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Fishery bycatch is a serious threat to several protected, endangered, and threatened species (PETs), requiring urgent action to develop and implement conservation measures. This study performs an Ecological Risk Assessment for the Effects of Fishing (ERAEF) using a spatially and temporally Productivity–Susceptibility Analysis (PSA) to calculate the potential risk to great shearwaters (Ardenna gravis) from direct interaction with the metiers of the artisanal tuna fishing fleet at the Bay of Biscay (baitboats and trollers). The PSA incorporates productivity attributes based on the Fecundity Factor Index; and susceptibility attributes calculated from the species spatio-temporal abundance patterns obtained developing density surface models and distribution and intensity of fishing activity based on pooled Vessel Monitoring System and logbook data. The PSA shows an overall moderate risk to great shearwaters by the artisanal tuna fishery also revealing that baitboats are less risky than trollers (risk score of 3.12 ± 0.09 and 2.70 ± 0.05, respectively). Spatially, the likelihood of presence of high potential risk areas was associated with prey availability for both the PET and the commercial fish species. The systematic, repeatable, and standardized ERAEF followed in this study can be used to advice for ecosystem-based fisheries management to improve management measures for reducing bycatch of PETs around the world.

14 pages, 3 figures, 1 table, supplementary information https://doi.org/10.1007/s00227-022-04079-y.-- Data availability: The datasets generated during and/or analysed during the current study are available from the corresponding author upon reasonable request, Understanding the linkages within complex and evolving marine food webs is essential to comprehend marine ecosystem structure and dynamics. Carbon (δ13C) and nitrogen (δ15N) stable isotope signatures are recognized to be powerful descriptors of the trophic ecology and trophic relationships within marine communities. Apex predators such as seabirds can influence the structure of communities by predating in lower trophic levels. They also convey information both over a range of spatial and temporal scales due to their high mobility and longevity, respectively. For this reason, here, we studied the trophic ecology of northern gannets and the extent of niche overlap with other apex predators within the Bay of Biscay (North-East Atlantic), a key feeding area for numerous predatory species. Mixing models indicated that northern gannets fed primarily on European anchovy Engraulis encrasicolus and on a mixed group composed of European sardine Sardina pilchardus, European sprat Sprattus sprattus, juvenile hake Merluccius merluccius, Atlantic mackerel Scomber scombrus and Atlantic horse mackerel Trachurus trachurus. Within the apex predator community, the northern gannets trophic niche overlapped the most with common guillemots Uria aalge (15.58%, based on Stable Isotope Bayesian Ellipses (SIBER)) and overlapped to a lesser extent with cetacean species occupying shelf habitats (i.e., the harbour porpoise Phocoena phocoena (9.99%) and the short-beaked common dolphin Delphinus delphis (10.37%)). Overall, the overlap found was moderate indicating trophic similarities and dissimilarities between these species. Information on trophic interactions between co-existing species is necessary for holistic environmental management, particularly in areas where several megafauna species share their foraging grounds with fisheries activity, This study is a contribution to the EPELECO project (Evaluating the pelagic realm from an integrated ecosystem based perspective in a changing world: insights from the NE Atlantic, RTI2018-101591-B-I00) supported by the “Ministerio de Ciencia, Innovación y Universidades”, the “Agencia Estatal de Investigación” and the “Fondo Europeo de Desarrollo Regional”, to the “Incidencia y cuantificación de microplásticos en depredadores marinos en el Golfo de Bizkaia” project, funded by Fundación Biodiversidad-Ecoembes (call for projects to combat marine litter), the PLASTFAUNA project funded by the “Departamento de Medio Ambiente, Planificación Territorial y Vivienda” (call for projects to generate knowledge for the conservation of Natural Heritage), and the Marie Curie Career Integration Grant CONPELHAB (PCIG09-GA-2011-293774) project and an ACAP (Agreement on the Conservation and Petrels) funded project (reference: 2013–12). CPER (Contrat de Projet Etat-Région) and the FEDER (Fonds Européen de Développement Régional) funded the IRMS of LIENSs laboratory. The IUF (Institut Universitaire de France) supported P. Bustamante as a Senior Member. M. Louzao was funded by a Ramón y Cajal (RYC-2012-09897) postdoctoral contract of the Spanish Ministry of Economy, Industry and Competitiveness. J. Giménez was supported by the Spanish National Program Juan de la Cierva-Formación (FJC2019-040016-I). This work acknowledges the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S) to the Institute of Marine Science (ICM-CSIC)

International audience; In habitat modelling, environmental variables are assumed to be proxies of lower trophic levels distribution and by extension, of marine top predator distributions. More proximal variables, such as potential prey fields, could refine relationships between top predator distributions and their environment. In situ data on prey distributions are not available over large spatial scales but, a numerical model, the Spatial Ecosystem And POpulation DYnamics Model (SEAPODYM), provides simulations of the biomass and production of zooplankton and six functional groups of micronekton at the global scale. Here, we explored whether generalised additive models fitted to simulated prey distribution data better predicted deep-diver densities (here beaked whales Ziphiidae and sperm whales Physeter macrocephalus ) than models fitted to environmental variables. We assessed whether the combination of environmental and prey distribution data would further improve model fit by comparing their explanatory power. For both taxa, results were suggestive of a preference for habitats associated with topographic features and thermal fronts but also for habitats with an extended euphotic zone and with large prey of the lower mesopelagic layer. For beaked whales, no SEAPODYM variable was selected in the best model that combined the two types of variables, possibly because SEAPODYM does not accurately simulate the organisms on which beaked whales feed on. For sperm whales, the increase model performance was only marginal. SEAPODYM outputs were at best weakly correlated with sightings of deep-diving cetaceans, suggesting SEAPODYM may not accurately predict the prey fields of these taxa. This study was a first investigation and mostly highlighted the importance of the physiographic variables to understand mechanisms that influence the distribution of deep-diving cetaceans. A more systematic use of SEAPODYM could allow to better define the limits of its use and a development of the model that would simulate larger prey beyond 1,000 m would probably better characterise the prey of deep-diving cetaceans.

Identifying the role that environmental factors and biotic interactions play in species distribution can be essential to better understand and predict how ecosystems will respond to changing environmental conditions. This study aimed at disentangling the assemblage of the pelagic predator–prey community by identifying interspecific associations and their main drivers. For this purpose, we applied the joint species distribution modelling approach, JSDM, to the co-occurrence patterns of both prey and top predator communities obtained from JUVENA surveys during 2013–2016 in the Bay of Biscay. Results showed that the co-occurrence patterns of top predators and prey were driven by a combination of environmental and biotic factors, which highlighted the importance of considering both components to fully understand the community structure. In addition, results also revealed that many biotic interactions, such as schooling in prey (e.g. anchovy–sardine), local enhancement/facilitation in predators (e.g. Cory’s shearwater–fin whale), and predation between predator–prey species (e.g. northern gannet–horse mackerel), were led by positive associations, although predator avoidance behaviour was also suggested between negatively associated species (e.g. striped dolphin–blue whiting). The identification of interspecific associations can therefore provide insights on the functioning of predators–prey network and help advance towards an ecosystem-based management.

Changing environmental conditions can have non-linear effects from populations to ecosystems, which could increase following the strengthening of human activities. Investigating the potential role of threshold responses to increasing extreme events could help elucidate the mechanisms conferring resilience to populations and ecosystems, since extreme events could have a higher impact than mean changes in ecological systems. Among the potential impacts of extreme climatic events, the assessment of mortality deserves particular attention for long-lived species. In the NE Atlantic, the vulnerability of birds was emphatically demonstrated in the winter of 2013/2014 when at least 54,982 individuals were reported dead in cumulative mass-mortality events. The aim of the present work is to uncover the link between extreme wind events and bird mortality for the 2004–2014 period in southern European waters to detect potential threshold responses. As extreme wind events can be estimated in different ways, we employed a multi threshold wind speed approach to assess which criteria yielded the strongest predictions. By focusing on a highly vulnerable species, the common guillemot Uria aalge, we hypothesized that bird mortality would be related to a cumulative effect of extreme wind events. At the weekly scale, cumulative patterns of extreme wind events and bird mortality were correlated following similar sigmoidal curves. The period of maximum mortality fell within the time frame of maximum extreme wind events during winter (beginning of December-end of February). We identified a threshold response of bird mortality in relation to extreme wind events above which birds experienced consistent increased mortality, which was especially evident in the heavier winter (e.g. 2013/2014). Our methodological approach provides insights on the definition of the number of extreme wind events that should serve as a warning signal to activate the coordination of local administrations and volunteers to anticipate the occurrence of mass-mortality events under future climatic scenarios.

