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Chauvaud Laurent, Thébault Julien, Clavier Jacques, Lorrain Anne, Strand Øivind, . (2011). Whats Hiding Behind Ontogenetic 13C Variations in Mollusk Shells? New Insights from the Great Scallop (Pecten maximus)
. ESTUARIES AND COASTS, 34(2), 211–220-.
Abstract: Mollusk shells contain geochemical information about environmental conditions that prevailed at the time of formation. We investigated ontogenetic and seasonal variations of δ13C in calcitic shells of Pecten maximus. Ontogenetic variations of δ13Cshell in three large specimens collected in Norway, France, and Spain exhibited a similar linear decrease with increasing shell height. We removed this linear drift (detrending). These three residual time series displayed variations that could be linked to environmental fluctuations. To check it, we reanalyzed the isotopic datasets of Lorrain et al. (Journal of Experimental Marine Biology and Ecology 275:47–61, 2002, Geochimica et Cosmochimica Acta 68:3509–3519, 2004), who worked on three scallops harvested in 2000 in the bay of Brest (France), a well-monitored ecosystem. Lowest values of δ13Cshell detrended were recorded in all shells in late spring–early summer, most likely reflecting corresponding variations in food availability. Our results indicate that ontogenetic and seasonal variations of δ13Cshell cannot be used as a proxy for past δ13CDIC variations but should be considered as promising tools for ecophysiological studies.
Keywords: Scallop shells, Carbon isotopes, Phytoplankton, Ontogeny, Proxy,
Programme: 1090
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Eléaume Marc, Hemery LenaïgG, Bowden DavidA, Roux Michel, . (2011). A large new species of the genus Ptilocrinus (Echinodermata, Crinoidea, Hyocrinidae) from Antarctic seamounts
. 0722-4060, 34(9), 1385–1397-.
Abstract: Ptilocrinus amezianeae n. sp. is a new species of stalked crinoid attributed to the family Hyocrinidae. Forty-five specimens were collected from seamounts north of the Ross Sea, and one specimen from the Kerguelen Plateau at depths ranging from 450 to 1,680 m. The collection from Admiralty and Scott seamounts constitutes the first example of a hyocrinid population known both from in situ photographs and from numerous collected specimens ranging from small juvenile to large adult. Variation in theca and stalk articulation characters throughout ontogeny is congruent with the molecular data and indicates that all the specimens examined belong to a single species. Tegmen and pinnule architecture, brachial arrangement, and stalk articular facets indicate that Ptilocrinus amezianeae n. sp. has close affinities with P. clarki and P. pinnatus from the northeastern Pacific and displays the most derived characters among these three species. Two cases of true arm division into two unequal branches suggest that Ptilocrinus and Calamocrinus are closely related. The picture and video transects on Admiralty seamount show a patchy distribution of living specimens with patches of mean density ca. 2.6 individuals m-2. In situ photographs also document predation by a sea urchin and a sea star on tegmen and proximal arms. The COI gene sequences analyzed in 25 specimens from Admiralty and Scott seamounts display low pairwise distances, low nucleotidic diversity, and intermediate haplotype diversity. These results, together with disarticulated ossicles and attachment disks observed on in situ photographs, indicate that the population investigated here is in decline.
Keywords: Echinodermata, Stalked crinoids, Hyocrinidae, Ptilocrinus, Antarctica, Seamount, Ross sea, Kerguelen plateau,
Programme: 1044
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Barbraud Christophe, Weimerskirch Henri, . (2012). Assessing the effect of satellite transmitters on the demography of the Wandering Albatross Diomedea exulans
. Wilson J Ornithol, 153(2), 375–383-.
