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| Registros recuperados: 14 | |
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| Boyd, Charlotte; Woillez, Mathieu; Bertrand, Sophie; Castillo, Ramiro; Bertrand, Arnaud; Punt, Andre E.. |
| Small pelagic fish aggregate within areas of suitable habitat to form patchy distributions with localized peaks in abundance. This presents challenges for geostatistical methods designed to investigate the processes underpinning the spatial distribution of stocks and simulate distributions for further analysis. In two-stage models, presence/absence is treated as separable and independent from the process explaining non-zero densities. This is appropriate where gaps in the distribution are attributable to one process and conditional abundance to another, but less so where patchiness is attributable primarily to the strong schooling tendencies of small pelagic fish within suitable habitat. We therefore developed a new modelling framework based on a truncated... |
| Tipo: Text |
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| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00222/33367/31773.pdf |
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| Barbraud, Christophe; Bertrand, Arnaud; Bouchon, Marilu; Chaigneau, Alexis; Delord, Karine; Demarcq, Herve; Gimenez, Olivier; Gutierrez Torero, Mariano; Gutierrez, Dimitri; Oliveros Ramos, Ricardo; Passuni, Giannina; Tremblay, Yann; Bertrand, Sophie. |
| In marine ecosystems top predator populations are shaped by environmental factors affecting their prey abundance. Coupling top predators' population studies with independent records of prey abundance suggests that prey fluctuations affect fecundity parameters and abundance of their predators. However, prey may be abundant but inaccessible to their predators and a major challenge is to determine the relative importance of prey accessibility in shaping seabird populations. In addition, disentangling the effects of prey abundance and accessibility from the effects of prey removal by fisheries, while accounting for density dependence, remains challenging for marine top predators. Here, we investigate how climate, population density, and the accessibility and... |
| Tipo: Text |
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| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00450/56117/57647.pdf |
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| Roy, Amedee; Delord, Karine; Tavares Nunes, Guilherme; Barbraud, Christophe; Bugoni, Leandro; Bertrand, Sophie. |
| Background Considerable progress in our understanding of long-distance migration has been achieved thanks to the use of small lightweight geolocator devices. Such global location sensors (GLS) are particularly suitable for studying non-breeding movement and behaviour due to their small size and low energy consumption allowing multiyear deployment. Errors of geolocation are however important, difficult to estimate, have a complex structure leading to poor precision and accuracy. Therefore, understanding movement ecology of short-distance migrants or resident birds during extensive time periods remains challenging. We aimed at elucidating the sex-specific marine space uses of a resident tropical seabird, the masked booby over the full annual life cycle,... |
| Tipo: Text |
Palavras-chave: Activity pattern; Breeding constraints; GLS; Masked boobies; Saltwater immersion; Sexual dimorphism; Sula dactylatra. |
| Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00682/79438/82044.pdf |
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| Belsher, Thomas; Youenou, Gilles; Dimeet, Joel; Raillard, Jean-michel; Bertrand, Sophie; Mereau, N.. |
| Deux campagnes océanographiques, menées à partir du N.O. "Roselys 2", au cours de l'année 1992, ont permis d'établir la cartographie de l'algue Caulerps taxifolia pour plusieurs secteurs des côtes des Alpes Maritimes et de la Principauté de Monaco. Des survols, effectués à bord de l'hélicoptère des Douanes, ont précédé chacune de ces campagnes. L'expansion rapide de l'algue, ses capacités de fixation à grande profondeur, ainsi que d'importantes variations saisonnières ont pu ainsi être mises en évidence. |
| Tipo: Text |
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| Ano: 1993 |
URL: http://archimer.ifremer.fr/doc/00105/21611/19191.pdf |
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| Belsher, Thomas; Youenou, Gilles; Dimeet, Joel; Raillard, Jean-michel; Bertrand, Sophie; Mereau, N. |
| Deux campagnes océanographiques, menées à partir du N.O. "Roselys 2", au cours de l'année 1992, ont permis d'établir la cartographie de l'algue Caulerpa taxifolia pour plusieurs secteurs des côtes des Alpes Maritimes et de la Principauté de Monaco. Des survols, effectués à bord de l'hélicoptère des Douanes, ont précédé chacune de ces campagnes. L'expansion rapide de l'algue, ses capacités de fixation à grande profondeur, ainsi que d'importantes variations saisonnières ont pu ainsi être mises en évidence. |
| Tipo: Text |
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| Ano: 1993 |
URL: http://archimer.ifremer.fr/doc/00104/21561/19141.pdf |
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| Campos, L. F. A. S.; Andrade, A. B.; Bertrand, Sophie; Efe, M. A.. |