The JUVENA survey was funded by the ‘Viceconsejería de Agricultura, Pesca y Políticas Alimentarias ‐ Departamento de Desarrollo Económico y Sostenibilidad y Medio Ambiente’ of the Basque Government, the ‘Secretaría General de Pesca, Ministerio de Agricultura, Alimentación y Medio Ambiente’ of the Spanish Government and by the Spanish Institute of Oceanography (IEO). This research was funded by the Spanish Government (Ministry of Science and Innovation) through the CHALLENGES (CTM2013‐47032‐R) and the EPELECO (RTI2018‐101591‐B‐I00) projects, the Basque Government (‘Viceconsejería de Agricultura, Pesca y Políticas Alimentarias ‐ Departamento de Desarrollo Económico, Sostenibilidad y Medio Ambiente’) through the ECOPES project as well as the Horizon 2020 programme of the European Commission (Contract No. 862428, Atlantic Mission: Mapping and assessing present and future status of Atlantic marine ecosystems under climate change and exploitation). A.A. has benefited from a Basque Government scholarship (PRE_2016_1_0134) and M.L. from Ramón y Cajal funding (Ministerio de Ciencia e Innovación, RYC‐2012‐09897). Special thanks are given to the crew on board R/V Emma Bardán and R/V Ramón Margalef and all the AZTI and Spanish Institute of Oceanography (IEO) staff who participated in JUVENA surveys for their excellent job and collaborative support. This paper received contribution nº 1013 from AZTI, Marine Research, Basque Research and Technology Alliance (BRTA). Aim: Understanding the mechanisms that allow the coexistence of species is key to preserve full ecosystem functioning. In dynamic environments, the study of ecological niches faces the complexity associated to the three dimensionality of the habitat and requires information that reflects such heterogeneity. Within this context, this study intends to identify the segregation mechanisms behind the co-occurrence of five phylogenetically related pelagic birds by applying a functional perspective based on seabirds' vertical ranges and prey availability features such as depth and body size. Location: Bay of Biscay. Methods Based on the hypothesis that niche differentiation may occur in any of the three dimensions of the marine environment, we (a) identified the biologically meaningful vertical range affecting seabird species, (b) modelled their environmental and trophic niches, (c) estimated an environmental and trophic overlap index for each pairwise species, and (d) developed a conceptual framework with the most plausible segregation hypotheses. Results: The application of the conceptual framework revealed that in this particular area, pelagic birds coexist through environmental and trophic niche partitioning and potentially through vertical segregation, based on the different biologically meaningful vertical ranges we identified for each species. Indeed, some species responded to prey and oceanographic conditions on the surface (10 m), while others responded to the conditions on deeper waters (above the depth of maximum temperature gradient). These different responses could be interpreted as an additional mechanism to reduce competition, although seabirds diving records would be needed to contrast this hypothesis. Main conclusions: Niche differentiation was found to be primarily driven by trophic and environmental niche partitioning, although species were also influenced by conditions on the vertical dimension. Considering all the dimensions of the niche is essential to fully understand how diving seabirds coexist in dynamic systems and provides insights on species' 3D niches that may help advance into their management. Publisher PDF

10 pages, 4 figures.-- Data availability: All relevant data are publicly available in the Seabird Tracking Database: http://seabirdtracking.org/mapper/?dataset_id=879 and http://seabirdtracking.org/mapper/?dataset_id=1409, Foraging distribution of flying seabirds is constrained by environmental factors influencing individual decision-making. This must be particularly true during the breeding period, when individuals face additional limitations imposed by their central-place foraging behaviour. We used GPS data loggers and Argos PTTs to track the foraging flights of Balearic shearwaters (Puffinus mauretanicus) during the chick-rearing period of 2011–2014 in the Balearic Islands (Western Mediterranean). We identified main areas used by tracked birds and characterised their productivity patterns. Based on a spatial seascape approach of flight costs varying with time, shaped by environmental processes as winds, we also estimated flight costs to reach foraging grounds in outward and return trips from the colony. Individuals repeatedly used the closest areas on the Iberian continental shelf. However, sporadic and favourable wind conditions facilitated low-cost flight to more distant and equally productive areas of the western North African shelf, Funding support was provided to LPO and SEO/BirdLife through Interreg project FAME, LIFE + project INDEMARES, and the Ibiza Preservation Fund, and to the IEO through a Marie Curie Career Integration Grant (CONPELHAB; PCIG09-GA-2011-293774). ML was funded by a Juan de la Cierva (JCI-2010-07639) and a Ramón y Cajal (RYC-2012-09897) postdoctoral contract. FR was funded by a Juan de la Cierva (JCI-2015-24531) postdoctoral contract, With the funding support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S), of the Spanish Research Agency (AEI)

Increasing human activities have detrimental consequences on marine ecosystems and their impact can have cumulative effects. Within marine ecosystems, seabirds respond to ecosystem variability and face multiple human pressures, especially threatened species. In long-lived species, juveniles and immatures could represent up to 50% of the total population, but their migratory movements remain largely unknown. Here, we depict the migratory patterns of juvenile Balearic shearwaters Puffinus mauretanicus, the most threatened European seabird, using miniaturised satellite transmitters. At the end of the 2012 breeding season, five tagged juveniles left the breeding colonies of Eivissa Island (western Mediterranean) the first week of July. They moved westwards to reach the Atlantic Ocean between 3 and 13 days afterwards. Juveniles showed a twophase migratory pattern: they first travelled slower close to the breeding colonies, and then moved towards their wintering areas in the Atlantic Ocean by rapid directional movements. Environmental cues (e.g.,marine productivity, water mass distribution, frontal systems) might have a prominent role in driving the migratory patterns of juvenile Balearic shearwaters, moving from warm and poor marine areas in the Mediterranean Sea to cooler and rich non-breeding grounds in the Atlantic Ocean. Based on observational findings, we observed certain spatial overlap of juvenile Balearic shearwaters with areas of high human impact, but the relationship between flying travel speed and both fishing effort and cumulative human impacts were not statistically significant. These results suggest that more research is needed to assess whether the movement patterns of migrating juveniles are affected by human activities. Therefore, understanding the at-sea spatial ecology of juveniles should be a priority for research and conservation due to the importance of this population component in long-lived species, as well as assessing their vulnerability to multiple anthropogenic pressures

17 pages, 7 tables, 5 figures, Distribution maps of cetaceans and seabirds at basin and monthly scales are needed for conservation and marine management. These are usually created from standardized and systematic aerial and vessel surveys, with recorded animal densities interpolated across study areas. However, distribution maps at basin and monthly scales have previously not been possible because individual surveys have restricted spatial and temporal coverage. This study develops an alternative approach consisting of: (a) collating diverse survey data to maximize spatial and temporal coverage, (b) using detection functions to estimate variation in the surface area covered (km2) among these surveys, standardizing measurements of effort and animal densities, and (c) developing species distribution models (SDM) that overcome issues with heterogeneous and uneven coverage. 2.68 million km of survey data in the North‐East Atlantic between 1980 and 2018 were collated and standardized. SDM using Generalized Linear Models and General Estimating Equations in a hurdle approach were developed. Distribution maps were then created for 12 cetacean and 12 seabird species at 10 km and monthly resolution. Qualitative and quantitative assessment indicated good model performance. Synthesis and applications. This study provides the largest ever collation and standardization of diverse survey data for cetaceans and seabirds, and the most comprehensive distribution maps of these taxa in the North‐East Atlantic. These distribution maps have numerous applications including the identification of important areas needing protection, and the quantification of overlap between vulnerable species and anthropogenic activities. This study demonstrates how the analysis of existing and diverse survey data can meet conservation and marine management needs, JJW, PGHE, JGH and SW are supported through the NERC/DEFRA funded Marine Ecosystems Research Programme (MERP: NE/L003201/1).

Aim: Deep‐diving cetaceans are oceanic species exposed to multiple anthropogenic pressures including high intensity underwater noise, and knowledge of their distribution is crucial to manage their conservation. Due to intrinsic low densities, wide distribution ranges and limited presence at the sea surface, these species are rarely sighted. Pooling data from multiple visual surveys sharing a common linetransect methodology can increase sightings but requires accounting for heterogeneity in protocols and platforms. Location: North Atlantic Ocean and Mediterranean Sea. Time period: 1998 to 2015. Major taxa: Ziphiidae; Physeteriidae; Kogiidae. Methods: About 1,240,000 km of pooled effort provided 630 sightings of ziphiids, 836 of physeteriids and 106 of kogiids. For each taxon, we built a hierarchical model to estimate the effective strip width depending on observation conditions and survey types. We then modelled relative densities in a generalized additive modelling framework. Geographical predictions were limited to interpolations identified with a gap analysis of environmental space coverage. Results: Deeper areas of the North Atlantic gyre were mostly environmental extrapolation in the predictions, thereby highlighting gaps in sampling across the different surveys. For the three species groups, the highest relative densities were predicted along continental slopes, particularly in the western North Atlantic Ocean where the Gulf Stream creates dynamic frontal zones and eddies. Main conclusions: Pooling a large number of surveys provided the first basin‐wide models of distribution for deep‐diving cetaceans, including several data‐deficient taxa, across the North Atlantic Ocean and the Mediterranean Sea. These models can help the conservation of elusive and poorly known marine megafauna.

