bluuebunny/crossref_metadata_2025 huggingface dataset:
An airborne perfluorocarbon tracer system and its first application for a Lagrangian experiment
Authors: Ren Y. , Baumann R. , Schlager H.
Published: July 2014

Abstract. A perfluorocarbon tracer system (PERTRAS), specifically designed for Lagrangian aircraft experiments, has been developed by the Deutsches Zentrum für Luft- und Raumfahrt (German Aerospace Center, DLR). It consists of three main parts: a tracer release unit (RU), an adsorption tube sampler (ATS) and a tracer analytical system. The RU was designed for airborne tracer release experiments; meanwhile, it can be used on various platforms for different experimental purpose (here research vessel). PERTRAS was for the first time applied in the field campaign Stratospheric ozone: halogen Impacts in a Varying Atmosphere (SHIVA) in November 2011. An amount of 8.8 kg perfluoromethylcyclopentane (PMCP) was released aboard the research vessel Sonne (RV Sonne) near the operational site of this campaign, Miri, Malaysia, on 21 November. The tracer samples collected using the ATS on board the DLR research aircraft Falcon were analyzed in the laboratory using a thermal desorber/gas chromatography/mass spectrometry (TD/GC/MS) system. Guided by forecasts calculated with the Lagrangian model, Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT), 64 tracer samples were collected onboard the Falcon approximately 5 and 25 h after the release, respectively, mostly with a time resolution of 1 min. Enhanced PMCP concentrations relative to ambient PMCP background values (mean: 6.62 fmol mol−1) were detected during three intersects of the fresh tracer plume (age 5 h), with a maximum value of 301.33 fmol mol−1. This indicates that the fresh tracer plume was successfully intercepted at the forecasted position. During the second flight, 25 h after the release, the center of tracer plume was not detected by the sampling system due to a faster advection of the plume than forecasted. The newly developed PERTRAS system has been successfully deployed for the first time. The instrumental set-up and comparisons between the measurements and HYSPLIT simulations are presented in this study.
Development and validation of inexpensive, automated, dynamic flux chambers
Authors: Almand-Hunter B. B. , Walker J. T. , Masson N. P. , Hafford L. , Hannigan M. P.
Published: July 2014

Abstract. We developed and validated an automated, inexpensive, and continuous multiple-species gas-flux monitoring system that can provide data for a variety of relevant atmospheric pollutants, including O3, CO2, and NOx. Validation consisted of conducting concurrent gas-phase dry-deposition experiments, using both dynamic flux chambers and an eddy-covariance system, in a grassy clearing in the Duke Forest (Chapel Hill, NC). Experiments were carried out in June and September, under a variety of meteorological conditions. Ozone-deposition measurements from the two methods matched very well (4–10% difference in mean flux rate) when the leaf-area index (LAI) inside the chambers was representative of the average LAI in the field. The dynamic flux chambers can be considered an accurate measurement system under these conditions. CO2 measurements were conducted for one 20 h period, and the flux chamber captured the diurnal trend in CO2 flux well, although the quantity of the data was not sufficient to validate chamber performance. Flux-chamber NOx measurements could be calculated when ambient NOx concentrations were above 1 ppb. Unfortunately, the eddy-covariance system for measuring NOx was not available during this field campaign, so comparisons cannot be made. NOx fluxes were in a reasonable range for the field site.
On the potential vegetation feedbacks that enhance phosphorus availability – insights from a process-based model linking geological and ecological timescales
Authors: Buendía C. , Arens S. , Hickler T. , Higgins S. I. , Porada P. , Kleidon A.
Published: July 2014

Abstract. In old and heavily weathered soils, the availability of P might be so small that the primary production of plants is limited. However, plants have evolved several mechanisms to actively take up P from the soil or mine it to overcome this limitation. These mechanisms involve the active uptake of P mediated by mycorrhiza, biotic de-occlusion through root clusters, and the biotic enhancement of weathering through root exudation. The objective of this paper is to investigate how and where these processes contribute to alleviate P limitation on primary productivity. To do so, we propose a process-based model accounting for the major processes of the carbon, water, and P cycles including chemical weathering at the global scale. Implementing P limitation on biomass synthesis allows the assessment of the efficiencies of biomass production across different ecosystems. We use simulation experiments to assess the relative importance of the different uptake mechanisms to alleviate P limitation on biomass production. We find that active P uptake is an essential mechanism for sustaining P availability on long timescales, whereas biotic de-occlusion might serve as a buffer on timescales shorter than 10 000 yr. Although active P uptake is essential for reducing P losses by leaching, humid lowland soils reach P limitation after around 100 000 yr of soil evolution. Given the generalized modelling framework, our model results compare reasonably with observed or independently estimated patterns and ranges of P concentrations in soils and vegetation. Furthermore, our simulations suggest that P limitation might be an important driver of biomass production efficiency (the fraction of the gross primary productivity used for biomass growth), and that vegetation on old soils has a smaller biomass production rate when P becomes limiting. With this study, we provide a theoretical basis for investigating the responses of terrestrial ecosystems to P availability linking geological and ecological timescales under different environmental settings.
Effect of enhanced pCO2 levels on the production of dissolved organic carbon and transparent exopolymer particles in short-term bioassay experiments
Authors: MacGilchrist G. A. , Shi T. , Tyrrell T. , Richier S. , Moore C. M. , Dumousseaud C. , Achterberg E. P.
Published: July 2014

