Interactions between seabirds and fisheries, such as collisions or entanglement with fishing gear and bycatch, occur in all oceans and most fisheries. These interactions primarily occur as seabirds attempt to feed on bait, resources in nets or fisheries' by-products such as discards and offal. The Black-browed Albatross Thalassarche melanophris is the most abundant albatross species on the Argentine Continental Shelf. This species is currently listed as 'Least Concern' by the International Union for Conservation of Nature (IUCN) but it is considered to be threatened in Argentina where it is known to interact significantly with diverse fisheries. Little is known about how these interactions vary with intrinsic factors such as age, a key knowledge gap. This study aimed to evaluate the effect of fishing effort by trawl and squid-jigging vessels on the foraging behaviour of adult and immature Black-browed Albatrosses wintering on the Argentine Continental Shelf. Our analysis used data from 15 satellite transmitters deployed on six adults (2011-2013) and nine immature individuals (2015). Foraging behaviour was identified using the Expectation Maximisation Binary Clustering algorithm. Generalised Linear Mixed Models (GLMMs) were fitted to determine the effect of fishing effort by different trawl and jigging fleets (measured as the number of fishing points per hour per grid cell) on the likelihood of albatrosses engaging in foraging behaviour. In both age classes, the probability of foraging behaviour was positively correlated with trawl fishing effort. For immature albatrosses, foraging behaviour was notably affected by double beam trawlers only. For adults, it was associated with fishing effort from double beam trawlers, coastal trawlers, and high-seas ice-trawlers, although the effect was of lesser magnitude. All mentioned trawl fisheries are known to produce significant amounts of discards. Identifying these associations can help to pinpoint potential conflict areas between albatrosses and fishing activities and facilitate the planning of effective conservation measures through an ecosystem-based approach to fisheries management.

Human activities have transformed natural environments. For example, fisheries can alter prey availability and cause trophic changes in seabirds. Along the southeastern coast of South America inhabits the vulnerable Olrog’s Gull (Larus atlanticus), considered a specialist for having an estuarine crab-based diet. Since the 1970s fishing activity in Argentina has increased. Moreover, there are reports of Olrog’s Gulls interacting with fishing activities, whose discards can provide a predictable anthropogenic food source for the gulls. This trophic modification can be studied using stable isotope analysis. Here, we compare the isotopic niches of Olrog’s Gull based on historical material (1918–1960) and recent measurements (2014). We expected recent samples to show lower δ¹³C and higher δ¹⁵N values, reflecting increased consumption of fish from fisheries at the expense of estuarine crabs. Our results showed a decrease in both δ¹³C and δ¹⁵N values in recent samples, but only δ¹⁵N values were statistically significant. These results may reflect environmental isotopic changes driven by human activities which have caused a trophic shift in Olrog’s Gull’s diet. However, the results do not show fishing activity as the main cause of change through the recent period, but other anthropogenic disturbances as agricultural development and urban waste availability might be playing a role. These findings provide insights for conservation, as they indicate that anthropogenic alterations in coastal ecosystems are influencing feeding ecology of this threatened species.

La Gaviota Cangrejera (Larus atlanticus) es una especie de lárido endémica de la costa atlántica sudamericana considerada ‘Vulnerable’ en Argentina. Su área de nidificación se encuentra restringida a áreas insulares estuariales, a baja altitud sobre el nivel del mar, poco vegetadas y cercanas a cangrejales. Casi toda la población reproductiva nidifica en la provincia de Buenos Aires, dentro de áreas protegidas con diferentes categorías de conservación. Durante los censos aéreos realizados para actualizar los números poblacionales, el 17 de octubre de 2025 registramos la presencia de dos nuevos sitios de anidación de Gaviota Cangrejera en el estuario de Bahía Blanca, uno en el extremo noreste de Isla Trinidad (39°05’S, 61°55’O) y otro en el extremo noreste de Isla Ariadna (39°14’S, 61°58’O), ambos dentro de la Reserva Natural Bahía Blanca, Bahía Falsa, Bahía Verde. Se contaron los Nidos Aparentemente Ocupados, que representan una estimación del número de parejas reproductivas, obteniéndose un total de 26 ± 2 (n = 7 fotos) y 22 ± 1 (n = 4 fotos), respectivamente. Las colonias se encuentran cercanas a la línea de marea, por lo que enfrentarían riesgos ante modificaciones drásticas de la superficie, que pueden ser causadas por tormentas intensas o actividades antrópicas como dragados o actividades recreativas. Estos sectores se encuentran actualmente por fuera del área intangible de la reserva, por lo que a partir de este hallazgo se incorporaron en la revisión que se está llevando a cabo para la modificación de la zonificación del área a fin de extremar las medidas de protección efectiva durante este período crítico para la especie

