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Romero MB, Polizzi PS, Chiodi L, Dolagaratz A, Gerpe M. Legacy and emerging contaminants in marine mammals from Argentina. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 906:167561. [PMID: 37802361 DOI: 10.1016/j.scitotenv.2023.167561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Revised: 09/26/2023] [Accepted: 10/01/2023] [Indexed: 10/10/2023]
Abstract
Marine mammals are recognized sentinels of ecosystem health. They are susceptible to the accumulation and biomagnification of pollutants, which constitute one of the greatest threats to their survival. Legacy, such as organochlorine pesticides, and emerging contaminants, like microplastics and pharmaceuticals, may have effects on marine mammals' health at individual and population levels. Therefore, the evaluation of the risks associated with pollutants in this group is of great importance. The aim of this review is to provide information on the occurrence of legacy and emerging contaminants in marine mammals that inhabit Argentine waters. Also, to identify knowledge gaps and suggest best practices for future research. Reports of legacy contaminants referring to organochlorine pesticides and polychlorinated biphenyls were found in five species of cetaceans and two of pinnipeds. With respect to emerging pollutants, the presence of plastics was only evaluated in three species. Reported data was from at least a decade ago. Therefore, it is necessary to update existing information and conduct continuous monitoring to assess temporary trends in pollutants. All the studies were carried out in the province of Buenos Aires and Northern Patagonia indicating a knowledge gap in the southern zone of the Argentine Sea. In addition, pollutants of global environmental concern that have not been studied in Argentina are discussed. Future studies should fill these gaps and a greater effort to understand the relationships between pollutants and their effects on marine mammals is suggested. This issue will make it possible to determine thresholds for all the substances and species evaluated in order to carry out more detailed risk assessments and make decisions for the conservation of marine mammals in Argentine waters.
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Affiliation(s)
- M B Romero
- Toxicología Ambiental, Instituto de Investigaciones Marinas y Costeras (IIMyC), Argentina; Facultad de Ciencias Exactas y Naturales (FCEyN), Universidad Nacional de Mar del Plata (UNMDP), Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Funes 3350, CC7600 Mar del Plata, Argentina.
| | - P S Polizzi
- Toxicología Ambiental, Instituto de Investigaciones Marinas y Costeras (IIMyC), Argentina; Facultad de Ciencias Exactas y Naturales (FCEyN), Universidad Nacional de Mar del Plata (UNMDP), Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Funes 3350, CC7600 Mar del Plata, Argentina
| | - L Chiodi
- Toxicología Ambiental, Instituto de Investigaciones Marinas y Costeras (IIMyC), Argentina; Facultad de Ciencias Exactas y Naturales (FCEyN), Universidad Nacional de Mar del Plata (UNMDP), Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Funes 3350, CC7600 Mar del Plata, Argentina
| | - A Dolagaratz
- Toxicología Ambiental, Instituto de Investigaciones Marinas y Costeras (IIMyC), Argentina; Facultad de Ciencias Exactas y Naturales (FCEyN), Universidad Nacional de Mar del Plata (UNMDP), Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Funes 3350, CC7600 Mar del Plata, Argentina
| | - M Gerpe
- Toxicología Ambiental, Instituto de Investigaciones Marinas y Costeras (IIMyC), Argentina; Facultad de Ciencias Exactas y Naturales (FCEyN), Universidad Nacional de Mar del Plata (UNMDP), Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Funes 3350, CC7600 Mar del Plata, Argentina
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Durante CA, Loizaga R, McCracken GR, Crespo EA, Ruzzante DE. Commerson's dolphin population structure: evidence for female phylopatry and male dispersal. Sci Rep 2022; 12:22219. [PMID: 36564404 PMCID: PMC9789068 DOI: 10.1038/s41598-022-26192-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 12/12/2022] [Indexed: 12/24/2022] Open
Abstract
A key in species conservation is understanding the amount and distribution of genetic diversity and how environmental changes that occurred in the recent past may have influenced current patterns of population structure. Commerson's dolphin, Cephalorhynchus commersonii, has two subspecies, one of which is endemic to South America (C. commersonii commersonii) and little is known about its population genetics. Our objective was to investigate the population genetics of this subspecies throughout its distribution. Using 70 skin samples and information available in GenBank, 308 mitochondrial DNA sequences and 28 species-specific microsatellites were analyzed. The species presented low genetic diversity when compared to other dolphin species, but was consistent with other species within the genus. Strong population structure based on mitochondrial DNA was exhibited throughout its entire distribution, a pattern consistent with female philopatry. However, this pattern was not detected when using microsatellites, suggesting male-mediated gene flow. Demographic tests suggested a population expansion beginning approximately 15,000 years ago, after the Last Glacial Maximum. In a climate change scenario, we recommended considering each sampling location as an independent population management unit in order to evaluate the impact of possible environmental changes on the distribution of genetic information within the species.