Due to the growth of nature-based tourism worldwide, behavioural studies are needed to assess the impact of this industry on wildlife populations and understand their short-term effect. Tourism impact on dolphin populations remain poorly documented in developing countries. This study investigates the effects of nature-based tourism on the behaviour of the Indo-Pacific bottlenose dolphins (Tursiops aduncus) in southern Kenya. We used Markov chain models to estimate transition probabilities between behavioural states in the presence and absence of tourist boats, and assess the overall behavioural budgets. Based on these data and the tourism intensity in the area, we quantified the potential tourist boat disturbance over the period 2006–2013. Our results demonstrated that tourist boat interactions affected dolphins’ behavioural budgets, with a significant decrease in the overall amount of time travelling and an increase in diving. The average duration of travelling and resting decreased significantly in the presence of boats. Although the cumulative tourism exposure was not significant for the dolphin population at their current levels, these impacts should be taken into consideration with the potential tourism growth in the area. This is particularly important if tourism reaches periods of high intensity, as we have shown that these periods could have a significant impact for the species, particularly where home-range and core areas are highly overlap by this activity. Understanding the effect of human disturbance variations from previous years may help to predict the consequences on dolphin populations, towards achieving a more ecological and economic sustainability of the activity.

11 pages, 5 figures, 4 tables, In the last few decades, there has been a remarkable development of niche models to help understand the ecological response of species to current rapid environmental changes. In the present study, we applied niche modelling to the megafauna community of shelf waters of the northwestern (NW) and northern Iberian Peninsula in order to analyse the coexistence of different species taking into consideration their niche preferences. The Spanish Institute of Oceanography conducts the PELACUS multidisciplinary survey annually to assess pelagic fish stocks and collect information on the status of other ecosystem components, such as oceanographic conditions, phytoplankton, zooplankton and marine megafauna. Using data collected from these surveys, we developed niche models for 14 marine megafauna taxa (3 cetaceans, 10 seabirds and 1 fish) incorporating multi-trophic ecological descriptors collected simultaneously during the surveys alongside the more commonly used oceanographic variables (e.g. chlorophyll a and sea surface temperature). Megafauna niche models were developed by pooling observations from 2007 to 2013 and were found to be driven by mean fish biomass and its variability, in addition to sea surface temperature. Hierarchical clustering identified four distinct megafauna assemblages, the first comprising wide-ranging species and the other three associated with shelf-slope waters in Galicia, coastal/shelf waters in Galicia, and the eastern Cantabrian Sea, respectively. Community-level hotspot areas were found in shelf and shelf-break sectors of Galicia, along with small diversity spots scattered throughout the Cantabrian coastal area. Our results showed that synoptically collected survey-based ecological descriptors, especially acoustic-based preyscapes, were among the most important variables explaining megafauna niche preference. These findings highlight the advantage of using integrated ecosystem surveys to collect simultaneous information on a suite of ecosystem components for spatial assessments, Surveys were funded by the Instituto Español de Oceanografía's ECOPEL project, partially co-funded by the European Union Data Collection Framework program. Additional funding was contributed by the CONPELHAB (Marie Curie Career Integration Grant PCIG09-GA-2011-293774), REPRODUCE (MariFish 8120-09-9), LOTOFPEL (Plan Nacional de I+D+I, CTM 2010-16053) and CHALLENGES (CTM2013-47032-R) projects. Maite Louzao was funded by Juan de la Cierva (JCI-2010-07639) and Ramón y Cajal (RYC-2012-09897) postdoctoral contracts

Aim During their migration, highly mobile species cross multiple jurisdictional boundaries and multiple not‐specic marine protected areas (MPAs). When identifying the critical habitats where individuals aggregate, these areas can be ideal candidates for MPAs. This study was focused on the endangered n whale (Balaenoptera physalus) for which there is little knowledge on its distribution and abundance in non‐breeding temperate latitudes. Location Bay of Biscay (BoB). Methods Firstly, we modelled the relative abundance of n whales by means of generalized additive models (GAMs) using data collected on the PELACUS (2007–2008) and JUVENA (2013–2016) oceanographic surveys during late summer. Secondly, we evaluated the reliability of the predictions by distinguishing environmental extrapolations and interpolations. Finally, we identied critical areas of highest predicted abundance and we assessed whether existing MPAs comprised within the Natura 2000 network and designated for other species oer protection to n whales in the BoB Results Fin whales were especially abundant in deep o‐shore waters, mainly associated with intermediate temperature water values in the inner part of the BoB. The years with the highest relative predicted abundances (an average of 1,500 whales) matched with years when warmer sea surface temperature extended into larger areas. In colder years, the average predicted abundance dropped to 400 whales. The main critical area for n whales (dened by the highest 40% of abundance) was common for both surveys, and it was located in the south‐eastern part of the BoB. Main conclusions Our study contributes to the identication of important concentration areas of n whales during late summer, based on reliable spatial predictions. The assessment of the current Natura 2000 network highlights the fact that only three MPAs marginally covered the critical area we have identied for n whales. We propose a transboundary potential MPA to aid the conservation of the species in the BoB, Sí

Gelatinous zooplankton (GZ) have long been regarded as organisms taking over perturbed systems (e.g. competing with fisheries and damaging aquaculture), but more detailed studies are required in order to better understand their role in marine ecosystem functioning. The present study characterised the GZ in the Bay of Biscay (BoB), (1) determining biodiversity, abundance and community composition of GZ assemblages, and (2) exploring the influence of oceanographic variability on GZ communities. Simultaneous GZ and oceanographic samples were obtained in May 2011 from 100 hydrographic stations. From the 30,194 GZ specimens analysed, 19 taxa were identified within Appendicularia, Thaliacea, Hydrozoa, Scyphozoa, and Tentaculata classes. There were few highly abundant taxa (e.g. Fritillaria pellucida represented almost the 60% of the collected individuals), but most of the species were diverse and less common. The most common species showed heterogeneous spatial abundance patterns, structuring 6 assemblages. Spatial configuration of GZ was shaped by depth, mean salinity and total chlorophyll a, suggesting a close relationship with main mesoscale oceanographic features in the BoB, such as shelf-break fronts and river plumes. This novel information complements the limited existing information of the main abundant gelatinous species within the “Bay of Biscay and Iberian coast ecoregion” of the Marine Strategy Framework Directive and could provide useful data for future ecosystem-based monitoring efforts.

Effective conservation and management measures are needed to face the unprecedented changes that marine ecosystems, and particularly marine megafauna, are suffering. These measures require the identification of highvalue biodiversity areas (HVBAs) which in turn require the identification of the essential ocean variables (EOVs) that shape the environmental envelope of communities (i.e. space defined by a set of environmental variables). The aim of this study was to delineate and characterise the HVBAs for the north and northwestern Spanish seabird and cetacean community taking advantage of the sightings collected during the annual PELACUS oceanographic survey (2007–2016). We used distance sampling methodology to analyse the species detectability based on environmental conditions. Then, we delimitated the HVBAs and identified the EOVs defining the environmental envelope of the community based on a spatio-temporal modelling approach using Generalized Additive Models. Overall, the main environmental variables driving species abundance were the sea surface temperature (SST), the distance to the shelf-break and the chlorophyll-a concentration (Chl-a). The SST and Chla were identified as dynamic EOVs due to their highest relative predictor importance, driving the environmental envelope and shaping areas of higher density. HVBAs were located mainly over the northwestern Spanish waters and decreased towards the inner Bay of Biscay remaining spatially stable over the study period. By identifying community-level HVBAs, we can understand the underlying ecological and oceanographic processes driving the spatio-temporal patterns of biological communities, such as those composed by seabirds and cetaceans. This information would identify conservation targets to assist the allocation of management resources. In addition, the location of HVBAs can help to fulfil the emergent need for sound spatial information to support the implementation of marine spatial planning., SI

Motivation The BioTIME database contains raw data on species identities and abundances in ecological assemblages through time. These data enable users to calculate temporal trends in biodiversity within and amongst assemblages using a broad range of metrics. BioTIME is being developed as a community-led open-source database of biodiversity time series. Our goal is to accelerate and facilitate quantitative analysis of temporal patterns of biodiversity in the Anthropocene. Main types of variables included The database contains 8,777,413 species abundance records, from assemblages consistently sampled for a minimum of 2 years, which need not necessarily be consecutive. In addition, the database contains metadata relating to sampling methodology and contextual information about each record. Spatial location and grain BioTIME is a global database of 547,161 unique sampling locations spanning the marine, freshwater and terrestrial realms. Grain size varies across datasets from 0.0000000158 km2 (158 cm2) to 100 km2 (1,000,000,000,000 cm2). Time period and grain BioTIME records span from 1874 to 2016. The minimal temporal grain across all datasets in BioTIME is a year. Major taxa and level of measurement BioTIME includes data from 44,440 species across the plant and animal kingdoms, ranging from plants, plankton and terrestrial invertebrates to small and large vertebrates. Software format .csv and .SQL., Global Ecology and Biogeography, 27 (7), ISSN:1466-822X, ISSN:1466-8238

