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Hallam J, Harris NC. What's going to be on the menu with global environmental changes? GLOBAL CHANGE BIOLOGY 2023; 29:5744-5759. [PMID: 37458101 DOI: 10.1111/gcb.16866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Accepted: 05/13/2023] [Indexed: 07/18/2023]
Abstract
Ongoing anthropogenic change is altering the planet at an unprecedented rate, threatening biodiversity, and ecosystem functioning. Species are responding to abiotic pressures at both individual and population levels, with changes affecting trophic interactions through consumptive pathways. Collectively, these impacts alter the goods and services that natural ecosystems will provide to society, as well as the persistence of all species. Here, we describe the physiological and behavioral responses of species to global changes on individual and population levels that result in detectable changes in diet across terrestrial and marine ecosystems. We illustrate shifts in the dynamics of food webs with implications for animal communities. Additionally, we highlight the myriad of tools available for researchers to investigate the dynamics of consumption patterns and trophic interactions, arguing that diet data are a crucial component of ecological studies on global change. We suggest that a holistic approach integrating the complexities of diet choice and trophic interactions with environmental drivers may be more robust at resolving trends in biodiversity, predicting food web responses, and potentially identifying early warning signs of diversity loss. Ultimately, despite the growing body of long-term ecological datasets, there remains a dearth of diet ecology studies across temporal scales, a shortcoming that must be resolved to elucidate vulnerabilities to changing biophysical conditions.
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Affiliation(s)
- Jane Hallam
- Applied Wildlife Ecology Lab, Yale School of the Environment, Yale University, New Haven, Connecticut, USA
| | - Nyeema C Harris
- Applied Wildlife Ecology Lab, Yale School of the Environment, Yale University, New Haven, Connecticut, USA
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2
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van Neer A, Nachtsheim D, Siebert U, Taupp T. Movements and spatial usage of harbour seals in the Elbe estuary in Germany. Sci Rep 2023; 13:6630. [PMID: 37095305 PMCID: PMC10125962 DOI: 10.1038/s41598-023-33594-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Accepted: 04/15/2023] [Indexed: 04/26/2023] Open
Abstract
Harbour seals are top predators in the North Sea and regarded as sentinels for ecosystem health. A few hundred also occur in adjacent estuaries, such as the Elbe estuary, Germany. However, only little is known about how these animals use this dynamic tidally influenced habitat, which has been under high anthropogenic pressure for decades. In this context, nine harbour seals (Phoca vitulina) from the Elbe estuary were equipped with biotelemetry devices to track their movements over multiple months. Harbour seal movements were characterised by short trips (trip length outside pupping season for females: 9.0 ± 1.12 km, males: 7.0 ± 1.24 km) as well as small home ranges (median 50% home range for females: 16.3 km2, males: 36.1 km2) compared to harbour seals from marine regions. Within the estuary, the animals utilised the fairway, river branches and tributaries. During the pupping season in June and July, four seals showed strongly reduced trip lengths and durations, increased daily haul out durations as well as smaller home ranges. Even though a continuous exchange with harbour seals from the Wadden Sea likely occurs, most individuals in this study spent the entire deployment duration inside the estuary. This indicates that the Elbe estuary provides a suitable habitat for harbour seals, despite extensive anthropogenic usage, calling for further studies on the consequences of living in such an industrialised habitat.
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Affiliation(s)
- Abbo van Neer
- Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Foundation, Werftstraße 6, 25761, Büsum, Germany
| | - Dominik Nachtsheim
- Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Foundation, Werftstraße 6, 25761, Büsum, Germany.
| | - Ursula Siebert
- Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Foundation, Werftstraße 6, 25761, Büsum, Germany
| | - Thomas Taupp
- Department of Animal Ecology, Federal Institute of Hydrology (BfG), Am Mainzer Tor 1, 56068, Koblenz, Germany
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3
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Kraufvelin P, Bergström L, Sundqvist F, Ulmestrand M, Wennhage H, Wikström A, Bergström U. Rapid re-establishment of top-down control at a no-take artificial reef. AMBIO 2023; 52:556-570. [PMID: 36324024 PMCID: PMC9849640 DOI: 10.1007/s13280-022-01799-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 07/09/2022] [Accepted: 09/21/2022] [Indexed: 05/26/2023]
Abstract
Establishment of artificial reefs and no-take areas are management measures available for restoring deteriorated marine ecosystems, compensating for habitat loss and strengthening harvested populations. Following the establishment of no-take artificial reefs in western Sweden to compensate for hard bottoms lost to a shipping lane, we detected rapid positive effects on crustaceans and demersal fish compared to fished reference areas. The relative abundance and size structure of European lobster (Homarus gammarus) increased strongly in the no-take area indicating more than doubled and tripled egg production in 5 and 10 years, respectively. For benthic fish and crustacean communities, the abundances of gadoids and wrasses increased and the abundances of small decapod crustaceans decreased in the no-take area, likely indicating cascading effects of increased predation. The study demonstrates that relatively small no-take areas, enhanced by artificial reefs, can rapidly invigorate populations of lobster and fish that in turn may re-initiate local top-down control.