| We used miniaturized GPS loggers and site observations to access foraging patterns and nest behaviour of the White-tailed Tropicbird Phaethon lepturus (WTTB), an endangered species at its South Atlantic breeding colony. Dual foraging pattern was observed with alternation between long and short foraging trips. Birds responsible for nest attendance engaged in short foraging trips with mean distance from colony of 25 +/- 17 km, total distance covered of 79 +/- 65 km and mean duration of 4.02 +/- 5.28 hours. Birds flew by dawn and returned before dusk while partners were at sea for long foraging trips that ranged from four to 11 days, with mean maximum distance from colony of 105 +/- 47.48 km. Chicks were usually left alone for hours and chick predation by... |
| Tipo: Text |
Palavras-chave: Tropicbird; GPS; Dual foraging; Behavior. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00626/73778/74931.pdf |
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| Bertrand, Sophie; Joo, Rocio; Fablet, Ronan. |
| How organisms move and disperse is crucial to understand how population dynamics relates to the spatial heterogeneity of the environment. Random walk (RW) models are typical tools to describe movement patterns. Whether Levy or alternative RW better describes forager movements is keenly debated. We get around this issue using the Generalized Pareto Distribution (GPD). GPD includes as specific cases Normal, exponential and power law distributions, which underlie Brownian, Poisson-like and Levy walks respectively. Whereas previous studies typically confronted a limited set of candidate models, GPD lets the most likely RW model emerge from the data. We illustrate the wide applicability of the method using GPS-tracked seabird foraging movements and fishing... |
| Tipo: Text |
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| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00275/38641/37160.pdf |
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| Queffelec, Betty; Bonnin, Marie; Ferreira, Beatrice; Bertrand, Sophie; Teles Da Silva, Solange; Diouf, Fatou; Trouillet, Brice; Cudennec, Annie; Brunel, Adrien; Billant, Odeline; Toonen, Hilde; Flannery, Wesley. |
| Ocean grabbing occurs when traditional users, such as small-scale fishers, are pushed aside by new development activities. This grabbing must be prevented to avoid sea uses that maintain or increase social inequity. In this paper, we show that in tropical Atlantic countries, such as Brazil and Senegal, examples of ocean grabbing already occur. In this context, we analyse if Maritime Spatial Planning (MSP) may be an opportunity to limit ocean grabbing or, to the contrary, poses a risk to increase it. MSP calls for an ecosystem approach that requires integrated coastal and marine management and involves stakeholders in developing a shared vision of the future, where society and environment are preserved. However, recent studies have shown that MSP is a... |
| Tipo: Text |
Palavras-chave: Brazil; Fisheries; Maritime spatial planning; Ocean grabbing; Senegal; Stakeholders; Tropical Atlantic. |
| Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00683/79487/82079.pdf |
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| Bonnin, Marie; Ly, Ibrahima; Fotso, Philippe; Queffelec, Betty; Bertrand, Sophie; Teles Da Silva, Solange. |
| The SDGs promote sustainable use of resources through the implementation of ambitious measures to strengthen the achievement of ecological, economic and social needs. Although they do not constitute a legally binding instrument, they encourage and support States’ efforts to implement these environmental policies. The sea is not forgotten in these objectives, Objective 14 (SDO 14) is to «conserve and sustainably use oceans, seas and marine resources for sustainable development». Marine spatial planning is a political process that aims to reconcile uses at sea. Its implementation in African countries requires a combination of environmental protection, the right to development and social progress and could help to achieve MDG 14. |
| Tipo: Text |
Palavras-chave: Droit de l’environnement; Planification spatiale marine.; Environmental law; Marine spatial planning.. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00637/74888/75286.pdf |
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| Hill, Simeon L.; Hinke, Jefferson; Bertrand, Sophie; Fritz, Lowell; Furness, Robert W.; Ianelli, James N.; Murphy, Matthew; Oliveros‐ramos, Ricardo; Pichegru, Lorien; Sharp, Rowland; Stillman, Richard A.; Wright, Peter J.; Ratcliffe, Norman. |
| Ecosystem‐based management of fisheries aims to allow sustainable use of fished stocks while keeping impacts upon ecosystems within safe ecological limits. Both the FAO Code of Conduct for Responsible Fisheries and the Aichi Biodiversity Targets promote these aims. We evaluate implementation of ecosystem‐based management in six case‐study fisheries in which potential indirect impacts upon bird or mammal predators of fished stocks are well publicized and well studied. In particular, we consider the components needed to enable management strategies to respond to information from predator monitoring. Although such information is available in all case‐studies, only one has a reference point defining safe ecological limits for predators and none has a method to... |
| Tipo: Text |
