scholarly journals Aerial Survey Estimates of Abundance of the Eastern Chukchi Sea Stock of Beluga Whales (Delphinapterus leucas) in 2012

ARCTIC ◽  
2017 ◽  
Vol 70 (3) ◽  
pp. 273 ◽  
Author(s):  
Lloyd F. Lowry ◽  
Michael C.S. Kingsley ◽  
Donna D.W. Hauser ◽  
Janet Clarke ◽  
Robert Suydam
Keyword(s):  
Alaska Native ◽  
Marine Mammals ◽  
Chukchi Sea ◽  
Aerial Survey ◽  
Delphinapterus Leucas ◽  
Line Transect ◽  
Beluga Whales ◽  
Abundance Estimate ◽  
Time Period ◽  
Survey Estimates

The eastern Chukchi Sea (ECS) stock of beluga whales is one of three stocks in western Alaska that are co-managed by the National Marine Fisheries Service and the Alaska Beluga Whale Committee. Abundance of this stock was estimated as 3710 in 1991 from incomplete data. Analysis of data from satellite-linked time-depth recorders (SDRs) attached to belugas in summer concentration areas of the ECS and Beaufort Sea (BS) stocks provided an overview of beluga distribution and movements and allowed the identification of an area (140˚ W to 157˚ W in the BS) and a time period (19 July – 20 August) in which the distributions of the two stocks do not overlap. Aerial survey data were collected by the Aerial Surveys of Arctic Marine Mammals (ASAMM) project in that region and time period in 2012. We used those data in a line transect analysis that estimated there were 5547 (CV = 0.22) surface-visible belugas in the study area. Data from SDRs were used to develop correction factors to account for animals that were missed because they were either outside of the study area or diving too deep to be seen, resulting in a total abundance estimate of 20 752 (CV = 0.70). The average annual Alaska Native subsistence harvest from the ECS stock (57) is about 0.3% of the population estimate. Without data collected by the ASAMM project and from satellite-linked tags, this analysis would not have been possible. Additional surveys and tagging of ECS belugas are warranted.

scholarly journals Spatio-temporal summer distribution of Cumberland Sound beluga whales (Delphinapterus leucas) in Clearwater Fiord

2021 ◽  
Author(s):  
Karyn Booy ◽  
Xavier Mouy ◽  
Steven H. Ferguson ◽  
Marianne Marcoux
Keyword(s):  
Aerial Survey ◽  
Biological Information ◽  
Delphinapterus Leucas ◽  
Diel Variation ◽  
Beluga Whales ◽  
Cumberland Sound ◽  
Spatio Temporal ◽  
Summer Distribution ◽  
Beluga Whale Delphinapterus Leucas ◽  
Passive Acoustic

The Cumberland Sound (Nunavut, Canada) beluga whale (Delphinapterus leucas) population has been designated as threatened and updated biological information about summer distribution is required for a sound recovery plan. Variation in aerial survey counts are speculated to occur due to movement of belugas in and out of the fiord, and there is still uncertainty related to their distribution within key summer habitat. To address these knowledge gaps, non-invasive passive acoustic monitoring (PAM) systems were deployed in August of 2010 and 2011. An automated detector was used to determine presence/absence and quantify calls by recorder site. Results were verified by partial manual analysis of 20% of the files. The detector had a minimum accuracy of 85% for presence/absence and 42% for call quantification. Belugas were detected primarily at the uppermost site of Clearwater Fiord, with detections subsiding with increasing proximity to the fiord entrance. Diel variation in call patterns were quantified at two separate sites in different years, but no correlation was observed between tidal cycles and number of detections. This study indicates that Cumberland Sound beluga may prefer sites at the head of Clearwater Fiord. Further research is required to identify which environmental variables contribute to this observed summer distribution.

scholarly journals First abundance estimate for white whales Delphinapterus leucas in Svalbard, Norway

2020 ◽  
Vol 41 ◽  
pp. 253-263
Author(s):  
J Vacquié-Garcia ◽  
C Lydersen ◽  
TA Marques ◽  
M Andersen ◽  
KM Kovacs
Keyword(s):  
Environmental Changes ◽  
Distance Sampling ◽  
Aerial Survey ◽  
Open Ocean ◽  
The Arctic ◽  
Delphinapterus Leucas ◽  
Svalbard Archipelago ◽  
Stock Size ◽  
Small Areas ◽  
Abundance Estimate