Part of special issue: Future of oceanic animals in a changing ocean., Ecotones can be described as transition zones between neighbouring ecological systems that can be shaped by environmental gradients over a range of space and time scales. In the marine environment, the detection of ecotones is complex given the highly dynamic nature of marine systems and the paucity of empirical data over ocean-basin scales. One approach to overcome these limitations is to use stable isotopes from animal tissues since they can track spatial oceanographic variability across marine systems and, in turn, can be used as ecological tracers. Here, we analysed stable isotopes of deep-sea fishes to assess the presence of ecological discontinuities across the western Mediterranean. We were specifically interested in exploring the connection between deep-sea biological activity and particular oceanographic features (i.e., surface fronts) occurring in the pelagic domain. We collected samples for three different abundant deep-sea species in May 2004 from an experimental oceanographic trawling cruise (MEDITS): the Mictophydae jewel lanternfish Lampanyctus crocodilus and two species of the Gadidae family, the silvery pout Gadiculus argenteus and the blue whiting Micromesistius poutassou. The experimental survey occurred along the Iberian continental shelf and the upper and middle slopes, from the Strait of Gibraltar in the SW to the Cape Creus in the NE. The three deep-sea species were highly abundant throughout the study area and they showed geographic variation in their isotopic values, with decreasing values from north to south disrupted by an important change point around the Vera Gulf. Isotopic latitudinal gradients were explained by pelagic oceanographic conditions along the study area and confirm the existence of an ecotone at the Vera Gulf. This area could be considered as an oceanographic boundary where waters of Atlantic origin meet Mediterranean surface waters forming important frontal structures such as the Almeria-Oran front. In fact, our results relate geographical variation in stable isotopes of deep-sea fishes to regional changes in surface oceanography, highlighting the importance of mesoscale oceanographic features., Research funds were provided by several Grants from the Spanish Government (P06-RNM-02362, REN2002-00450, BOS2003-01960 and CGL2006-04325/BOS). ML was supported by a PhD fellowship of the Balearic Government (FPI02-72474662Y) and a Ramón y Cajal (RYC-2012-09897) postdoctoral contract. JN was supported by a postdoctoral contract (Ref.: 291780) of the Andalucía Talent Hub Program (launched by the Andalusian Knowledge Agency, which is co-funded by the European Union's Seventh Framework Program, Marie Skłodowska-Curie Actions, the Ministry of Economy, Industry and Competitiviness and Enploymnet of the Junta de Andalucía, Spain). This is contribution number 796 from the Marine Research Division (AZTI).

International audience; Marine protected areas (MPAs) are considered one of the main tools in both fisheries and conservation management to protect threatened species and their habitats around the globe. However, MPAs are underrepresented in marine environments compared to terrestrial environments. Within this context, we studied the Atlantic non-breeding distribution of the southern population of Balearic shearwaters (Puffinus mauretanicus) breeding in Ibiza during the 2011-2012 period based on global location sensing (GLS) devices. Our objectives were (1) to identify overall Important Atlantic Areas (IAAs) from a southern population, (2) to describe spatio-temporal patterns of oceanographic habitat use, and (3) to assess whether existing conservation areas (Natura 2000 sites and marine Important Bird Areas (IBAs)) cover the main IAAs of Balearic shearwaters. Our results highlighted that the Atlantic staging (from June to October in 2011) dynamic of the southern population was driven by individual segregation at both spatial and temporal scales. Individuals ranged in the North-East Atlantic over four main IAAs (Bay of Biscay: BoB, Western Iberian shelf: WIS, Gulf of Cadiz: GoC, West of Morocco: WoM). While most individuals spent more time on the WIS or in the GoC, a small number of birds visited IAAs at the extremes of their Atlantic distribution range (i.e., BoB and WoM). The chronology of the arrivals to the IAAs showed a latitudinal gradient with northern areas reached earlier during the Atlantic staging. The IAAs coincided with the most productive areas (higher chlorophyll a values) in the NE Atlantic between July and October. The spatial overlap between IAAs and conservation areas was higher for Natura 2000 sites than marine IBAs (areas with and without legal protection, respectively). Concerning the use of these areas, a slightly higher proportion of estimated positions fell within marine IBAs compared to designated Natura 2000 sites, with Spanish and Portuguese conservation areas being the most visited. Our results support the current design of conservation areas in Spain and Portugal regarding the protection of adult breeders of this highly mobile species.

Migratory marine species (MMS) include many of the world's most charismatic organisms such as marine mammals, seabirds, turtles, sharks, and tuna. Many are now among the most threatened due to the diverse range of pressures they encounter during their extensive movements. This paper shows that 21% of MMS are classified as threatened (i.e. categorized as Critically Endangered, Endangered or Vulnerable). Sea turtles are the most threatened group (85%), followed by seabirds (27%), cartilaginous fish (26%), marine mammals (15%) and bony fish (11%). Taken together 48% of MMS are threatened, Near Threatened or Data Deficient. As well as being threatened they share in common being wide-ranging animals, travelling through the waters of multiple nations as well as in Areas Beyond National Jurisdiction (ABNJ) during different times of the year. This makes their conservation a challenge, requiring coordinated action by many nations, international organizations, Multilateral Environmental Agreements (MEAs) and other stakeholders if their populations are to recover to healthy levels and be safeguarded into the future. Even though they are wide-ranging, long-term studies reveal considerable site fidelity and well-defined habitats for many species and areas. These sites are prime candidates for enhanced management such as via Marine Protect Area (MPA) designations. However, existing management frameworks do not yet contribute sufficiently to MMS conservation, MPA networks need to be expanded to capture key areas, in many cases through the application of new dynamic management techniques such as time area closures. Data on the distribution, abundance, behaviours and threats faced by many MMS are now available. These data should be used to inform the design of effective management regimes, such as MPAs, both within and beyond national jurisdictions. MEAs should ensure a full complement of MMS are included within species listings, and encourage further action to safeguard their populations. Copyright © 2014 John Wiley & Sons, Ltd.

International audience; Knowledge about the spatial distribution of seabirds at sea is important for conservation. During marine conservation planning, logistical constraints preclude seabird surveys covering the complete area of interest and spatial distribution of seabirds is frequently inferred from predictive statistical models. Increasingly complex models are available to relate the distribution and abundance of pelagic seabirds to environmental variables, but a comparison of their usefulness for delineating protected areas for seabirds is lacking. Here we compare the performance of five modelling techniques (generalised linear models, generalised additive models, Random Forest, boosted regression trees, and maximum entropy) to predict the distribution of Balearic Shearwaters (Puffinus mauretanicus) along the coast of the western Iberian Peninsula. We used ship transect data from 2004 to 2009 and 13 environmental variables to predict occurrence and density, and evaluated predictive performance of all models using spatially segregated test data. Predicted distribution varied among the different models, although predictive performance varied little. An ensemble prediction that combined results from all five techniques was robust and confirmed the existence of marine important bird areas for Balearic Shearwaters in Portugal and Spain. Our predictions suggested additional areas that would be of high priority for conservation and could be proposed as protected areas. Abundance data were extremely difficult to predict, and none of five modelling techniques provided a reliable prediction of spatial patterns. We advocate the use of ensemble modelling that combines the output of several methods to predict the spatial distribution of seabirds, and use these predictions to target separate surveys assessing the abundance of seabirds in areas of regular use.

11 pages, 6 figures, 5 tables, While breeding, seabirds are limited to exploiting resources within a restricted area around their breeding site and should exploit the closest productive marine areas within their distribution range. We investigated this hypothesis in one of the most endangered European seabirds, the Balearic shearwater Puffinus mauretanicus (ca. 3200 breeding pairs), restricted to the Balearic Islands. Our aims were (1) to assess whether isotopic evidence (i.e. stable isotopes of δ13C and δ15N) of foraging habitat partitioning occurs among northern, central and southern populations, (2) to geographically locate population-specific potential foraging grounds along the Iberian continental shelf, and (3) to assess whether oceanographic conditions could explain observed patterns of stable isotopes (SI). SI values showed a latitudinal gradient, with birds from the northern population having lower δ15N and δ13C values than central and southern populations. Potential foraging grounds of northern, central and southern populations were centred in Cape Creus, Ebro Delta and Cape La Nao, respectively, results which were supported by habitat models. Oceanographic conditions in each potential foraging ground were different; the northern population used richer, colder and deeper waters compared to the central and southern populations. Chlorophyll a was the main oceanographic variable that explained variation in SI values. We hypothesised that SI differences among Balearic shearwater populations might be a consequence of differences in baseline isotopic values among potential foraging grounds rather than real differences in diet. Our comprehensive study also provides important information for management strategies to conserve this critically endangered shearwater, This study was funded by Govern de les Illes Balears, DISCBIRD (QLRT-2000-00839) and LIFE projects (European Commission) and the Spanish Ministries of Education and Science (ref. BOS2003-01960 and REN2002-00450) and of the Environment (ref. 024A/2002). M.L. was supported by fellowships from Govern de les Illes Balears and Institut Menorquí d’Estudis, as well as by a postdoctoral contract of the Spanish Ministry of Education and Science (ref. EX-2007-1148) and Marie Curie Individual Fellowship (PIEF-GA-2008-220063). J.N. was supported by a researcher contract from of the Spanish Ministry of Science and Innovation (Juan de la Cierva program). M.G.F. and M.G. by Ramon y Cajal and I3P contracts, respectively, of the Spanish Ministry of Education and Science