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Affiliation(s)
- Patrik Kraufvelin
- Department of Aquatic Resources, Swedish University of Agricultural Sciences (SLU), Skolgatan 6, 742 42 Öregrund, Sweden
- Åland University of Applied Sciences, PB 1010, AX-22111 Mariehamn, Åland, Finland
| | - Lena Bergström
- Department of Aquatic Resources, Swedish University of Agricultural Sciences (SLU), Skolgatan 6, 742 42 Öregrund, Sweden
| | - Frida Sundqvist
- Department of Aquatic Resources, Swedish University of Agricultural Sciences (SLU), Skolgatan 6, 742 42 Öregrund, Sweden
- Department of Aquatic Resources, Institute of Coastal Research, Swedish University of Agricultural Sciences, Yttre Skällåkra 6, 432 65 Väröbacka, Sweden
| | - Mats Ulmestrand
- Department of Aquatic Resources, Havsfiskelaboratoriet, Swedish University of Agricultural Sciences, Turistgatan 5, Box 4, 453 30 Lysekil, Sweden
| | - Håkan Wennhage
- Department of Aquatic Resources, Havsfiskelaboratoriet, Swedish University of Agricultural Sciences, Turistgatan 5, Box 4, 453 30 Lysekil, Sweden
| | - Andreas Wikström
- Department of Aquatic Resources, Havsfiskelaboratoriet, Swedish University of Agricultural Sciences, Turistgatan 5, Box 4, 453 30 Lysekil, Sweden
| | - Ulf Bergström
- Department of Aquatic Resources, Swedish University of Agricultural Sciences (SLU), Skolgatan 6, 742 42 Öregrund, Sweden
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Boyi JO, Heße E, Rohner S, Säurich J, Siebert U, Gilles A, Lehnert K. Deciphering Eurasian otter (
Lutra lutra
L.) and seal (
Phoca vitulina
L.;
Halichoerus grypus
F.) diet: metabarcoding tailored for fresh and saltwater fish species. Mol Ecol 2022; 31:5089-5106. [DOI: 10.1111/mec.16635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 07/13/2022] [Accepted: 07/25/2022] [Indexed: 11/30/2022]
Affiliation(s)
- Joy Ometere Boyi
- Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Foundation Büsum Germany
| | - Eileen Heße
- Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Foundation Büsum Germany
| | - Simon Rohner
- Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Foundation Büsum Germany
| | - Josefin Säurich
- Institute for Animal Breeding and Genetics, University of Veterinary Medicine Hannover, Foundation Hannover Germany
| | - Ursula Siebert
- Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Foundation Büsum Germany
| | - Anita Gilles
- Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Foundation Büsum Germany
| | - Kristina Lehnert
- Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Foundation Büsum Germany
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Birenbaum Z, Do H, Horstmyer L, Orff H, Ingram K, Ay A. SEALNET: Facial recognition software for ecological studies of harbor seals. Ecol Evol 2022; 12:e8851. [PMID: 35505998 PMCID: PMC9047973 DOI: 10.1002/ece3.8851] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Revised: 03/25/2022] [Accepted: 03/30/2022] [Indexed: 11/06/2022] Open
Abstract
Methods for long‐term monitoring of coastal species such as harbor seals (Phoca vitulina) are often costly, time‐consuming, and highly invasive, underscoring the need for improved techniques for data collection and analysis. Here, we propose the use of automated facial recognition technology for identification of individual seals and demonstrate its utility in ecological and population studies. We created a software package, SealNet, that automates photo identification of seals, using a graphical user interface (GUI) software to detect, align, and chip seal faces from photographs and a deep convolutional neural network (CNN) suitable for small datasets (e.g., 100 seals with five photos per seal) to classify individual seals. We piloted the SealNet technology with a population of harbor seals located within Casco Bay on the coast of Maine, USA. Across two years of sampling, 2019 and 2020, at seven haul‐out sites in Middle Bay, we obtained a dataset optimized for the development and testing of SealNet. We processed 1752 images representing 408 individual seals and achieved 88% Rank‐1 and 96% Rank‐5 accuracy in closed set seal identification. In identifying individual seals, SealNet software outperformed a similar face recognition method, PrimNet, developed for primates but retrained on seals. The ease and wealth of image data that can be processed using SealNet software contributes a vital tool for ecological and behavioral studies of marine mammals in the developing field of conservation technology.
