fur seal
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2021 ◽  
Vol 109 (1) ◽  
Author(s):  
Mathilde Martin ◽  
Tess Gridley ◽  
Simon Harvey Elwen ◽  
Isabelle Charrier
Keyword(s):  
Fur Seal ◽  

2021 ◽  
Vol 8 ◽  
Author(s):  
Mickie R. Edwards ◽  
Susana Cárdenas-Alayza ◽  
Michael J. Adkesson ◽  
Mya Daniels-Abdulahad ◽  
Amy C. Hirons

Peru’s coastal waters are characterized by significant environmental fluctuation due to periodic El Niño- La Niña- Southern Oscillation (ENSO) events. This variability results in ecosystem-wide food web changes which are reflected in the tissues of the Peruvian fur seal (Arctocephalus australis). Stable isotope ratios (δ13C and δ15N) in Peruvian fur seal vibrissae (whiskers) are used to infer temporal primary production and dietary variations in individuals. Sea surface temperature anomaly (SSTA) recordings from the Niño 1+2 Index region captured corresponding ENSO conditions. Fluctuations in δ15N values were correlated to SSTA records, indicating that ENSO conditions likely impact the diet of these apex predators over time. Anomalous warm phase temperatures corresponded to decreased δ15N values, whereas cold phase anomalous conditions corresponded to increased δ15N values, potentially from upwelled, nutrient-rich water. Vibrissae δ13C values revealed general stability from 2004 to 2012, a moderate decline during 2013 (La Niña conditions) followed by a period of increased values concurrent with the 2014–2016 El Niño event. Both δ13C and δ15N values were inversely correlated to each other during the strongest El Niño Southern Oscillation event on record (2014–2016), possibly indicating a decline in production leading to an increase in food web complexity. Lower δ13C and δ15N values were exhibited in female compared to male fur seal vibrissae. Findings suggest ENSO conditions influence resource availability, possibly eliciting changes in pinniped foraging behavior as well as food web of the endangered Peruvian fur seal.


Pathogens ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1415
Author(s):  
Micaela Martins ◽  
Nuno Urbani ◽  
Carla Flanagan ◽  
Ursula Siebert ◽  
Stephanie Gross ◽  
...  

Toxoplasma gondii infection has been reported in numerous species of marine mammals, some of them with fatal consequences. A serosurvey for T. gondii infection was conducted in pinnipeds from an oceanographic park in Portugal (n = 60); stranded pinnipeds on the Portuguese coast (n = 10); and pinnipeds captured in Lorenzensplate, Germany (n = 99). Sera from 169 pinnipeds were tested for the presence of antibodies to T. gondii by the modified agglutination test with a cut-off titre of 25. An overall seroprevalence of 8.9% (95% confidence interval: 5.1–14.2) was observed. Antibody titres of 25, 50, 100, 1600 and ≥3200 were found in five (33.3%), two (13.3%), five (33.3%), one (6.7%) and two (13.3%) animals, respectively. Pinnipeds under human care had a seroprevalence of 20.0% (12/60), in contrast to 2.8% (3/109) in wild pinnipeds (p < 0.001). General results suggest a low exposure of wild pinnipeds to T. gondii, while the seroprevalence found in pinnipeds under human care highlights the importance of carrying out further studies. This is the first serological survey of T. gondii in pinnipeds in Portugal and the first infection report in South African fur seal (Arctocephalus pusillus pusillus).


2021 ◽  
Author(s):  
Mariel Fulham ◽  
Fiona McDougall ◽  
Michelle Power ◽  
Rebecca R McIntosh ◽  
Rachael Gray

The rapid emergence of antimicrobial resistance (AMR) is a major concern for wildlife and ecosystem health globally. Genetic determinants of AMR have become indicators of anthropogenic pollution due to their greater association with humans and rarer presence in environments less affected by humans. The objective of this study was to determine the distribution and frequency of the class 1 integron, a genetic determinant of AMR, in both the faecal microbiome and in  Escherichia coli  isolated from neonates of three pinniped species. Australian sea lion ( Neophoca cinerea ), Australian fur seal ( Arctocephalus pusillus doriferus ) and long-nosed fur seal ( Arctocephalus forsteri ) pups from eight breeding colonies along the Southern Australian coast were sampled between 2016-2019. DNA from faecal samples ( n =309) and from  E. coli  ( n =795) isolated from 884 faecal samples were analysed for class 1 integrons using PCRs targeting the conserved integrase gene ( intI ) and the gene cassette array. Class 1 integrons were detected in  A. p. doriferus  and  N. cinerea  pups sampled at seven of the eight breeding colonies investigated in 4.85% of faecal samples ( n =15) and 4.52% of  E. coli  isolates ( n =36). Integrons were not detected in any  A. forsteri  samples. DNA sequencing of the class 1 integron gene cassette array identified diverse genes conferring resistance to four antibiotic classes. The relationship between class 1 integron carriage and the concentration of five trace elements and heavy metals was also investigated, finding no significant association. The results of this study add to the growing evidence of the extent to which antimicrobial resistant bacteria are polluting the marine environment. As AMR determinants are frequently associated with bacterial pathogens, their occurrence suggests that these pinniped species are vulnerable to potential health risks. The implications for individual and population health as a consequence of AMR carriage is a critical component of ongoing health investigations.


