Assessment of claw growth-layer groups from ringed seals (Pusa hispida) as biomonitors of inter- and intra-annual Hg, δ15N, and δ13C variation

2011 ◽  
Vol 89 (9) ◽  
pp. 774-784 ◽  
Author(s):  
Elizabeth O. Ferreira ◽  
Lisa L. Loseto ◽  
Steven H. Ferguson
Keyword(s):  
Life History ◽  
Marine Mammals ◽  
Ringed Seal ◽  
The Body ◽  
Conservation Strategies ◽  
Growth Layer ◽  
Annual Variations ◽  
Ringed Seals ◽  
Pusa Hispida ◽  
Layer Groups

The ringed seal ( Pusa hispida (Schreber, 1775)) is a sentinel species of arctic marine mammals; therefore, methods to monitor its life-history changes are crucial to establish effective conservation strategies. We evaluate the potential use of claws of ringed seals as a proxy for counts of tooth growth-layer groups (age) and a biomonitor of total mercury burden (THg) and diet (stable isotope ratios expressed as δ15N and δ13C). The count of claw growth-layer groups was indicative of age up to 8 years and we infer differentiation of dark and light annuli as being associated with the spring moult. No differences of THg, δ15N, or δ13C were observed among flipper digits. The proximal claw annulus representing the most recent growth had δ13C values that were correlated to both muscle and liver δ13C, supporting the use of claws to monitor visceral δ13C. Claw log10THg from the proximate annulus was significantly correlated to liver and whisker log10THg, while significant interannual THg accumulation was observed in 18 of 32 seals ≥4 years, suggesting the claws receive and disperse Hg from active tissues of the body. Results support the use of claw tissue from ringed seal to provide a chronological record of inter- and intra-annual variations representing seal diet, contaminant load, and life history.

scholarly journals Ringed seal (Pusa hispida) breeding habitat on the landfast ice in northwest Alaska during spring 1983 and 1984

PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0260644
Author(s):  
Donna D. W. Hauser ◽  
Kathryn J. Frost ◽  
John J. Burns
Keyword(s):  
Sea Ice ◽  
Marine Mammals ◽  
Environmental Changes ◽  
Chukchi Sea ◽  
Ringed Seal ◽  
Breeding Habitat ◽  
Future Research ◽  
Ringed Seals ◽  
Pusa Hispida ◽  
Kotzebue Sound

There has been significant sea ice loss associated with climate change in the Pacific Arctic, with unquantified impacts to the habitat of ice-obligate marine mammals such as ringed seals (Pusa hispida). Ringed seals maintain breathing holes and excavate subnivean lairs on sea ice to provide protection from weather and predators during birthing, nursing, and resting. However, there is limited baseline information on the snow and ice habitat, distribution, density, and configuration of ringed seal structures (breathing holes, simple haul-out lairs, and pup lairs) in Alaska. Here, we describe historic field records from two regions of the eastern Chukchi Sea (Kotzebue Sound and Ledyard Bay) collected during spring 1983 and 1984 to quantify baseline ringed seal breeding habitat and map the distribution of ringed seal structures using modern geospatial tools. Of 490 structures located on pre-established study grids by trained dogs, 29% were pup lairs (25% in Kotzebue Sound and 33% in Ledyard Bay). Grids in Ledyard Bay had greater overall density of seal structures than those in Kotzebue Sound (8.6 structures/km2 and 7.1 structures/km2), but structures were larger in Kotzebue Sound. Pup lairs were located in closer proximity to other structures and characterized by deeper snow and greater ice deformation than haul-out lairs or simple breathing holes. At pup lairs, snow depths averaged 74.9 cm (range 37–132 cm), with ice relief nearby averaging 76 cm (range 31–183 cm), and ice deformation 29.9% (range 5–80%). We compare our results to similar studies conducted in other geographic regions and discuss our findings in the context of recent declines in extent and duration of seasonal cover of landfast sea ice and snow deposition on sea ice. Ultimately, additional research is needed to understand the effects of recent environmental changes on ringed seals, but our study establishes a baseline upon which future research can measure pup habitat in northwest Alaska.

scholarly journals Stable ringed seal (Pusa hispida) demography despite significant habitat change in Svalbard, Norway

2021 ◽  
Vol 40 ◽  
Author(s):  
Magnus Andersen ◽  
Kit M. Kovacs ◽  
Christian Lydersen
Keyword(s):  
Life History ◽  
Sea Ice ◽  
Close Association ◽  
Ringed Seal ◽  
Breeding Habitat ◽  
Small Scale ◽  
Recent Period ◽  
Ringed Seals ◽  
Time Periods ◽  
Circumpolar Arctic