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Affiliation(s)
- Zach Birenbaum
- Department of Computer Science Colgate University Hamilton New York USA
| | - Hieu Do
- Department of Computer Science Colgate University Hamilton New York USA
- Department of Mathematics Colgate University Hamilton New York USA
| | | | - Hailey Orff
- Department of Biology Colgate University Hamilton New York USA
| | - Krista Ingram
- Department of Biology Colgate University Hamilton New York USA
| | - Ahmet Ay
- Department of Mathematics Colgate University Hamilton New York USA
- Department of Biology Colgate University Hamilton New York USA
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Aarts G, Mul E, Fieberg J, Brasseur S, van Gils JA, Matthiopoulos J, Riotte-Lambert L. Individual-Level Memory Is Sufficient to Create Spatial Segregation among Neighboring Colonies of Central Place Foragers. Am Nat 2021; 198:E37-E52. [PMID: 34260868 DOI: 10.1086/715014] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
AbstractCentral place foragers often segregate in space, even without signs of direct agonistic interactions. Using parsimonious individual-based simulations, we show that for species with spatial cognitive abilities, individual-level memory of resource availability can be sufficient to cause spatial segregation in the foraging ranges of colonial animals. The shapes of the foraging distributions are governed by commuting costs, the emerging distribution of depleted resources, and the fidelity of foragers to their colonies. When colony fidelity is weak and foragers can easily switch to colonies located closer to favorable foraging grounds, this leads to space partitioning with equidistant borders between neighboring colonies. In contrast, when colony fidelity is strong-for example, because larger colonies provide safety in numbers or individuals are unable to leave-it can create a regional imbalance between resource requirements and resource availability. This leads to nontrivial space-use patterns that propagate through the landscape. Interestingly, while better spatial memory creates more defined boundaries between neighboring colonies, it can lower the average intake rate of the population, suggesting a potential trade-off between an individual's attempt for increased intake and population growth rates.
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Damseaux F, Siebert U, Pomeroy P, Lepoint G, Das K. Habitat and resource segregation of two sympatric seals in the North Sea. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 764:142842. [PMID: 33342563 DOI: 10.1016/j.scitotenv.2020.142842] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 09/29/2020] [Accepted: 10/01/2020] [Indexed: 06/12/2023]
Abstract
The study of ecological niche segregation in sympatric species is essential to understand ecosystem functioning and its response to potential changes. In the North Sea, sympatric grey and harbour seals may present competition for food resources sustained by intense fishing activities and recent increase of seal populations. In order to coexist and reduce inter-specific competition, sympatric species must segregate at least one aspect of their ecological niches: temporal, spatial or resource segregation. We aim to study the foraging resources and foraging distributions of grey seals and harbour seals and the potential competition between these species in the North Sea. Therefore, we analysed stable isotopic composition of C, N and S (δ13C, δ15N and δ34S values), and the concentrations of Hg and Se in blood of harbour and grey seals from the North Sea. Blood samples were collected on 45 grey seals and 37 harbour seals sampled along German and Scottish coasts. Stable isotope ratios were performed with an isotope ratio mass spectrometer coupled to an N-C-S elemental analyser for automated analyses. Total mercury concentrations (T-Hg) were determined by atomic absorption spectroscopy and Se concentrations by ICP-MS. The multi-tracer approach shown spatial and resource partitioning within grey and harbour seal living along German and Scottish coasts. Data indicate 1) the offshore foraging distribution of grey seals as reflected by the lower δ15N values and T-Hg concentrations and higher Se concentrations and 2) the inshore foraging distribution of harbour seals because of higher δ15N values and T-Hg concentrations and lower Se concentrations. The SIAR mixing model revealed 3) a more selective diet of grey seals compared to harbour seals and 4) the importance of sandeels in grey seal diet reflected by their high δ34S values. Lastly, diet ellipse overlaps between grey seals and harbour seals sampled along the German coasts suggested 5) a potential sharing of food resources, possibly due to the increase number of grey seals number in this area during the foraging season - all year except breeding and moulting periods. The multi-tracer approach of this study provides a more robust discrimination among diet resources and spatial foraging distributions of grey seals and harbour seals in the North Sea.