The Svalbard Archipelago (Norway) is experiencing rapid declines in the seasonal duration and extent of sea-ice cover, and local tidewater glaciers are melting. These environmental changes represent a threat to ice-associated species in the region, including white whales Delphinapterus leucas. However, no estimates of stock size or trends are available for this stock. An aerial survey was conducted during the summer of 2018, covering the coastlines of all major islands in Svalbard, as well fjords and open ocean areas. A total count was attempted for the coastlines, while coverage of the fjords and open ocean areas was designed as distance-sampling line transects. In total, 265 white whales were detected in 22 groups along the 4965 km of coastline coverage. No whales were observed on fjord (1481 km) or open ocean transects (535 km). After correcting for surface availability using behavioural data from the same area (in summer) and making adjustments for small areas not flown during the survey, the stock size was estimated to be 549 individuals (95% CI: 436%%CONV_ERR%%723). This estimate is surprisingly low given that this species is one of the most frequently observed cetaceans in the area, but it confirms suspicions based on difficulties in finding animals when operating white whale tagging programmes over the past decade. This first population estimate is important in the context of the rapid environmental change taking place in the Arctic and for providing a baseline for comparison with future estimates.

scholarly journals Alaska Beluga Whale Committee—a unique model of co-management

2021 ◽  
Vol 40 ◽  
Author(s):  
Kathryn J. Frost ◽  
Tom Gray ◽  
Willie Goodwin, Sr. ◽  
Roswell Schaeffer ◽  
Robert Suydam
Keyword(s):  
Local Governments ◽  
Cost Effective ◽  
Aerial Survey ◽  
Beluga Whale ◽  
Delphinapterus Leucas ◽  
Funding Agency ◽  
Federal State ◽  
Bristol Bay ◽  
Subsistence Hunting ◽  
Beluga Whales

The Alaska Beluga Whale Committe (ABWC) was formed in 1988 to conserve beluga whales (Delphinapterus leucas) and manage beluga subsistence hunting in western and northern Alaska in cooperation with the National Marine Fisheries Service (NMFS). When the ABWC was formed, there was no consistently funded research or management programme for belugas in Alaska, and co-management was a new concept. The ABWC brought together representatives from beluga hunting communities; federal, state, tribal and local governments; and beluga researchers to develop and implement a programme to manage belugas. With funding from NMFS and others, the ABWC has collected data necessary for informed management decisions including the following: harvest data; aerial surveys of belugas in Bristol Bay and the eastern Bering and Chukchi seas; beluga tracking studies, including training hunters to attach transmitters; a pioneering genetics study of beluga stock identity that has facilitated collection of >2000 beluga skin samples; and a genetics-based mark–recapture study to estimate beluga abundance in Bristol Bay and validate aerial survey estimates. The ABWC is currently engaged in regional management planning in Kotzebue Sound and the eastern Bering Sea. It produces results that are scientifically valid, locally accepted and cost-effective and is an example of what can be achieved when Native hunters, scientists and managing agencies respect and listen to one another and work together. However, the current NMFS co-management funding process has fundamentally altered the relationship between NMFS and ABWC, with NMFS now acting more like a funding agency than a partner.

scholarly journals Mapping Arctic cetaceans from space: A case study for beluga and narwhal

PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0254380
Author(s):  
Bertrand Charry ◽  
Emily Tissier ◽  
John Iacozza ◽  
Marianne Marcoux ◽  
Cortney A. Watt
Keyword(s):  
Satellite Imagery ◽  
Marine Mammals ◽  
New Technologies ◽  
Open Water ◽  
Delphinapterus Leucas ◽  
Baffin Island ◽  
Beluga Whales ◽  
The North ◽  
Maximum Resolution