Abstract. It has been proposed that increasing levels of pCO2 in the surface ocean will lead to more partitioning of the organic carbon fixed by marine primary production into the dissolved rather than the particulate fraction. This process may result in enhanced accumulation of dissolved organic carbon (DOC) in the surface ocean and/or concurrent accumulation of transparent exopolymer particles (TEPs), with important implications for the functioning of the marine carbon cycle. We investigated this in shipboard bioassay experiments that considered the effect of four different pCO2 scenarios (ambient, 550, 750 and 1000 μatm) on unamended natural phytoplankton communities from a range of locations in the northwest European shelf seas. The environmental settings, in terms of nutrient availability, phytoplankton community structure and growth conditions, varied considerably between locations. We did not observe any strong or consistent effect of pCO2 on DOC production. There was a significant but highly variable effect of pCO2 on the production of TEPs. In three of the five experiments, variation of TEP production between pCO2 treatments was caused by the effect of pCO2 on phytoplankton growth rather than a direct effect on TEP production. In one of the five experiments, there was evidence of enhanced TEP production at high pCO2 (twice as much production over the 96 h incubation period in the 750 μatm treatment compared with the ambient treatment) independent of indirect effects, as hypothesised by previous studies. Our results suggest that the environmental setting of experiments (community structure, nutrient availability and occurrence of phytoplankton growth) is a key factor determining the TEP response to pCO2 perturbations.
Biogeochemical implications of comparative growth rates of Emiliania huxleyi and Coccolithus species
Authors: Daniels C. J. , Sheward R. M. , Poulton A. J.
Published: July 2014

Abstract. Coccolithophores are a diverse and biogeochemically important group of phytoplankton in terms of the production and export of calcite, yet the comparative physiology and ecology of species other than the ubiquitous Emiliania huxleyi is poorly understood. Despite assumptions that Emiliania huxleyi is a fast growing species, we found it had comparable growth rates (0.16–0.85 d−1) with strains of Coccolithus pelagicus and Coccolithus braarudii when grown under identical temperature and light conditions. A recently isolated Arctic strain of C. pelagicus (RCC4092) exhibited only a 12% slower growth rate, on average, than a recently isolated Arctic strain of E. huxleyi (RCC3533), over a temperature range of 6–12 °C. Established temperate strains of E. huxleyi and C. braarudii (RCC1228 and RCC1198) exhibited a slightly larger difference in growth rates, with E. huxleyi growing 28% faster on average than C. braarudii over a temperature range of 12–19 °C. Coupled with the 30–80 times higher cellular calcite content of C. pelagicus and C. braarudii compared to E. huxleyi, this suggests that Coccolithus species could be major calcite producers in mixed populations. The relative abundance of coccolithophore species is key for determining which species will dominate calcite production in mixed communities growing at similar rates. Field samples from the North Atlantic show that C. pelagicus is in a high enough relative abundance in 69% of samples collected in the spring and summer of 2010 to be a larger source of calcite production than E. huxleyi.
Adding a dynamical cryosphere to iLOVECLIM (version 1.0): coupling with the GRISLI ice-sheet model
Authors: Roche D. M. , Dumas C. , Bügelmayer M. , Charbit S. , Ritz C.
Published: July 2014

Abstract. We present a coupling approach to and the first results of the GRISLI ice-sheet model within the iLOVECLIM-coupled climate model. The climate component is a relatively low-resolution earth system model of intermediate complexity, well suited for long-term integrations and thus for coupled climate–cryosphere studies. We describe the coupling procedure with emphasis on the downscaling scheme and the methods to compute the snow fraction from total precipitation fields. We then present results for the Greenland ice sheet under pre-industrial climate conditions at the end of a 14 000 yr long integration. The simulated ice sheet presents too large a thickness in its central part owing to the overestimation of precipitation in the atmospheric component. We find that including downscaling procedures for temperature improves the temperature distributions over Greenland for both the summer and annual means. We also find an ice-sheet areal extent that is overestimated with respect to the observed Greenland ice sheet.
A lithosphere-scale structural model of the Barents Sea and Kara Sea region
Authors: Klitzke P. , Faleide J. I. , Scheck-Wenderoth M. , Sippel J.
Published: July 2014