Ringed seals, which are small phocid seals, range across the circumpolar Arctic, and have evolved in close association with sea ice and depend on it for all aspects of their life history. This research study compares age structure, reproductive parameters, body size and condition during three time periods—1981–82 (n = 277), 2002–04 (n = 272) and 2012–18 (n = 212)—to study potential changes in demography in ringed seals in western Svalbard, Norway, an area that has undergone dramatic changes in sea-ice conditions during recent decades. Age distributions for the three time periods were similar, with the exception that the most recent period had a higher proportion of young animals. Age at sexual maturity for both sexes was similar for the two most recent periods, both being lower than in the 1980s. Ovulation rates did not vary significantly among the three periods (range 0.86–0.94). Pregnancy rates were only available for the most recent study period (0.71); this value falls within the range reported from other Arctic regions. Body length showed no clear temporal patterns; males were slightly longer in the most recent period, while females were slightly longer in the first period. Data from May in all periods suggest that body condition has not varied significantly through time. In conclusion, although the ringed seal breeding habitat in Svalbard has declined significantly in recent decades, demographic parameters appear to be largely unaffected. Life-history plasticity in combination with a small-scale regional variation in environmental conditions might explain the lack of changes in demography over time.

COUNTS OF GROWTH LAYER GROUPS IN CEMENTUM AND DENTINE IN RINGED SEALS (PHOCA HISPIDA)

1996 ◽  
Vol 12 (3) ◽  
pp. 383-401 ◽  
Author(s):  
Robert E. A. Stewart ◽  
Barbara E. Stewart ◽  
Ian Stirling ◽  
Elaine Street
Keyword(s):  
Growth Layer ◽  
Phoca Hispida ◽  
Ringed Seals ◽  
Layer Groups

scholarly journals Aerial photogrammetry and tag-derived tissue density reveal patterns of lipid-store body condition of humpback whales on their feeding grounds

2021 ◽  
Vol 288 (1943) ◽  
pp. 20202307
Author(s):  
Kagari Aoki ◽  
Saana Isojunno ◽  
Charlotte Bellot ◽  
Takashi Iwata ◽  
Joanna Kershaw ◽  
...  
Keyword(s):  
Life History ◽  
Body Condition ◽  
Marine Mammals ◽  
The Body ◽  
Humpback Whales ◽  
Body Density ◽  
Aerial Photogrammetry ◽  
Free Ranging ◽  
Negatively Buoyant ◽  
Feeding Grounds

Monitoring the body condition of free-ranging marine mammals at different life-history stages is essential to understand their ecology as they must accumulate sufficient energy reserves for survival and reproduction. However, assessing body condition in free-ranging marine mammals is challenging. We cross-validated two independent approaches to estimate the body condition of humpback whales ( Megaptera novaeangliae ) at two feeding grounds in Canada and Norway: animal-borne tags ( n = 59) and aerial photogrammetry ( n = 55). Whales that had a large length-standardized projected area in overhead images (i.e. whales looked fatter) had lower estimated tissue body density (TBD) (greater lipid stores) from tag data. Linking both measurements in a Bayesian hierarchical model to estimate the true underlying (hidden) tissue body density (uTBD), we found uTBD was lower (−3.5 kg m −3 ) in pregnant females compared to adult males and resting females, while in lactating females it was higher (+6.0 kg m −3 ). Whales were more negatively buoyant (+5.0 kg m −3 ) in Norway than Canada during the early feeding season, possibly owing to a longer migration from breeding areas. While uTBD decreased over the feeding season across life-history traits, whale tissues remained negatively buoyant (1035.3 ± 3.8 kg m −3 ) in the late feeding season. This study adds confidence to the effectiveness of these independent methods to estimate the body condition of free-ranging whales.

Pathological changes of stomach in ringed seal (Pusa hispida) from Arviat (North Canada) caused by anisakid nematodes

2013 ◽  
Vol 16 (1) ◽  
pp. 63-67
Author(s):  
Z. Sołtysiak ◽  
M. Simard ◽  
J. Rokicki
Keyword(s):  
Mononuclear Cells ◽  
Gastric Wall ◽  
Ringed Seal ◽  
Gastric Lesions ◽  
Ringed Seals ◽  
Pseudoterranova Decipiens ◽  
Mucosal Layer ◽  
Pusa Hispida ◽  
Contracaecum Osculatum ◽  
Anisakid Nematodes