Abstract: Satellite transmitters and other tracking devices are valuable tools for furthering our understanding of bird movements, and their use has been steadily increasing. Since the necessary handling of birds to deploy transmitters can have deleterious consequences and the transmitter itself can add substantial mass, particularly to small species, or bring discomfort to the individual birds to which they are attached, it is important to quantify the effect such devices on both the behavior and the fitness of equipped animals. Very few studies have focused on the demographic effects of equipping birds with a satellite transmitter, with the vast majority of such studies focusing on short-term behavioral effects. We have assessed the demographic effects of attaching a satellite transmitter to the back of adult breeding Wandering Albatross individuals using long-term demographic data (20 years) and recent developments in capture–recapture methodology. We found no evidence of any negative effects of the attached devices on the probability of survival, breeding, or breeding successfully in the current or following season in either males or females. We conclude that the current satellite transmitters and smaller devices used by researchers are valuable conservation and research tools that do not adversely affect the demographic traits of large albatrosses. Similar tests should be carried out on smaller species, which are more likely to be affected.
Keywords: Adult survival, Breeding success, Capturerecapture, Multistate, Satellite transmitters, Wandering Albatross,
Programme: 109
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Barbraud Christophe, Weimerskirch Henri, . (2012). Estimating survival and reproduction in a quasi-biennially breeding seabird with uncertain and unobservable states
. Wilson J Ornithol, 152(2), 605–615-.
Abstract: Estimating the effects of environmental factors on the population dynamics of albatrosses is necessary for their conservation. This requires estimation of demographic parameters, long-time series of capture–recapture data, and knowledge of their at-sea distribution. For biennial albatrosses, multistate mark–recapture models (MSMR) considering individuals during their sabbatical year as unobservable could provide reliable estimates. However, this requires that state assignment is determined with certainty which may not be the case in historical data. We applied multievent mark–recapture models (MEMR) to data on adult Wandering Albatross (Diomedea exulans) at Possession Island collected between 1966 and 2006. The models accounted for state uncertainty for those breeding states where the breeding outcome was uncertain. Survival estimates obtained from models not accounting for temporary emigration were higher than those obtained from models accounting for temporary emigration. For males and females, survival estimates from the MEMR models were higher than those from CJS and MSMR models. Annual survival probability was 0.924 (SE = 0.034) for breeding females, 0.971 (SE = 0.038) for non-breeding females, 0.954 (SE = 0.018) for breeding males, and 0.938 (SE = 0.017) for non-breeding males. Whereas Wandering Albatrosses are generally considered as obligate biennial breeders, we found that the probability that successful breeders attempted to breed in a subsequent year was 0.069 for females and 0.048 for males, although their probability of success was 44–62% lower than that of individuals that skipped breeding.
Keywords: Capturerecapture, Multievent, Multistate, Temporary emigration, Wandering Albatross,
Programme: 109
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Gauthier Gilles, Milot Emmanuel, Weimerskirch Henri, . (2012). Estimating dispersal, recruitment and survival in a biennially breeding species, the Wandering Albatross
. J. Ornithol., 152(2), 457–467-.
Abstract: The study of dispersal or recruitment in long-lived birds using capture–recapture methods is challenging because temporary emigration is often a source of heterogeneity in detection probabilities. To deal with this problem, we introduced unobservable states in the multistate, spatial recruitment model of Lebreton et al. (Oikos 101:253–264, 2003) to study dispersal, recruitment and survival in the Wandering Albatross (Diomedea exulans), a species with a biennial reproduction (individuals skip breeding following a successful reproduction). We highlight some of the limitations and challenges encountered in using this approach. Our dataset came from a 36-year capture–recapture study conducted at three colonies of the Crozet archipelago. The model had five reproductive stages: pre-breeders, successful breeders, failed breeders, and birds in the year after a successful or a failed breeding attempt, which are unobservable. In adults, movements between colonies (i.e. breeding dispersal) were nested within reproductive stages. Several models with different constraints on survival equally fitted the data but had some rank deficiencies (i.e. non-identifiable parameters). Survival estimates were most biologically realistic (from 0.91 to 0.95) when survival was set equal between observable/unobservable states but free to vary between successful/failed breeders and among colonies. Age-specific recruitment probabilities peaked at 9–10 years and appeared well estimated despite limitations in setting the age of constant recruitment probability. Modelling natal dispersal and recruitment required a simplification of the structure of the model due to computer limitations. When applying the complete and reduced versions of the model to the same dataset, we found that survival was well estimated in both cases. Some transition probability estimates were also similar, but transitions from unobservable to observable states were poorly estimated in the simplified version. We conclude that the simplified version of the model should be limited to the estimation of natal dispersal and that the model with a full structure should be used to estimate breeding dispersal.