Abstract. The Barents Sea and Kara Sea region as part of the European Arctic shelf, is geologically situated between the Proterozoic East-European Craton in the south and early Cenozoic passive margins in the north and the west. Proven and inferred hydrocarbon resources encouraged numerous industrial and academic studies in the last decades which brought along a wide spectrum of geological and geophysical data. By evaluating all available interpreted seismic refraction and reflection data, geological maps and previously published 3-D-models, we were able to develop a new lithosphere-scale 3-D-structural model for the greater Barents Sea and Kara Sea region. The sedimentary part of the model resolves four major megasequence boundaries (earliest Eocene, mid-Cretaceous, mid-Jurassic and mid-Permian). Downwards, the 3-D-structural model is complemented by the top crystalline crust, the Moho and a newly calculated lithosphere-asthenosphere boundary (LAB). The thickness distribution of the main megasequences delineates five major subdomains differentiating the region (the northern Kara Sea, the southern Kara Sea, the eastern Barents Sea, the western Barents Sea and the oceanic domain comprising the Norwegian-Greenland Sea and the Eurasia Basin). The vertical resolution of five sedimentary megasequences allows comparing for the first time the subsidence history of these domains directly. Relating the sedimentary structures with the deeper crustal/lithospheric configuration sheds some light on possible causative basin forming mechanisms that we discuss. The newly calculated LAB deepens from the typically shallow oceanic domain in three major steps beneath the Barents and Kara shelves towards the West-Siberian Basin in the east. Thereby, we relate the shallow continental LAB and slow/hot mantle beneath the southwestern Barents Sea with the formation of deep Paleozoic/Mesozoic rift basins. Thinnest continental lithosphere is observed beneath Svalbard and the NW Barents Sea where no Mesozoic/early Cenozoic rifting has occurred but strongest Cenozoic uplift and volcanism since Miocene times. The East Barents Sea Basin is underlain by a LAB at moderate depths and a high-density anomaly in the lithospheric mantle which follows the basin geometry and a domain where the least amount of late Cenozoic uplift/erosion is observed. Strikingly, this high-density anomaly is not present beneath the adjacent southern Kara Sea. Both basins share a strong Mesozoic subsidence phase whereby the main subsidence phase is younger in the South Kara Sea Basin.
A New Isoxazolic Compound Acts as α7 Nicotinic Receptor Agonist in Human Umbilical Vein Endothelial Cells
Authors: Cortés Magdalena P. , Alvarez Rocío , Sepúlveda Evelyn , Jiménez-Aspee Felipe , Astudillo Luis , Vallejos Gabriel , Gutiérrez Margarita
Published: July 2014

Recent evidence suggests that the α7 nicotinic acetylcholine receptors (α7 nAChRs) participate in the development of angiogenesis and could be a new endothelial target for revascularization in therapeutic angiogenesis. It has been shown that in human umbilical vein endothelial cells (HUVECs) α7 nAChR agonists increase the intracellular calcium concentration ([Ca2+]i), thus inducing proliferation and vessel formation which are important stages of angiogenesis. In the present study we evaluated the effect of new isoxazole compounds on the cytosolic Ca2+ signal in HUVECs using the fluorescent Ca2+ indicator Fluo-3AM and probing the involvement of α7 nAChR by means of pharmacological tools. HUVECs expressed mainly α7 nAChR, since there was no significant difference in the increase in [Ca2+]i induced by nicotine, a non-selective nicotinic agonist, in relation to choline, a selective α7 nAChR agonist. The increase in [Ca2+]i induced by 1 mM choline was inhibited significantly (p = 0.014) in cells which had been pre-incubated for 15 min with methyllycaconitine (MLA), a selective α7 nAChR antagonist. The studied compounds 1, 2, and 3 induced an increase in [Ca2+]i in a dose-dependent manner. Compound 1 at 10 mM induced a greater increase in [Ca2+]i than compounds 2 and 3. The increase in [Ca2+]i induced by compound 1 was significantly inhibited by MLA (p = 0.013) and completely inhibited by mecamylamine, a non-selective nAChR antagonist, indicating that the isoxazolic compound 1 acts as an α7 nAChR agonist.
De l’émergence des stations balnéaires au tourisme sportif
Authors: Bodin Dominique , Javerlhiac Sophie , Héas Stéphane , Robène Luc
Published: July 2014

Tourisme, loisirs, et sports tendent en ce début de XXIe siècle à se confondre ou tout au moins à se conjuguer. Les modifications et le mélange de ces trois secteurs sont le reflet des profondes transformations sociales et culturelles de notre société que les organisateurs d’événements sportifs, les collectivités locales ou territoriales ou encore les entreprises privées ont su saisir. Les relations entre ces trois pôles distincts jusqu’alors sont telles que les uns et les autres s’influencent : les touristes demandent de plus en plus d’activités ludosportives tandis que les grands événements sportifs drainent de plus en plus de touristes; la demande oblige à la construction d’équipements, mais les équipements attirent de nouveaux touristes. En bref, tourisme, loisirs et sports participent au développement local et régional tout autant qu’à la satisfaction des individus.
Une accroche locale dans le réseau Internet
Authors: Guyon Frédérick
Published: July 2014

L’analyse du coeur des sites Internet des accompagnateurs en moyenne montagne (AMM) nous montre que ces professionnels de l’économie rurale et touristique fondent leur identité professionnelle en proposant un produit spécifique : un « panier de produits du terroir ». La spécificité de ce dernier tient dans le fait qu’il rassemble les notions de lieu et de patrimoine dans une tendance à la mondialisation des destinations. L’étude des sites Internet et de cet outil de mercatique révèle une inévitable exploitation des ressources locales, qu’elles soient naturelles, géologiques, architecturales, alimentaires, techniques ou culturelles. Le paysage devient alors un objet de consommation décliné en catégories (géographique, naturelle, sportive, alimentaire, artisanale, etc.). L’AMM participe donc à la dynamique des territoires par sa contribution économique, en tant qu’acteur du tourisme, et sociale par la transmission des savoirs vernaculaires.
Le cadre juridique des activités touristiques et non gouvernementales en Antarctique
Authors: Choquet Anne
Published: July 2014

