Mariela Dassis

Mariela Dassis
Instituto de Investigaciones Marinas y Costeras (IIMyC), CONICET Universidad Nacional de mar del Plata Argentina · Grupo de investigación: Biología, Ecología y Conservación de Mamíferos Marinos

PhD

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29
Publications
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338
Citations

Publications

Publications (29)
Article
The aim of this study was to make the first characterization of the electrocardiogram (ECG) of the Burmeister porpoise (Phocoena sipinipinnis). A total of three ECGs were made in one, wild juvenile female (body weight = 32.5 kg, Lt = 1.45 m), temporarily held in captivity for rehabilitation at Mar del Plata Aquarium (Argentina). For ECG recordings,...
Article
The mammalian heart has been described as a highly evolutionarily conserved structure and the cardiovascular system allometry has been fully studied among many mammalian species, but few of these studies have been focused on marine mammals. Previously reported electrocardiogram (ECG) of anesthetized Southern sea lions (SSL; n = 13) and South Americ...
Conference Paper
Full-text available
La ballena jorobada solía tener una presencia esporádica a lo largo de la costa de la Provincia de Buenos Aires (PBA), Argentina. A partir del año 2018 los avistamientos y varamientos han aumentado notablemente. El objetivo del presente trabajo es realizar una recopilación de los registros de ballena jorobada en la PBA, identificando: tendencias, e...
Article
Full-text available
In this paper, we analyze the occurrence, abundance, and type of plastic debris (PD) present on the digestive tracts of 65 white croakers (Micropogonias furnieri) catches from Rio de la Plata Estuary System (RLPES). Eighty percent of individuals analyzed had ingested PD, of which 156 were thread-like plastics (FO = 83.9 %) and 30 were fragments (FO...
Conference Paper
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La colección biológica del Grupo de Investigación “Biología, Ecología y Conservación de Mamíferos Marinos” del Instituto de Investigaciones Marinas y Costeras (IIMyC, UNMdP- CONICET, Argentina), reúne material óseo, diversos órganos, datos biométricos y fotográficos de mamíferos marinos colectados principalmente en la costa de la provincia de Bueno...
Article
Full-text available
The goal of this study was to characterize the Electrocardiogram (ECG) of anesthetized South American Fur Seals (SAFS). Nineteen wild SAFS females were anesthetized with isofluorane at Isla de Lobos (Uruguay). ECG recording was performed at ventral recumbence following standardized procedures. All animals showed normal sinus rhythm. Amplitude and d...
Poster
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La Foca Leopardo (Hydrurga leptonyx) es una especie de pinnípedo antártico, con presencia ocasional en las costas argentinas, cuya histología está escasamente descripta, particularmente del corazón. El objetivo es presentar resultados preliminares del análisis histológico e histomorfométrico de corazón en dicha especie. Se tomaron muestras (n=9) de...
Poster
Full-text available
Existe limitada bibliografía sobre descripciones histológicas, en particular del corazón, de la Foca Leopardo (Hydrurga leptonyx), pinnípedo característico del continente Antártico. Esto se debe en gran parte a la dificultad de recolectar muestras de esta especie. El estudio de los componentes tisulares del corazón es importante para conocer adapta...
Article
Full-text available
The goal of this study was to test transthoracic echocardiography as a method to characterize heart morphology and function in the southern sea lion (SSL) (Otaria flavescens) for health evaluation. Four clinically healthy captive SSLs (mean weight 110 ± 17.5 kg) were trained to be examined by transthoracic echocardiography at Mar del Plata Aquarium...
Article
Full-text available
During the last centuries, populations of marine megafauna—such as seabirds, turtles, and mammals—were intensively exploited. At present, other threats such as bycatch and pollution affect these species, which play key ecological roles in marine ecosystems as apex consumers and/or nutrient transporters. This study analyses the distribution of six m...
Poster
Full-text available
El objetivo de este trabajo es presentar los resultados de la revisión de la colección ósea de Mamíferos Marinos perteneciente a la Universidad Nacional de Mar del Plata (UNMdP) La revisión consistió en la cuantificación del material óseo de cetáceos y pinnípedos y su clasificación al menor nivel taxonómico posible. La información complementaria ta...
Article
Objectives: The goal of this study was to characterize for the first time the electrocardiogram (ECG) of the southern sea lion (SSL) Otaria flavescens. Animals, materials and methods: Thirteen wild SSL females were captured at Isla de Lobos (Uruguay) and anaesthetized with isoflurane. Electrocardiographic recording was performed on anaesthetized...
Article
Full-text available
Few studies have investigated regional and natural climate variability on seabird populations using ocean reanalysis datasets (e.g. Simple Ocean Data Assimilation (SODA)) that integrate atmospheric information to supplement ocean observations and provide improved estimates of ocean conditions. Herein we use a non-systematic dataset on Australasian...
Article
Full-text available
Three Heaviside's dolphins Cephalorhynchus heavisidii were fitted with satellite depth recorders off the west coast of South Africa during February–April 1997 and monitored for 51, 73 and 130 days, respectively. In total, 345 locations were received from the three animals, but only 27 from one male. Using α-local convex hull and minimum convex poly...
Article
Full-text available
Patchily distributed marine pelagic prey present considerable challenges to predatory seabirds, including Gannets (Morus spp.) departing from large breeding colonies. Here, for the first time, we used GPS data loggers to provide detailed spatial, temporal, and habitat metrics of chick-rearing Australasian Gannets (Morus serrator) foraging behaviour...
Article
Full-text available
Hair bleaching marking technique in South American sea lions Otaria flavescens: Description and evaluation of method. The aim of this paper is to describe and evaluate the use of the hair discoloration method in South American sea lions, with an emphasis on its advantages and its potential use in future studies. For marking, stamp removable letters...
Article
Full-text available
The aim of this paper is to describe and evaluate the use of the hair discoloration method in South American sea lions, with an emphasis on its advantages and its potential use in future studies. For marking, stamp removable letters and numbers were used, connected to an extensible rod. The bleached marks obtained had a maximum duration of 347 days...
Article
We measured the metabolic rate of nineteen wild and three captive, trained Southern sea lions (Otaria flavescens, Shaw 1800) during three behavioral states: resting in air (_ V O2 rest air), resting in water (_ V O2 rest water) and sub-merged swimming (_ V O2 sub swim) using open flow respirometry. We then used these values to estimate total cost o...
Article
Full-text available
a b s t r a c t At-sea behavior and effects of hydrographic conditions on the pelagic habitat use of South American fur seals (Arctocephalus australis) seasonally inhabiting the surrounding waters of shallow rocky reefs off Punta Mogotes (Mar del Plata, Argentina) were analyzed integrating geographic locations of fur seal groups (FSGs) with coastal...
Chapter
Full-text available
Given the problems that the South American sea lion or Southern sea lion Otaria flavescens presents in its entire range from the south of Brazil in the Atlantic Ocean to the coasts of Peru in the Pacific Ocean, including the extreme south of the continent of South America, a group of specialists composed of Enrique A. Crespo, Doris Oliva, Silvana L...