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Affiliation(s)
- Cristian Alberto Durante
- Laboratorio de Mamíferos Marinos, Centro Para El Estudio de Sistemas Marinos (CESIMAR) - CONICET, Bv. Brown 2915, U9120ACD Puerto Madryn, Chubut, Argentina.
- Universidad Nacional del Comahue, San Carlos de Bariloche, Rio Negro, Argentina.
| | - Rocio Loizaga
- Laboratorio de Mamíferos Marinos, Centro Para El Estudio de Sistemas Marinos (CESIMAR) - CONICET, Bv. Brown 2915, U9120ACD Puerto Madryn, Chubut, Argentina
| | | | - Enrique Alberto Crespo
- Laboratorio de Mamíferos Marinos, Centro Para El Estudio de Sistemas Marinos (CESIMAR) - CONICET, Bv. Brown 2915, U9120ACD Puerto Madryn, Chubut, Argentina
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Funes M, Saravia LA, Cordone G, Iribarne OO, Galván DE. Network analysis suggests changes in food web stability produced by bottom trawl fishery in Patagonia. Sci Rep 2022; 12:10876. [PMID: 35760984 PMCID: PMC9237026 DOI: 10.1038/s41598-022-14363-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Accepted: 06/06/2022] [Indexed: 11/30/2022] Open
Abstract
Demersal fisheries are one of the top anthropic stressors in marine environments. In the long term, some species are more vulnerable to fishery impacts than others, which can lead to permanent changes on the food web. The trophic relationships between predator and prey constitute the food web and it represents a network of the energy channels in an ecosystem. In turn, the network structure influences ecosystem diversity and stability. The first aim of this study was to describe for the first time the food web of the San Jorge Gulf (Patagonia Argentina) with high resolution, i.e. to the species level when information is available. The San Jorge Gulf was subject to intense fisheries thus our second aim is to analyse the food web structure with and without fishery to evaluate if the bottom-trawl industrial fishery altered the network structure and stability. We used several network metrics like: mean trophic level, omnivory, modularity and quasi-sign stability. We included these metrics because they are related to stability and can be evaluated using predator diets that can weight the links between predators and prey. The network presented 165 species organized in almost five trophic levels. The inclusion of a fishery node adds 69 new trophic links. All weighted and unweighted metrics showed differences between the two networks, reflecting a decrease in stability when fishery was included in the system. Thus, our results suggested a probable change of state of the system. The observed changes in species abundances since the fishery was established, could represent the state change predicted by network analysis. Our results suggests that changes in the stability of food webs can be used to evaluate the impacts of human activity on ecosystems.
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Affiliation(s)
- Manuela Funes
- Instituto de Investigaciones Marinas y Costeras (IIMyC-CONICET), Rodriguez Peña 4046 Nivel 1, B7602GSD, Mar del Plata, Buenos Aires, Argentina
| | - Leonardo A Saravia
- Centro Austral de Investigaciones Científicas del Consejo Nacional de Investigaciones Científicas y Técnicas (CADIC-CONICET), Bernardo Houssay 200, V9410CAB, Ushuaia, Tierra del Fuego, Argentina. .,Instituto de Ciencias, Universidad Nacional de General Sarmiento, J.M. Gutierrez 1159 (1613), Los Polvorines, Buenos Aires, Argentina.
