Address: Instituto de Investigaciones Marinas y Costeras
Facultad de Ciencias Exactas y Naturales,
Universidad Nacional de Mar del Plata - CONICET.
Funes 3350, (7600) Mar del Plata,
Argentina
New Zealand Journal of Marine and Freshwater Research, , 2025
The Franciscana dolphin (Pontoporia blainvillei) is facing significant threats in the Southwester... more The Franciscana dolphin (Pontoporia blainvillei) is facing significant threats in the Southwestern Atlantic Ocean, largely due to entanglement in artisanal fishing nets, which makes it the most threatened dolphin species in the region Its conservation calls for a standardised methodology that enables the detection and monitoring of dolphin populations on a longer temporal scale. This study represents the first acoustic monitoring of wild Franciscana dolphins in Argentina, focusing on understanding their diel patterns of activity and their relationship with environmental variables. Our findings show that Franciscana dolphin acoustic presence in summer in Chapadmalal (Argentina) is more frequent in January than in February and March and is influenced by the interaction between tide and wind direction. Specifically, at higher tide levels, wind direction has a reduced impact on dolphin detections. This interaction varies seasonally, with shifts observed in February and March. This research advances standardised methodologies for detecting and monitoring Franciscana dolphin populations, supporting efforts to improve their conservation.
The franciscana dolphin is a small, vulnerable species often caught in artisanal gillnets. This s... more The franciscana dolphin is a small, vulnerable species often caught in artisanal gillnets. This study aims to provide a comprehensive assessment of their acoustic capabilities by using advanced equipment to collect a large dataset of wideband, continuous recordings. We examined the detailed acoustic signals of franciscana dolphins, comparing the sounds from rehabilitated dolphins in captivity with those of wild dolphins near fishing nets. Significant differences in acoustic characteristics were found between neonates and older dolphins, with juvenile and wild dolphins showing similar features. For the first time, repetition patterns in click production were identified, highlighting the importance of understanding the context of these sounds in regards to feeding and communication. This study emphasizes the need for detecting neonates for species protection and suggests the potential for developing acoustic classifiers specific to different age groups. Our findings offer valuable insights for conservation efforts and the development of protection strategies for franciscana dolphins.
Niche segregation has been recognized as a valuable mechanism for sympatric species to reduce int... more Niche segregation has been recognized as a valuable mechanism for sympatric species to reduce interspecific competition and facilitate coexistence. The differential use of habitats is one of the behavioural mechanisms that may shape coexistence among marine predators. In this study, we provide a dietary and nutritional assessment of two pinnipeds, the South American sea lion (SASL) and the South American fur seal (SAFS) and explore their sympatric coexistence within the Warm Temperate Southwestern Atlantic biogeographic province (WTSA province). Pelagic prey species within the WTSA province showed significantly higher proportional composition of lipids than demersal counterparts, evidencing a nutritional variability in a vertical dimension accessible to marine predators. By modelling the dietary niches of these pinnipeds through a nutritional lens, we showed high overlapping prey composition niche breadths suggesting that both species consumed prey with similar nutritional composition; however, distinct realized nutritional niches showed that diets are likely shaped by differences in foraging behaviours. The SAFS combined pelagic and demersal prey, whereas SASL mostly preyed upon demersal species. This paper provides crucial information on how nutritional variability in the water column likely drives the feeding strategies of both pinnipeds in the WTSA province. Given that this variation can influence the stability of the contrasting population trends shown by these two pinnipeds, nutritional dynamics must be taken into consideration when defining conservation strategies.
