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Juan Jose Alava; Peter S. Ross; Michael G. Ikonomou; Marilyn Cruz; Gustavo Jimenez-Uzcátegui; Cory Dubetz; Sandie Salazar; Daniel P. Costa; Stella Villegas-Amtmann; Peter Howorth; Frank A.P.C. Gobas
... We characterize for the first time the presence of DDT and its metabolites in tropical Galapagos sea lions (Zalophus wolleabeki). ∑DDT concentrations in Galapagos sea lion pups sampled in 2005 and 2008 ranged from 16 to 3070μg/kg lipid. Concentrations of ∑DDT in pups in 2008 averaged 525μg/kg lipid and were 1.9 times higher than that (281μg/kg lipid) detected in pups in 2005. These concentrations ...
... In the article ‘Haulout site selection by southern elephant seals at Marion Island’ that appeared in African Zoology43(1): 25–33 (April 2008), the institutional affiliations of the authors should have read: ...
Mirounga; adults; breeding; data collection; females; food availability; mark-recapture studies; models; population growth; predation; time series analysis; wildlife management; Indian Ocean; Pacific Ocean
Abstract:
... The means by which populations are regulated form a central theme in conservation biology, and much debate has revolved around density dependence as a mechanism driving population change. Marion Island (46°54‘S, 37°45‘E) is host to a relatively small breeding population of southern elephant seals, which like its counterparts in the southern Indian and southern Pacific Oceans, have declined precipi ...
... To survey the diversity of fungal species that may be cultured from Antarctic penguins and pinnipeds, and to test the in vitro susceptibility to triazole drugs of any medically important Aspergillus spp. isolates. During an expedition to Argentinean Antarctic research stations at Potter Peninsula (South Shetland Islands) and Primavera Cape (Antarctic Peninsula) in February 2019, samples (n = 212) ...
... Elephant Point is an ice-free area in the SW corner of Livingston Island (Maritime Antarctica). The retreat of Rotch Dome glacier during the Holocene has exposed a land area of 1.16km². Up to 17.3% of this surface has become ice-free between 1956 and 2010. A detailed geomorphological mapping of this ice-free environment was conducted in late January 2014. A wide range of active periglacial landfor ...
Mirounga; breeding; molting; winter; young animals
Abstract:
... Using data from an ongoing mark–resight programme at Marion Island, we tested empirically whether southern elephant seals prefer certain terrestrial sites to others during the breeding, moulting and winter haulouts, and whether the pattern of site use is the same for different age and sex groups. Southern elephant seals preferred some sites, while discriminating against other sites, with different ...
... The foraging success, and thus the survival and reproductive success, of deep-diving pinnipeds such as the northern elephant seal, Mirounga angustirostris, depends on the ability to withstand repetitive breath-hold dives. Health parameters can be incorporated as potential explanatory variables for differences observed in diving and migratory performance of individual seals. Furthermore, biomedical ...
... The Medieval Climate Anomaly (MCA) is a well-recognized climate perturbation in many parts of the world, with a core period of 1000–1200 CE. Here we are mapping the MCA across the Antarctic region based on the analysis of published palaeotemperature proxy data from 60 sites. In addition to the conventionally used ice core data, we are integrating temperature proxy records from marine and terrestri ...
Mirounga; seals; polychlorinated biphenyls; pollutants; toxicity; body fat; blood serum; fasting; circulatory system physiology; field experimentation; gender differences; bioaccumulation; California
Abstract:
... Northern elephant seals (Mirounga angustirostris) are characterized by extended fasting during which they rely entirely on their own body reserves. During fasts, lipids are mobilized from blubber to match the energy requirements of the animal. This transfer frees toxic fat-soluble pollutants into the blood circulation, which may exert adverse health effects, especially in young and developing anim ...
... Functional data often exhibit both amplitude and phase variation around a common base shape, with phase variation represented by a so called warping function. The process of removing phase variation by curve alignment and inference of the warping functions is referred to as curve registration. When functional data are observed with substantial noise, model-based methods can be employed for simulta ...
... At birth, the Mediterranean monk seal (Monachus monachus) is covered with dark lanugo This is shed earlier and faster in females, so they complete the moult when they are significantly younger (64 days) than males (82 days). Moulted pups present a greyish dorsal and a white ventral pelage. Only the hair is shed in the first moult. In subsequent moults, the hairs are shed along with large sheets of ...
