period before 1952 was dominated by large catches south of 66o N that peaked with 1,380 reported kills in 1922. Catch levels in the past five decades are evaluated on the basis of official catch statistics, trade in mattak (whale skin), sampling of jaws and reports from local residents and other observers. Options are given for corrections of catch statistics based upon auxiliary statistics on trade of mattak, catches in previous decades for areas without reporting and on likely levels of loss rates in different hunting operations. The fractions of the reported catches that are caused by ice entrapments of whales are estimated. During 1954-1999 total reported catches ranged from 216 to 1,874 and they peaked around 1970. Correcting for underreporting and killed-but-lost whales increases the catch reports by 42% on average for 1954-1998. If the whales killed in ice entrapments are removed then the corrected catch estimate is on average 28% larger than the reported catches.","PeriodicalId":30560,"journal":{"name":"NAMMCO Scientific Publications","volume":"4 1","pages":"127-142"},"PeriodicalIF":0.0,"publicationDate":"2014-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71335238","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Heide-Jørgensen, P. Richard, M. Ramsay, S. Akeeagok
Three ice entrapments of Monodontids have been reported in the western North Atlantic since 1993. Hunters in Disko Bay, West Greenland, discovered one in March 1994 that included about 150 narwhals ( Monodon monoceros ). The entrapment occurred during a sudden cold period which caused ice to form rapidly. The trapped whales were subject to hunting, but about 50 of the killed whales could not be retrieved in the ice. The whales were trapped in a small opening in the ice and because of that they would probably have succumbed even if not discovered by hunters. Two entrapments involving white whales or belugas ( Delphinapterus leucas ) occurred in the eastern Canadian Arctic in May 1999; one in Lancaster Sound discovered by polar bear ( Ursus maritimus ) researchers and one in Jones Sound discovered by hunters. The first included one bowhead whale ( Balaena mysticetus ) and about 40 belugas that were being preyed upon by polar bears. The second involved at least 170 belugas, of which about 100 were killed by polar bears and 17 were taken by hunters. The entrapments in Disko Bay and Jones Sound both occurred in areas where entrapments have previously been reported, whereas the one in Lancaster Sound was in a new area.
{"title":"Three recent ice entrapments of Arctic cetaceans in West Greenland and the eastern Canadian High Arctic","authors":"M. Heide-Jørgensen, P. Richard, M. Ramsay, S. Akeeagok","doi":"10.7557/3.2841","DOIUrl":"https://doi.org/10.7557/3.2841","url":null,"abstract":"Three ice entrapments of Monodontids have been reported in the western North Atlantic since 1993. Hunters in Disko Bay, West Greenland, discovered one in March 1994 that included about 150 narwhals ( Monodon monoceros ). The entrapment occurred during a sudden cold period which caused ice to form rapidly. The trapped whales were subject to hunting, but about 50 of the killed whales could not be retrieved in the ice. The whales were trapped in a small opening in the ice and because of that they would probably have succumbed even if not discovered by hunters. Two entrapments involving white whales or belugas ( Delphinapterus leucas ) occurred in the eastern Canadian Arctic in May 1999; one in Lancaster Sound discovered by polar bear ( Ursus maritimus ) researchers and one in Jones Sound discovered by hunters. The first included one bowhead whale ( Balaena mysticetus ) and about 40 belugas that were being preyed upon by polar bears. The second involved at least 170 belugas, of which about 100 were killed by polar bears and 17 were taken by hunters. The entrapments in Disko Bay and Jones Sound both occurred in areas where entrapments have previously been reported, whereas the one in Lancaster Sound was in a new area.","PeriodicalId":30560,"journal":{"name":"NAMMCO Scientific Publications","volume":"4 1","pages":"143-148"},"PeriodicalIF":0.0,"publicationDate":"2014-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71335273","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper is based on 748 observations of belugas ( Delphinapterus leucas ) and 382 observations of baleen whales in the Russian Arctic, the majority of the data provided by aerial reconnaissance of sea ice (ARSI). Although the data are not suitable for the estimation of the number and density of the animals, they represent a multi-year (1958-1995) range of observations to update our knowledge on the seasonal distribution and migrations of the species. Belugas inhabit not only shelf waters but also the zone of the shelf slope and the abyssal zone of the Arctic Ocean, where the animals appear mostly in summer. In winter belugas were observed only in the Barents Sea. In June-August, the frequency of beluga observations was highest in the Laptev Sea, which has previously been believed to have considerably lower numbers of beluga than the Kara and Barents seas. Patterns of seasonal distribution and ice cover suggest the existence of a natural border preventing or reducing population exchange between belugas inhabiting the western and eastern parts of the Russian Arctic. A brief review of available data on distribution of the narwhal ( Monodon monoceros ) in the Russian Arctic is also given. Two species of baleen whales were frequently seen in the Russian Arctic: the bowhead whale ( Balaena mysticetus ), and the grey whale ( Eschrichtius robustus ). The majority of such observations were made in the southeastern part of the East-Siberian Sea and the southern part of the Chukchi Sea. In the Bering Sea baleen whales were usually seen near the Chukotka Peninsula, in Anadyr Bay and southeast of it. Whales were usually seen in ice-free water: observations of whales among rarefied ice and near the ice edge were rare. There were considerable annual and seasonal variations in distribution and migrations of baleen whales in the region, probably caused mainly by the dynamics of ice conditions.