In this study, we evaluate the relationship between the abundance of seabirds and the different p... more In this study, we evaluate the relationship between the abundance of seabirds and the different phases of a seismic operation aimed at locating offshore oil fields and taking place in the high seas east of Tierra del Fuego in the southwest Atlantic Ocean. The composition of the bird assemblages and their abundances per species were recorded by means of counts throughout the seismic operation comprising a total of 75 seismic exploration stations between the end of August and the beginning of November 2012. At least 16 species of seabirds were identified, over 60% of which belonged to the Procellariiformes. Seabirds were more abundant during exploration operations in the absence of seismic activity (i.e., compressed air guns were not active). This was also true for two groups of seabirds with contrasting feeding habits (divers and surface divers/scavengers). Our study provides evidence of an avoidance behavior by an assemblage of seabirds to the sounds generated by anthropogenic activities in the Argentine Sea, Southwest Atlantic Ocean. Additionally, our results indicate the need for greater environmental regulation of human activities that introduce low frequency and high intensity sounds in the study area.
BioOne Complete (complete.BioOne.org) is a full-text database of 200 subscribed and open-access t... more BioOne Complete (complete.BioOne.org) is a full-text database of 200 subscribed and open-access titles in the biological, ecological, and environmental sciences published by nonprofit societies, associations, museums, institutions, and presses.
Sightings and strandings of humpback whales (Megaptera novaeangliae) along the coast of Buenos Ai... more Sightings and strandings of humpback whales (Megaptera novaeangliae) along the coast of Buenos Aires Province in Argentina were once sporadic but have increased by up to 640% since 2018. Here, we assess the trends and seasonality of occurrence and anthropogenic-derived mortality in this population between 2003 and 2021. Most of the humpback whales found dead were young animals, and 27% of the stranded whales showed signs of anthropogenic interactions. The information collected from Buenos Aires Province over the past two decades clearly indicates that humpback whales are becoming more frequent and growing in numbers along the Argentinean coast. For their protection, governmental regulations need to be implemented as soon as possible.
In this study, we evaluate the relationship between the abundance of seabirds and the different p... more In this study, we evaluate the relationship between the abundance of seabirds and the different phases of a seismic operation aimed at locating offshore oil fields and taking place in the high seas east of Tierra del Fuego in the southwest Atlantic Ocean. The composition of the bird assemblages and their abundances per species were recorded by means of counts throughout the seismic operation comprising a total of 75 seismic exploration stations between the end of August and the beginning of November 2012. At least 16 species of seabirds were identified, over 60% of which belonged to the Procellariiformes. Seabirds were more abundant during exploration operations in the absence of seismic activity (i.e., compressed air guns were not active). This was also true for two groups of seabirds with contrasting feeding habits (divers and surface divers/scavengers). Our study provides evidence of an avoidance behavior by an assemblage of seabirds to the sounds generated by anthropogenic activities in the Argentine Sea, Southwest Atlantic Ocean. Additionally, our results indicate the need for greater environmental regulation of human activities that introduce low frequency and high intensity sounds in the study area. Resumen • Aves marinas al este de Tierra del Fuego, Argentina durante una evaluación sísmica 3D En este trabajo evaluamos la relación entre la abundancia de aves marinas y las distintas fases de una operación sísmica destinada a la localización de yacimientos petrolíferos en alta mar frente a las costas de Tierra del Fuego, Atlántico Suroccidental. La composición de los ensambles de aves asociadas y sus abundancias por especie se registraron mediante conteos a lo largo de la operatoria sísmica, comprendiendo un total de 75 estaciones de exploración sísmica entre fines de agosto y principios de noviembre de 2012. Fueron identificadas al menos 16 especies de aves marinas, más del 60% de las cuales, fueron Procellariiformes. Las aves marinas resultaron más abundantes durante operaciones de exploración en ausencia de actividad sísmica (i.e., los cañones de aire comprimido no se encontraban activos). Esto también sucedió cuando se consideraron dos grupos de aves marinas con hábitos de alimentación contrastante (buceadores y zambullidores superficiales/ carroñeros). Este estudio proporciona evidencia de un comportamiento de evitación por parte de un ensamble de aves marinas a los sonidos generados por actividades antropogénicas en el Mar Argentino, Atlántico Suroccidental. Nuestros resultados indican la necesidad de una mayor regulación ambiental de las actividades humanas que introducen sonidos de baja frecuencia y alta intensidad en el área de estudio.