Les voyagistes doivent composer avec une concurrence de plus en plus vive. La solution passe par la mise en place d’une stratégie de différenciation de l’offre touristique, comme en témoigne le développement du tourisme en Antarctique. Compte tenu de la grande vulnérabilité de cet espace, il s’agit de rechercher comment concilier deux activités a priori contradictoires, le développement d’activités humaines et la protection de l’environnement. En effet, il n’y a qu’un moyen de ne pas endommager la région australe : ne pas y aller! Il reste que les activités touristiques et non gouvernementales constituent des occupations légitimes de la région. Initialement soumis aux règles communes à l’ensemble des activités humaines en Antarctique, le tourisme voit son cadre juridique progressivement renforcé. Le développement du tourisme antarctique conduit les États à élaborer des mesures réglementaires non seulement pour minimiser les répercussions des touristes sur l’environnement, mais également pour renforcer la sécurité des personnes sur place.
Changement climatique, authenticité et marketing des régions nordiques
Authors: Hall C. Michael
Published: July 2014

Cet article expose le rôle du père Noël comme élément central du marketing et de la compétitivité des hautes latitudes nordiques. Bien que souvent associé à la Finlande et à la Laponie, nous démontrons qu’un certain nombre de destinations tendent à utiliser le père Noël dans leur effort de développer un avantage construit. Nous soutenons par ailleurs que la valeur du père Noël comme moyen de différencier une destination s’amoindrira à court terme en raison de la perte d’authenticité qui découle de la concurrence d’autres destinations et peut-être davantage à long terme comme une des conséquences du changement climatique.
Regard chinois sur le « plus beau paysage sous le ciel »
Authors: Taunay Benjamin
Published: July 2014

Cet article s’intéresse aux pratiques des touristes intérieurs en Chine en analysant le regard qu’ils portent sur la nature dans différents sites naturels du sud-ouest de la Chine, comme le fleuve Li, les grottes de Guilin ou d’autres sites de la région du Guangxi (voire du Guizhou). Une analyse qualitative des pratiques cherche à déterminer si, chez les touristes intérieurs, une « autre » manière de regarder la nature et les paysages, singulière et originale par rapport à celles connues en Occident, est avérée.
Valorisation du patrimoine et offre géotouristique
Authors: Meignan Julien
Published: July 2014

Les sites de carrières souterraines ouvertes au public en France constituent-ils une offre géotouristique? À l'occasion d'une étude de faisabilité pour la valorisation des carrières souterraines de Lezennes (banlieue de Lille, département du Nord), une étude comparative de 12 sites souterrains a été menée. À travers une grille d'analyse fine, cette étude a permis de mettre en évidence certaines spécificités de l'offre touristique des carrières souterraines en France en termes de dimensionnement, de mode de fonctionnement et de gestion, de fréquentation, mais aussi en ce qui concerne le contenu et les thématiques développées vers le public. Cette analyse permet de poser la question plus vaste de la réalité d'une offre géotouristique au niveau national et de rappeler certains exemples internationaux. Sur cette base, l'article tente d'expliquer les différences observées et propose des pistes de réflexion et d'actions en vue de développer le géotourisme.
Geotourism and Climate Change
Authors: Hall C. Michael , Saarinen Jarkko
Published: July 2014

Geotourism has achieved considerable prominence since the early 1990s as a means of conserving geological and geomorphological heritage. However, most accounts of the effects of geotourism are at a site-specific level while interpretation tends to focus on deep geological time rather than the Anthropocene. This restriction in consideration of time and space has meant that the broader effects of geotourism-related travel throughout the tourism system have been ignored, along with the potential role of climate change in affecting geosites and attractions. These issues are discussed with respect to the paradoxes of geotourism in polar regions with the polar cryospheric environment being both threatened by climate change yet simultaneously becoming more accessible and attractive to tourists. The article concludes that, like any form of tourism, geotourism needs to be understood within the broader context of tourism and physical systems rather than in isolation in order to fully access its contribution to geoconservation.
Femmes, coeur de cible et construction d’un discours promotionnel
Authors: Bugnot Marie-Ange , Cortés Carmen , Turci Isabel
Published: July 2014

Les magazines de tourisme et de voyage utilisent un discours verbal apparemment neutre. Pourtant, une analyse qualitative du discours promotionnel, véhiculé aussi bien par le texte journalistique que par la publicité payante, nous permet de révéler la nature des mécanismes d’accroche et de persuasion, c’est-à-dire les composantes iconiques et textuelles qui interpellent très particulièrement les femmes. En effet, les discours des magazines vont montrer de subtiles marques de genre à travers lesquelles le public féminin peut se reconnaître. Nous avons circonscrit notre corpus aux textes consacrés aux prestations de bien-être, où nous avons dégagé des modèles de comportement et des tendances nouvelles ou revisitées qui nourrissent l’architecture du sens. La quête du bonheur guide l’expérience individuelle dans un parcours dépaysant qui conjugue renouveau, jouvence et beauté. Des réseaux thématiques, dont nous étudions les plus représentatifs, s’entrelacent pour orienter l’interprétation du message en vue de persuader le coeur de cible.
Diffusing EU Law beyond the Borders of the Union: The Judicialization of the European Trading Area
Authors: Tatham Allan F.
Published: July 2014