2021 ◽  
Vol 57 (4) ◽  
Author(s):  
Galaxia Cortés-Hinojosa ◽  
Michael J. Adkesson ◽  
Susana Cárdenas-Alayza ◽  
Mauricio Seguel ◽  
Héctor Pavés ◽  
...  
Keyword(s):  

2021 ◽  
Author(s):  
Rebecca Nagel ◽  
Sylvia Kaiser ◽  
Claire Stainfield ◽  
Camille Toscani ◽  
Cameron Fox-Clarke ◽  
...  

Individuals are unique in how they interact with and respond to their environment. Correspondingly, unpredictable challenges or stressors often produce an individualized response of the hypothalamic-pituitary-adrenal axis and its downstream effector cortisol. We used a fully crossed, repeated measures design to investigate the factors shaping individual variation in baseline cortisol and cortisol responsiveness in Antarctic fur seal pups and their mothers. Saliva samples were collected from focal individuals at two breeding colonies, one with low and the other with high population density, during two consecutive years of contrasting food availability. Mothers and pups were sampled concurrently at birth and shortly before weaning, while pups were additionally sampled every 20 days. We found that heritability was low for both baseline cortisol and cortisol responsiveness, while within-individual repeatability and among-individual variability were high. A substantial proportion of the variation in baseline cortisol could be explained in pups and mothers by a combination of intrinsic and extrinsic factors including sex, weight, day, season, and colony of birth. However, the same variables explained little of the variation in cortisol responsiveness. Our findings provide detailed insights into the individualization of endocrine phenotypes in a wild pinniped.


2021 ◽  
Vol 8 (10) ◽  
Author(s):  
Mathilde Martin ◽  
Tess Gridley ◽  
Simon Harvey Elwen ◽  
Isabelle Charrier

Communication is fundamental for the survival of animal species as signals are involved in many social interactions (mate selection, parental care, collective behaviours). The acoustic channel is an important modality used by birds and mammals to reliably exchange information among individuals. In group-living species, the propagation of vocal signals is limited due to the density of individuals and the background noise. Vocal exchanges are, therefore, challenging. This study is the first investigation into the acoustic communication system of the Cape fur seal (CFS), one of the most colonial mammals with breeding colonies of hundreds of thousands of individuals. We described the acoustic features and social function of five in-air call types from data collected at two colonies. Intra-species variations in these vocalizations highlight a potential ability to convey information about the age and/or sex of the emitter. Using two classification methods, we found that the five call types have distinguishable frequency features and occupy distinct acoustic niches indicating acoustic partitioning in the repertoire. The CFS vocalizations appear to contain characteristics advantageous for discrimination among individuals, which could enhance social interactions in their noisy and confusing acoustic environment. This study provides a basis for our understanding of the CFS acoustic communication system.


2021 ◽  
Vol 47 (3) ◽  
Author(s):  
Carlos Javier Tamayo-Millán ◽  
Miguel Ángel Ahumada-Sempoal ◽  
Adriana Cortés-Gómez ◽  
Ivon Marcela Chacón-Romo Leroux ◽  
Dennis Bermúdez-Díaz ◽  
...  

Several sightings of different pinniped species have been recorded outside their typical areas of distribution. In May 2019, pinniped yearlings were sighted on 4 occasions on the central coast of Oaxaca, Mexico. One of them was found injured in La Escobilla (Oaxaca, Mexico) and was transported immediately to the Centro Mexicano de la Tortuga for rehabilitation. Visual identification of the species was inconclusive, as young individuals of several fur seal species can be very similar. A molecular analysis was thus performed to confirm the species. DNA was extracted from the individual, and a fragment of the mitochondrial DNA control region was sequenced and aligned with several sequences of other fur seal species. A parsimony analysis was performed, and the tree revealed that the individual was a Galapagos fur seal, Arctocephalus galapagoensis. This is the first record of this species on the central coast of Oaxaca. The atypical presence of this species in the country could be related to high sea surface temperatures associated with events such as El Niño.


2021 ◽  
Vol 9 (9) ◽  
pp. 975
Author(s):  
Jeffrey W. Short ◽  
Harold J. Geiger ◽  
Lowell W. Fritz ◽  
Jonathan J. Warrenchuk

The Pribilof northern fur seal (Callorhinus ursinus) herd in the eastern Bering Sea has declined by ~70% since the 1970s, for elusive reasons. Competition for pollock (Gadus chalcogramma) with the commercial fishery has been suspected as a contributing factor, but no correlative relationship between fishing activity and fur seal population declines has heretofore been demonstrated. Here, we present evidence for a moderately strong inverse relationship between fishery catches of pollock and first-year survival of fur seals, based on three different approaches to evaluation. We suspect this relationship results from the dependence of lactating female fur seals on locating dense and extensive schools of pollock near the Pribilof Islands to efficiently provide nutrition for their pups, because the pollock fishery also targets these same schools, and when fished, the remnants of these schools are fragmented and dispersed, making them more difficult for fur seals to locate and exploit. Inadequately fed pups are less likely to survive their initial independent residence at sea as they migrate south from the Pribilof Islands in the fall. Our results imply that pollock catches above ~1,000,000 t within ~300 km of the Pribilof Islands may continue to suppress first-year survival of Pribilof fur seals below the estimated equilibrium survival value of 0.50, leading to continued decline of the population.


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