The interaction between recreational fishers and birds has historically received little attention. The Mar Chiquita Coastal Lagoon (Argentina) is a site recognised under multiple conservation frameworks in which the spatial overlap between recreational fishing and birds may lead to interactions with potential ecological consequences. This study aims to address the following questions: (1) What is the spatio-temporal overlap between birds and recreational fishers? (2) Which bird species interact with fishers, and how frequently? (3) How do fishers and birds interact? and (4) What factors trigger these interactions? To answer these, 556 scans samplings and 200 behavioural observations of birds associated with fishers were conducted. A total of 1652 fishers (22 +/- 17 fishers/day), 1925 fishing rods (25 +/- 19 rods/day) and 14,152 birds (186 +/- 340 birds/day) from 26 species were recorded sharing the same space. In the behavioural observations, a total of 515 associated birds were observed (5.15 +/- 6.80 birds/h) corresponding to six species. A total of 1163 non-contact interactions were recorded (11.64 +/- 14.80 NCI/h) mostly flying (93%). On the other hand, 143 contact interactions were observed (1.43 +/- 4.60 CI/h), of which 90% were bait stealing. Both types of interactions were affected by season, site, number of fishers and number of baits offers. This study is the first to describe the nature of the fishers-bird interactions, quantify their frequency and identify the behavioural triggers involved. This study provides valuable information that can inform awareness-raising strategies aimed at fishers and other coastal users. La interacci & oacute;n entre pescadores recreativos y aves ha recibido hist & oacute;ricamente poca atenci & oacute;n. La Laguna Costera Mar Chiquita (Argentina) es un sitio reconocido bajo m & uacute;ltiples figuras de conservaci & oacute;n, en la cual la superposici & oacute;n espacial entre la pesca recreativa y las aves marinas y costeras puede dar lugar a interacciones con posibles consecuencias ecol & oacute;gicas sobre las mismas. En este estudio se propone responder las siguientes preguntas: 1) & iquest;Cu & aacute;l es la superposici & oacute;n espacio-temporal entre las aves y los pescadores recreativos?; 2) & iquest;Qu & eacute; especies de aves interact & uacute;an con los pescadores y con qu & eacute; frecuencia?; 3) & iquest;C & oacute;mo interact & uacute;an los pescadores y las aves?; y 4) & iquest;Qu & eacute; factores desencadenan estas interacciones? Para responder esto, se realizaron 556 escaneos y 200 observaciones comportamentales de aves asociadas a pescadores recreativos. Se registr & oacute; un total de 1.652 pescadores (22 +/- 17 pescadores/d & iacute;a), 1.925 ca & ntilde;as de pesca (25 +/- 19 ca & ntilde;as/d & iacute;a) y 14.152 aves (186 +/- 340 aves/d & iacute;a) pertenecientes a 26 especies compartiendo el mismo espacio. En las observaciones comportamentales, se registraron 515 aves asociadas (5,15 +/- 6,60 aves/h), correspondientes a seis especies. Se registraron un total de 1.163 interacciones sin contacto (11,64 +/- 14,80 NCI/h) en su mayor & iacute;a vuelos (93%). Por otro lado, se observaron 143 interacciones con contacto (1,43 +/- 4,60 CI/h), de los cuales el 90% correspondieron al robo de carnada. Ambos tipos de interacciones fueron afectadas por la estaci & oacute;n del a & ntilde;o, el sitio, el n & uacute;mero de pescadores y la cantidad de carnada ofrecida. Este estudio es el primero en describir la naturaleza de las interacciones entre pescadores recreativos y aves, cuantificar su frecuencia e identificar los desencadenantes comportamentales involucrados. Adem & aacute;s, este estudio aporta informaci & oacute;n valiosa que puede servir de base para dise & ntilde;ar estrategias de comunicaci & oacute;n dirigidas a pescadores y otros usuarios del ambiente costero.