| | - Georgina Cordone
- Centro para el Estudio de Sistemas Marinos-Consejo Nacional de Investigaciones Científicas y Técnicas (CESIMAR-CONICET), Bv. Almirante Brown 2915, U9120ACV, Puerto Madryn, Chubut, Argentina
| | - Oscar O Iribarne
- Instituto de Investigaciones Marinas y Costeras (IIMyC-CONICET), Rodriguez Peña 4046 Nivel 1, B7602GSD, Mar del Plata, Buenos Aires, Argentina
| | - David E Galván
- Centro para el Estudio de Sistemas Marinos-Consejo Nacional de Investigaciones Científicas y Técnicas (CESIMAR-CONICET), Bv. Almirante Brown 2915, U9120ACV, Puerto Madryn, Chubut, Argentina
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Bestley S, Ropert-Coudert Y, Bengtson Nash S, Brooks CM, Cotté C, Dewar M, Friedlaender AS, Jackson JA, Labrousse S, Lowther AD, McMahon CR, Phillips RA, Pistorius P, Puskic PS, Reis AODA, Reisinger RR, Santos M, Tarszisz E, Tixier P, Trathan PN, Wege M, Wienecke B. Marine Ecosystem Assessment for the Southern Ocean: Birds and Marine Mammals in a Changing Climate. Front Ecol Evol 2020. [DOI: 10.3389/fevo.2020.566936] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
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Tschopp A, Cristiani F, García NA, Crespo EA, Coscarella MA. Trophic niche partitioning of five skate species of genus Bathyraja in northern and central Patagonia, Argentina. JOURNAL OF FISH BIOLOGY 2020; 97:656-667. [PMID: 32492179 DOI: 10.1111/jfb.14416] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 05/29/2020] [Accepted: 05/31/2020] [Indexed: 06/11/2023]
Abstract
Overexploitation of marine communities can lead to modifications in the structure of the food web and can force organisms like elasmobranchs to change their feeding habits. To evaluate the impact that fisheries have on food webs and on the interactions between species, it is necessary to describe and quantify the diet of the species involved and follow it through time. This study compares the diet of five skate species using the data obtained from the by-catch of the Argentine hake (Merluccius hubbsi) fishery in north and central Patagonia, Argentina. Diet composition was assessed by analysing the digestive tract contents and trophic overlapping between species of the genus Bathyraja: Bathyraja albomaculata, Bathyraja brachyurops, Bathyraja macloviana, Bathyraja magellanica and Bathyraja multispinis. A total of 184 stomachs were analysed. The diets of B. albomaculata and B. macloviana mainly comprised annelids, whereas that of B. brachyurops primarily comprised fish, including hake heads discarded by the fishery. The diets of B. magellanica and B. multispinis were largely based on crustaceans. Despite the morphological similarities and their shared preference for benthic habitats, no complete diet overlaps were found between the different species. These results suggest that these skate species have undergone a process of diet specialisation. This is a common feeding strategy that occurs to successfully eliminate competition when resources are limited, which corresponds to the conditions found in an environment being affected by the pressures of overfishing.