Bottom trawl fishing provides substantial amounts of normally unavailable demersal prey to seabirds (e.g., discards), affecting their life-history traits and population dynamics, as well as community structure. Within this framework, we studied seabird-trawling interactions throughout the annual cycle in a poorly studied ecosystem in the Mediterranean, the Balearic archipelago, on a both species-specific and a community level. Whereas the species-specific approach showed a significant influence of season (phenology) on shaping seabird’s trawling attendance patterns, the spatio-temporal coupling of regional community was a result of a complex interaction between fisheryrelated variables. The most frequent and abundant species were the yellow-legged gull Larus michahellis and Cory’s shearwater Calonectris diomedea, the latter attending vessels in higher numbers than expected from local population figures. Conversely, the remaining breeding species occurred in lower numbers than expected according to their local breeding populations, suggesting that discards were of relatively little importance. Discarding activity took place over the entire shelf and continental slope surrounding Mallorca, but especially in the southwest, adjacent to the breeding grounds of approximately 12% of the Balearic total seabird breeding population, including 13% the Balearic shearwater Puffinus mauretanicus world population. Overall discards corresponded to 0.74 of landings (range: 0.09‐ 6.00) and consisted primarily of fish followed by crustaceans and molluscs (approximately 80, 15, and 5%, respectively). Seabird-trawling interactions should be taken into account in the frame of an ecosystem-based approach to fisheries management, and particular attention should be devoted to the critically endangered Balearic shearwater.

1. Currently pelagic ecosystems are changing significantly due to multiple threats. An important management policy is to establish marine protected areas, until now overlooked due to the difficulty of declaring ‘high seas’ protected areas, obtaining long-term distribution data on indicator species and the dynamic nature of these ecosystems. 2. Within this framework, we developed predictive habitat suitability models of an oceanic predator, the vulnerable wandering albatross Diomedea exulans , in the highly dynamic Southern Ocean. Based on a long-term tracking database (1998–2008), we estimated three quantitative ecological indices that complementarily describe the hierarchical habitat use of the species at multiple spatial scales: where the species (i) spent more time (the seascape, based on the time spent per area), (ii) searched for prey (the foraging habitat, based on zones of increased foraging intensity using first passage time), and (iii) fed (the feeding habitat, based on prey capture data). 3. Predictive habitat models reasonably matched the observed distribution patterns and described albatross multi-scale habitat use as a hierarchical arrangement: albatrosses foraged over topographic features in subtropical waters, nested within the wider seascape due to the constraint imposed by the colony effect, whereas feeding occurred nested over the continental shelf and seamounts in areas of low oceanographic variability within the Polar Frontal Zone. 4. Within the current oceanographic conditions, the location of key pelagic habitats for albatrosses breeding in the southern Indian Ocean encompassed certain topographic features such as pelagic areas surrounding main breeding sites, seamounts and submarine mountain ranges. The placement of these pelagic hotspots depends on the current sea surface temperature conditions. 5. Synthesis and applications . The present study provides two key conservation and management tools. First, we provide the first map to support the development of a prospective network of priority conservation zones across the southern Indian Ocean based on habitat predictions of an oceanic indicator species. This could be used not only to support conservation of top predators but also the underlying biodiversity associated with pelagic key habitats. Secondly, the developed habitat modelling procedure is widely applicable and could be used to track changes in species distribution in both marine and terrestrial environments within the current global change scenario.

Marine environments experience seasonal variation in physical and biological parame- ters, with consequent changes in predator distributions. During the breeding period, proximity to suitable feeding sites is essential for central place foragers, whereas during the non-breeding period their distribution is relatively unconstrained. We combined light-based geolocation and satellite tracking to investigate seasonal variation in foraging grounds and behaviour of white-chinned petrels from Kerguelen Island. Birds were associated with highly productive areas throughout the year. During breeding (summer), they performed long commuting trips from the colony to distant, productive Antarctic waters. Thereafter, birds migrated 5200 km westwards to the Benguela upwelling system off Namibia and South Africa to spend the winter. This seasonal shift of foraging grounds coincides with a change in activity patterns; much less time was spent in flight in winter than in summer. Individual variability in the locations of foraging zones and seasonal/daily activity pat- terns was low. Trip durations were shorter during chick-rearing than incubation, although birds often travelled as far or farther, tracking the gradual break up of pack ice. Habitat use models revealed an association with distance to sea-ice edge and chlorophyll a gradient during incubation, whereas sea surface temperature and chlorophyll a gradient best explained habitat use during chick rearing. White-chinned petrels are likely to overlap with other marine predators and fisheries throughout the year. Fishery bycatch constitutes the most significant direct threat to petrels at sea. Moreover, future climate-induced reductions in productivity could affect birds year-round.

Deep-sea ecosystems are highly diverse, and European countries seek to protect these environments by identifying conservation targets. One of these is the Aviles Canyon, southern Bay of Biscay, NE Atlantic, Spain. We present the first analysis of historical benthic communities (1987–1988) of this canyon ecosystem, which is a valuable source of biodiversity baseline information. We found 810 taxa divided in five main macrobenthic assemblages, showing a highly diverse benthic community. Bathymetry was the major structuring agent of benthic community, separating shallow (assemblages I and II, 31 to 307 m depth) from deep stations (assemblages III, IV and V, 198 to 1400 m depth). Especially diverse was assemblage IV, located at the easternmost part of the continental slope (378–1100 m depth) where we found reef-forming corals Lophelia pertusa and Madrepora oculata. These and other communities (sea-pens [Order Pennatulacea, Phylum Cnidaria] and burrowing macrofauna) represent key habitats in NE Atlantic continental slopes, which are currently threatened. The present dataset has produced the most comprehensive assessment of diversity in this area to date, focusing on the taxonomic groups which may best reflect the health of the marine ecosystem and supporting previous studies which indicate that the continental slope of the southern Bay of Biscay hosts key benthic habitats.

Pelagic seabirds obtain food from oceans where the availability of their prey changes rapidly both seasonally and spatially. Here, we investigated changes in the trophic habits of the critically endangered Balearic shearwater (Puffinus mauretanicus) through the breeding season and tested for dietary differences between sexes and age classes. We analysed δ15N and δ13C values in blood of adults during the pre-incubation, incubation and chick-rearing periods and of their chicks. Using a two-isotope mixing model, we estimated dietary contributions based on isotope values from potential prey species which included small pelagic species available naturally and demersal fish species available only from trawling discards. Balearic shearwaters showed clear isotopic and dietary variation through the breeding season. During pre-incubation, breeding adults appeared to exploit demersal fish, whereas during the incubation and chick-rearing period, they fed mainly on pelagic anchovies (Engraulis encrasicolus) and pilchards (Sardina pilchardus). Similarly, chicks were fed mainly with anchovies, a resource with a high energetic value. This variation in the dietary habits of adult shearwaters during the breeding season was probably related to both natural and fishery-induced seasonal changes in the availability of potential prey species within their main feeding grounds. However, changes in the nutritional requirements of the shearwaters could also play an important role. Indeed, diet differed between sexes during pre-incubation: females fed less on trawling discards and more on small pelagic fish than males. This sexual segregation in diet could be the consequence of higher nutritional requirements of females during this period. Our study reveals the differential importance of both trawling discards and small pelagic fish species for a pelagic seabird depending on the breeding period and illustrates the importance of considering the entire breeding season when making inferences about the importance of specific prey in seabird dietary studies. © Springer-Verlag 2009.