Reducing fisheries bycatch is a global challenge, with social factors playing a significant role in the adoption of mitigation measures (MMs). This study investigates these factors within Argentina's offshore commercial bottom trawl fleet, where research remains limited. Through a qualitative approach, 29 interviews with key stakeholders were conducted to explore perceptions of bycatch and MMs. Analysis revealed four main barriers to MMs uptake: perceptions of cumbersomeness, ineffectiveness, lack of an adequate control system, and Argentine cultural influences. Participants emphasized the need for improved governance strategies, collaboration among stakeholders, and tailored educational programs to enhance MMs uptake. Additionally, effective communication, trust-building, and incentives emerged as essential elements for fostering the use of MMs.

Analysis of fatty acid composition can provide information about the effect of anthropogenic activities on the trophic choices of different species, including seabirds. The Olrog’s Gull Larus atlanticus, a threatened species found along the coast of Buenos Aires Province, Argentina, exhibits carcinophagus feeding habits. However, its association with human activities, such as recreational fishing and others, is increasing, particularly during the non-breeding season. During the non-breeding seasons of 2018 and 2019, we analysed the circulating fatty acid composition in Olrog’s gulls from two contrasting sites regarding the level of urbanization and human disturbance: Mar Chiquita, a non-urban site, with low human impact and presence of crab mudflats, and Mar del Plata, an urban site, with high human impact and absence of crab mudflats. Significant differences in fatty acid composition were observed between the two sites that can be related to non-urban and urban diets, and for ‍n-3/n-6 ratio that differentiates aquatic vs. terrestrial diets. Distinct segregation patterns between individuals at each site were observed, resulting in two major groupings: birds sampled at the non-urban site and those at the urban site. However, some birds exhibited mixed patterns, suggesting variability in the consumption of trophic sources. This study contributes to the broader understanding of trophic ecology of seabirds during non-breeding season in environments influenced by anthropogenic activities, employing non-lethal techniques.

El sistema fluvio-marino del Río de la Plata (SFMRP) es un ambiente complejo, dinámico y altamente productivo dentro del cual las aves marinas tienen particular relevancia. Este sistema, de gran importancia ecológica, meteorológica y oceanográfica para la región, propicia el desarrollo de actividades humanas que traen aparejados problemas de conservación. En este trabajo caracterizamos los ensambles de aves marinas y su relación con las actividades que ocurren en el área desde una perspectiva ambiental. Dentro del ensamble de aves marinas (ca. 74 especies) del SFMRP, las gaviotas y gaviotines son los grupos más representativos y dominantes. El SFMRP también contiene una buena representación de Procellariiformes que utilizan principalmente aguas de altamar. Las principales actividades humanas desarrolladas en el área de interés, que incluyen el desarrollo urbano e industrial, las pesquerías comerciales y recreacionales, y la exploración-explotación de hidrocarburos, ocasionan fragmentación y degradación del paisaje, sobreexplotación de recursos, y contaminación (e.g., química, lumínica y sonora, entre otras). Las problemáticas ambientales destacadas afectan principalmente los movimientos, alimentación, y estado sanitario de las aves marinas que utilizan el SFMRP. Se identificaron y caracterizaron siete unidades de conservación a modo de enfoque para organizar y facilitar el desarrollo e implementación de herramientas de manejo. Destacamos la necesidad de reforzar la colaboración entre diferentes actores y sectores involucrados en el área para mitigar los impactos sobre la biodiversidad de aves marinas. Se recomienda además el establecimiento de programas de evaluación y/o monitoreo de los ensambles de aves marinas y desarrollar e implementar los planes de manejo de las unidades de conservación identificadas.

Las prácticas de investigación con aves marinas son variadas e involucran metodologías que van desde la mera observación directa de los animales hasta la colocación de dispositivos en los individuos, el cautiverio, entre otras. La propia comunidad científico/académica reconoce el efecto negativo de algunas de estas prácticas en diferentes aspectos de la biología de los individuos y las poblaciones. Dichas metodologías han ido cambiando a través del tiempo tanto con el devenir del desarrollo tecnológico como así también con nuevas reflexiones en torno a la conciencia, el sufrimiento y el dolor de los animales como base de la ética. En este trabajo nos interesa reflexionar sobre las prácticas de investigación con aves marinas desde un abordaje filosófico, integrando aspectos epistemológicos, éticos y afectivos y considerando a su vez una perspectiva histórica. Creemos que habilitar preguntas y reflexiones en este tema, que exigen pausas y diálogos, nos permitirán abrir posibilidades a otras formas de abordar las prácticas de investigación, de relacionarnos y acercarnos a las aves e incluso habilitar otras maneras de co-habitar en el mundo.