Abstract This is a report of lesions associated with the nematodes (Anisakidae) from the stomach of ringed seals (Pusa hispida). On thirty one examined ringed seals from Arviat, thirteen were infected by 1 to 24 anisakids. Identification of nematodes from their stomachs showed two species; Contracaecum osculatum (sensu lato) (79 specimens) and Pseudoterranova decipiens (sensu lato) (11 specimens). In the gastric sections with parasites, larvae and adults of nematodes were present mainly in the fundic portion of the stomach. The anterior parts of the nematodes were embedded in mucosa and submucosa. Anisakids were associated with ulcerous gastric lesions and raised inflammatory areas in the stomachs. The histological examination of a sample taken from the tissue surrounding anisakids revealed the presence of more or less confluent focal necrotic areas. Most small petechial hemorrhages were located in the mucosal layer of the gastric wall and were surrounded by inflammatory mononuclear cells such as lymphocytes, histiocytes, eosinophils and fibroblasts. The Anisakidae larvae in the stomach caused atrophy of glands, hemorrhaging and eosinophilic infiltrations that consequently healed, creating fibrotic scars.

Comparison between spring and autumn infection by Corynosoma (Acanthocephala) in the ringed seal Pusa hispida in the Bothnian Bay of the Baltic Sea

Parasitology ◽  
1981 ◽  
Vol 82 (2) ◽  
pp. 287-296 ◽  
Author(s):  
Eero Helle ◽  
E. Tellervo Valtonen
Keyword(s):  
Baltic Sea ◽  
Feeding Habits ◽  
Ringed Seal ◽  
The Other ◽  
The Baltic Sea ◽  
Rate Of Development ◽  
Ringed Seals ◽  
Pusa Hispida ◽  
The Baltic ◽  
Bothnian Bay

SUMMARYCorynosoma spp. (Acanthocephala) infection in ringed seals (Pusa hispida) is compared in spring and in autumn in the Bothnian Bay, northern Baltic Sea. The material consists of more than 13400 specimens: 7590 from the intestines of 13 seals captured in April and May 1978 and 5850 from 29 seals captured in October and November.Corynosoma strumosum infection had approximately the same intensity in spring and autumn (mean 76 and 66 individuals/infected seal, maxmum 313 and 324 individuals, respectively). C. semerme specimens, on the other hand, were 37 times more numerous in spring than in autumn (504 compared with 136/infected seal, maximum 1700 and 1230 individuals, respectively). The ratio of C. strumosum to C. semerme was 1:6·3 in spring and 1:2·0 in autumn, as calculated from the total material. Corynosoma infection was more recent on average in spring than in autumn, as judged both from the proportion of males and immature females and from the distribution of C. semerme in the intestine. The feeding habits of the ringed seals and the rate of development of Corynosoma infection are discussed.

Thermal Significance of the Topographical Distribution of Blubber in Ringed Seals (Phoca hispida)

1988 ◽  
Vol 45 (6) ◽  
pp. 985-992 ◽  
Author(s):  
Morten Ryg ◽  
Thomas G. Smith ◽  
Nils Are Øritsland
Keyword(s):  
Surface Area ◽  
Heat Loss ◽  
Thermal Effects ◽  
Marine Mammals ◽  
The Body ◽  
Phoca Hispida ◽  
Ringed Seals ◽  
Linear Dimensions ◽  
Topographical Distribution ◽  
Body Core

The distribution of blubber in ringed seals (Phoca hispida) and relationships between surface area, body mass, and linear dimensions are described. The blubber was distributed in such a way that the ratio of blubber thickness to body radius is nearly constant over the body, maximizing the available blubber for insulation. The hind part of the body has a higher thickness to radius ratio and is thus "overinsulated." During periods of mass loss, fat is lost fastest from this overinsulated region, thus reducing the negative thermal effects of the fat loss. We present formulae for calculating body surface area and an effective, or "equivalent blubber thickness," for calculations of heat loss and suggest that these formulae are independent of size and shape. By combining these equations, we arrive at a general formula for calculating a lower limit for heat loss from marine mammals. According to this formula, thermal stability can be maintained when blubber is lost if mass is simultaneously lost from the body core.

scholarly journals Spring distribution of ringed seals (Pusa hispida) in Eclipse Sound and Milne Inlet, Nunavut: implications for potential ice-breaking activities

2019 ◽  
Vol 5 (1) ◽  
pp. 54-61 ◽  
Author(s):  
David J. Yurkowski ◽  
Brent G. Young ◽  
J. Blair Dunn ◽  
Steven H. Ferguson
Keyword(s):  
Iron Ore ◽  
Policy Decision ◽  
Resource Development ◽  
Ringed Seal ◽  
Mitigation Strategies ◽  
Decision Makers ◽  
Sea Ice Extent ◽  
Ringed Seals ◽  
Aerial Surveys ◽  
Pusa Hispida