The European Union (EU) lies at the heart of a network of free trade agreements (FTAs), negotiated with partner countries in Europe and beyond.Within such a context, this paper focuses on the extent to which the judicialization of trade policy in the Union and its diffusion externally have impacted on states which are members of the European Free Trade Association (EFTA), reflecting the process of Europeanization as a manifestation of the Union external governance.
Addressing Human Rights in the Court of Justice of the Andean Community and the Tribunal of the Southern African Development Community
Authors: Molano-Cruz Giovanni , Kingah Stephen
Published: July 2014

The article compares how the regional tribunals of the Andean Community (CAN) and the Southern African Development Community (SADC) have dealt with human rights issues in order to explore options for South-South judicial cooperation through adjudicative cross-fertilization, while taking into account specificities that characterize both regions. In doing so, focus is placed on four elements: a) the scope of human rights covered by each of the regional tribunals; b) the locus standi of individuals before the tribunals; c) the added value of the regional tribunals; and d) the restrictive role of politics in the functioning of the tribunals.
Una evaluación del Programa de Convergencia Macroeconómica de la Comunidad Andina de Naciones: el caso colombiano
Authors: Gómez Olaya Álvaro Pío
Published: July 2014

The article evaluates the international coordination process of macroeconomic policies carried out by Colombia within the framework of the Macroeconomic Convergence Program of the Andean Community of Nations (CAN, from its Spanish initials). It examines the relationship between the achievement of macroeconomic policy goals and the international coordination of CAN policies by consulting a group of experts in this field.
An enigmatic group of arctic island caribou and the potential implications for conservation of biodiversity
Authors: McFarlane Keri , Miller Frank L. , Barry Samuel J. , Wilson Gregory A.
Published: July 2014

We investigated the status of caribou classified as Rangifer tarandus pearyi by DNA analyses, with an emphasis on those large-bodied caribou identified as ultra pearyi that were collected in summer 1958 on Prince of Wales Island, south-central Canadian Arctic Archipelago. Our comparative assessment reveals that the ultra pearyi from Prince of Wales Island belong to a group of pearyi and are not hybrids of pearyi x groenlandicus, as we found for the caribou occurring on nearby Banks Island and northwest Victoria Island. The ultra pearyi from Prince of Wales Island cluster with high arctic pearyi and are separated genetically from the caribou populations that we sampled on the low Canadian Arctic Islands and the Canadian mainland. Our findings reveal biodiversity below the level of subspecies or regional designations. These results support the position that to retain the biodiversity present among caribou populations on the Canadian Arctic Islands, conservation efforts should be targeted at the smaller scale level of the geographic population, rather than on a wider regional or subspecific range-wide basis.
Harbour porpoises (Phocoena phocoena) in the North Atlantic: Distribution and genetic population structure
Authors: Andersen Liselotte Wesley
Published: July 2014

The known geographical distribution (based on ship surveys, aerial surveys, incidental sightings, stranding and bycatch data) and the population genetic structure obtained from mitochondria DNA and nuclear DNA (isozymes and microsatellites) data analyses of the harbour porpoise in the North Atlantic have recently been reviewed and revised by the International Whaling Commission. The present review builds on these documents by integrating more recent genetic and distributional studies. Studies of the genetic structure of harbour porpoise populations tend to be concentrated in areas where samples are available which coincide with areas where incidental or directed catches or stranding take place. Nevertheless, recently, several genetic studies on the population structure have been able to reveal a more comprehensive picture of the harbour porpoise population structure in the Northwest and Northeast Atlantic, although not all areas have been subjected to analyses.
Life history and ecology of harbour porpoises (Phocoena phocoena) from West Greenland
Authors: Lockyer C , Heide-Jørgensen M P , Jensen J , Walton M J
Published: July 2014

During 1988, 1989 and 1995, 187 harbour porpoises (Phocoena phocoena) were sampled from the catches off West Greenland. The samples were taken in 3 areas between 62° N and 70° N: northerly (n=134, Maniitsoq and locations Kangaamiut, Qeqertarsuaq and Qasigiannguit further north), southerly (n=30, Nuuk) and southernmost (n=23, Paamiut). A suite of biological measurements and data were collected from these samples. Comparison of age and length distributions between years and areas indicated that while there were no statistical differences between the Maniitsoq and northerly samples in different years, the southerly Nuuk and Paamiut samples were biased to younger age classes. Application of the Gompertz growth model to length and weight at age data indicated an asymptotic length of 154 cm in females and 143 cm in males with weights of 64 kg and 52 kg respectively. A number of correlations were observed between length, midgirth(G3), body and blubber weights and blubber thickness. Indicators of body condition showed that overall pregnant females were fattest but that blubber thickness was greatest in juveniles. The blubber lipid content was generally 92-95% wet weight of tissue. Stomach content analysis for 92 animals indicated regional differences, although capelin (Mallotus villosus) was predominant in all samples. The presence of fish, squid and crustaceans indicated opportunistic feeding. Females ovulated from age 3-4 years at a length of about 140 cm; combined testis weights >200 g indicated maturation in males from age 2 years upwards at a length >125 cm. Several small embryos were found, consistent with a mating season in late summer. Testis hypertrophy in August also supported a late summer breeding. Analysis of ovarian corpora indicated annual ovulation. Certain biological parameters, including body condition indicators, indicate differences between WestGreenland and eastern North Atlantic populations that agree with published genetic findings.
The harbour porpoise (Phocoena phocoena) in the North Atlantic: Variability in habitat use, trophic ecology and contaminant exposure
Authors: Bjørge Arne
Published: July 2014