Palavras-chave: Adaptive management; Aichi Biodiversity Targets; Ecosystem interactions; Indirect impacts; Management strategy; Precautionary approach. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00602/71400/69850.pdf |
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| Tavares Nunes, Guilherme; Bertrand, Sophie; Bugoni, Leandro. |
| Identifying associations between phenotypes and environmental parameters is crucial for understanding how natural selection acts at the individual level. In this context, genetically isolated populations can be useful models for identifying the forces selecting fitness-related traits. Here, we use a comprehensive dataset on a genetically and ecologically isolated population of the strictly marine bird, the brown booby Sula leucogaster, at the tropical and remote Saint Peter and Saint Paul Archipelago, mid-Atlantic Ocean, in order to detect phenotypic adjustments from interindividual differences in diet, foraging behaviour, and nest quality. For this, we took biometrics of all individuals of the colony breeding in 2014 and 2015 and tested their associations... |
| Tipo: Text |
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| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00626/73793/75007.pdf |
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| Passuni, Giannina; Barbraud, Christophe; Chaigneau, Alexis; Demarcq, Herve; Ledesma, Jesus; Bertrand, Arnaud; Castillo, Ramiro; Perea, Angel; Mori, Julio; Viblanc, Vincent A.; Torres-maita, Jose; Bertrand, Sophie. |
| In fluctuating environments, matching breeding timing to periods of high resource availability is crucial for the fitness of many vertebrate species, and may have major consequences on population health. Yet, our understanding of the proximate environmental cues driving seasonal breeding is limited. This is particularly the case in marine ecosystems, where key environmental factors and prey abundance and availability are seldom quantified. The Northern Humboldt Current System (NHCS) is a highly productive, low-latitude ecosystem of moderate seasonality. In this ecosystem, three tropical seabird species (the Guanay Cormorant Phalacrocorax bougainvillii, the Peruvian Booby Sula variegata, and the Peruvian Pelican Pelecanus thagus) live in sympatry and prey... |
| Tipo: Text |
Palavras-chave: Anchovy; Engraulis ringens; Guanay Cormorant; Northern Humboldt Current System; Occupancy model; Oceanographic variability; Pelecanus thagus; Peru; Peruvian Booby; Peruvian Pelican; Phalacrocorax bougainvillii; Prey abundance; Seasonal breeding; Sula variegata. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00317/42844/74394.pdf |
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| Gimenez, Olivier; Buckland, Stephen T.; Morgan, Byron J. T.; Bez, Nicolas; Bertrand, Sophie; Choquet, Remi; Dray, Stephane; Etienne, Marie-pierre; Fewster, Rachel; Gosselin, Frederic; Merigot, Bastien; Monestiez, Pascal; Morales, Juan M.; Mortier, Frederic; Munoz, Francois; Ovaskainen, Otso; Pavoine, Sandrine; Pradel, Roger; Schurr, Frank M.; Thomas, Len; Thuiller, Wilfried; Trenkel, Verena; De Valpine, Perry; Rexstad, Eric. |
| The desire to predict the consequences of global environmental change has been the driver towards more realistic models embracing the variability and uncertainties inherent in ecology. Statistical ecology has gelled over the past decade as a discipline that moves away from describing patterns towards modelling the ecological processes that generate these patterns. Following the fourth International Statistical Ecology Conference (1–4 July 2014) in Montpellier, France, we analyse current trends in statistical ecology. Important advances in the analysis of individual movement, and in the modelling of population dynamics and species distributions, are made possible by the increasing use of hierarchical and hidden process models. Exciting research perspectives... |
| Tipo: Text |
Palavras-chave: Citizen science; Hidden Markov model; Hierarchical model; Movement ecology; Software package; Spatially explicit capture-recapture; Species distribution modelling; State-space model. |
| Ano: 2014 |
URL: https://archimer.ifremer.fr/doc/00249/36026/35298.pdf |
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| Cardiec, Floriane; Bertrand, Sophie; Witt, Matthew J.; Metcalfe, Kristian; Godley, Brendan J.; Mcclellan, Catherine; Vilela, Raul; Parnell, Richard J.; Le Loch, Francois. |
| In many developing countries, small-scale fisheries provide employment and important food security for local populations. To support resource management, the description of the spatiotemporal extent of fisheries is necessary, but often poorly understood due to the diffuse nature of effort, operated from numerous small wooden vessels. Here, in Gabon, Central Africa, we applied Hidden Markov Models to detect fishing patterns in seven different fisheries (with different gears) from GPS data. Models were compared to information collected by on-board observers (7 trips) and, at a larger scale, to a visual interpretation method (99 trips). Models utilizing different sampling resolutions of GPS acquisition were also tested. Model prediction accuracy was high with... |
| Tipo: Text |
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| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00633/74526/74363.pdf |
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| Registros recuperados: 14 | |
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