· In this study, we evaluate the relationship between the abundance of seabirds and the different... more · In this study, we evaluate the relationship between the abundance of seabirds and the different phases of a seismic operation aimed at locating offshore oil fields and taking place in the high seas east of Tierra del Fuego in the southwest Atlantic Ocean. The composition of the bird assemblages and their abundances per species were recorded by means of counts throughout the seismic operation comprising a total of 75 seismic exploration stations between the end of August and the beginning of November 2012. At least 16 species of seabirds were identified, over 60% of which belonged to the Procellariiformes. Seabirds were more abundant during exploration operations in the absence of seismic activity (i.e., compressed air guns were not active). This was also true for two groups of seabirds with contrasting feeding habits (divers and surface divers/scavengers). Our study provides evidence of an avoidance behavior by an assemblage of seabirds to the sounds generated by anthropogenic act...
Journal of the Marine Biological Association of the United Kingdom, 2019
In South-western Atlantic waters, individuals of the southern right whale (SRW) Eubalaena austral... more In South-western Atlantic waters, individuals of the southern right whale (SRW) Eubalaena australis spend part of the year (the austral winter and spring) in northern inshore waters where they breed and then migrate to southern feeding grounds during the summer. Mar del Plata (MDP) is located between two main reproductive areas (Península Valdés-Argentina and Santa Catarina-Brazil). The purpose of the present study is to report the presence of SRWs on their journey off the coast of MDP based on sighting records during the past half century. We carried out whale observations through systematic weekly coastal marine mammal surveys in different points of the MDP area from 1966 to 2016. The first SRW sighting was recorded in 1970; since then, sighting frequency has gradually increased, reaching a peak of 28 sightings (N = 63 whales) in 2016. These are unique long-term sighting records of SRWs in Argentina and the first on their journey off the shores of Buenos Aires province. We expect ...
Abstract. This work aims to provide information regarding the behavioral ecology of the least stu... more Abstract. This work aims to provide information regarding the behavioral ecology of the least studied of the two sheathbill species, the Snowy Sheathbill (Chionis albus), wintering in northern Argentina in a male South American Sea Lion (Otaria flavescens) haul-out. Data about bird abundances and time allocated to behaviors was gathered during the final stage of three consecutive non-breeding seasons. Significant differences were found in the abundance between and within seasons. Overall, sheathbills allocated most of their time to foraging, followed by resting and self-maintaining, with the least of the time allocated to agonistic behaviors. The results obtained by the authors demonstrated that the Snowy Sheathbill recurrently used the local sea-lion haul-out as a foraging ground, with steady numbers throughout the non-breeding seasons.
Journal of Experimental Marine Biology and Ecology, 2021
Niche segregation has been recognized as a valuable mechanism for sympatric species to reduce int... more Niche segregation has been recognized as a valuable mechanism for sympatric species to reduce interspecific competition and facilitate coexistence. The differential use of habitats is one of the behavioural mechanisms that may shape coexistence among marine predators. In this study, we provide a dietary and nutritional assessment of two pinnipeds, the South American sea lion (SASL) and the South American fur seal (SAFS) and explore their sympatric coexistence within the Warm Temperate Southwestern Atlantic biogeographic province (WTSA province). Pelagic prey species within the WTSA province showed significantly higher proportional composition of lipids than demersal counterparts, evidencing a nutritional variability in a vertical dimension accessible to marine predators. By modelling the dietary niches of these pinnipeds through a nutritional lens, we showed high overlapping prey composition niche breadths suggesting that both species consumed prey with similar nutritional composition; however, distinct realized nutritional niches showed that diets are likely shaped by differences in foraging behaviours. The SAFS combined pelagic and demersal prey, whereas SASL mostly preyed upon demersal species. This paper provides crucial information on how nutritional variability in the water column likely drives the feeding strategies of both pinnipeds in the WTSA province. Given that this variation can influence the stability of the contrasting population trends shown by these two pinnipeds, nutritional dynamics must be taken into consideration when defining conservation strategies.