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Affiliation(s)
- Ayelen Tschopp
- Centro Para el Estudio de Sistemas Marinos (CESIMAR) Centro Nacional Patagónico, CENPAT-CONICET, Puerto Madryn, Argentina
| | - Franco Cristiani
- Departamento de Biología, Facultad de Ciencias Naturales y Ciencias de la Salud, Universidad Nacional de la Patagonia San Juan Bosco, Puerto Madryn, Argentina
| | - Nestor Aníbal García
- Centro Para el Estudio de Sistemas Marinos (CESIMAR) Centro Nacional Patagónico, CENPAT-CONICET, Puerto Madryn, Argentina
| | - Enrique Alberto Crespo
- Centro Para el Estudio de Sistemas Marinos (CESIMAR) Centro Nacional Patagónico, CENPAT-CONICET, Puerto Madryn, Argentina
- Departamento de Biología, Facultad de Ciencias Naturales y Ciencias de la Salud, Universidad Nacional de la Patagonia San Juan Bosco, Puerto Madryn, Argentina
| | - Mariano Alberto Coscarella
- Centro Para el Estudio de Sistemas Marinos (CESIMAR) Centro Nacional Patagónico, CENPAT-CONICET, Puerto Madryn, Argentina
- Departamento de Biología, Facultad de Ciencias Naturales y Ciencias de la Salud, Universidad Nacional de la Patagonia San Juan Bosco, Puerto Madryn, Argentina
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Romero MA, Grandi MF, Koen-Alonso M, Svendsen G, Ocampo Reinaldo M, García NA, Dans SL, González R, Crespo EA. Analysing the natural population growth of a large marine mammal after a depletive harvest. Sci Rep 2017; 7:5271. [PMID: 28706228 PMCID: PMC5509669 DOI: 10.1038/s41598-017-05577-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Accepted: 05/30/2017] [Indexed: 11/25/2022] Open
Abstract
An understanding of the underlying processes and comprehensive history of population growth after a harvest-driven depletion is necessary when assessing the long-term effectiveness of management and conservation strategies. The South American sea lion (SASL), Otaria flavescens, is the most conspicuous marine mammal along the South American coasts, where it has been heavily exploited. As a consequence of this exploitation, many of its populations were decimated during the early 20th century but currently show a clear recovery. The aim of this study was to assess SASL population recovery by applying a Bayesian state-space modelling framework. We were particularly interested in understanding how the population responds at low densities, how human-induced mortality interplays with natural mechanisms, and how density-dependence may regulate population growth. The observed population trajectory of SASL shows a non-linear relationship with density, recovering with a maximum increase rate of 0.055. However, 50 years after hunting cessation, the population still represents only 40% of its pre-exploitation abundance. Considering that the SASL population in this region represents approximately 72% of the species abundance within the Atlantic Ocean, the present analysis provides insights into the potential mechanisms regulating the dynamics of SASL populations across the global distributional range of the species.
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Affiliation(s)
- M A Romero
- Instituto de Biología Marina y Pesquera Almirante Storni, Escuela Superior de Ciencias Marinas - Universidad Nacional del Comahue, San Martín 247, 8520, San Antonio, Oeste (RN), Argentina.
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina.
| | - M F Grandi
- Laboratorio de Mamíferos Marinos, Centro para el Estudio de Sistemas Marinos (CESIMAR) CCT-CENPAT-CONICET, Bvd. Brown 2915, 9120, Puerto Madryn, Chubut, Argentina
| | - M Koen-Alonso
- Northwest Atlantic Fisheries Centre, Fisheries and Oceans Canada, 80 East White Hills Road, St. John's, A1C 5X1, Newfoundland and Labrador, Canada
| | - G Svendsen
- Instituto de Biología Marina y Pesquera Almirante Storni, Escuela Superior de Ciencias Marinas - Universidad Nacional del Comahue, San Martín 247, 8520, San Antonio, Oeste (RN), Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - M Ocampo Reinaldo
- Instituto de Biología Marina y Pesquera Almirante Storni, Escuela Superior de Ciencias Marinas - Universidad Nacional del Comahue, San Martín 247, 8520, San Antonio, Oeste (RN), Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - N A García
- Laboratorio de Mamíferos Marinos, Centro para el Estudio de Sistemas Marinos (CESIMAR) CCT-CENPAT-CONICET, Bvd. Brown 2915, 9120, Puerto Madryn, Chubut, Argentina