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Affiliation(s)
- France Damseaux
- Freshwater and Oceanic sciences Unit of reSearch (FOCUS), Laboratory of Oceanology, University of Liège B6c, 11 Allée du 6 Août, 4000 Liège, Belgium
| | - Ursula Siebert
- Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Foundation, 25761 Büsum, Germany
| | - Patrick Pomeroy
- Sea Mammal Research Unit, Scottish Oceans Institute, East Sands, University of St Andrews, KY16 8LB, UK
| | - Gilles Lepoint
- Freshwater and Oceanic sciences Unit of reSearch (FOCUS), Laboratory of Oceanology, University of Liège B6c, 11 Allée du 6 Août, 4000 Liège, Belgium
| | - Krishna Das
- Freshwater and Oceanic sciences Unit of reSearch (FOCUS), Laboratory of Oceanology, University of Liège B6c, 11 Allée du 6 Août, 4000 Liège, Belgium.
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8
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Chudzinska M, Nabe-Nielsen J, Smout S, Aarts G, Brasseur S, Graham I, Thompson P, McConnell B. AgentSeal: Agent-based model describing movement of marine central-place foragers. Ecol Modell 2021. [DOI: 10.1016/j.ecolmodel.2020.109397] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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9
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Nikolic N, Thompson P, de Bruyn M, Macé M, Chevalet C. Evolutionary history of a Scottish harbour seal population. PeerJ 2020; 8:e9167. [PMID: 32728487 PMCID: PMC7357561 DOI: 10.7717/peerj.9167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 04/19/2020] [Indexed: 12/02/2022] Open
Abstract
Efforts to conserve marine mammals are often constrained by uncertainty over their population history. Here, we examine the evolutionary history of a harbour seal (Phoca vitulina) population in the Moray Firth, northeast Scotland using genetic tools and microsatellite markers to explore population change. Previous fine-scale analysis of UK harbour seal populations revealed three clusters in the UK, with a northeastern cluster that included our Moray Firth study population. Our analysis revealed that the Moray Firth cluster is an independent genetic group, with similar levels of genetic diversity across each of the localities sampled. These samples were used to assess historic abundance and demographic events in the Moray Firth population. Estimates of current genetic diversity and effective population size were low, but the results indicated that this population has remained at broadly similar levels following the population bottleneck that occurred after post-glacial recolonization of the area.
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Affiliation(s)
- Natacha Nikolic
- ARBRE (Reunion Island Biodiversity Research Agency), Saint-Leu, La Réunion
- Génétique Physiologie et Systèmes d’Elevage - UMR1388, INRAE, Castanet Tolosan, France
| | - Paul Thompson
- Lighthouse Field Station, Sciences School of Biological Sciences, University of Aberdeen, Cromarty, United Kingdom
| | - Mark de Bruyn
- School of Life and Environmental Sciences, University of Sydney, Sydney, Australia
| | - Matthias Macé
- Laboratoire d’Anthropologie Moléculaire et d’Imagerie de Synthèse - UMR 5288, CNRS, Toulouse, France
| | - Claude Chevalet
- Génétique Physiologie et Systèmes d’Elevage - UMR1388, INRAE, Castanet Tolosan, France
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Hertz M, Jensen L, Pertoldi C, Aarestrup K, Thomsen S, Alstrup A, Asmus H, Madsen S, Svendsen J. Investigating fish migration, mortality, and physiology to improve conservation planning of anadromous salmonids: a case study on the endangered North Sea houting (Coregonus oxyrinchus). CAN J ZOOL 2019. [DOI: 10.1139/cjz-2019-0045] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Understanding migratory behavior, mortality, and physiology is essential for conservation of many species, particularly anadromous fish. In this study, freshwater and marine migrations of the endangered salmonid North Sea houting (Coregonus oxyrinchus (Linnaeus, 1758)) were investigated using telemetry. Furthermore, physiological samples were collected from North Sea houting and from resident and anadromous populations of the closely related European whitefish (Coregonus lavaretus (Linnaeus, 1758)) to compare hypo-osmotic tolerances. On average, North Sea houting spent 193 days at sea where the mortality was 36%. Most fish returned from sea in the autumn, and river entry correlated inversely with river temperature and positively with discharge. Fish spent an average of 49 days in the estuarine area. Artificial lakes negatively affected migration speeds. Migration speeds did not differ consistently between individuals (i.e., not a repeatable trait) but correlated positively with water temperature. Fish arrived at spawning areas in November. In the post-spawning state, Na+/K+-ATPase activities were elevated in North Sea houting and anadromous whitefish compared with resident whitefish, while osmolality was elevated only in North Sea houting. Our study provides important information for conservation planning related to the Habitat Directive of the European Union that lists the North Sea houting as critically endangered.
