Constable Andrew J, Melbourne-Thomas Jessica, Corney Stuart P, Arrigo Kevin R, Barbraud Christophe, Barnes David K A, Bindoff Nathaniel L, Boyd Philip W, Brandt Angelika, Costa Daniel P, Davidson Andrew T, Ducklow Hugh W, Emmerson Louise, Fukuchi Mitsuo, Gutt Julian, Hindell Mark A, Hofmann Eileen E, Hosie Graham W, Iida Takahiro, Jacob Sarah, Johnston Nadine M, Kawaguchi So, Kokubun Nobuo, Koubbi Philippe, Lea Mary-Anne, Makhado Azwianewi, Massom Rob A, Meiners Klaus, Meredith Michael P, Murphy Eugene J, Nicol Stephen, Reid Keith, Richerson Kate, Riddle Martin J, Rintoul Stephen R, Smith Walker O, Southwell Colin, Stark Jonathon S, Sumner Michael, Swadling Kerrie M, Takahashi Kunio T, Trathan Phil N, Welsford Dirk C, Weimerskirch Henri, Westwood Karen J, Wienecke Barbara C, Wolf-Gladrow Dieter, Wright Simon W, Xavier Jose C, Ziegler Philippe, . (2014). Climate change and Southern Ocean ecosystems I: how changes in physical habitats directly affect marine biota.
. Glob Chang Biol, 20(10), 3004–25.
Abstract: Antarctic and Southern Ocean (ASO) marine ecosystems have been changing for at least the last 30 years, including in response to increasing ocean temperatures and changes in the extent and seasonality of sea ice; the magnitude and direction of these changes differ between regions around Antarctica that could see populations of the same species changing differently in different regions. This article reviews current and expected changes in ASO physical habitats in response to climate change. It then reviews how these changes may impact the autecology of marine biota of this polar region: microbes, zooplankton, salps, Antarctic krill, fish, cephalopods, marine mammals, seabirds, and benthos. The general prognosis for ASO marine habitats is for an overall warming and freshening, strengthening of westerly winds, with a potential pole-ward movement of those winds and the frontal systems, and an increase in ocean eddy activity. Many habitat parameters will have regionally specific changes, particularly relating to sea ice characteristics and seasonal dynamics. Lower trophic levels are expected to move south as the ocean conditions in which they are currently found move pole-ward. For Antarctic krill and finfish, the latitudinal breadth of their range will depend on their tolerance of warming oceans and changes to productivity. Ocean acidification is a concern not only for calcifying organisms but also for crustaceans such as Antarctic krill; it is also likely to be the most important change in benthic habitats over the coming century. For marine mammals and birds, the expected changes primarily relate to their flexibility in moving to alternative locations for food and the energetic cost of longer or more complex foraging trips for those that are bound to breeding colonies. Few species are sufficiently well studied to make comprehensive species-specific vulnerability assessments possible. Priorities for future work are discussed.
Keywords: Antarctic Regions, Aquatic Organisms, Biota, Climate Change, Ecosystem, Ice Cover, Oceans and Seas, Water Movements, Wind,
Programme: 109
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Thiebot Jean-Baptiste, Demay Jérémie, Marteau Cédric, Weimerskirch Henri, . (2015). The rime of the modern mariner: evidence for capture of yellow-nosed albatross from Amsterdam Island in Indian Ocean longline fisheries
. Polar Biol., 38(8), 1297–1300.
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Collet J, Patrick SC, Weimerskirch H, . (2015). Albatrosses redirect flight towards vessels at the limit of their visual range
. Mar Ecol Prog Ser, 526, 199–205.
Abstract: Seabird-fishery interactions are important to seabird ecology and conservation since some species obtain a significant amount of food from fisheries, but mortality from bycatch is a primary cause of population declines in several species. While the availability of high resolution GPS data for both seabirds and vessels over the past few years has allowed analyses of fine-scale behavioural responses of seabirds near fishing vessels, little information is available on the distance at which seabirds respond to vessels. Indeed, previous studies have focused on the foraging behaviour of individuals within the vicinity of vessels but have not considered the approach phase of birds. Here we provide such an estimate by examining changes in the flight direction of GPS-tracked wandering albatrosses breeding on the Crozet Islands in response to the toothfish fishing fleet operating around the breeding grounds, monitored using GPS vessel monitoring system data. We show that although we detect increases in feeding behaviour only when albatrosses are within 3 km of boats, they display clear changes in flight direction, towards vessels, at distances up to 30 km. This distance is nearly 3 times as large as previous estimates, almost reaching the theoretical maximum visual range of an albatross. We discuss these results in the light of previous estimates, and pinpoint factors likely to affect the attraction distance. We suggest that this simple estimate of attraction distance could be investigated in other seabird-fishery systems, to improve our understanding of the factors affecting seabird interaction behaviour, and thus better predict when overlap will lead to interactions.