Marine recreational fishing in Argentina is an activity with a high socioeconomic impact. Its effects on the ecosystem have been poorly explored, for example, impacts of anglers on coastal birds. This study assessed perceptions and feelings of anglers towards their interaction with coastal birds, with the ultimate goal of generating information of socioecological value to be incorporated into national conservation instruments. A total of 240 structured questionnaires were conducted on active recreational fishers from the Mar Chiquita Reserve, Argentina. Main motivations to visit the fishing site expressed by respondents were the fishing quality and the peaceful and natural features of the reserve. Most anglers knew about the protected status of the site and have seen coastal birds during their fishing day, considering them to be beneficial to the ecosystem. Anglers observed coastal birds feeding on discards frequently; birds stealing the bait or the catch at moderate frequency; and birds entangled in fishing lines rarely. Most anglers indicated the occurrence of interaction with coastal birds during their activities, and expressed sadness when spotting a bird entangled in a fishing line. The information that emerged from this study could be used to develop informational strategies, for example guidelines for responsible fishing and signage aimed to inform anglers about the potential impacts of their interaction with coastal birds.

Seabirds, particularly albatrosses, are among the most threatened birds as a result of their continuous exposure to anthropic pressures including interaction with commercial fisheries, climate change and pollution. Several studies that have focused on the spatial distribution of foraging seabirds have identified a certain level of segregation between age classes. The black-browed albatross Thalassarche melanophris is the most abundant albatross species in the South-west Atlantic Ocean and the main pelagic seabird interacting with a range of fishing fleets. There is a considerable lack of knowledge about the biology of immature individuals and on habitat suitability of the species during non-breeding season (winter). The aim of this study was to assess the foraging habitat suitability of the black-browed albatross in the South-west Atlantic during the austral winter, analysing differences between adults and immatures individuals. Habitat suitability models were based on foraging locations recorded by 15 satellite transmitters deployed on six adults and nine immature individuals between 2011 and 2015. Remotely sensed oceanographic data were used to characterize suitable foraging habitat for the albatrosses. Differences were found in foraging habitat suitability by age class, with adult selecting areas located in deeper waters over the continental shelf break as well as in neritic zones under cooler water temperatures, whereas immature individuals foraged chiefly off coastal waters having more moderate temperatures. Knowing habitat suitability and segregation patterns within-species is key for the conservation of critical marine habitats given that, by only considering one age class, other important habitats would be neglected and not considered in conservation efforts to mitigate threats such as incidental mortality. It is important to include all age classes when studying patterns of associations with threats, such as fishing activity as a proxy of risk of bycatch, and for the development of Marine Protected Areas.

Individual traits such as age-class can have profound effects on space utilisation by individual birds, with juvenile birds more often exhibiting dispersive movements. We studied the origin of juvenile Olrog's Gulls Larus atlanticus, a threatened species, using stable isotopes ratios of carbon (δ13C), nitrogen (δ15N) and sulphur (δ34S). We analysed feathers from individuals captured in the wintering season at Mar Chiquita Coastal Lagoon, Argentina, and the potential trophic sources of their breeding sites at Bahía Blanca and San Blas. Mean δ13C was similar for trophic sources and mean δ15N was higher for Bahía Blanca. The δ34S showed a greater variation among prey species than among sites. The mean contributions of the main colonies resulted in assigning 37.5% individuals as from Bahía Blanca, 16.7% from San Blas, and 45.8% undetermined. Results indicate that Mar Chiquita coastal lagoon attracts juvenile Olrog's Gulls dispersing from the two main breeding grounds of the species. This work is one of the first approaches to study the origin of dispersive juvenile larids through the application of stable isotope analysis. This isotopic approach allows obtaining trophic and movement information when it is not possible to use other tools.