Within the current context of changing ecosystems, many organisms are experiencing phenological changes in the timing of migration. Here, we assessed whether the abundance patterns of two trans-equatorial migrating pelagic seabirds, the great shearwater and the sooty shearwater (Puffinus gravis and Puffinus griseus, respectively), have changed over recent decades in the Bay of Biscay (BoB) in relation to the main drivers shaping their migratory journey: climatic factors and food availability. Specifically, we studied the staging dynamic by estimating dates of arrival and departure, staging duration and abundance during a 16-year temporal window (1995–2010) based on monthly at-sea observations performed onboard a commercial ferry. Climatic effects were studied at two temporal scales: oceanic winds and global oscillations indices (North Atlantic Oscillation–NAO) that represent climate variability at short and long time scales, respectively. Based on oceanic winds, we also estimated a hypothetical cost of flying on a monthly basis considering wind speed and the angle between flight and wind direction. Our results showed that both great and sooty shearwaters were influenced by the large scale NAO index but the shape of the relationship was different, while the sooty shearwater was also influenced by food availability. Thus, each species might rely on different cues before and during their migration to adjust to optimal flying conditions and foraging grounds. Both species shape their arrival in the BoB with periods of potential minimum flying costs, following their migration from the western to the eastern North Atlantic. We foresee that the quantification of flying costs can integrate different processes at the level of migration and provide a wider understanding of the migratory dynamic of pelagic predators within current changing ecosystems., ML was funded by a Juan de la Cierva (JCI-2010-07639) and a Ramón y Cajal (RYC-2012-09897) postdoctoral contract. This study is a contribution to the CONPELHAB (PCIG09-GA-2011-293774) and CHALLENGES (CTM2013-47032-R) projects. The contribution number is 726 from AZTI.

© 2015 Pérez-Jorge et al. Along the East African coast, marine top predators are facing an increasing number of anthropogenic threats which requires the implementation of effective and urgent conservation measures to protect essential habitats. Understanding the role that habitat features play on the marine top predator' distribution and abundance is a crucial step to evaluate the suitability of an existing Marine Protected Area (MPA), originally designated for the protection of coral reefs. We developed species distribution models (SDM) on the IUCN data deficient Indo-Pacific bottlenose dolphin (Tursiops aduncus) in southern Kenya. We followed a comprehensive ecological modelling approach to study the environmental factors influencing the occurrence and abundance of dolphins while developing SDMs. Through the combination of ensemble prediction maps, we defined recurrent, occasional and unfavourable habitats for the species. Our results showed the influence of dynamic and static predictors on the dolphins' spatial ecology: dolphins may select shallow areas (5-30 m), close to the reefs (< 500 m) and oceanic fronts (< 10 km) and adjacent to the 100m isobath (< 5 km).We also predicted a significantly higher occurrence and abundance of dolphins within the MPA. Recurrent and occasional habitats were identified on large percentages on the existing MPA (47% and 57% using presence-absence and abundance models respectively). However, the MPA does not adequately encompass all occasional and recurrent areas and within this context, we propose to extend the MPA to incorporate all of them which are likely key habitats for the highly mobile species. The results from this study provide two key conservation and management tools: (i) an integrative habitat modelling approach to predict key marine habitats, and (ii) the first study evaluating the effectiveness of an existing MPA for marine mammals in the Western Indian Ocean. Copyright, ML was funded by a Juan de la Cierva postdoctoral contract (JCI-2010-07639, Spanish Ministry of Science and Innovation - http://www.idi.mineco.gob.es/) and a Ramón y Cajal postdoctoral contract (RYC-2012-09897). Funds were partially provided by a grant from the Spanish Ministry of Economy - http://www.idi.mineco.gob.es/ (CGL2013-42203-R)

International audience; Recent studies have shown that pelagic seabirds with little breeding experience are wide ranging individuals exploring different foraging grounds and occupying generally more pelagic habitats than more experienced birds. This study compared the spatial dynamic of the year-round distribution and behaviour between two different population components: experienced (Exp; >2 years of successful breeding) and inexperienced (Inexp; ≤2 successful years) Cory’s shearwaters (Calonectris borealis) individuals from Berlenga Island, offshore the Portuguese coast. Our aim was to verify the occurrence of variations in the at-sea activity, foraging habitats and isotopic niches of Exp (N = 11) and Inexp (N = 11) individuals, during their breeding and non-breeding phases. Our results confirmed differences in the migratory routes and foraging grounds during the annual cycle between these two population components: Inexp birds exhibited a more pelagic behaviour than Exp birds, with extensive migratory routes, marked by several stopovers, and a higher number of non-breeding areas. Exp individuals migrated through shorter routes, and wintered in fewer locations. Exp individuals foraged on coastal, shallow and cold water areas and showed higher carbon and nitrogen isotopic values, while Inexp birds foraged more on pelagic, windy and frontal zones and exhibited lower carbon and nitrogen isotopic values. Our results suggest that experience plays a relevant role in explaining the spatial distribution and behaviour of pelagic seabirds such as Cory’s shearwaters. Future research with larger sample sizes should focus on comparing the behaviour of juvenile, immature, first-time breeders and breeders with increasing experience and age.

Summary: Seabirds have been incidentally caught in distant-water longline fleets operating in the Southern Ocean since at least the 1970s, and breeding numbers for some populations have shown marked trends of decline and recovery concomitant with longline fishing effort within their distributions. However, lacking is an understanding of how forms of among-individual heterogeneity may interact with fisheries bycatch and influence population dynamics. We develop a model that uses comprehensive data on the spatial and temporal distributions of fishing effort and seabird foraging to estimate temporal overlaps, fishery catchability and consequent bycatch. We apply a population model that is structured by age, sex, life stage and spatially to Crozet Island wandering albatross and explore how heterogeneity in susceptibility to capture may have influenced the population's demography over time. A model where some birds were assumed to be more susceptible to fisheries bycatch was able to successfully replicate the observed trend in breeding pairs. Considerably poorer fits were found without this assumption. Results suggested that the more susceptible birds may have been removed from the population by the 1990s. The model was also able to highlight areas, times and fleets prone to increased bycatch. Knowledge of these factors should assist fisheries and conservation management bodies to quantify and reduce seabird bycatch through spatial management and fleet-specific mitigation efforts. Synthesis and application. Many seabirds show complex life histories that make them highly susceptible to additional incidental mortality from fishing vessels. By applying a population model that integrates key aspects of seabird and fishery dynamics, we were able to explain the observed trends in the breeding population of Crozet wandering albatross and identify key areas and fleets where further mitigation may be required. In addition, the potential removal of a category of birds that shows increased susceptibility to capture has important implications for the conservation management of this population and other iconic species incidentally caught by large-scale commercial fisheries. Many seabirds show complex life histories that make them highly susceptible to additional incidental mortality from fishing vessels. By applying a population model that integrates key aspects of seabird and fishery dynamics, we were able to explain the observed trends in the breeding population of Crozet wandering albatross and identify key areas and fleets where further mitigation may be required. In addition, the potential removal of a category of birds that shows increased susceptibility to capture has important implications for the conservation management of this population and other iconic species incidentally caught by large-scale commercial fisheries.

Conservation diagnosis should identify which demographic parameters (or vital rates) are having a negative effect on the population growth rate of a threatened organism. Diagnosis can analyse how the environment is influencing the vital rates of this organism. In the present study, we tried to improve the diagnosis of a critically endangered seabird, the Balearic shearwater Puffinus mauretanicus, through analysis of the spatio-temporal variability of breeding performance, using long-term data sets covering most of its breeding range. We also analysed the potential influence of 2 food resources, namely small pelagic fish and trawling discards, as measured by purse-seine and trawling landings, respectively. We found inter-annual variability in breeding performance, which could be related to the changes in the availability of both small pelagic fish and trawling discards. Results showed that these variations affected all study colonies in a similar way, thus supporting previous investigations that identified a major foraging area for the whole breeding population. A fitness landscape suggested that current values of breeding success are not responsible for the sharp decline of the species, although incoming fisheries policies could affect its breeding performance in the long term. Factors affecting adult survival, both at sea and in colonies, remain the most important threat, and conservation efforts should concentrate on these issues to prevent the extinction of this endemic species of the Mediterranean region. © Inter-Research 2006., This study was funded by the Cabrera National Park, Govern de les Illes Balears DISCBIRD and LIFE projects (European Commission) and the Spanish Ministries of Science and Technology (Ref. BOS2003-01960) and of the Environment (Ref. 024A/2002). M.L. was supported by a fellowship of the Conselleria de Innovació, Hisenda i Economia (Govern de les Illes Balears)

Several demographic parameters of Balearic shearwater (Puffinus mauretanicus) were estimated and used to model extinction probabilities for the species, which is an endemic seabird confined to a Mediterranean archipelago. Adult survival was analyzed through capture-recapture models at two colonies free of adult predators during 1997-2002. Extinction probabilities for the world breeding population were modelled using Monte Carlo simulations of population trajectories, introducing stochasticity both demographic and environmental. Adult survival estimate (0.780, SE = 0.020, 95% Confidence Intervals: 0.739-0.816) was unusually low for a Procellariiform, suggesting that sources of mortality other than predators (e.g. fishing gears) also occur. A deterministic model showed a declining trend for the world breeding population (λ = 0.952), and significantly less than 1. Population viability analysis showed that in the presence of environmental and demographic stochasticities, mean extinction time for the world population was estimated at 40.4 years (SE = 0.2), and mean growth rate showed a 7.4% decrease per year. Demographic stochasticity played a more important role than environmental stochasticity in population growth rate. © 2003 Elsevier Ltd. All rights reserved., Funds were provided by a Life Nature European Union EU project (ref. B-4/3200/97/246) granted to SEO/Birdlife and Conselleria de Medi Ambient (Govern de les Illes Balears), and by the Programme Quality of Life and Management of Living Resources of the 5th Frame Programme of the EU (ref. QLRT-2000-00839)

