scholarly journals Validation of a novel method to create temporal records of hormone concentrations from the claws of ringed and bearded seals

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Shawna A Karpovich ◽  
Larissa A Horstmann ◽  
Lori K Polasek
Keyword(s):  
Physiological Stress ◽  
Fold Increase ◽  
The Arctic ◽  
Bearded Seal ◽  
Paired Samples ◽  
Pregnancy Status ◽  
Pusa Hispida ◽  
Novel Method ◽  
As Stress ◽  
Bearded Seals

Abstract Ringed (Pusa hispida) and bearded seals (Erignathus barbatus) inhabit vast and often remote areas in the Arctic, making it difficult to obtain long-term physiological information concerning health and reproduction. These seals are experiencing climate-driven changes in their habitat that could result in physiological stress. Chronic physiological stress can lead to immunosuppression, decreased reproduction and decreased growth. Recently, keratin has become a popular matrix to measure steroid hormones, such as stress-related cortisol and reproduction-related progesterone. We developed and validated methods to extract cortisol and progesterone from the claws of adult female ringed (n = 20) and bearded (n = 3) seals using enzyme immunosorbent assays. As ringed and bearded seal claws grow, a pair of dark- and light-colored bands of keratin is deposited annually providing a guide for sampling. Two processing methods were evaluated, removal of claw material with a grinding bit or grinding followed by mechanical pulverization (102 paired samples from six claws, two each from three seals). Adding the mechanical pulverization step resulted in a 1.5-fold increase in hormone extraction. Progesterone from the proximal claw band was evaluated to biologically validate claw material as a measure of pregnancy in ringed seals (n = 14). Claws from pregnant seals had significantly higher claw progesterone concentrations than from non-pregnant seals. This suggests that the elevated progesterone associated with gestation was reflected in the claws, and that the most proximal claw band was indicative of pregnancy status at time of death. Thus, although the sample size was low and the collection dates unbalanced, this study demonstrates the potential to use claws to examine an extended time series (up to 12 yrs) of cortisol and progesterone concentrations in ringed and bearded seal claws.

Underwater vocalizations of the bearded seal (Erignathus barbatus)

1989 ◽  
Vol 67 (8) ◽  
pp. 1900-1910 ◽  
Author(s):  
Holly J. Cleator ◽  
Ian Stirling ◽  
T. G. Smith
Keyword(s):  
Spectral Characteristics ◽  
Early Morning ◽  
The Arctic ◽  
Spectral Features ◽  
Bearded Seal ◽  
Daily Cycle ◽  
Sequential Organization ◽  
Erignathus Barbatus ◽  
Bearded Seals

The underwater vocalizations of bearded seals (Erignathus barbatus) were recorded between March and June in 1979, 1982, and 1983 at six sites in the Arctic. In total, 970 trills were measured for temporal and spectral characteristics and then classified as one of six types. Trills were narrow in bandwidth and frequency modulated. The repertoires of vocalizing bearded seals varied amongst the six recording sites. Between-site differences in temporal and spectral features, call use, and sequential organization were measured. The results suggest that bearded seals may be relatively sedentary and that geographically different vocal repertoires may be characteristic of discrete breeding stocks. A prominent daily cycle in rate of calling during April and May was found at two sites; rate of calling was higher during the early morning hours (i.e., 03:00–04:00 sun time) than at other times of the day. No distinct temporal cycle occurred during late May and early June. Rate of calling appeared to be negatively correlated with pattern of haul out. In simultaneous recordings, a few (13 of 156) bearded seal trills were recorded up to a distance of 25 km underwater.

Winter Distribution of Bearded Seals (Erignathus barbatus) in the Penny Strait Area, Northwest Territories, as Determined by Underwater Vocalizations

1990 ◽  
Vol 47 (6) ◽  
pp. 1071-1076 ◽  
Author(s):  
Holly J. Cleator ◽  
Ian Stirling
Keyword(s):  
Northwest Territories ◽  
Absolute Number ◽  
Bearded Seal ◽  
Vocal Behaviour ◽  
Winter Distribution ◽  
Odobenus Rosmarus ◽  
Erignathus Barbatus ◽  
Break Up ◽  
A Site ◽  
Bearded Seals

Vocalization surveys conducted in Penny Strait, Northwest Territories, indicated that before ice break-up, bearded seals (Erignathus barbatus) preferred regions of less stable ice where break-up occurred early and avoided stable, landfast ice or areas heavily used by walruses (Odobenus rosmarus). Water depth did not appear to influence distribution. Numbers of calls increased between mid-April and early June, probably because of an increase in rate of calling by individual seals. Vocalization surveys can be used to separate preferred habitats from unsuitable ones. Using a single hydrophone and our current understanding of bearded seal vocal behaviour, it is not possible to determine the absolute number of bearded seals at or near a site using vocalizations. However, it is possible to measure the relative abundance of seals for spatial and temporal comparisons.