Harbour porpoises inhabit coastal waters, in habitats that are characterized by high diversity and complexity in terms of their bathymetry, substrate, fish communities and point sources of contaminants. The complexity in these habitats influences both the habitat use and feeding ecology of porpoises. Congregations of porpoises feeding primarily on one species are observed in some areas and seasons, while wide movements and diets composed of several species are observed in other areas. Due to these observations, this paper suggests that caution is needed when extrapolatingknowledge from one area to another with regard to porpoise habitat use, exposure to contaminants, and interactions with fisheries. Management plans should be site specific and based on local knowledge incorporating porpoise population structure, habitat use, and multiple environmental factors in order to ensure appropriate conservation of this abundant but still vulnerable small cetacean species.
An experimental study of postmortem ocular fluid and core temperature analysis in incidentally captured harbour porpoise (Phocoena phocoena)
Authors: Hood C , Daoust P-Y , Lien J , Richter C
Published: July 2014

Determination of elapsed time since death in small cetaceans can be important to our understanding of the nature of their interactions with fishing operations. This pilot study was conducted to determine the potential diagnostic usefulness of ocular fluid (vitreous humour) and core body temperature to estimate postmortem intervals in harbour porpoises (Phocoena phocoena). Core temperature and concentrations of various constituents of vitreous humour (glucose, urea, sodium, potassium, chloride, magnesium, calcium, and phosphorus) were determined in 24 harbour porpoises incidentally caught in groundfish gillnets in the waters of the Gulf of Maine and the Bay of Fundy. These parameters were compared to published values for rectal temperatures and the serum concentrations of several selected elements in live harbour porpoises. Glucose in vitreous humour decreased in dead animals compared to serum values in live ones; its level was positively correlated with core temperature. Potassium and magnesium in vitreous humour increased following death. These data suggest that most animals analysed had been dead for several hours. For the present, the methodology affords researchers an approach that appears to hold some promise. However, the most practical technique requires testing animals with a known time of death in order to derive a set of curves for ocular fluid values and temperature versus time that are appropriate for a statistical presentation of predictability for the time since death.
Geographical, and seasonal variation in the diet of harbour porpoises (Phocoena phocoena) in Icelandic coastal waters
Authors: Víkingsson Gísli A , Ólafsdóttir Droplaug , Sigurjónsson Jóhann
Published: July 2014

The stomach contents of 1,047 harbour porpoises (Phocoena phocoena) bycaught in gillnets off Iceland were analysed. Most of the samples were obtained southwest (SW) and southeast (SE) of Iceland and the majority were taken in March and April. The sex ratio was biased towards males (63% males), particularly in the SE area (76%). The proportion of sexually mature porpoises was 35% and was higher in the northern part of the study area. Most examined stomachs contained identifiable food remains (97%). More than 40 fish and invertebrate prey taxa were identified.Overall capelin (Mallotus villosus) comprised the predominant prey, followed by sandeel (Ammodytidae sp.), then gadids, cephalopods and redfish (Sebastes marinus), while other taxa were of less importance. Differences were detected in diet composition among 5 areas around Iceland with redfish and gadids more prominent in the northern areas. Off SW Iceland there was considerable seasonal variation in the porpoise diet, where capelin appeared to be dominant in late winter and spring and sandeel in the summer through early winter. Predominance of capelin in the diet coincided with the spawning migration of capelin from northern waters along the east, south and west coasts of Iceland. Mature females appeared to have a more diverse diet than other reproductive classes. The length distributions of fish consumed by the porpoises ranged from 1 to 51 cm although most fish prey were less than 30 cm.
Bycatch as a potential threat to harbour porpoises (Phocoena phocoena) in Polish Baltic waters
Authors: Skóra Krzysztof E , Kuklik Iwona
Published: July 2014

Sixty-two verified reports obtained in the years 1990-1999 on the bycatch, strandings and sightings of harbour porpoises in the Polish Baltic were analysed in this study. In relative terms the highest number of reports (22) was noted in Puck Bay. Forty-five (72.6%) reports referred to specimens from bycatch, 10 (16.1%) were individuals observed at sea, and 7 (11.3%) were stranded. A large proportion (42.2%) of the bycatch occurred in the fishing grounds of Puck Bay. Forty carcassesof harbour porpoises were obtained for further analysis. Most of the bycatch took place from December to April with a maximum in March. In the rest of the year there were 1 to 3 bycaught animals reported per month with no cases of bycatch in June. Taking into account data on fishing effort collected for the study area it appears that by far the greatest threat to harbour porpoises is posed by nets used for salmonids. Among all the bycaught animals, most (40.0%) perished in salmon semi-drift nets. A considerable number of the harbour porpoises perished inbottom set nets for cod (33.3%) while only a single bycatch event was reported from herring trawl nets. To assess the danger from different fishing gear and to determine the areas where the threats are the highest, direct observation of the fisheries was conducted. In the course of boat inspections various types of fishing gear were identified and geographical positions of 1,069 nets were marked. The majority (92%) consisted of semi-drift nets for sea trout and salmon. Relatively lowrates of bycatch were reported from bottom set nets, which had a density over 20 times less than that of surface salmon nets in the area in the autumn months. The density and distribution of both types of nets in the surveyed area was comparable during autumn and winter, when the majority of bycaught animals in bottom set nets were reported.
Sealworm (Pseudoterranova decipiens) infection in the benthic cottid (Taurulus bubalis) in relation to population increase of harbour seal (Phoca vitulina) in Skagerrak, Sweden
Authors: Lunneryd Sven-Gunnar , Ugland Karl Inne , Aspholm Paul Eric
Published: July 2014