International audience; In tropical waters resources are usually scarce and patchy, and predatory speciesgenerally show specific adaptations for foraging. Tropical seabirds often forage inassociation with sub-surface predators that create feeding opportunities by bringing preyclose to the surface, and the birds often aggregate in large multispecific flocks. Here wehypothesize that frigatebirds, a tropical seabird adapted to foraging with low energeticcosts, could be a good predictor of the distribution of their associated predatory species,including other seabirds (e.g. boobies, terns) and subsurface predators (e.g., dolphins,tunas). To test this hypothesis, we compared distribution patterns of marine predators inthe Mozambique Channel based on a long-term dataset of both vessel- and aerialsurveys, as well as tracking data of frigatebirds. By developing species distributionmodels (SDMs), we identified key marine areas for tropical predators in relation tocontemporaneous oceanographic features to investigate multi-species spatial overlapareas and identify predator hotspots in the Mozambique Channel. SDMs reasonablymatched observed patterns and both static (e.g. bathymetry) and dynamic (e.g.Chlorophyll a concentration and sea surface temperature) factors were importantexplaining predator distribution patterns. We found that the distribution of frigatebirdsincluded the distributions of the associated species. The central part of the channelappeared to be the best habitat for the four groups of species considered in this study(frigatebirds, brown terns, boobies and sub-surface predators).

International audience; Spatial modelling studies stress the importance of predicting future species distribution in changing environments, but it is also important to establish historical distribution ranges of species to provide baseline conditions for understanding distribution shifts. We focused on pelagic ecosystems, the largest ecosystem on Earth. Based on boosting algorithms, we reconstructed the foraging patterns of an oceanic predator, wandering albatross Diomedea exulans, in the highly dynamic Southern Ocean over the last half century. To access the unobserved past oceanographic conditions, we used simulations of the OPA-PISCES oceanic model for the 1958-2001 period. Firstly, we validated the simulated oceanographic variables (sea surface temperature and height, wind speed and chlorophyll a) for the 1998-2001 period with remotely sensed oceanographic data, which were highly correlated, except chlorophyll a. Secondly, we developed two habitat models (based on simulated and observed oceanographic variables) describing the foraging probability of albatrosses. We detected no statistically significant differences between the two models and predictions of both models matched the observed distribution patterns reasonably. Finally, we projected the most likely historical key pelagic habitats of albatross for the 1958 to 2001 period and characterised recurrent, occasional and unfavourable foraging areas in a decadal basis based on average predictions and their standard deviations. Our findings 1) provided a historical baseline (1958-1968) of recurrent, occasional and unfavourable foraging habitats, 2) evidenced a progressive habitat shift the following decades driven by a propagation of sea surface height from SE South Africa towards Antarctica from 1958 to 2001 and 3) measured habitat change rates of wandering albatross over the last half century. To our knowledge, our study provides the first quantitative long-term assessment of the spatial response of a marine top predator to changing pelagic habitats of the Southern Ocean and highlighted the oceanographic mechanisms involved, offering new insights on future effects of climate change on the pelagic realm

International audience; Shifts in the diet of top predators can be linked to changes in environmental conditions. In this study, we tested relationships between environmental variation and seasonal changes in diet of a top predator, the grey-headed albatross Thalassarche chrysostoma, breeding at Bird Island, South Georgia in an austral summer of 1999/2000. Oceanographic conditions in that year around South Georgia were abnormal (i.e. anomalously high sea surface temperature to a relative 19-year long-term mean). The diet of grey-headed albatrosses showed high seasonal variation, shifting from cephalopods (42.9 % by mass) in late February to Antarctic krill Euphausia superba (58.3 %) in late April, and grey-headed albatrosses breeding performance was low (16.8 %). This study shows these albatrosses did not manage to find sufficient alternative prey and highlight the risk to top predators if there is an increase in the frequency or severity of food shortages in Antarctic waters.

Riding the Wind Pelagic seabirds rely on wind to move between breeding and foraging areas, and albatrosses—which travel thousands of kilometers over sea—are well-known wind riders. Weimerskirch et al. (p. 211 ; see the cover) monitored foraging and reproduction in wandering albatrosses over 40 years and found that a change in wind patterns, probably induced by climate change, had a notable impact on important life history traits. Greater wind strength increased the rate of travel for the birds and shortened their foraging trips. These shorter trips improved breeding success and resulted in an increase in adult mass. Thus, over the past half-century, environmental changes have improved conditions for the albatross.

International audience; The protection of key areas for biodiversity at sea is not as widespread as on land and research investment is necessary to identify biodiversity hotspots in the open ocean. Spatially explicit conservation measures such as the creation of representative networks of marine protected areas (MPAs) is a critical step towards the conservation and management of marine ecosystems, as well as to improve public awareness. Conservation efforts in ecologically rich and threatened ecosystems are specially needed. This is particularly urgent for the Mediterranean marine biodiversity, which includes highly mobile marine vertebrates. Here, we studied the at sea distribution of one of the most endangered Mediterranean seabird, the critically endangered Balearic shearwater Puffinus mauretanicus. Present knowledge, from vessel-based surveys, suggests that this species has a coastal distribution over the productive Iberian shelf in relation to the distribution of their main prey, small pelagic fish. We used miniaturised satellite transmitters to determine the key marine areas of the southern population of Balearic shearwaters breeding on Eivissa and spot the spatial connections between breeding and key marine areas. Our tracking study indicates that Balearic shearwaters do not only forage along the Iberian continental shelf but also in more distant marine areas along the North African coast, in particular W of Algeria, but also NE coast of Morocco. Birds recurrently visit these shelf areas at the end of the breeding season. Species distribution modelling identified chlorophyll a as the most important environmental variable in defining those oceanographic features characterizing their key habitats in the western Mediterranean. We identified persistent oceanographic features across time series available in the study area and discuss our results within the current conservation scenario in relation to the ecology of the species.

8 pages, 4 figures, 1 table, Understanding how marine ecosystems are structured and how they function is a scientific challenge. Nowadays, to learn about ecosystem trophic dynamics ecologists use two complementary methodological approximations, mass-balance ecosystem models and isotopic tools. However, despite the wide applications of these methodologies, the comparison and combination of both are still scarce. The aim of this study was to examine the trophic dynamics of representative species of the South Catalan marine ecosystem (North-western Mediterranean) using the Ecopath ecosystem modelling tool and the stable isotope approach. By using the two methodologies we depicted the trophic position (trophic level and δ15N values) and trophic width (omnivory index and total isotopic area) of several species of fish, cephalopods, cetaceans, seabirds and one sea turtle. Our results show a clear correlation between the trophic levels estimated by the Ecopath model and the δ15N values, which validate the trophic position of several species in the study area and indicate that both methodologies are useful to determine the trophic position of marine species in Mediterranean marine food webs. In contrast, the two estimators of trophic width (the omnivore index and the total isotopic area) were not strongly related, since the relationship between modelling and stable isotope results was evident only for some species. Further comparisons of trophic width calculated in other marine food webs may provide a better understanding of our results and validate the accuracy of both methodological approaches to calculate trophic width, Research funds were provided by three projects from the Spanish Government (REN2000-0878/MAR, P06-RNM-02362, REN2002-00450). J. N. was supported by a postdoctoral contract of the Juan de la Cierva programme (MICINNJDC, Spanish Ministry of Science and Innovation). M. C. was funded by the European Commission through the Marie Curie International Outgoing Fellowships (ECOFUN project, FP7-PEOPLE-2007-4-1-IOF). M.L. was funded by a PhD fellowship of the Balearic Government, as well as by a postdoctoral contract of the Spanish Ministry of Education and Science (EX-2007-1148) and Marie Curie Individual Fellowship (PIEF-GA-2008-220063)

Dietary studies of seabirds provide information on food webs and oceanographic variability. Studying fatty acid signatures (FAS), which reflect changes in the composition of the diet, has several advantages over traditional methods. In the context of the Mediterranean marine ecosystem, we studied tissue FAS in captive-fed and wild seabirds. Yellow-legged gulls Larus michahellis were experimentally fed either pelagic (sardine Sardina pilchardus) or demersal (spotted flounder Citharus linguatula) fish for 8 wk, and FAS in the birds’ plasma and adipose tissue were studied. The FAS developed patterns characteristic of the sardine or flounder diet, showing the reliability of both types of samples. In addition, plasma samples of 20 endangered wild Balearic shearwaters Puffinus mauretanicus and their most likely prey items from the Mediterranean Sea were collected and analyzed for FAS. Based on FAS of Mediterranean fish, and the results from the feeding experiment, the diet of the endangered wild shearwaters was estimated. In terms of the composition of polyunsaturated fatty acids, the plasma FAS of the shearwaters resembled those of the captive gulls kept on a sardine diet, suggesting that pelagic feeding resources dominate shearwater diet. However, the high level of 20:1n-11, likely metabolized from 22:1n-11 by the birds themselves, suggested that the diet also contained a demersal component rich in 22:1n-11. Contrary to the situation in the open oceans, the levels of the C20 and C22 monounsaturated fatty acids are low in the Mediterranean food web and characteristic of most demersal species. Our results support the findings of previous field studies that the diet of the shearwaters is frequently supplemented by demersal fish from fishery discards.