Mammals of central North Greenland

Polar Record ◽  
1989 ◽  
Vol 25 (152) ◽  
pp. 43-49 ◽  
Author(s):  
O. Bennike ◽  
A. K. Higgins ◽  
M. Kelly
Keyword(s):  
Arctic Ocean ◽  
Polar Bear ◽  
Ringed Seal ◽  
The Arctic ◽  
Arctic Fox ◽  
Bearded Seal ◽  
The Arctic Ocean ◽  
Arctic Hare ◽  
Musk Ox ◽  
North Greenland

AbstractCentral North Greenland, an uninhabited and rarely visited region bordering the Arctic Ocean, supports arctic hare, collared lemming, wolf, arctic fox, polar bear, stoat, ringed seal and musk ox. Their distribution and abundance were noted during Geological Survey of Greenland expeditions in 1984–85, which visited virtually all land areas in the region, including nunataks and islands. Bones of reindeer, bearded seal and narwhal were also found. Ringed seal and reindeer are known to have been present in the region by the early Holocene.

scholarly journals FIRST INSTRUMENTAL AERIAL SURVEY OF RINGED SEALS (PUSA HISPIDA) AND BEARDED SEALS (ERIGNATHUS BARBATUS) IN THE RUSSIAN ZONE OF THE CHUKCHI AND EAST-SIBERIAN SEAS IN SPRING 2016

2019 ◽  
Vol 199 ◽  
pp. 152-162
Author(s):  
V. I. Chernook ◽  
I. S. Trukhanova ◽  
A. N. Vasiliev ◽  
D. I. Litovka ◽  
D. M. Glazov ◽  
...  
Keyword(s):  
Coastal Waters ◽  
Chukchi Sea ◽  
Aircraft Engine ◽  
Aerial Survey ◽  
Ringed Seals ◽  
East Siberian Sea ◽  
Pusa Hispida ◽  
Abundance And Distribution ◽  
Different Parts ◽  
Bearded Seals

An instrumental aerial survey was conducted in the Russian part of the Chukchi Sea and the eastern East-Siberian Sea in the spring of 2016 to investigate new technical capabilities for estimating abundance and distribution of ringed and bearded seals on the spring ice. Density of both species decreased with distance to the mainland; the largest concentrations of ringed seals were detected in coastal waters, including the Koluchinskaya and Chaunskaya Bays. Taking into account the portion of seals in the water (on average 32 %) and the portion of seals that were disturbed by the aircraft engine noise and dove (on average 30.2 % of ringed seals and 5.9 % of bearded seals), the number of ringed seals in the surveyed area was estimated as 50,839 (СI 95 %: 25,400–73,859; CV = 23.8 %), and the number of bearded seals as 14,590 (CI 95 %: 6,404–24,560; CV = 31.1 %). These estimates are considered to be biased low, primarily due to asynchronic collapse of the ringed seal snow lairs in different parts of the surveyed area, which caused a highly variable detection probability of this species that was difficult to account for.

scholarly journals Extreme wet seasons – their definition and relationship with synoptic-scale weather systems

2021 ◽  
Vol 2 (1) ◽  
pp. 71-88
Author(s):  
Emmanouil Flaounas ◽  
Matthias Röthlisberger ◽  
Maxi Boettcher ◽  
Michael Sprenger ◽  
Heini Wernli
Keyword(s):  
Rossby Waves ◽  
Grid Point ◽  
The Arctic ◽  
Synoptic Scale ◽  
Wet Season ◽  
Conveyor Belts ◽  
Novel Method ◽  
Warm Conveyor Belts ◽  
The Tropics ◽  
Tropical Moisture

Abstract. An extreme aggregation of precipitation on the seasonal timescale, leading to a so-called extreme wet season, can have substantial environmental and socio-economic impacts. This study has a twofold aim: first to identify and statistically characterize extreme wet seasons around the globe and second to elucidate their relationship with specific weather systems. Extreme wet seasons are defined independently at every grid point of ERA-Interim reanalyses as the consecutive 90 d period with the highest accumulated precipitation in the 40-year period of 1979–2018. In most continental regions, the extreme seasons occur during the warm months of the year, especially in the midlatitudes. Nevertheless, colder periods might be also relevant, especially in coastal areas. All identified extreme seasons are statistically characterized in terms of climatological anomalies of the number of wet days and of daily extreme events. Results show that daily extremes are decisive for the occurrence of extreme wet seasons in regions of frequent precipitation, e.g., in the tropics. This is in contrast to arid regions where wet seasons may occur only due to anomalously frequent wet days. In the subtropics and more precisely within the transitional zones between arid areas and regions of frequent precipitation, both an anomalously high occurrence of daily extremes and of wet days are related to the formation of extreme wet seasons. A novel method is introduced to define the spatial extent of regions affected by a particular extreme wet season and to relate extreme seasons to four objectively identified synoptic-scale weather systems, which are known to be associated with intense precipitation: cyclones, warm conveyor belts, tropical moisture exports and breaking Rossby waves. Cyclones and warm conveyor belts contribute particularly strongly to extreme wet seasons in most regions of the globe. But interlatitudinal influences are also shown to be important: tropical moisture exports, i.e., the poleward transport of tropical moisture, can contribute to extreme wet seasons in the midlatitudes, while breaking Rossby waves, i.e., the equatorward intrusion of stratospheric air, may decisively contribute to the formation of extreme wet seasons in the tropics. Three illustrative examples provide insight into the synergetic effects of the four identified weather systems on the formation of extreme wet seasons in the midlatitudes, the Arctic and the (sub)tropics.