... The Southern Ocean plays a key role in ocean–atmosphere carbon dioxide fluxes. Estimation of carbon exchanges between ocean and atmosphere must rely on accurate estimations of primary productivity which require measurements of phytoplankton concentration within the water column. In this paper, we are interested in relationships between primary productivity and light in the Antarctic ocean. The ori ...
... In highly dynamic and unpredictable environments such as the Southern Ocean, species that have evolved behaviors that reduce the effects of intra-specific competition may have a selective advantage. This is particularly true when juveniles face disadvantages when foraging due to morphological or physiological limitation, which is the case for many marine mammals. We tracked the at-sea movements of ...
... In mammals, maternal expenditure on offspring is a complex mix of several factors including the species’ mating system, offspring sex and the condition and age of the mother. While theory suggests that in polygynous species mothers should wean larger male offspring than females when resources and maternal conditions allow, the evidence for this remains equivocal. Southern elephant seals are highly ...
Mirounga leonina; age; bioacoustics; body size; breeding; correlation; frequency; information; males; mating behavior; paper; phenotype; repeatability; sexual selection; variance; vocalization
Abstract:
... Male vocalisations have an important role in mating tactics, breeding strategies and sexual selection. Most studies of vocalisations are concentrated on the time and frequency domains, while the intensity of sound, an important acoustic parameter that should be related to body size, is almost completely ignored as a possible honest signal of resource holding potential (RHP) and cue for mate choice ...
... Pinnipeds are a diverse clade of semi-aquatic mammals, which act as key indicators of ecosystem health. Their transition from land to marine environments provides a complex microbial milieu, making them vulnerable to both aquatic and terrestrial pathogens, thereby contributing to pinniped population decline. Indeed, viral pathogens such as influenza A virus and phocine distemper virus (PDV) have b ...
... Rod and cone visual pigments of 11 marine carnivores were evaluated. Rod, middle/long-wavelength sensitive (M/L) cone, and short-wavelength sensitive (S) cone opsin (if present) sequences were obtained from retinal mRNA. Spectral sensitivity was inferred through evaluation of known spectral tuning residues. The rod pigments of all but one of the pinnipeds were similar to those of the sea otter, po ...
... Mixed layers are defined to have homogeneous density, temperature, and salinity. However, bio‐optical profiles may not always be fully homogenized within the mixed layer. The relative timescales of mixing and biological processes determine whether bio‐optical gradients can form within a uniform density mixed layer. Vertical profiles of bio‐optical measurements from biogeochemical Argo floats and e ...
... The aim of this study was to determine if antimicrobial drug use increases resistance of commensal gastrointensinal Escherichia coli of wild northern elephant seals (Mirounga angustirostris) treated in rehabilitation, and, if so, identify the risk factors involved. Minimum inhibitory concentration (MIC) levels of twelve antimicrobial drugs were determined for 289 E. coli isolates from 99 seals sam ...
Omar Santana‐Morales; Rebeca Zertuche‐Chanes; Edgar M. Hoyos‐Padilla; Chugey Sepúlveda; Edgar E. Becerril‐García; Juan P. Gallo‐Reynoso; Isai Barba‐Acuña; Adán Mejía‐Trejo; Marc Aquino‐Baleytó; Oscar Sosa‐Nishizaki; James T. Ketchum; Rodrigo Beas‐Luna
Carcharodon carcharias; Mirounga; adults; age structure; cages; conservation areas; females; juveniles; observational studies; tourism; young of the year; California; Mexico
Abstract:
... In the eastern North Pacific, the Guadalupe Island Biosphere Reserve (GIBR) is one of the most renowned white shark (Carcharodon carcharias) aggregation sites studied to date, and an important tourism activity has been developed in the reserve. This study used tourist‐based cage diving activities to biologically monitor white sharks from 2014 to 2019 within the GIBR. The data indicated a gradual i ...
Mirounga; body condition; breeding; ecosystems; fasting; foraging; mixing; molting; predators; Antarctic region
Abstract:
... As top predators, it has been suggested that southern elephant seals serve as sentinels of ecosystem status to inform management and conservation. This is because southern elephant seals annually undertake two large‐scale foraging migrations for 2–3 and 7–8 months to replenish resources after fasting during breeding and moulting and often rely on dynamic macroscale latitudinal fronts to provide fa ...
... The Southern Ocean ecosystem is undergoing rapid physical and biological changes that are likely to have profound implications for higher‐order predators. Here, we compare the long‐term, historical responses of Southern Ocean predators to climate change. We examine palaeoecological evidence for changes in the abundance and distribution of seabirds and marine mammals, and place these into context w ...