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Projects (3)
Project
- Ecología trófica [Feeding ecology] - Composición nutricional de las presas [Proximate composition of prey] -Calidad nutricional de las presas [Prey quality] - Ecología nutricional [Nutritional ecology]
Project
La presente propuesta tiene como objetivo general determinar las estrategias y eficiencia de forrajeo en juveniles de Otaria flavescens en distintas áreas del Estuario del Río de la Plata (ERP). Como hipótesis de trabajo se plantea que los juveniles del Lobo Marino de un Pelo presentan estrategias de forrajeo diferentes que los adultos, explotando áreas que les impongan menores restricciones fisiológicas para el buceo bentónico y para el desplazamiento desde sus colonias de descanso. En especies de lobos marinos de un pelo que presentan, al igual que Otaria, tendencias poblacionales decrecientes, se ha establecido que la fracción juvenil de las poblaciones se constituye en un elemento clave que contribuiría al marcado descenso numérico, debido principalmente al estrés nutricional producido por la falta de experiencia en la obtención del alimento, las limitantes fisiológicas al buceo bentónico y las altas demandas energéticas del período de crecimiento y madurez. Así, la mortalidad juvenil se ha establecido como el principal freno a la recuperación poblacional, de manera que teniendo en cuenta la vulnerable situación poblacional en la que se encuentra el lobo marino de un pelo en el ERP, la escasez de estudios sobre la fracción juvenil de los stocks de esta especie y la importancia que las estrategias de obtención de alimento tienen en las etapas tempranas de desarrollo, se plantearon como objetivos particulares: a) Establecer las áreas de de forrajeo de juveniles de Otaria, definiendo los rangos de movimientos y las áreas de mayor utilización. b) Comparar las estrategias de forrajeo entre juveniles y adultos, principalmente a lo que hace a la duración de viajes de forrajeo, área barrida, intensidad de uso y fidelidad a las áreas de descanso. Para cumplir con los objetivos planteados se ha diseñado un estudio basado en la colocación de telémetros satelitales de posicionamiento en ejemplares juveniles de lobos marinos de un pelo, los cuales, proveen información muy precisa sobre la localización de los animales en mar abierto, permitiendo analizar la localización y duración de los viajes de forrajeo, distancia recorrida, direccionalidad de los movimientos, velocidad de desplazamiento, área cubierta y profundidad media del área. Los resultados obtenidos serán analizados en entornos de Sistemas de Información Geográfica, que serán de aplicación en herramientas de gestión y conservación de esta especie.