{"title":"Distribution and migrations of cetaceans in the Russian Arctic according to observations from aerial ice reconnaissance","authors":"S. Belikov, A. Boltunov","doi":"10.7557/3.2838","DOIUrl":"https://doi.org/10.7557/3.2838","url":null,"abstract":"This paper is based on 748 observations of belugas ( Delphinapterus leucas ) and 382 observations of baleen whales in the Russian Arctic, the majority of the data provided by aerial reconnaissance of sea ice (ARSI). Although the data are not suitable for the estimation of the number and density of the animals, they represent a multi-year (1958-1995) range of observations to update our knowledge on the seasonal distribution and migrations of the species. Belugas inhabit not only shelf waters but also the zone of the shelf slope and the abyssal zone of the Arctic Ocean, where the animals appear mostly in summer. In winter belugas were observed only in the Barents Sea. In June-August, the frequency of beluga observations was highest in the Laptev Sea, which has previously been believed to have considerably lower numbers of beluga than the Kara and Barents seas. Patterns of seasonal distribution and ice cover suggest the existence of a natural border preventing or reducing population exchange between belugas inhabiting the western and eastern parts of the Russian Arctic. A brief review of available data on distribution of the narwhal ( Monodon monoceros ) in the Russian Arctic is also given. Two species of baleen whales were frequently seen in the Russian Arctic: the bowhead whale ( Balaena mysticetus ), and the grey whale ( Eschrichtius robustus ). The majority of such observations were made in the southeastern part of the East-Siberian Sea and the southern part of the Chukchi Sea. In the Bering Sea baleen whales were usually seen near the Chukotka Peninsula, in Anadyr Bay and southeast of it. Whales were usually seen in ice-free water: observations of whales among rarefied ice and near the ice edge were rare. There were considerable annual and seasonal variations in distribution and migrations of baleen whales in the region, probably caused mainly by the dynamics of ice conditions.","PeriodicalId":30560,"journal":{"name":"NAMMCO Scientific Publications","volume":"62 1","pages":"69-86"},"PeriodicalIF":0.0,"publicationDate":"2014-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71335185","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sixty-two verified reports obtained in the years 1990-1999 on the bycatch, strandings and sightings of harbour porpoises in the Polish Baltic were analysed in this study. In relative terms the highest number of reports (22) was noted in Puck Bay. Forty-five (72.6%) reports referred to specimens from bycatch, 10 (16.1%) were individuals observed at sea, and 7 (11.3%) were stranded. A large proportion (42.2%) of the bycatch occurred in the fishing grounds of Puck Bay. Forty carcasses of harbour porpoises were obtained for further analysis. Most of the bycatch took place from December to April with a maximum in March. In the rest of the year there were 1 to 3 bycaught animals reported per month with no cases of bycatch in June. Taking into account data on fishing effort collected for the study area it appears that by far the greatest threat to harbour porpoises is posed by nets used for salmonids. Among all the bycaught animals, most (40.0%) perished in salmon semi-drift nets. A considerable number of the harbour porpoises perished in bottom set nets for cod (33.3%) while only a single bycatch event was reported from herring trawl nets. To assess the danger from different fishing gear and to determine the areas where the threats are the highest, direct observation of the fisheries was conducted. In the course of boat inspections various types of fishing gear were identified and geographical positions of 1,069 nets were marked. The majority (92%) consisted of semi-drift nets for sea trout and salmon. Relatively low rates of bycatch were reported from bottom set nets, which had a density over 20 times less than that of surface salmon nets in the area in the autumn months. The density and distribution of both types of nets in the surveyed area was comparable during autumn and winter, when the majority of bycaught animals in bottom set nets were reported.