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Affiliation(s)
- M. Hertz
- Department of Chemistry and Bioscience, Section of Biology and Environmental Science, Aalborg University, Fredrik Bajers Vej 7H, 9220 Aalborg Ø, Denmark
| | - L.F. Jensen
- Department of Chemistry and Bioscience, Section of Biology and Environmental Science, Aalborg University, Fredrik Bajers Vej 7H, 9220 Aalborg Ø, Denmark
| | - C. Pertoldi
- Department of Chemistry and Bioscience, Section of Biology and Environmental Science, Aalborg University, Fredrik Bajers Vej 7H, 9220 Aalborg Ø, Denmark
- Aalborg Zoo, Mølleparkvej 63, 9000, Aalborg, Denmark
| | - K. Aarestrup
- National Institute of Aquatic Resources, Technical University of Denmark, Vejlsøvej 39, 8600 Silkeborg, Denmark
| | - S.N. Thomsen
- Department of Chemistry and Bioscience, Section of Biology and Environmental Science, Aalborg University, Fredrik Bajers Vej 7H, 9220 Aalborg Ø, Denmark
| | - A.K.O. Alstrup
- Department of Nuclear Medicine and PET Center, Institute of Clinical Medicine, Aarhus University Hospital, Nørrebrogade 44, 10C, 8000 Aarhus, Denmark
| | - H. Asmus
- Alfred Wegener Institute, Hafenstraße 43, D-25992 List, Sylt, Germany
| | - S.S. Madsen
- Department of Biology, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark
| | - J.C. Svendsen
- National Institute of Aquatic Resources, Technical University of Denmark, Jægersborg Alle 1, 2920, Denmark
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Kahle P, Rolvien T, Kierdorf H, Roos A, Siebert U, Kierdorf U. Age-related changes in size, bone microarchitecture and volumetric bone mineral density of the mandible in the harbor seal (Phoca vitulina). PLoS One 2019; 14:e0224480. [PMID: 31648278 PMCID: PMC6812799 DOI: 10.1371/journal.pone.0224480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Accepted: 10/15/2019] [Indexed: 12/05/2022] Open
Abstract
Detailed knowledge of age-related changes in the structure and mineralization of bones is important for interpreting osseous changes in wild mammals caused by exposure to environmental contaminants. This study analyzed mandibular size, microarchitecture and volumetric bone mineral density (vBMD) in harbor seals (n = 93, age range 0.5 months to 25 years) from the German North Sea. Bone microarchitecture and vBMD were assessed using high-resolution peripheral quantitative computed tomography (HR-pQCT). Significant differences were observed between the analyzed age classes (i) young juveniles (0.5–10 months), (ii) yearlings (12–23 months), and (iii) adults (12–25 years) for several of the variables, indicating an overall increase in cortical and trabecular area, cortical thickness and total and cortical vBMD with age. Furthermore, for juvenile animals (≤ 23 months), significant positive correlations with age were observed for mandible length and perimeter, cortical area, cortical thickness, trabecular separation, and total and cortical vBMD. The findings demonstrate a rapid increase in overall size, cortical dimensions and the degree of mineralization of the harbor seal mandible during the first two years after birth. Negative correlations with age existed for trabecular number and thickness as well as for trabecular bone volume fraction in the juveniles. The findings suggest a reduction in trabecular bone volume fraction with age, due to the bone trabeculae becoming thinner, less numerous and more widely spaced. Given the strong age dependence of most analyzed parameters, it is recommended to standardize samples with respect to age in future studies comparing microarchitecture and mineralization of harbor seal mandibles from different populations or different collection periods.
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Affiliation(s)
- Patricia Kahle
- Department of Biology, University of Hildesheim, Hildesheim, Germany
| | - Tim Rolvien
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Department of Orthopedics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Horst Kierdorf
- Department of Biology, University of Hildesheim, Hildesheim, Germany
| | - Anna Roos
- Department of Contaminant Research, Swedish Museum of Natural History, Stockholm, Sweden
| | - Ursula Siebert
- Institute of Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Uwe Kierdorf
- Department of Biology, University of Hildesheim, Hildesheim, Germany
- * E-mail:
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