Keywords: Dispersal, Philopatry, Recruitment, Multistate model, Unobservable state,
Programme: 109
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Smith PJ, Steinke D, Dettai A, McMillan P, Welsford D, Stewart A, Ward RD, . (2012). DNA barcodes and species identifications in Ross Sea and Southern Ocean fishes
. Polar Biol., 35(9), 1297–1310-.
Abstract: The Southern Ocean occupies about 10 % of the world’s oceans but has low species richness with only ~1.5 % of the marine fishes. Within the Southern Ocean, the Ross Sea region is one of the least exploited sea areas in the world, but is subject to commercial fishing. The fauna are not well known, and preliminary IPY molecular studies have indicated that species diversity has been underestimated in this region. DNA barcodes of fishes from the Ross Sea region were compared with barcodes of fishes from the Atlantic and Indian Ocean sectors of the Southern Ocean. Barcoding resolved 87.5 % of 112 species that typically exhibited high inter-specific divergences. Intra-specific divergence was usually low with shared haplotypes among regions. The Zoarcid Ophthalmolycus amberensis showed shallow divergences (0.1 %) within the Ross Sea and Australian Antarctic Territory but high inter-region divergence (2 %), indicative of cryptic species. Other potential cryptic species with high intra-specific divergences were found in Notolepis coatsi and Gymnoscopelus bolini. In contrast, several taxa showed low inter-specific divergences and shared haplotypes among morphological species. COI provided limited phylogenetic resolution of the genera Pogonophryne and Bathydraco. Trematomus loennbergii and T. lepidorhinus shared COI haplotypes, as previously noted in other regions, as did Cryodraco antarcticus and C. atkinsoni. There was a marked lack of congruence between morphological descriptions and COI divergences among the Ross Sea liparids with shallow or zero divergences among recently described species. Barcodes for the Ross Sea fishes highlighted several initial misidentifications that were corrected when specimens were re-examined.
Keywords: DNA barcode, Southern Ocean, Fishes, Species identification,
Programme: 1124
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Ledoux J-B, Tarnowska K, Gérard K, Lhuillier E, Jacquemin B, Weydmann A, Féral J-P, Chenuil A, . (2012). Fine-scale spatial genetic structure in the brooding sea urchin Abatus cordatus suggests vulnerability of the Southern Ocean marine invertebrates facing global change
. POLAR BIOLOGY, 35(4), 611–623-.
Abstract: The Southern Ocean benthic communities are characterized by their levels of endemism and their diversity of invertebrate brooding species. Overall, biological processes acting within these species remain poorly understood despite their importance to understand impacts of ongoing global change. We take part in filling this gap by studying the genetic structure over different spatial scales (from centimeters to tens of kilometers) in Abatus cordatus, an endemic and brooding sea urchin from the Kerguelen Islands. We developed three microsatellites and two exon-primed intron crossing markers and conducted a two-scale sampling scheme (from individuals to patches) within two dense localities of Abatus cordatus. Between patches, all pairwise comparisons, covering distances from few meters (between patches within locality) to 25 km (between localities), revealed significant genetic differentiation, a higher proportion of the molecular variance being explained by the comparisons between localities than within localities, in agreement with an isolation by distance model. Within patches, we found no significant correlation between individual pairwise spatial and genetic distances, except for the most polymorphic locus in the patch where the largest range of geographical distances had been analyzed. This study provides an estimation of the dispersal capacities of Abatus cordatus and highlights its low recolonization ability. Similar low recolonization capacities are thus expected in other Antarctic and Subantarctic brooding invertebrate species and suggest a high vulnerability of these species facing global change.