| | - S L Dans
- Laboratorio de Mamíferos Marinos, Centro para el Estudio de Sistemas Marinos (CESIMAR) CCT-CENPAT-CONICET, Bvd. Brown 2915, 9120, Puerto Madryn, Chubut, Argentina
- Universidad Nacional de la Patagonia San Juan Bosco, Bvd. Brown 3051, 9120, Puerto Madryn, Chubut, Argentina
| | - R González
- Instituto de Biología Marina y Pesquera Almirante Storni, Escuela Superior de Ciencias Marinas - Universidad Nacional del Comahue, San Martín 247, 8520, San Antonio, Oeste (RN), Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - E A Crespo
- Laboratorio de Mamíferos Marinos, Centro para el Estudio de Sistemas Marinos (CESIMAR) CCT-CENPAT-CONICET, Bvd. Brown 2915, 9120, Puerto Madryn, Chubut, Argentina
- Universidad Nacional de la Patagonia San Juan Bosco, Bvd. Brown 3051, 9120, Puerto Madryn, Chubut, Argentina
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Dellabianca NA, Pierce GJ, Raya Rey A, Scioscia G, Miller DL, Torres MA, Paso Viola MN, Goodall RNP, Schiavini ACM. Spatial Models of Abundance and Habitat Preferences of Commerson's and Peale's Dolphin in Southern Patagonian Waters. PLoS One 2016; 11:e0163441. [PMID: 27783627 PMCID: PMC5082685 DOI: 10.1371/journal.pone.0163441] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Accepted: 09/08/2016] [Indexed: 11/18/2022] Open
Abstract
Commerson's dolphins (Cephalorhynchus c. commersonii) and Peale's dolphins (Lagenorhynchus australis) are two of the most common species of cetaceans in the coastal waters of southwest South Atlantic Ocean. Both species are listed as Data Deficient by the IUCN, mainly due to the lack of information about population sizes and trends. The goal of this study was to build spatially explicit models for the abundance of both species in relation to environmental variables using data collected during eight scientific cruises along the Patagonian shelf. Spatial models were constructed using generalized additive models. In total, 88 schools (212 individuals) of Commerson's dolphin and 134 schools (465 individuals) of Peale's dolphin were recorded in 8,535 km surveyed. Commerson's dolphin was found less than 60 km from shore; whereas Peale's dolphins occurred over a wider range of distances from the coast, the number of animals sighted usually being larger near or far from the coast. Fitted models indicate overall abundances of approximately 22,000 Commerson's dolphins and 20,000 Peale's dolphins in the total area studied. This work provides the first large-scale abundance estimate for Peale's dolphin in the Atlantic Ocean and an update of population size for Commerson's dolphin. Additionally, our results contribute to baseline data on suitable habitat conditions for both species in southern Patagonia, which is essential for the implementation of adequate conservation measures.
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Affiliation(s)
- Natalia A. Dellabianca
- Centro Austral de Investigaciones Científicas (CADIC-CONICET), Ushuaia, Tierra del Fuego, Argentina
- Museo Acatushún de Aves y Mamíferos Marinos Australes, Ushuaia, Tierra del Fuego, Argentina
- * E-mail:
| | - Graham J. Pierce
- Oceanlab, University of Aberdeen, Newburgh, Aberdeenshire, Scotland, United Kingdom
- CESAM & Departamento de Biologia, Universidade de Aveiro, Aveiro, Portugal
| | - Andrea Raya Rey
- Centro Austral de Investigaciones Científicas (CADIC-CONICET), Ushuaia, Tierra del Fuego, Argentina
| | - Gabriela Scioscia
- Centro Austral de Investigaciones Científicas (CADIC-CONICET), Ushuaia, Tierra del Fuego, Argentina
| | - David L. Miller
- Integrated Statistics, Woods Hole, Massachusetts, United States of America
- Centre for Research into Ecological and Environmental Modelling, and School of Mathematics and Statistics, University of St Andrews, St Andrews, Scotland, United Kingdom
| | - Mónica A. Torres
- Centro Austral de Investigaciones Científicas (CADIC-CONICET), Ushuaia, Tierra del Fuego, Argentina
- Museo Acatushún de Aves y Mamíferos Marinos Australes, Ushuaia, Tierra del Fuego, Argentina
| | - M. Natalia Paso Viola
- Centro Austral de Investigaciones Científicas (CADIC-CONICET), Ushuaia, Tierra del Fuego, Argentina
| | - R. Natalie P. Goodall
- Centro Austral de Investigaciones Científicas (CADIC-CONICET), Ushuaia, Tierra del Fuego, Argentina