Unintended mortality in longlines emerged in the early 1990s as one of the most important threats for pelagic seabirds worldwide. Most of the studies were focused on highly developed industrial fisheries, overlooking bycatch in small-scale artisanal fisheries. However, bycatch in small-scale fisheries might have negative effects similar to those of industrial fisheries when they overlap with hotspot areas of top predators. Moreover, different types of fishing gear coexist in the same oceanographic area, particularly in highly exploited marine ecosystems such as the western Mediterranean. We quantify for the first time the influence of trawling regime on Cory’s shearwater Calonectris diomedea bycatch in the western Mediterranean longline artisanal fishery. The availability of trawling discards has substantial influence on the foraging and breeding ecology of many seabirds, and trawling inactivity may drive shearwaters to seek alternative food resources, such as baits used in longline fishing. Based on our previous knowledge of the system, we also tested other variables affecting bycatch over 8 yr (1998 to 2005). Within this 2-fishery framework, we found that trawling regime, longline fishing time and breeding stage were key factors explaining shearwater attendance to longline vessels, but mainly trawling regime and fishing time increased the incidental capture of Cory’s shearwaters. More specifically, during the pre-breeding and chick-rearing periods, bycatch dramatically increased during sunrise sets in the absence of trawling activity. Importantly, this study indicates the need for an integrated multi-fisheries management approach for the conservation of seabirds and highlights the necessity of banning longline fishing during periods of trawling inactivity.

International audience; An understanding of the distribution and habitat associations of far-ranging marine predators is being increasingly applied to protect these species from anthropogenic threats at sea (e.g. oil spills and fisheries bycatch). Within this framework, this research on Cory's shearwater Calonectris diomedea integrates vessel-based survey and tracking data to provide 2 distinct, yet complementary, perspectives of the habitats of this species in the western Mediterranean during incubation in June and chick rearing in August of 2007. We used a hierarchical modelling approach to (1) delineate the foraging habitat of the species using vessel-based surveys and (2) identify its feeding habitat based on tracking data within the Information-Theoretic framework. Our habitat modelling analyses suggest that shearwaters respond to complex bio-physical coupling, illustrated by their association with frontal features and elevated ocean productivity. Our models yielded moderate predictions of Cory's shearwater habitats within 2 distinct spatial scales. At the mesoscale, the foraging range of the species comprised the continental and insular shelf-slope waters of the Iberian Peninsula and the Balearic Islands, between the Gulf of Lions to the north and Cape Palos to the south. At the coarse scale, the tracking data highlighted important feeding areas within this larger foraging range: 3 continental shelf-slope ‘hotspots'—(1) Gulf of Lions, (2) Cape Creus–Barcelona–Ebro Delta and (3) Cape La Nao–Cape Palos; from north to south—as well as the insular shelf-slope areas around the Balearic Islands. These results match previous observations of the foraging range and feeding patterns of the species, and are consistent with the interpretation of the regional oceanography. This study highlights how the integration of tracking and vessel-based survey data can provide a wider understanding of the predictability of aggregation (i.e. hotspots) and the key oceanographic habitats of far-ranging seabirds at multiple spatial scales. Thus, complementary data integration is a step forward in conservation studies of far-ranging marine top predators.

Studies on spatiotemporal pattern of population abundance predict that close populations should exhibit a high level of synchrony, reflected in a parallel time variation of at least one demographic parameter. We tested this prediction for two threatened species of Procellariiformes sharing similar life history traits: the European Storm Petrel (Hydrobates pelagicus) and the Balearic Shearwater (Puffinus mauretanicus). Within each species, we compared adult survival, proportion of transients (breeders that do not settle), and average productivity at two neighboring colonies. Physical and environmental features (e.g., food availability) of the breeding sites were similar. However, while Balearic Shearwater colonies were free of predators, aerial predators occurred especially in one colony of the European Storm Petrel. Despite this difference, we found similar results for the two species. A high proportion of transient birds was detected in only one colony of each species, ranging between 0.00-0.38 and 0.10-0.63 for the petrels and shearwaters, respectively. This seems to be an emergent feature of spatially structured populations of seabirds, unrelated to colony size or predator pressure, that can have important demographic consequences for local population dynamics and their synchrony. Local survival of resident birds was different at each colony, an unexpected result, especially for predator-free colonies of Balearic Shearwater. Productivity varied between the two colonies of European Storm Petrels, but not between the two colonies of Balearic Shearwaters. We demonstrated that within each species, several demographic parameters were colony specific and sufficiently different to generate short-term asynchronous dynamics. Our findings suggest that, in spatially structured populations, local factors, such as predation or small-scale habitat features, or population factors, such as individual quality or age structure, can generate unexpected asynchrony between neighboring populations. © 2008 by the Ecological Society of America., The study has been partially funded by grants from the Spanish Ministry of Science and Technology (ref. BOS2003-01960 and CGL2006-04325/BOS), the Balearic Government, and the European Commission (LIFE Program and DISCBIRD project)

The hormonal environment experienced during prenatal development may affect adult phenotype and behaviour. Digit lengths may provide an estimate of steroid levels encountered during embryonic development in humans and other vertebrates. Finger patterns in humans have been shown to reveal sexual orientation or cooperative behaviour. We explored individual breeding behaviour in a monogamous seabird, the Balearic shearwater Puffinus mauretanicus and unexpectedly detected some cooperative breeders. Furthermore, we show evidence of correlation between digit lengths and cooperative breeding in this species. Additionally, we suggest that the first digit could be a possible indicator of prenatal steroid levels. These results are the starting point for further tests of the hypothesis that first digit length is an indicator of prenatal hormone levels in other vertebrate species. Moreover, these results may offer practical use in wild populations to study the implications of the changes in prenatal environment for adult social behaviour. © 2008 The Royal Society.

Marine protected areas (MPAs) require ecologically meaningful designs capable of taking into account the particularities of the species under consideration, the dynamic nature of the marine environment, and the multiplicity of anthropogenic impacts. MPAs have been most often designated to protect benthic habitats and their biota. Increasingly, there is a need to account for highly mobile pelagic taxa, such as marine birds, mammals and turtles, and their oceanic habitats. For breeding seabirds foraging from a central place, particular attention should be paid to distant foraging grounds and movement corridors, which can often extend to hundreds of kilometers from breeding colonies. We assessed the habitat use by the most threatened Mediterranean seabird, the Balearic Shearwater, Puffinus mauretanicus, using vessel-based surveys during the chick-rearing period (May-June). We used a hierarchical modeling approach to identify those environmental variables that most accurately reflected the oceanographic habitat of this species by (1) delineating its foraging range using presence/absence data and (2) identifying important foraging grounds where it concentrates in dense aggregations. The foraging range comprised the frontal systems along the eastern Iberian continental shelf waters (depth, This study was funded by EC project DISCBIRD (QLRT-2000-00839), Spanish Ministries of Science and Technology (BOS2003-01960) and of the Environment (ref. 024 A/2002)

Human fishing activities are negatively altering marine ecosystems in many ways [1,2], but scavenging animals such as seabirds are taking advantage of such activities by exploiting fishery discards [3,4,5]. Despite the well-known impact of fisheries on seabird population dynamics [6,7,8,9,10], little is known about how discard availability affects seabird movement patterns. Using scenarios with and without trawling activity, we present evidence that fisheries modify the natural way in which two Mediterranean seabirds explore the seascape to look for resources during the breeding season. Based on satellite tracking data and a mathematical framework to quantify anomalous diffusion phenomena, we show how the interplay between traveling distances and pause periods contributes to the spatial spreading of the seabirds at regional scales (i.e., 10250 km). When trawlers operate, seabirds show exponentially distributed traveling distances and a strong site fidelity to certain foraging areas, the whole foraging process being subdiffusive. In the absence of trawling activity, the site fidelity increases, but the whole movement pattern appears dominated by rare but very large traveling distances, making foraging a superdiffusive process. Our results demonstrate human involvement on landscape-level behavioral ecology and provide a new ecosystemic approach in the study of fishery-seabird interactions., This study was funded by Spanish Ministry of Science grants BOS2003-01960 and CGL2006-04325/BOS. F.B. was funded by postdoctoral research grantMEC-EX1011 from the Spanish government. F.B., L.G., and S.A.L. were also funded by National Science Foundation grant DEB-0434319 and Defense Advanced Research Projects Agency grant HR0011-05-1-0057. M.L. was supported by a predoctoral research grant from the Balearic regional government.