Resource development in Arctic waters is proceeding rapidly leading to increased interactions with Arctic wildlife. As sea ice extent decreases, the demand for shipping and ice-breaking operations will expand into winter and spring with greater impact on ice-dependent pinnipeds. However, knowledge of the distribution of these species, such as ringed seals (Pusa hispida (Schreber, 1775)), during spring within areas of resource development is lacking. Baffinland Iron Mines Corporation’s Mary River iron ore port in southern Milne Inlet, Nunavut opened in 2015 with proposed ice-breaking activities in spring — an important period in ringed seal seasonal life-history. We conducted infrared and photographic aerial surveys in June 2016 and 2017 to overlay the proposed ice-breaking route with ringed seal hotspots (i.e., areas of higher density). We identified four areas of overlap where proposed ice-breaking would traverse through ringed seal hotspots: eastern and western Eclipse Sound (a ringed seal pupping ground identified by local knowledge), the middle of Milne Inlet, and southern Milne Inlet. We identified potential negative implications of spring ice-breaking operations on ringed seals such as displacement, separation of mothers and pups, destruction of resting and birth lairs, and vessel–seal collisions. Results are relevant to policy decision-makers who can develop mitigation strategies in the rapidly melting and developing Arctic.

scholarly journals Growth and population parameters of ringed seals (Pusa hispida) from Svalbard, Norway, 2002–2004

2006 ◽  
Vol 63 (6) ◽  
pp. 1136-1144 ◽  
Author(s):  
Bjørn A. Krafft ◽  
Kit M. Kovacs ◽  
Anne Kirstine Frie ◽  
Tore Haug ◽  
Christian Lydersen
Keyword(s):  
Ringed Seal ◽  
The Arctic ◽  
Strong Impact ◽  
Climate Change Scenarios ◽  
Population Parameters ◽  
Ringed Seals ◽  
Asymptotic Values ◽  
Seal Population ◽  
Pusa Hispida ◽  
Sexually Mature

AbstractSamples were collected in Svalbard, Norway, during April and May 2002–2004 from 272 ringed seals (Pusa hispida; 62.5% males, 37.5% females) to study growth and population parameters. The age of the animals ranged from 1 to 32 years. Asymptotic values for standard length and body mass were 127.7 ± 1.6 (s.e.) cm and 69.0 ± 2.7 kg for males (maxima: 144 cm and 92 kg) and 127.6 ± 2.3 cm and 68.9 ± 2.5 kg for females (maxima: 141 cm and 91 kg). All animals were sexually mature at an age ≥6 years and the ovulation rate was 0.86. Mean Age at Maturity (MAM) was 4.2 ± 0.2 years for males and 3.5 ± 0.3 years for females, values significantly lower than calculated for ringed seals from the same area 20 years ago. This change in MAM suggests that either the prey base for ringed seals in the area has increased or alternatively that the density of ringed seals has declined, such that more resources are available per capita. If the climate of the Arctic changes in the manner predicted by a host of climate-change scenarios, it is likely to have a strong impact on ringed seal populations in future, although there are no data to suggest that dramatic changes have taken place yet in fish and invertebrate populations in the Svalbard area. Although cause-and-effect cannot be firmly established, there is a possibility that the substantial increase in the number of polar bears (Ursus maritimus) over the past 20 years, since hunting the species in Svalbard ceased in 1973, may have played a role in the observed change in the ringed seal population.

scholarly journals A review of age estimation methods in marine mammals with special reference to monodontids

2018 ◽  
Vol 10 ◽  
Author(s):  
Fiona L. Read ◽  
Aleta A. Hohn ◽  
Christina H. Lockyer
Keyword(s):  
Age Estimation ◽  
Marine Mammals ◽  
Estimation Methods ◽  
Growth Layer ◽  
Mineral Density ◽  
Relative Age ◽  
Accuracy And Precision ◽  
Absolute Age ◽  
Hard Structures ◽  
Layer Groups

This paper presents a critical review of methods for estimating absolute or relative age in marine mammals. Absolute age is achieved by counting growth layer groups (GLGs) in hard structures such as teeth, ear plugs, baleen, bones and claws. Relative age can be obtained by methods such as aspartic acid racemisation, genetic telomeres, bone mineral density, fatty acid signatures and other methods. Each method is discussed in detail. Accuracy and precision, including inter-reader calibration and anomalies, as well as methods of validating GLG deposition rates are also addressed. Each section concludes with methods of age estimation applicable to monodontids, and suggestions on the focus of future age-estimation research.

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