Programme: 109
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Barbraud Christophe, Delord Karine, Weimerskirch Henri, . (2015). Extreme ecological response of a seabird community to unprecedented sea ice cover.
. Royal Society open science, 2(5), 140456.
Abstract: Climate change has been predicted to reduce Antarctic sea ice but, instead, sea ice surrounding Antarctica has expanded over the past 30 years, albeit with contrasted regional changes. Here we report a recent extreme event in sea ice conditions in East Antarctica and investigate its consequences on a seabird community. In early 2014, the Dumont d'Urville Sea experienced the highest magnitude sea ice cover (76.8%) event on record (1982-2013: range 11.3-65.3%; mean±95% confidence interval: 27.7% (23.1-32.2%)). Catastrophic effects were detected in the breeding output of all sympatric seabird species, with a total failure for two species. These results provide a new view crucial to predictive models of species abundance and distribution as to how extreme sea ice events might impact an entire community of top predators in polar marine ecosystems in a context of expanding sea ice in eastern Antarctica.
Programme: 109
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Thiebot Jean-Baptiste, Delord Karine, Barbraud Christophe, Marteau Cédric, Weimerskirch Henri, . (2015). 167 individuals versus millions of hooks: bycatch mitigation in longline fisheries underlies conservation of Amsterdam albatrosses
. Aquatic Conservation: Marine and Freshwater Ecosystems, .
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Jenouvrier Stéphanie, Péron Clara, Weimerskirch Henri, . (2015). Extreme climate events and individual heterogeneity shape life-history traits and population dynamics
. Ecological Monographs, 85(4), 605–624.
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Bost Charles A, Cotté Cedric, Terray Pascal, Barbraud Christophe, Bon Cécile, Delord Karine, Gimenez Olivier, Handrich Yves, Naito Yasuhiko, Guinet Christophe, Weimerskirch Henri, . (2015). Large-scale climatic anomalies affect marine predator foraging behaviour and demography.
. Nature communications, 6, 8220.
Abstract: Determining the links between the behavioural and population responses of wild species to environmental variations is critical for understanding the impact of climate variability on ecosystems. Using long-term data sets, we show how large-scale climatic anomalies in the Southern Hemisphere affect the foraging behaviour and population dynamics of a key marine predator, the king penguin. When large-scale subtropical dipole events occur simultaneously in both subtropical Southern Indian and Atlantic Oceans, they generate tropical anomalies that shift the foraging zone southward. Consequently the distances that penguins foraged from the colony and their feeding depths increased and the population size decreased. This represents an example of a robust and fast impact of large-scale climatic anomalies affecting a marine predator through changes in its at-sea behaviour and demography, despite lack of information on prey availability. Our results highlight a possible behavioural mechanism through which climate variability may affect population processes.
Programme: 109,394
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Labrousse Sara, Vacquié-Garcia Jade, Heerah Karine, Guinet Christophe, Sallée Jean-Baptiste, Authier Matthieu, Picard Baptiste, Roquet Fabien, Bailleul Frédéric, Hindell Mark, Charrassin Jean-Benoit, . (2015). Winter use of sea ice and ocean water mass habitat by southern elephant seals: The length and breadth of the mystery
. Prog. Oceanogr., 137(A), 52–68.