In Koster archipelago (northern Skagerrak, Sweden) the harbour seal population increased from approximately 350 to more than 1000 individuals between 1988 and 1998. During the same period, sealworm (Pseudoterranova decipiens) abundance in the most heavily infected fish species, bullrout (Myoxocepahulus scorpius) and sea scorpion (Taurulus bubalis), did not increase. Since harbour seals do not normally feed on those cottids an infection route via cod (Gadus morhua), which consume cottids, is proposed. The abundance of sealworm in the final host is therefore related to the probability of cod preying on infected cottids prior to being preyed upon by seals. Our model predictsthat the abundance of larval sealworm in benthic fishes is not related to the number of seals when the colony is over a specific threshold size.
Establishing the relative importance of sympatric definitive hosts in the transmission of the sealworm, Pseudoterranova decipiens: a host-community approach
Authors: Aznar F Javier , Balbuena Juan A , Fernández Mercedes , Raga J Antonio
Published: July 2014

The importance of a given host to a particular parasite can be determined according to three different criteria: host preference, host physiological suitability and host contribution to transmission. Most studies on the sealworm Pseudoterranova decipiens have focussed on the latter factor, but few attempts have been made to develop a quantitative transmission model evaluating the relative importance of each host. The purpose of this study was to propose a flow-chart model to study sealworm transmission within a seal community. The model was applied to hypothetical data of four seal species acting as definitive hosts of P. decipiens sensu stricto in eastern Canada: harp seal Phoca groenlandica, harbour seal P. vitulina, grey seal Halichoerus grypus and hooded seal Cystophora cristata. The dynamics of the model was studied using population estimates from 1990 to 1996. To illustrate the interrelationship of the seal populations in the flow dynamics, the model’s behaviour was explored by manipulation of the harp seal population size. The results showed that grey seals accounted by far for most transmission from and to the seals. The harbour seal population also sustained a biologically significant proportion of the flow, whereas the role of hooded and harp seals seemed negligible despite their large population sizes. The hypothetical removal of the harp seal population resulted in small increases in the relative flows to the other seals. These results conform to previous qualitative assessments on the relative importance of these seal species in sealworm transmission. The model provided some heuristic rules useful to understand transmission patterns. The data suggested that the harbour seal population should be about twice that of the grey seals to account for a larger share of transmission than grey seals. Although this is unlikely to occur at a large geographic scale, harbour seals outnumber grey seals in some areas and, therefore, the role of each host may change locally. To make this approach more realistic, further work should seek accurate estimates of parasite population parameters, better definition of the host community boundaries (at a local scale) and improved control of confounding variables.
First independent feeding of harp seal (Phoca groenlandica) and hooded seal (Cystophora cristata) pups in the Greenland Sea
Authors: Haug Tore , Nilssen Kjell T , Lindblom Lotta
Published: July 2014

Data were collected from harp seal (Phoca groenlandica) and hooded seal (Cystophora cristata) pups belonging to the Greenland Sea (or "West Ice") stocks in 1995-1997. Pups of both species were observed to feed independently shortly after weaning, and their first food was almost exclusively crustaceans. Parathemisto sp., particularly P. libellula, dominated the diet of both the harp and the hooded seal pups, but the diet also contained sympagic amphipods of the genus Gammarus. Krill (Thysanoessa sp.) was of minor importance as food for seal pups in 1995, but occurred more frequentlyin the diet of both species in 1996 and 1997. Considerable niche overlap may suggest some interspecific competition between harp and hooded seal pups in the West Ice.
Feeding habits of harp (Phoca groenlandica) and hooded seals (Cystophora cristata) during late winter, spring and early summer in the Greenland Sea
Authors: Potelev Vladimir , Nilssen Kjell Tormod , Svetochev Vladislav , Haug Tore
Published: July 2014

Diet data were collected in the Greenland Sea pack ice (the West Ice) from March to June from harp seals (Phoca groenlandica) in 1987, 1990-1992 and 1997, and from hooded seals (Cystophora cristata) in 1992 and 1994, during Soviet Russian commercial sealing and on Norwegian scientific expeditions. The majority of both harp and hooded seal stomachs were empty but intestinal contents were found in most of the seals. The harp seal diet was totally dominated by the amphipods Parathemisto sp. and Gammarus sp., but krlll (Thysanoessa sp.) and polar cod (Boreogadus saida) were also eaten quite frequently. Hooded seals had been feeding mainly on the squid Gonatus fabricii, which was found most frequently in the intestines, but which also dominated in the few stomachs with contents. Polar cod also occurred quite frequently in the hooded seal diet, while crustaceans, such as amphipods and krill, occurred only sporadically.
Feeding habits of harp and hooded seals in Greenland waters
Authors: Kapel Finn O
Published: July 2014