- Museo Acatushún de Aves y Mamíferos Marinos Australes, Ushuaia, Tierra del Fuego, Argentina
| | - Adrián C. M. Schiavini
- Centro Austral de Investigaciones Científicas (CADIC-CONICET), Ushuaia, Tierra del Fuego, Argentina
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Assessing the effects of demersal fishing and conservation strategies of marine mammals over a Patagonian food web. Ecol Modell 2016. [DOI: 10.1016/j.ecolmodel.2015.10.025] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Anthropozoonotic Endoparasites in Free-Ranging "Urban" South American Sea Lions (Otaria flavescens). J Vet Med 2016; 2016:7507145. [PMID: 27051860 PMCID: PMC4804068 DOI: 10.1155/2016/7507145] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Revised: 02/15/2016] [Accepted: 02/17/2016] [Indexed: 11/17/2022] Open
Abstract
The present study represents the first report on the gastrointestinal endoparasite fauna of a free-ranging "urban" colony of South American sea lions (Otaria flavescens) living within the city of Valdivia, Chile. A total of 40 individual faecal samples of South American sea lions were collected during the year 2012 within their natural habitat along the river Calle-Calle and in the local fish market of Valdivia. Coprological analyses applying sodium acetate acetic formalin methanol (SAF) technique, carbol fuchsin-stained faecal smears and Giardia/Cryptosporidium coproantigen ELISAs, revealed infections with 8 different parasites belonging to protozoan and metazoan taxa with some of them bearing anthropozoonotic potential. Thus, five of these parasites were zoonotic (Diphyllobothriidae gen. sp., Anisakidae gen. sp., Giardia, Cryptosporidium, and Balantidium). Overall, these parasitological findings included four new parasite records for Otaria flavescens, that is, Giardia, Cryptosporidium, Balantidium, and Otostrongylus. The current data serve as a baseline for future monitoring studies on anthropozoonotic parasites circulating in these marine mammals and their potential impact on public health.
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Environmental Niche Overlap between Common and Dusky Dolphins in North Patagonia, Argentina. PLoS One 2015; 10:e0126182. [PMID: 26091542 PMCID: PMC4474694 DOI: 10.1371/journal.pone.0126182] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2014] [Accepted: 02/24/2015] [Indexed: 11/24/2022] Open
Abstract
Research on the ecology of sympatric dolphins has increased worldwide in recent decades. However, many dolphin associations such as that between common dolphins (Delphinus delphis) and dusky dolphins (Lagenorhynchus obscurus) are poorly understood. The present study was conducted in the San Matías Gulf (SMG) ecosystem (North Patagonia, Argentina) where a high diet overlap among both species was found. The main objective of the present work was to explore the niche overlap of common and dusky dolphins in the habitat and temporal dimensions. The specific aims were (a) to evaluate the habitat use strategies of both species through a comparison of their group attributes (social composition, size and activity), and (b) to evaluate their habitat preferences and habitat overlap through Environmental Niche modeling considering two oceanographic seasons. To accomplish these aims, we used a historic database of opportunistic and systematic records collected from 1983 to 2011. Common and dusky dolphins exhibited similar patterns of group size (from less than 10 to more than 100 individuals), activity (both species use the area to feed, nurse, and copulate), and composition (adults, juveniles, and mothers with calves were observed for both species). Also, both species were observed travelling and feeding in mixed-species groups. Specific overlap indices were higher for common dolphins than for dusky dolphins, but all indices were low, suggesting that they are mainly segregated in the habitat dimension. In the case of common dolphins, the best habitats were located in the northwest of the gulf far from the coast. In the warm season they prefer areas with temperate sea surface and in the cold season they prefer areas with relatively high variability of sea surface temperature. Meanwhile, dusky dolphins prefer areas with steep slopes close to the coast in the southwestern sector of the gulf in both seasons.