Abstract: Understanding the responses of animals to the environment is crucial for identifying critical foraging habitat. Elephant seals (Mirounga leonina) from the Kerguelen Islands (49°20′S, 70°20′E) have several different foraging strategies. Why some individuals undertake long trips to the Antarctic continent while others utilize the relatively close frontal zones is poorly understood. Here, we investigate how physical properties within the sea ice zone are linked to foraging activities of southern elephant seals (SES). To do this, we first developed a new approach using indices of foraging derived from high temporal resolution dive and accelerometry data to predict foraging behaviour in an extensive, low resolution dataset from CTD-Satellite Relay Data Loggers (CTD-SRDLs). A sample of 37 post-breeding SES females were used to construct a predictive model applied to demersal and pelagic dive strategies relating prey encounter events (PEE) to dive parameters (dive duration, bottom duration, hunting-time, maximum depth, ascent speed, descent speed, sinuosity, and horizontal speed) for each strategy. We applied these models to a second sample of 35 seals, 20 males and 15 females, during the post-moult foraging trip to the Antarctic continental shelf between 2004 and 2013, which did not have fine-scale behavioural data. The females were widely distributed with important foraging activity south of the Southern Boundary Front, while males predominately travelled to the south-eastern part of the East Antarctica region. Combining our predictions of PEE with environmental features (sea ice concentration, water masses at the bottom phase of dives, bathymetry and slope index) we found higher foraging activity for females over shallower seabed depths and at the boundary between the overlying Antarctic Surface Water (AASW) and the underlying Modified Circumpolar Deep Water (MCDW). Increased biological activity associated with the upper boundary of MCDW, may provide overwintering areas for SES prey. Male foraging activity was strongly associated with pelagic dives within the Antarctic Slope Front where upwelling of nutrient rich Circumpolar Deep Water onto surface water may enhance and concentrate resources. A positive association between sea ice and foraging activity was found for both sexes where increased biological activity may sustain an under-ice ecosystem. Variability of the East Antarctic sea ice season duration is likely a crucial element to allow air-breathing predators to benefit from profitable prey patches within the pack ice habitat.
Programme: 109
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O'Toole Malcolm D, Lea Mary-Anne, Guinet Christophe, Schick Robert, Hindell Mark A, . (2015). Foraging strategy switch of a top marine predator according to seasonal resource differences
. Frontiers in Marine Science, 2, 21.
Abstract: The spatio-temporal variability in marine resources influences the foraging behaviour and success of top marine predators. However, little is known about the links between these animals and ocean productivity, specifically, how plankton density influences their foraging behaviour. Southern elephant seals (Mirounga leonina) have two annual at-sea foraging trips: a two month post-breeding foraging trip (Nov – Jan) that coincides with elevated summer productivity; and an eight month post-moulting foraging trip (Feb – Oct) over winter, when productivity is low. Physical parameters are often used to describe seal habitat, whereas information about important biological parameters is lacking. We used electronic tags deployed on elephant seals during both trips to determine their movement and foraging behaviour. The tags also recorded light, which measured the bio-optical properties of the water column, the bulk of which is presumably influenced by phytoplankton. We investigated the relationship between plankton density and seal foraging behaviour; comparing trends between summer and winter trips. We found a positive relationship between plankton density and foraging behaviour, which did not vary seasonally. We propose that profitable concentrations of seal prey are more likely to coincide with planktonic aggregations, but we also acknowledge that trophic dynamics may shift in response to seasonal trends in productivity. Seal prey (mid-trophic level) and plankton (lower-trophic level) are expected to overlap in space and time during summer trips when peak phytoplankton blooms occur. In contrast, aggregated patches of lower trophic levels are likely to be more dispersed during winter trips when plankton density is considerably lower and heterogeneous. These results show that southern elephant seals are able to exploit prey resources in different ways throughout the year as demonstrated by the variation observed between seal foraging behaviour and trophic dynamics.
Keywords: Antarctica, Mirounga leonina, Ross Sea, Trophic link, elephant seal, foraging behavior, lower-trophic distribution,
Programme: 109
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Costantini David, Goutte Aurelie, Barbraud Christophe, Faivre Bruno, Sorci Gabriele, Weimerskirch Henri, Delord Karine, Chastel Olivier, . (2015). Demographic Responses to Oxidative Stress and Inflammation in the Wandering Albatross (Diomedea exulans).
. PloS one, 10(8), e0133967.
Abstract: One of the major challenges in ecological research is the elucidation of physiological mechanisms that underlie the demographic traits of wild animals. We have assessed whether a marker of plasma oxidative stress (TBARS) and plasma haptoglobin (protein of the acute inflammatory phase response) measured at time t predict five demographic parameters (survival rate, return rate to the breeding colony, breeding probability, hatching and fledging success) in sexually mature wandering albatrosses over the next four years (Diomedea exulans) using a five-year individual-based dataset. Non-breeder males, but not females, having higher TBARS at time t had reduced future breeding probabilities; haptoglobin was not related to breeding probability. Neither TBARS nor haptoglobin predicted future hatching or fledging success. Haptoglobin had a marginally positive effect on female survival rate, while TBARS had a marginally negative effect on return rate. Our findings do not support the role for oxidative stress as a constraint of future reproductive success in the albatross. However, our data point to a potential mechanism underlying some aspects of reproductive senescence and survival. Our results also highlight that the study of the consequences of oxidative stress should consider the life-cycle stage of an individual and its reproductive history.
Programme: 109
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