Recreational fishing (RF) is a popular activity worldwide, which has the potential of providing social, cultural, food, economic, and environmental benefits, but may produce negative impacts on the ecosystems. In South America, RF is an important activity, which is developed in continental and coastal-marine ecosystems showing a growing trend in participation rates and catches. The aim of this study is to review current research trends in RF in South America, analyzing the main topics addressed in peer-reviewed papers. A systematic search addressing recreational fishing in the region was performed through three web scientific search engines, including publi-cations from 1995 to 2020. From each selected article, we extracted the title, authors, year of the publication, country where the research was conducted, and ecosystem (i.e. continental or coastal-marine). Articles were categorized in four types: 'Environmental Issues', 'Target Species', 'Management', and 'Socioeconomic'. These categories were also divided into subcategories. A total of 135 articles were found and the number of articles has increased to the present. 'Target Species' articles showed a peak during 2003-2008 and was constant until 2020, while 'Socioeconomic' showed an increase during the 2009-2014 period. The number of articles addressing 'Environmental Issues' and 'Management' steadily increased throughout the study period. Fifty-three percent of articles was carried out in continental ecosystems, 44 % in coastal-marine ecosystems, and 3 % in both. The most frequent category was 'Target Species'. There was no association between the distribution of categories and the ecosystems where the research was performed. The largest number of studies was conducted in Brazil. The present study is the first one systematically reviewing and characterizing articles addressing RFs in South America. Main gaps of knowledge in RF and future perspectives of research are discussed.

The fishery for Patagonian scallop (Zygochlamys patagonica) in Argentinean waters began over 25 years ago. This fishery -utilizing bottom otter trawl gear -was the first scallop fishery in the South-West Atlantic certified under the Marine Stewardship Council scheme, firstly in 2006, and recertified in 2012 and 2017. However, there is still no data available on its relationship with non-target species such as seabirds that attend these operations. This is the first study investigating the direct interactions between seabirds and this fishery. Records were obtained by observers tasked onboard two freezer trawlers (representing 50% of the whole fleet) from early October 2019 to mid-March 2020. Procellariiformes dominated the attending seabird assemblages; being the Black-browed al-batross (Thalassarche melanophris), White-chinned petrel (Procellaria aequinoctialis), Great shearwater (Ardenna gravis), Atlantic-yellow nosed albatross (T. chlororhynchos), Southern giant petrel (Macronectes giganteus), Royal albatrosses (Diomedea sandfordi/epomophora) and the Cape petrel (Daption capense) the most frequent and abundant species. Seabird abundance decreased with increasing swell height and increased with cloud coverage. Seabird interactions with the vessel or fishing gear were recorded in 4.3% of the surveys (i.e. number of hauls), resulting in an estimated rate of 0.11 seabird contacts with fishing gear per haul, the bulk of which corresponded to Black-browed albatrosses and Great shearwaters. A single individual was bycaught during the study period, meaning a mortality rate of < 0.001 birds per haul. The interactions increased during towing operations compared to shooting and haulback. The information presented in this study contribute to the implementation of actions in the Argentine National Plan of Action -Seabirds as well as monitoring and conservation actions that Argentina undertakes in compliance with international instruments. Moreover, this information is relevant to the current fishery certification process.

The cape petrel (Daption capense) is an abundant procellariform in seabird assemblages attending fishing vessels in the Southwestern Atlantic Ocean. The bulk of extant information comes from surveys conducted during the breeding season at Antarctic and sub-Antarctic sites; however, most of their ecological aspects during the non-breeding season remain largely unknown. We performed on-board census and stable isotope analysis in blood and feathers from 30 adult petrels during the non-breeding season in waters off Argentina. Cape petrels attending ice trawlers showed a higher abundance during winter compared to other seasons. The lack of correlation of isotopic values between tissues suggests changes in the diet and foraging locations between the moulting period and the non-breeding season. Isotopic mixing models revealed low-trophic-level sources as the main contributors to this petrel's diet while pelagic-demersal fish species targeted by fishing vessels showed the lower contribution. The discrepancies between methods could be a result of partial use of offal/discards or low use of these due to size/mechanic limitations. These findings reinforce the idea of zooplankton and small-pelagic fish facilitation during the hauling operatory and the relevance of combining different methods for a thorough understanding of prey-predator relationships.

Uno de los problemas de conservación más agudos que enfrenta la megafauna marina —incluyendo a las aves marinas— está asociado a la mortalidad incidental en pesquerías. Con diferentes dinámicas y planteando complejos desafíos para la conservación de especies amenazadas, este problema ocurre tanto en pesquerías jurisdiccionales como en aquellas que operan en aguas internacionales. Abordar este problema de conservación en especies altamente migratorias requiere gestiones complejas, y en ellas la cooperación multilateral resulta decisiva.