scholarly journals Variation in body size of ringed seals (Pusa hispida hispida) across the circumpolar Arctic: evidence of morphs, ecotypes or simply extreme plasticity?

2021 ◽  
Vol 40 ◽  
Author(s):  
Kit M. Kovacs ◽  
John Citta ◽  
Tanya Brown ◽  
Rune Dietz ◽  
Steve Ferguson ◽  
...  
Keyword(s):  
Body Size ◽  
The Arctic ◽  
Age At Maturity ◽  
Adaptation To Climate Change ◽  
Eastern Canada ◽  
Genetic Studies ◽  
Ringed Seals ◽  
Pusa Hispida ◽  
Potential Adaptation ◽  
Circumpolar Arctic

The ringed seal is a small phocid seal that has a northern circumpolar distribution. It has long been recognized that body size is variable in ringed seals, and it has been suggested that ecotypes that differ in size exist. This study explores patterns of body size (length and girth) and age-at-maturity across most of the Arctic subspecies’ range using morphometric data from 35 sites. Asymptotic lengths varied from 113 to 151 cm, with sites falling into five distinct size clusters (for each sex). Age-at-maturity ranged from 3.1 to 7.4 years, with sites that had early ages of sexual maturity generally having small length-at-maturity and small final body length. The sexes differed in length at some sites, but not in a consistent pattern of dimorphism. The largest ringed seals occurred in western Greenland and eastern Canada, and the smallest occurred in Alaska and the White Sea. Latitudinal trends occurred only within sites in the eastern Canadian Arctic. Girth (with length and season accounted for) was also highly variable but showed no notable spatial pattern; males tended to be more rotund than females. Genetic studies are needed, starting with the “giants” at Kangia (Greenland) and in northern Canada to determine whether they are genetically distinct ecotypes. Additional research is also needed to understand the ecological linkages that drive the significant regional size differences in ringed seals that were confirmed in this study, and also to understand their implications with respect to potential adaptation to climate change.

Development of an Automated Computer-Controlled Islet Isolation System

1997 ◽  
Vol 6 (1) ◽  
pp. 47-57 ◽  
Author(s):  
Jonathan R.T. Lakey ◽  
Garth L. Warnock ◽  
Mark Brierton ◽  
Ziliang Ao ◽  
Bernhard J. Hering ◽  
...  
Keyword(s):  
Computer Control ◽  
Fold Increase ◽  
Pancreatic Tissue ◽  
Extraction System ◽  
Diabetic Patients ◽  
Clinical Islet Transplantation ◽  
Novel Method ◽  
Group 2 ◽  
Group 1

Before clinical islet transplantation can become an effective and reliable treatment for type 1 diabetic patients, there must be significant improvements in the methods employed for the isolation of islets of Langerhans. We have developed an automated cell extraction system (ACES), which allows computer control of the isolation process. As well, it incorporates a novel method of recombining dissociated pancreatic tissue. Following initial system design and testing to determine the optimal system configuration, a series of 12 consecutive canine islet isolations were performed. Pancreases were perfused with collagenase via the duct and dissociated and recombined using either the standard Ricordi-based protocol (group 1, n = 6) or dissociated and recombined using the ACES system (group 2, n = 6). A total of 90.8 ± 21 x 103 islet equivalents (IE) (mean ± SEM) were recovered in group 1 vs. 99 ± 14 x 103 IE in group 2 (p = NS, student unpaired t-test). Following Ficoll purification the recovery was 56.2 ± 14 x 103 IE for group 1 vs. 54.7 ± 11 x 103 IE for group 2 (p = NS). Viability was equivalent with an 8.6-fold increase in insulin secretion for group 1 and an 8.8-fold increase for group 2 when the islets were exposed to high glucose solution supplemented with IBMX (3-isobutyl-1-methylxanthine) during static incubation. In vivo function was equivalent following transplantation of 2000 IE under the kidney capsule of alloxan-induced diabetic nude mice with five of six and five of seven mice surviving long-term (>50 days posttransplant) (groups 1 and 2, respectively). This data shows that an entirely automated pancreatic islet extraction system can result in effective canine islet recovery without compromising islet yields and viability. The ACES system has several ad van tages over the standard isolation protocol. These include: 1) computer control and monitoring over all phases of the isolation, 2) a single-use sterile disposable tubing set, and 3) a novel method of tissue recombination. Copyright © 1997 Elsevier Science Inc.