Emergence of new technologies in remote sensing give scientists a new way to detect and monitor wildlife populations. In this study we assess the ability to detect and classify two emblematic Arctic cetaceans, the narwhal (Monodon monoceros) and beluga whale (Delphinapterus leucas), using very high-resolution (VHR) satellite imagery. We analyzed 12 VHR images acquired in August 2017 and 2019, collected by the WorldView-3 satellite, which has a maximum resolution of 0.31 m per pixel. The images covered Clearwater Fiord (138.8 km2), an area on eastern Baffin Island, Canada where belugas spend a large part of the summer, and Tremblay Sound (127.0 km2), a narrow water body located on the north shore of Baffin Island that is used by narwhals during the open water season. A total of 292 beluga whales and 109 narwhals were detected in the images. This study contributes to our understanding of Arctic cetacean distribution and highlights the capabilities of using satellite imagery to detect marine mammals.

scholarly journals Surveys of belugas and narwhals in the Canadian High Arctic in 1996

2002 ◽  
Vol 4 ◽  
pp. 169 ◽  
Author(s):  
Stuart Innes ◽  
MP Heide-Jørgensen ◽  
Jeff L Laake ◽  
Kristin L Laidre ◽  
Holly J Cleator ◽  
...  
Keyword(s):  
High Arctic ◽  
Aerial Survey ◽  
Delphinapterus Leucas ◽  
Line Transect ◽  
Canadian High Arctic ◽  
Distance Measurements ◽  
Distance Information ◽  
Surface Time ◽  
Summer Range ◽  
Using Data

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).

scholarly journals Abundance of the Eastern Chukchi Sea Stock of Beluga Whales, 2012 – 17

ARCTIC ◽  
2020 ◽  
Vol 73 (4) ◽  
pp. 485-498
Author(s):  
Geof H. Givens ◽  
Megan C. Ferguson ◽  
Janet T. Clarke ◽  
Amy Willoughby ◽  
Amelia Brower ◽  
...  
Keyword(s):  
Large Scale ◽  
Prey Availability ◽  
Chukchi Sea ◽  
Small Scale ◽  
Line Transect ◽  
Study Region ◽  
Subsistence Hunting ◽  
Beluga Whales ◽  
Diverse Data ◽  
The Impact

  Aerial line transect surveys were conducted during 19 July – 20 August in each of the years 2012 – 17, with onshore – offshore transects covering a study area of approximately 110 000 km2, from 140˚ W to 157˚ W longitude and from shore to 72˚ N latitude. These data were used to estimate abundance of the eastern Chukchi Sea (ECS) stock of beluga whales. The data were stratified based on bathymetry to reflect strong large-scale gradients in beluga density. A half-normal key function was used to model detection from a dataset of 999 sightings of 2465 belugas. The detection function was found to depend significantly on sky condition and ice coverage. For the years 2012 through 2017, respectively, the estimated numbers of ECS belugas in the study area during the study period were 7355 (CV = 0.17), 6813 (CV = 0.18), 16 598 (CV = 0.21), 6456 (CV = 0.21), 6965 (CV = 0.23) and 13 305 (CV = 0.27). There is no statistically significant trend. These estimates do not correct for belugas outside the study region. Indeed, diverse data indicate that belugas venture far outside the study region and their distribution varies interannually due to prey availability and other factors. Recently reviewed tagging data suggest that correcting for whales outside the study area would approximately double our abundance estimates. These results provide no indication that the stock has substantially declined during these six years due to the impact of subsistence hunting, industrial activity or climate change, although interannual variation and estimated CVs are both large, thereby potentially masking small-scale impacts.

Microbiological Characteristics of White Whale (Delphinapterus leucas) From Capture Through Extended Captivity

1989 ◽  
Vol 46 (11) ◽  
pp. 1914-1921 ◽  
Author(s):  
John D. Buck ◽  
L. Louise Shepard ◽  
Patricia M. Bubucis ◽  
Stephen Spotte ◽  
Kate McClave ◽  
...  
Keyword(s):  
Staphylococcus Epidermidis ◽  
Marine Mammals ◽  
Pasteurella Multocida ◽  
Extended Period ◽  
Delphinapterus Leucas ◽  
Microbiological Analysis ◽  
Beluga Whales ◽  
Vibrio Fluvialis ◽  
Microbiological Characteristics ◽  
In Captivity