Keywords: Abatus cordatus, Microsatellites, Introns, Brooding, Genetic structure, Heterozygote deficiency,
Programme: 1044
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Greenslade Penelope, Vernon P, Smith D, . (2012). Ecology of Heard Island Diptera
. POLAR BIOLOGY, 35(6), 841–850-.
Abstract: Phenology, distribution and abundance of three Diptera species on Heard Island were investigated to provide baseline data for monitoring the effect on climate change on populations. Five vegetation types at two localities were sampled in two different years, firstly in the summer of 1987–1988 at Atlas Cove and secondly at Spit Bay over 12 months from summer 1992 to summer 1993. Pitfall traps and soil core extractions were operated in summer at both localities and pitfalls alone for 12 months from Spit Bay. The wingless Anatalanta aptera was the most abundant species in traps at Atlas Cove with most individuals collected from Poa tussock grassland, half as many from Pringlea and Azorella vegetation and fewest with a significantly higher level of asymmetry in the large katepisternal setae, from Azorella and Fellfield. Calycopteryx moseleyi was the most abundant fly in traps at Spit Bay, and A. maritima was the least abundant at both localities. Monthly pitfall catches from 1992–1993 indicated that A. aptera was active in most months of the year apart from winter, females early in the season and males active throughout the summer; teneral individuals only detected in January. C. moseleyi was more strongly seasonal with peak adult numbers occurring in January. Amalopteryx maritima was least seasonal in activity. Asymmetry in A. aptera suggests that it was at the limit of its ecological tolerance in Fellfield and Azorella on Heard Island. Changes caused by climate warming or invasive species are mooted.
Keywords: Anatalanta aptera, Calycopteryx moseleyi, Amalopteryx maritima, Fluctuating asymmetry, Climate change, Invasive species,
Programme: 136
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Lalouette L, Williams CM, Cottin M, Sinclair BJ, Renault D, . (2012). Thermal biology of the alien ground beetle Merizodus soledadinus introduced to the Kerguelen Islands
. POLAR BIOLOGY, 35(4), 509–517-.
Abstract: Thermal tolerance is one of the major determinants of successful establishment and spread of invasive aliens. Merizodus soledadinus (Coleoptera, Carabidae) was accidentally introduced to Kerguelen from the Falkland Islands in 1913. On Kerguelen, the climate is cooler than the Falklands Islands but has been getting warmer since the 1990s, in synchrony with the rapid expansion of M. soledadinus. We aimed to investigate the thermal sensitivity in adults of M. soledadinus and hypothesised that climate warming has assisted the colonisation process of M. soledadinus. We examined (1) survival of constant low temperatures and at fluctuating thermal regimes, (2) the critical thermal limits (CTmin and CTmax) of acclimated individuals (4, 8 and 16°C), (3) the metabolic rates of acclimated adults at temperatures from 0 to 16°C. The FTRs moderately increased the duration of survival compared to constant cold exposure. M. soledadinus exhibited an activity window ranged from −5.5 ± 0.3 to 38 ± 0.5°C. The Q 10 after acclimation to temperatures ranging from 0 to 16°C was 2.49. Our work shows that this species is only moderately cold tolerant with little thermal plasticity. The CTmin of M. soledadinus are close to the low temperatures experienced in winter on Kerguelen Islands, but the CTmax are well above summer conditions, suggesting that this species has abundant scope to deal with current climate change.
Keywords: Sub-Antarctic island, Insect, Critical thermal limit, Survival, Fluctuating thermal regime, Metabolic rate,
Programme: 136
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Lecomte Frédéric, Beall Edward, Chat Joëlle, Davaine Patrick, Gaudin Philippe, . (2013). The complete history of salmonid introductions in the Kerguelen Islands, Southern Ocean
.36(4), 457–475-.
Keywords: Introductions, Colonization, Salmo, Oncorhynchus, Salvelinus, Kerguelen Islands,
Programme: 1041
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