scholarly journals Behavioural and morphological changes in fish exposed to ecologically relevant boat noises

2019 ◽  
Vol 76 (10) ◽  
pp. 1845-1853
Author(s):  
Megan F. Mickle ◽  
Christopher M. Harris ◽  
Oliver P. Love ◽  
Dennis M. Higgs
Keyword(s):  
Sublethal Effects ◽  
Physiological Stress ◽  
Morphological Changes ◽  
Stress Hormones ◽  
Anthropogenic Noise ◽  
Black Bullhead ◽  
Behavioural Effects ◽  
Boat Traffic ◽  
As Stress ◽  
Ameiurus Melas

There is increasing concern about the effect of underwater noise on fish due to rising levels of anthropogenic noise. We performed experiments on the black bullhead (Ameiurus melas), a species with known hearing specializations and located within the Laurentian Great Lakes where there is considerable commercial and recreational boat traffic. We tested and compared physiology (baseline cortisol), behaviour (activity, sheltering), and morphology (ciliary bundles of hair cells) of bullhead to boat noise. At 140 dB re 1 μPa (−54.84 dB re 1 m·s−2), we saw clear behavioural effects in terms of both activity and sheltering levels despite no obvious morphological or physiological stress. Following both short- and long-period acute exposure to higher — but environmentally relevant — noise levels, bullhead were less active and sheltered more and also exhibited a decrease in ciliary bundles. These results suggest that there are sublethal effects of anthropogenic noise on fish behaviour and ciliary bundles, which may have direct implications on population health. Moreover, commonly used metrics such as stress hormones may not always offer the most relevant biomarker of the response to anthropogenic boat noise.

scholarly journals Sensitivity of remote aerosol distributions to representation of cloud-aerosol interactions in a global climate model

2013 ◽  
Vol 6 (1) ◽  
pp. 331-378 ◽  
Author(s):  
H. Wang ◽  
R. C. Easter ◽  
P. J. Rasch ◽  
M. Wang ◽  
X. Liu ◽  
...  
Keyword(s):  
Liquid Water ◽  
Climate Model ◽  
Global Climate Model ◽  
Fold Increase ◽  
Convective Transport ◽  
The Arctic ◽  
Cloud Base ◽  
High Latitudes ◽  
Upper Troposphere ◽  
Wet Removal

Abstract. Many global aerosol and climate models, including the widely used Community Atmosphere Model version 5 (CAM5), have large biases in predicting aerosols in remote regions such as upper troposphere and high latitudes. In this study, we conduct CAM5 sensitivity simulations to understand the role of key processes associated with aerosol transformation and wet removal affecting the vertical and horizontal long-range transport of aerosols to the remote regions. Improvements are made to processes that are currently not well represented in CAM5, which are guided by surface and aircraft measurements together with results from a multi-scale aerosol-climate model (PNNL-MMF) that explicitly represents convection and aerosol-cloud interactions at cloud-resolving scales. We pay particular attention to black carbon (BC) due to its importance in the Earth system and the availability of measurements. We introduce into CAM5 a new unified scheme for convective transport and aerosol wet removal with explicit aerosol activation above convective cloud base. This new implementation reduces the excessive BC aloft to better simulate observed BC profiles that show decreasing mixing ratios in the mid- to upper-troposphere. After implementing this new unified convective scheme, we examine wet removal of submicron aerosols that occurs primarily through cloud processes. The wet removal depends strongly on the sub-grid scale liquid cloud fraction and the rate of conversion of liquid water to precipitation. These processes lead to very strong wet removal of BC and other aerosols over mid- to high latitudes during winter months. With our improvements, the Arctic BC burden has a10-fold (5-fold) increase in the winter (summer) months, resulting in a much better simulation of the BC seasonal cycle as well. Arctic sulphate and other aerosol species also increase but to a lesser extent. An explicit treatment of BC aging with slower aging assumptions produces an additional 30-fold (5-fold) increase in the Arctic winter (summer) BC burden. This BC aging treatment, however, has minimal effect on other under-predicted species. Interestingly, our modifications to CAM5 that aim at improving prediction of high-latitude and upper tropospheric aerosols also produce much better aerosol optical depth over various other regions globally when compared to multi-year AERONET retrievals. The improved aerosol distributions have impacts on other aspects of CAM5, improving the simulation of global mean liquid water path and cloud forcing.

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