New Zealand Journal of Marine and Freshwater Research, , 2025
The Franciscana dolphin (Pontoporia blainvillei) is facing significant threats in the Southwester... more The Franciscana dolphin (Pontoporia blainvillei) is facing significant threats in the Southwestern Atlantic Ocean, largely due to entanglement in artisanal fishing nets, which makes it the most threatened dolphin species in the region Its conservation calls for a standardised methodology that enables the detection and monitoring of dolphin populations on a longer temporal scale. This study represents the first acoustic monitoring of wild Franciscana dolphins in Argentina, focusing on understanding their diel patterns of activity and their relationship with environmental variables. Our findings show that Franciscana dolphin acoustic presence in summer in Chapadmalal (Argentina) is more frequent in January than in February and March and is influenced by the interaction between tide and wind direction. Specifically, at higher tide levels, wind direction has a reduced impact on dolphin detections. This interaction varies seasonally, with shifts observed in February and March. This research advances standardised methodologies for detecting and monitoring Franciscana dolphin populations, supporting efforts to improve their conservation.
The franciscana dolphin is a small, vulnerable species often caught in artisanal gillnets. This s... more The franciscana dolphin is a small, vulnerable species often caught in artisanal gillnets. This study aims to provide a comprehensive assessment of their acoustic capabilities by using advanced equipment to collect a large dataset of wideband, continuous recordings. We examined the detailed acoustic signals of franciscana dolphins, comparing the sounds from rehabilitated dolphins in captivity with those of wild dolphins near fishing nets. Significant differences in acoustic characteristics were found between neonates and older dolphins, with juvenile and wild dolphins showing similar features. For the first time, repetition patterns in click production were identified, highlighting the importance of understanding the context of these sounds in regards to feeding and communication. This study emphasizes the need for detecting neonates for species protection and suggests the potential for developing acoustic classifiers specific to different age groups. Our findings offer valuable insights for conservation efforts and the development of protection strategies for franciscana dolphins.
Niche segregation has been recognized as a valuable mechanism for sympatric species to reduce int... more Niche segregation has been recognized as a valuable mechanism for sympatric species to reduce interspecific competition and facilitate coexistence. The differential use of habitats is one of the behavioural mechanisms that may shape coexistence among marine predators. In this study, we provide a dietary and nutritional assessment of two pinnipeds, the South American sea lion (SASL) and the South American fur seal (SAFS) and explore their sympatric coexistence within the Warm Temperate Southwestern Atlantic biogeographic province (WTSA province). Pelagic prey species within the WTSA province showed significantly higher proportional composition of lipids than demersal counterparts, evidencing a nutritional variability in a vertical dimension accessible to marine predators. By modelling the dietary niches of these pinnipeds through a nutritional lens, we showed high overlapping prey composition niche breadths suggesting that both species consumed prey with similar nutritional composition; however, distinct realized nutritional niches showed that diets are likely shaped by differences in foraging behaviours. The SAFS combined pelagic and demersal prey, whereas SASL mostly preyed upon demersal species. This paper provides crucial information on how nutritional variability in the water column likely drives the feeding strategies of both pinnipeds in the WTSA province. Given that this variation can influence the stability of the contrasting population trends shown by these two pinnipeds, nutritional dynamics must be taken into consideration when defining conservation strategies.
In this study, we evaluate the relationship between the abundance of seabirds and the different p... more In this study, we evaluate the relationship between the abundance of seabirds and the different phases of a seismic operation aimed at locating offshore oil fields and taking place in the high seas east of Tierra del Fuego in the southwest Atlantic Ocean. The composition of the bird assemblages and their abundances per species were recorded by means of counts throughout the seismic operation comprising a total of 75 seismic exploration stations between the end of August and the beginning of November 2012. At least 16 species of seabirds were identified, over 60% of which belonged to the Procellariiformes. Seabirds were more abundant during exploration operations in the absence of seismic activity (i.e., compressed air guns were not active). This was also true for two groups of seabirds with contrasting feeding habits (divers and surface divers/scavengers). Our study provides evidence of an avoidance behavior by an assemblage of seabirds to the sounds generated by anthropogenic activities in the Argentine Sea, Southwest Atlantic Ocean. Additionally, our results indicate the need for greater environmental regulation of human activities that introduce low frequency and high intensity sounds in the study area.