Results of stomach contents analyses of harp and hooded seals collected in West Greenland waters in the period 1986-1993 are reviewed, and compared with published data and circumstantial information from local hunters. The diet of harp seals in this region is variable but consists mainly of pelagic crustaceans (Thysanoessa spp. and Parathemisto libellula) and small fish species like capelin (Mallotus villosus), sandeel (Ammodytes spp.), polar cod (Boreogadus saida) and Arctic cod (Arctogadus glacialis). Species of importance for commercial fisheries in Greenland, such as Northern prawn (Pandalus borealis), Atlantic cod (Gadus morhua), and Greenland halibut (Reinhardtius hippoglossoides) play a minor role in the diet of harp seals in this area.Variation in the diet of hooded seals is less well documented, but in addition to the species also taken by harp seals, larger demersal fishes like Greenland halibut, redfish (Sebastes spp.), cod, and wolffish (Anarhichas minor) are apparently important prey items.
Exploitation of ringed seals (Phoca hispida) in Greenland
Authors: Teilmann Jonas , Kapel Finn O
Published: July 2014

The ringed seal (Phoca hispida) is the most important game for the Inuit hunters of Greenland, providing many of the basic needs in the original culture. It is distributed all around Greenland with the main distribution north of 69°N on the west coast and north of 66°N on the east coast. During 1974-76, studies were conducted in the most important ringed seal catching area, Upernavik, Northwest Greenland, and a total of 7,089 ringed seals were sampled. The methods used for catching ringed seals were categorised into five different groups. The most common hunting method used in the municipality of Upernavik during 1974-76 was netting under the ice, accounting for almost half of the total annual catch. Seals shot on the ice and seals shot at the ice edge accounted for one fifth and one tenth of the annual catch, respectively. In this region seals shot in open water made up about one fifth of the annual catch of ringed seals, while netting in open water contributed only a few percent.Of the seals sampled in Upernavik in 1974-76, 60% were males and 40% were females. In the ringed seal samples collected all around Greenland in the 1980s and 1990s the males comprised 56% and the females 44% (n=923). Similar ratios were found for all age classes and for all hunting methods suggesting either a skewed sex ratio in the ringed seal stock(s) around Greenland or a differencein availability to the hunters of male and female ringed seals. In tagging experiments a higher mobility was found for females than for males, which suggests differences in the behaviour of the two sexes.Catch and trade statistics on ringed seals are reviewed and evaluated for the period of 1954 until 1994, and the seasonal and regional variation is examined. The peak season for ringed seal hunting in Greenland as a whole is from January through May. This is particularly evident for the northern regions, where relatively few ringed seals are taken during the open water season from June to September. In the southern regions, however, the great majority of ringed seals are caught in openwater.In all regions, the catch of ringed seals showed great annual and long-term variation. The variations were not identical in all regions, but similar trends were found for Northwest and Central West, and for Southwest and South. From 1954 to 1994 there was a general, significant increase in the reported catches of ringed seals in west Greenland. For Greenland overall, the catch of ringed seals wasaround 43,000 per year in the 1950s, peaked in the late 1970s at almost 100,000 per year, but since decreased to about 70,000 in the early 1990s.
The numbers of ringed seals (Phoca hispida) in Baffin Bay and associated waters
Authors: Kingsley Michael C S
Published: July 2014

The size of the population of ringed seals (Phoca hispida) inhabiting Baffin Bay and associated waters was estimated by two methods. An approximate model of the energetics of the polar bear (Ursus maritimus) estimated an energetic need of about 16,000 MJ/bear per year. Modelled estimates of the energetic yield of a ringed seal population showed that a stable standing population of 140-170 ringed seals per bear would be needed to provide that much energy, assuming that all mortalities were due to polar bear predation. This result was sensitive to assumptions about the Field Metabolic Rate (FMR) of the bears and the energetic yield of individual ringed seals, but less sensitive to assumptions about relative incidence of predation on different age classes of seal or the age structure of the polar bear population. Estimated sizes of polar bear populations in Baffin Bay and associated waters (total about 4,025), and of the standing population needed to support an estimated hunter kill of 100,000 yielded a population estimate of, very roughly, 1.2 million ringed seals. Estimates of ice areas and of the density of hauled out seals from aerial surveys were used to generate another approximate figure for the ringed seal population, which was about the same. The density of seals in the pack-ice area of Baffin Bay, which is imperfectly known, has a large influence on the latter estimate.
Netting and conventional tagging used to study movements of ringed seals (Phoca hispida) in Greenland
Authors: Kapel Finn O , Christiansen Jens , Heide-Jørgensen Mads Peter , Härkönen Tero , Born Erik W , Knutsen Lars Øivind , Riget Frank , Teilmann Jonas
Published: July 2014

Seven studies of netting and tagging of ringed seals (Phoca hispida) in Greenland 1976-1997 are described. The areas of operation were: northern part of the Upernavik area (Northwest Greenland), Kong Oscars Fjord (Northeast Greenland), and Avanersuaq (Thule, North Greenland). Altogether, 135 seals were caught, of which 99 were tagged and released with Dalton Jumbo rototags. Recapture of 38 tagged seals has been reported to date. The recaptures demonstrate movements of ringed seals in Greenland of more than 100km within districts, as well as long-distance movementsof more than 1000km from the site of release.