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At-sea abundance and spatial distribution of South American sea lion (Otaria byronia) in Chilean Northern Patagonia: How many are there? Mamm Biol 2014. [DOI: 10.1016/j.mambio.2014.07.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Thompson FN, Abraham ER, Berkenbusch K. Common dolphin (Delphinus delphis) bycatch in New Zealand commercial trawl fisheries. PLoS One 2013; 8:e64438. [PMID: 23717614 PMCID: PMC3661492 DOI: 10.1371/journal.pone.0064438] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2012] [Accepted: 04/14/2013] [Indexed: 11/23/2022] Open
Abstract
Marine mammals are regularly reported as bycatch in commercial and artisanal fisheries, but data are often insufficient to allow assessment of these incidental mortalities. Observer coverage of the mackerel trawl fishery in New Zealand waters between 1995 and 2011 allowed evaluation of common dolphin Delphinus delphis bycatch on the North Island west coast, where this species is the most frequently caught cetacean. Observer data were used to develop a statistical model to estimate total captures and explore covariates related to captures. A two-stage Bayesian hurdle model was used, with a logistic generalised linear model predicting whether any common dolphin captures occurred on a given tow of the net, and a zero-truncated Poisson distribution to estimate the number of dolphin captures, given that there was a capture event. Over the 16-year study period, there were 119 common dolphin captures reported on 4299 observed tows. Capture events frequently involved more than one individual, with a maximum of nine common dolphin observed caught in a single tow. There was a peak of 141 estimated common dolphin captures (95% c.i.: 56 to 276; 6.27 captures per 100 tows) in 2002–03, following the marked expansion in annual effort in this fishery to over 2000 tows. Subsequently, the number of captures fluctuated although fishing effort remained relatively high. Of the observed capture events, 60% were during trawls where the top of the net (headline) was <40 m below the surface, and the model determined that this covariate best explained common dolphin captures. Increasing headline depth by 21 m would halve the probability of a dolphin capture event on a tow. While lack of abundance data prevents assessment of the impact of these mortalities on the local common dolphin population, a clear recommendation from this study is the increasing of headline depth to reduce common dolphin captures.
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Intestinal helminth fauna of the South American sea lion Otaria flavescens and fur seal Arctocephalus australis from northern Patagonia, Argentina. J Helminthol 2012; 87:336-47. [DOI: 10.1017/s0022149x12000454] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
AbstractWe report on the intestinal helminth fauna of 56 South American sea lions, Otaria flavescens, and 5 South American fur seals, Arctocephalus australis, from northern Patagonia, Argentina. A total of 97,325 helminth specimens were collected from sea lions. Gravid individuals were represented by 6 species of parasites: 1 digenean (Ascocotyle (Ascocotyle) patagoniensis), 1 cestode (Diphyllobothrium spp.), 3 nematodes (Uncinaria hamiltoni, Contracaecum ogmorhini s.s., Pseudoterranova cattani) and 1 acanthocephalan (Corynosoma australe). In addition, third-stage larvae of 2 nematodes (Contracaecum sp. and Anisakis sp. type I) and 3 juvenile acanthocephalans (Andracantha sp., Profilicollis chasmagnathi and Corynosoma cetaceum) were also collected. Andracantha sp., C. ogmorhini s.s. and P.chasmagnathi represent new host records. A total of 1516 helminth specimens were collected from fur seals. Gravid individuals were represented by three species of parasites, namely, Diphyllobothrium spp., C. ogmorhini s.s. and C. australe. In addition, larvae of Contracaecum sp. and P. cattani, juveniles of C. cetaceum and immature cestodes (Tetrabothriidae gen. sp.) were also collected. Corynosoma australe was the most prevalent and abundant parasite in both hosts, accounting for >90% of all specimens. Sea lions and furs seals from northern Patagonia harbour the intestinal helminth communities that could be predicted for otariids, i.e. the combination of species of the genera Corynosoma, Diphyllobothrium, Pseudoterranova, Contracaecum and, in pups, Uncinaria. Additionally, both species of otariid are apparently unsuitable hosts (i.e. non-hosts) for as many as five parasite taxa. The inclusion or exclusion of these species affects estimation of species richness at both component community (11 versus 6 species in sea lions; 7 versus 3 species in fur seals) and infracommunity (mean: 3.1 versus 2.6 in sea lions; 2.2 versus 1.7 species) levels. Information about the reproductive status of helminth species is often lacking in parasitological surveys on otariids and other marine vertebrates, but it is of significance to improve precision in parascript studies or ecological meta-analyses.