BioOne Complete (complete.BioOne.org) is a full-text database of 200 subscribed and open-access t... more BioOne Complete (complete.BioOne.org) is a full-text database of 200 subscribed and open-access titles in the biological, ecological, and environmental sciences published by nonprofit societies, associations, museums, institutions, and presses.
Sightings and strandings of humpback whales (Megaptera novaeangliae) along the coast of Buenos Ai... more Sightings and strandings of humpback whales (Megaptera novaeangliae) along the coast of Buenos Aires Province in Argentina were once sporadic but have increased by up to 640% since 2018. Here, we assess the trends and seasonality of occurrence and anthropogenic-derived mortality in this population between 2003 and 2021. Most of the humpback whales found dead were young animals, and 27% of the stranded whales showed signs of anthropogenic interactions. The information collected from Buenos Aires Province over the past two decades clearly indicates that humpback whales are becoming more frequent and growing in numbers along the Argentinean coast. For their protection, governmental regulations need to be implemented as soon as possible.
In this study, we evaluate the relationship between the abundance of seabirds and the different p... more In this study, we evaluate the relationship between the abundance of seabirds and the different phases of a seismic operation aimed at locating offshore oil fields and taking place in the high seas east of Tierra del Fuego in the southwest Atlantic Ocean. The composition of the bird assemblages and their abundances per species were recorded by means of counts throughout the seismic operation comprising a total of 75 seismic exploration stations between the end of August and the beginning of November 2012. At least 16 species of seabirds were identified, over 60% of which belonged to the Procellariiformes. Seabirds were more abundant during exploration operations in the absence of seismic activity (i.e., compressed air guns were not active). This was also true for two groups of seabirds with contrasting feeding habits (divers and surface divers/scavengers). Our study provides evidence of an avoidance behavior by an assemblage of seabirds to the sounds generated by anthropogenic activities in the Argentine Sea, Southwest Atlantic Ocean. Additionally, our results indicate the need for greater environmental regulation of human activities that introduce low frequency and high intensity sounds in the study area. Resumen • Aves marinas al este de Tierra del Fuego, Argentina durante una evaluación sísmica 3D En este trabajo evaluamos la relación entre la abundancia de aves marinas y las distintas fases de una operación sísmica destinada a la localización de yacimientos petrolíferos en alta mar frente a las costas de Tierra del Fuego, Atlántico Suroccidental. La composición de los ensambles de aves asociadas y sus abundancias por especie se registraron mediante conteos a lo largo de la operatoria sísmica, comprendiendo un total de 75 estaciones de exploración sísmica entre fines de agosto y principios de noviembre de 2012. Fueron identificadas al menos 16 especies de aves marinas, más del 60% de las cuales, fueron Procellariiformes. Las aves marinas resultaron más abundantes durante operaciones de exploración en ausencia de actividad sísmica (i.e., los cañones de aire comprimido no se encontraban activos). Esto también sucedió cuando se consideraron dos grupos de aves marinas con hábitos de alimentación contrastante (buceadores y zambullidores superficiales/ carroñeros). Este estudio proporciona evidencia de un comportamiento de evitación por parte de un ensamble de aves marinas a los sonidos generados por actividades antropogénicas en el Mar Argentino, Atlántico Suroccidental. Nuestros resultados indican la necesidad de una mayor regulación ambiental de las actividades humanas que introducen sonidos de baja frecuencia y alta intensidad en el área de estudio.