{"title":"Bycatch as a potential threat to harbour porpoises ( Phocoena phocoena ) in Polish Baltic waters","authors":"K. Skóra, I. Kuklik","doi":"10.7557/3.2831","DOIUrl":"https://doi.org/10.7557/3.2831","url":null,"abstract":"Sixty-two verified reports obtained in the years 1990-1999 on the bycatch, strandings and sightings of harbour porpoises in the Polish Baltic were analysed in this study. In relative terms the highest number of reports (22) was noted in Puck Bay. Forty-five (72.6%) reports referred to specimens from bycatch, 10 (16.1%) were individuals observed at sea, and 7 (11.3%) were stranded. A large proportion (42.2%) of the bycatch occurred in the fishing grounds of Puck Bay. Forty carcasses of harbour porpoises were obtained for further analysis. Most of the bycatch took place from December to April with a maximum in March. In the rest of the year there were 1 to 3 bycaught animals reported per month with no cases of bycatch in June. Taking into account data on fishing effort collected for the study area it appears that by far the greatest threat to harbour porpoises is posed by nets used for salmonids. Among all the bycaught animals, most (40.0%) perished in salmon semi-drift nets. A considerable number of the harbour porpoises perished in bottom set nets for cod (33.3%) while only a single bycatch event was reported from herring trawl nets. To assess the danger from different fishing gear and to determine the areas where the threats are the highest, direct observation of the fisheries was conducted. In the course of boat inspections various types of fishing gear were identified and geographical positions of 1,069 nets were marked. The majority (92%) consisted of semi-drift nets for sea trout and salmon. Relatively low rates of bycatch were reported from bottom set nets, which had a density over 20 times less than that of surface salmon nets in the area in the autumn months. The density and distribution of both types of nets in the surveyed area was comparable during autumn and winter, when the majority of bycaught animals in bottom set nets were reported.","PeriodicalId":30560,"journal":{"name":"NAMMCO Scientific Publications","volume":"5 1","pages":"303-315"},"PeriodicalIF":0.0,"publicationDate":"2014-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71335053","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Our current knowledge of the molecular genetics of High Arctic beluga ( Delphinapterus leucas ) populations (West Greenland, Lancaster Sound/Barrow Strait, Grise Fiord) and populations that are related (southeast Baffin, Beaufort Sea), is presented. In general, genetic analyses confirm the designation of putative stocks and suggest the existence of more stocks than previously described. Comparisons based on mitochondrial DNA haplotypes show that West Greenland (1992) belugas were significantly differentiated from Lancaster Sound/Barrow Strait, Kimmirut, Iqaluit, and/or Pangnirtung but not from Grise Fiord. Grise Fiord haplotypes were not significantly differentiated from Lancaster Sound/Barrow Strait and not from southeast Baffin locations in some years. Lancaster Sound and southeast Baffin collections were not significantly differentiated from each other. These patterns existed for most years within locations, however a few yearly collections within major locations had different patterns. The collections that differed were small groups with few haplotypes, most likely relatives. Patterns in microsatellite differentiation were slightly different than those for haplotypes. This may be due to the fact that individuals in sampled summering populations breed with individuals in other populations during migration or in overwintering areas. West Greenland and Grise Fiord microsatellites were not significantly differentiated from each other. However, Greenland differed from Lancaster Sound and southeast Baffin Island, while Grise Fiord did not. In southeast Baffin Island, Pangnirtung samples differed from Kimmirut using both haplotypes and microsatellites. Iqaluit samples had intermediate genetic characteristics between Pangnirtung and Kimmirut. Patterns of significant differentiation among collections within locations was believed to be due to a combination of temporal patterns, sampling of relatives, chance, seasonal hunting, small sample sizes, and actual differences among populations.
{"title":"An overview of genetic relationships of Canadian and adjacent populations of belugas ( Delphinapterus leucas ) with emphasis on Baffin Bay and Canadian eastern Arctic populations","authors":"B. D. March, L. Maiers, M. K. Friesen","doi":"10.7557/3.2835","DOIUrl":"https://doi.org/10.7557/3.2835","url":null,"abstract":"Our current knowledge of the molecular genetics of High Arctic beluga ( Delphinapterus leucas ) populations (West Greenland, Lancaster Sound/Barrow Strait, Grise Fiord) and populations that are related (southeast Baffin, Beaufort Sea), is presented. In general, genetic analyses confirm the designation of putative stocks and suggest the existence of more stocks than previously described. Comparisons based on mitochondrial DNA haplotypes show that West Greenland (1992) belugas were significantly differentiated from Lancaster Sound/Barrow Strait, Kimmirut, Iqaluit, and/or Pangnirtung but not from Grise Fiord. Grise Fiord haplotypes were not significantly differentiated from Lancaster Sound/Barrow Strait and not from southeast Baffin locations in some years. Lancaster Sound and southeast Baffin collections were not significantly differentiated from each other. These patterns existed for most years within locations, however a few yearly collections within major locations had different patterns. The collections that differed were small groups with few haplotypes, most likely relatives. Patterns in microsatellite differentiation were slightly different than those for haplotypes. This may be due to the fact that individuals in sampled summering populations breed with individuals in other populations during migration or in overwintering areas. West Greenland and Grise Fiord microsatellites were not significantly differentiated from each other. However, Greenland differed from Lancaster Sound and southeast Baffin Island, while Grise Fiord did not. In southeast Baffin Island, Pangnirtung samples differed from Kimmirut using both haplotypes and microsatellites. Iqaluit samples had intermediate genetic characteristics between Pangnirtung and Kimmirut. Patterns of significant differentiation among collections within locations was believed to be due to a combination of temporal patterns, sampling of relatives, chance, seasonal hunting, small sample sizes, and actual differences among populations.","PeriodicalId":30560,"journal":{"name":"NAMMCO Scientific Publications","volume":"4 1","pages":"17-38"},"PeriodicalIF":0.0,"publicationDate":"2014-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71335114","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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