El Mar Argentino es un ambiente de gran riqueza; su productividad lo convierte en una zona marítima por excelencia para la pesca comercial. Dicha actividad productiva se superpone espacial y temporalmente con especies que dependen de esta zona como área de alimentación. Una de las consecuencias de esta cohabitación es la captura incidental de aves marinas en las artes de pesca. Esta situación pone en tensión la actividad productiva y los compromisos internacionales de conservación marina asumidos por el Estado argentino. El presente trabajo hace un recorrido desde la concepción que primaba respecto a los recursos naturales hasta el surgimiento de nuevas formas de abordaje como el Enfoque Ecosistémico de la Pesca (EEP). Se describe la repercusión e incidencia que ello tiene en las economías latinoamericanas y en las políticas de gestión, que hacen a un modo de habitar el territorio, cargado de significados y construcciones sociales, en dialéctica constante con el sistema natural. Finalmente, se concluye que la problemática asociada a las aves marinas no constituye en el presente un conflicto ambiental, pero posee el potencial de convertirse en tal.

Los ecosistemas marinos son áreas donde convergen tanto actividades humanas como megafauna marina (aves, mamíferos y tortugas marinas). En el caso de las aves marinas pelágicas, como los albatros y los petreles, estas permanecen la mayor parte de sus vidas en el mar; consecuentemente, las amenazas a las que se enfrentan provienen, en gran parte, de las actividades humanas que se desarrollan en el mar, como por ejemplo, la actividad pesquera. La mortalidad incidental provocada por la pesca es una de las causas principales de la disminución de sus poblaciones. Para poder desarrollar herramientas espaciales que minimicen el impacto de la actividad pesquera sobre albatros y petreles, tales como la identificación de áreas de importancia para las aves en el mar, es necesario conocer la distribución de estas en el mar. A partir de la colocación de dispositivos miniaturizados en las aves, tales como transmisores satelitales, es posible estudiar sus movimientos e, incluso, su comportamiento (por ejemplo, áreas de alimentación vs. áreas de tránsito); además, es necesario modelar el esfuerzo de la flota pesquera. Presentamos información sobre la distribución en el mar del albatros de ceja negra (Thalassarche melanophris) y la superposición con actividad pesquera como estudio de caso y la identificación de áreas de importancia para su conservación en el mar.

Marine megafauna, namely sea turtles, seabirds, and marine mammals in this chapter, conforms a group that mainly includes large vertebrates associated with the marine environment during the whole or a significant part of their life history. They are mostly characterized by extreme life span, deferred maturity and slow growing rates; while the high heterogeneity of the environment they inhabit is reflected in a large diversification of diet and feeding tactics. Some representatives of the marine megafauna are considered top predators, playing an important role in the maintenance of the ecosystem and integrating ecological variations occurring in marine ecosystems at different spatiotemporal scales. Most of them have an important role as bio-vectors, transporting nutrients across ecosystem boundaries and favoring nutrient cycling. Marine megafauna is exposed to similar threats within a complex scenario, including bycatch, pollution, climate change, human disturbance, and habitat deterioration. As a result, several populations have undergone and are currently facing declining trends. Various international instruments have played quite an important role in improving conservation policies around the world. However, there is an urgent need to develop new technologies, apply emerging management paradigms and promote collaborations as opportunities to improve marine megafauna conservation and sustainable management.

Sexual segregation in habitat use occurs when sexes differ in their use of the physical environment and is widely reported among seabirds. The Black-browed Albatross (Thalassarche melanophris) is one of the most abundant seabird species in the south-west Atlantic, but whether the sexes differ in their habitat selection during winter remains unknown. Here, we tested for sexual segregation in adult and immature Black-browed Albatrosses during winter. Movement data from 21 satellite-tracked Black-browed Albatrosses across the south-west Atlantic Ocean between 2011 and 2015 were used to determine suitable foraging habitat for males (n = 7) and females (n = 14) using habitat selection models. Sexual segregation was then assessed using an index of niche overlap for immature and adult age classes. Variables with the highest importance in habitat selection models across all groups were depth and sea surface temperature. The highest probabilities of occurrence were in shallow waters and intermediate surface temperatures. No sexual segregation was found which may be because of the large abundance of prey in the region and moderate energy requirements during the non-breeding season. These results are relevant for spatially explicit conservation management in this region, including the designation of marine protected areas. Indeed, bycatch in fisheries is a major threat to seabirds in this area, and foraging behaviour and performance in winter of this keystone species will influence their future reproductive performance.