· In this study, we evaluate the relationship between the abundance of seabirds and the different... more · In this study, we evaluate the relationship between the abundance of seabirds and the different phases of a seismic operation aimed at locating offshore oil fields and taking place in the high seas east of Tierra del Fuego in the southwest Atlantic Ocean. The composition of the bird assemblages and their abundances per species were recorded by means of counts throughout the seismic operation comprising a total of 75 seismic exploration stations between the end of August and the beginning of November 2012. At least 16 species of seabirds were identified, over 60% of which belonged to the Procellariiformes. Seabirds were more abundant during exploration operations in the absence of seismic activity (i.e., compressed air guns were not active). This was also true for two groups of seabirds with contrasting feeding habits (divers and surface divers/scavengers). Our study provides evidence of an avoidance behavior by an assemblage of seabirds to the sounds generated by anthropogenic act...
Journal of the Marine Biological Association of the United Kingdom, 2019
In South-western Atlantic waters, individuals of the southern right whale (SRW) Eubalaena austral... more In South-western Atlantic waters, individuals of the southern right whale (SRW) Eubalaena australis spend part of the year (the austral winter and spring) in northern inshore waters where they breed and then migrate to southern feeding grounds during the summer. Mar del Plata (MDP) is located between two main reproductive areas (Península Valdés-Argentina and Santa Catarina-Brazil). The purpose of the present study is to report the presence of SRWs on their journey off the coast of MDP based on sighting records during the past half century. We carried out whale observations through systematic weekly coastal marine mammal surveys in different points of the MDP area from 1966 to 2016. The first SRW sighting was recorded in 1970; since then, sighting frequency has gradually increased, reaching a peak of 28 sightings (N = 63 whales) in 2016. These are unique long-term sighting records of SRWs in Argentina and the first on their journey off the shores of Buenos Aires province. We expect ...
Abstract. This work aims to provide information regarding the behavioral ecology of the least stu... more Abstract. This work aims to provide information regarding the behavioral ecology of the least studied of the two sheathbill species, the Snowy Sheathbill (Chionis albus), wintering in northern Argentina in a male South American Sea Lion (Otaria flavescens) haul-out. Data about bird abundances and time allocated to behaviors was gathered during the final stage of three consecutive non-breeding seasons. Significant differences were found in the abundance between and within seasons. Overall, sheathbills allocated most of their time to foraging, followed by resting and self-maintaining, with the least of the time allocated to agonistic behaviors. The results obtained by the authors demonstrated that the Snowy Sheathbill recurrently used the local sea-lion haul-out as a foraging ground, with steady numbers throughout the non-breeding seasons.
Journal of Experimental Marine Biology and Ecology, 2021
Niche segregation has been recognized as a valuable mechanism for sympatric species to reduce int... more Niche segregation has been recognized as a valuable mechanism for sympatric species to reduce interspecific competition and facilitate coexistence. The differential use of habitats is one of the behavioural mechanisms that may shape coexistence among marine predators. In this study, we provide a dietary and nutritional assessment of two pinnipeds, the South American sea lion (SASL) and the South American fur seal (SAFS) and explore their sympatric coexistence within the Warm Temperate Southwestern Atlantic biogeographic province (WTSA province). Pelagic prey species within the WTSA province showed significantly higher proportional composition of lipids than demersal counterparts, evidencing a nutritional variability in a vertical dimension accessible to marine predators. By modelling the dietary niches of these pinnipeds through a nutritional lens, we showed high overlapping prey composition niche breadths suggesting that both species consumed prey with similar nutritional composition; however, distinct realized nutritional niches showed that diets are likely shaped by differences in foraging behaviours. The SAFS combined pelagic and demersal prey, whereas SASL mostly preyed upon demersal species. This paper provides crucial information on how nutritional variability in the water column likely drives the feeding strategies of both pinnipeds in the WTSA province. Given that this variation can influence the stability of the contrasting population trends shown by these two pinnipeds, nutritional dynamics must be taken into consideration when defining conservation strategies.
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