For proper husbandry, it is important to sample the environment from which marine mammals for captivity are taken and to monitor the animals frequently over an extended period. Samples for microbiological analysis were collected from 20 beluga whales during capture in the Churchill River. Seven animals were retained in three U.S. aquaria with anal and blowhole cultures taken over a 945-d period. Bacteria isolated from whales at capture included many soil and water forms found also in environmental samples. Pasteurella multocida was isolated from three whales at capture and infrequently several times in captivity from two of these which were studied the most intensively. From this latter group maintained at Mystic (CT) Marinelife Aquarium, the most frequently recovered bacteria from both animals were members of the Achromobacter-Acinetobacter-Alcaligenes-CDC IV E-Moraxella-Pasteurella-Pseudomonas group, Escherichia coli, Pseudomonas putrefaciens, Staphylococcus epidermidis, Streptococcus faecalis, and Vibrio fluvialis. Only one of these whales yielded cultures of Klebsiella pneumoniae, Plesiomonas shigelloides, and coagulase positive Staphylococcus aureus. Species of Acinetobacter, Aeromonas, Pseudomonas, and Vibrio were most common in whales maintained at the other aquaria although, as noted for animals at Mystic, several species were isolated from some samples and were absent in others.

Organochlorines and Marine Mammal Reproduction

1989 ◽  
Vol 46 (2) ◽  
pp. 360-368 ◽  
Author(s):  
R. F. Addison
Keyword(s):  
Marine Mammals ◽  
Experimental Studies ◽  
Biological Information ◽  
Delphinapterus Leucas ◽  
Beluga Whales ◽  
Sea Lions ◽  
Harbour Seals ◽  
Pusa Hispida ◽  
Biochemical Mechanisms ◽  
Bothnian Bay

Reproductive failures in four populations of marine mammals (Californian sea lions (Zalophus californianus), Bothnian Bay ringed seals (Pusa hispida), Dutch Waddensee harbour seals (Phoca vitulina), and most recently, Gulf of St. Lawrence beluga whales (Delphinapterus leucas)) have been attributed to the effects of contamination by organochlorine (OC) residues. In this article, I review the evidence for these effects. I conclude that since (a) crucial biological information in the light of which OC residue data can be interpreted is often missing, (b) the nature of the supposed reproductive effect is variable, and (c) the OC residues to which these effects are attributed vary qualitatively and quantitatively, correlations between observed residue concentrations and apparent reproductive changes do not provide any firm evidence for a cause – effect relationship. In a single experimental study, a diet with a higher OC content than that used as a control impaired reproduction in harbour seals; however, dietary components other than OC content also differed. Although there appears to be no firm correlative evidence sinking residue concentrations in marine mammals with reproductive effects, there is enough concern about possible links to justify more experimental studies, with the aim of identifying the possible biochemical mechanisms involved.

scholarly journals Community-Based Observations of Marine Mammal Occurrences in Groswater Bay, Labrador

2013 ◽  
Vol 127 (1) ◽  
pp. 31
Author(s):  
Keith G. Chaulk ◽  
Daniel Michelin ◽  
Melva Williams ◽  
Tony Wolfrey
Keyword(s):  
Marine Mammal ◽  
Marine Mammals ◽  
Oil And Gas ◽  
Delphinapterus Leucas ◽  
Balaenoptera Acutorostrata ◽  
Mammal Species ◽  
Industrial Growth ◽  
Beluga Whales ◽  
Oil And Gas Exploration ◽  
Minke Whales

Experienced observers from the community of Rigolet, Newfoundland and Labrador, recorded marine mammal observations at Rigolet on the coast of Labrador from July to September 2012. During this study, a total of nine species of marine mammals were documented. A daily average of 2.6 (range 1–5) marine mammal species were observed, with Harp Seals (Pagophilus groenlandicus) and Common Minke Whales (Balaenoptera acutorostrata) being the most common. The area is thought to be regionally important for Ringed Seal (Pusa hispida) whelping; however, Ringed Seals were not observed in large numbers. Beluga Whales (Delphinapterus leucas) were also reported anecdotally, but were less common than the other species, with the possible exception of the Harbour Porpoise (Phocoena phocoena). Labrador is experiencing significant industrial growth related to hydroelectric development and offshore oil and gas exploration. These data should aid environmental assessment and environmental effects monitoring and assist researchers in understanding regional marine mammal ecology, including species diversity, seasonal occurrence, and relative abundance.

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