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Grandi MF, de Oliveira LR, Dans SL, Crespo E. A hunted population in recovery: Effective population size for South American sea lions from Patagonia. ANIM BIOL 2012. [DOI: 10.1163/157075612x642941] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Effective population size () is a parameter of central importance in evolutionary biology and conservation. Factors such as unequal sex ratios of breeding individuals, periodic fluctuation in population size and variance in reproductive success can affect the in general. At present, South American sea lions, Otaria flavescens, from northern Patagonia, Argentina, belongs to one of the several populations that are recovering from overhunting which occurred in the early 20th century. Here, we present the estimate of for this population that takes into account the effects of their polygynous mating system and variation in population size through time. The resultant overall ’s were 4171 ± 2450 or 4745 ± 2681 breeding animals depending on the inclusion of peripheral adult males. The estimated ’s are not critical, because they are close to the average mean minimum viable population for vertebrates (5000 breeding adults). Even though the northern Patagonian population of O. flavescens is increasing its abundance is still far below its historical numbers. The estimated should be considered the minimum range to be maintained, especially in light of bycatch related to fishery interactions along the Patagonian coast. We emphasise the importance of estimating for future management plans of the species within different populations.
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Affiliation(s)
- M. Florencia Grandi
- 1Laboratorio de Mamíferos Marinos, Centro Nacional Patagónico-CONICET, Bvd. Brown 2915, 9120 Puerto Madryn, Chubut, Argentina
| | - Larissa R. de Oliveira
- 2Laboratório de Ecologia de Mamíferos, Universidade do Vale do Rio dos Sinos (UNISINOS), Avenida Unisinos 950, 93022-000 São Leopoldo, RS, Brazil
- 3Grupo de Estudos de Mamíferos Aquáticos do Rio Grande do Sul (GEMARS), Rua Felipe Neri 382/203, 90440-150 Porto Alegre, RS, Brazil
| | - Silvana L. Dans
- 1Laboratorio de Mamíferos Marinos, Centro Nacional Patagónico-CONICET, Bvd. Brown 2915, 9120 Puerto Madryn, Chubut, Argentina
- 4Universidad Nacional de la Patagonia San Juan Bosco, Bvd. Brown 3051, 9120 Puerto Madryn, Chubut, Argentina
| | - Enrique A. Crespo
- 1Laboratorio de Mamíferos Marinos, Centro Nacional Patagónico-CONICET, Bvd. Brown 2915, 9120 Puerto Madryn, Chubut, Argentina
- 4Universidad Nacional de la Patagonia San Juan Bosco, Bvd. Brown 3051, 9120 Puerto Madryn, Chubut, Argentina
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de OLIVEIRA LR, LOIZAGA DE CASTRO R, CÁRDENAS-ALAYZA S, BONATTO SL. Conservation genetics of South American aquatic mammals: an overview of gene diversity, population structure, phylogeography, non-invasive methods and forensics. Mamm Rev 2011. [DOI: 10.1111/j.1365-2907.2011.00201.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Pimper LE, Baker CS, Goodall RNP, Olavarría C, Remis MI. Mitochondrial DNA variation and population structure of Commerson’s dolphins (Cephalorhynchus commersonii) in their southernmost distribution. CONSERV GENET 2010. [DOI: 10.1007/s10592-010-0102-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Behavior and seasonal variation in the relative abundance of Commerson’s dolphin (Cephalorhynchus commersonii) in northern Patagonia, Argentina. J ETHOL 2010. [DOI: 10.1007/s10164-010-0206-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Lucifora LO, García VB, Escalante AH. How can the feeding habits of the sand tiger shark influence the success of conservation programs? Anim Conserv 2009. [DOI: 10.1111/j.1469-1795.2009.00247.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Winter migration of rockhopper penguins (Eudyptes c. chrysocome) breeding in the Southwest Atlantic: is utilisation of different foraging areas reflected in opposing population trends? Polar Biol 2006. [DOI: 10.1007/s00300-006-0110-0] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Kock KH, Purves MG, Duhamel G. Interactions between Cetacean and Fisheries in the Southern Ocean. Polar Biol 2005. [DOI: 10.1007/s00300-005-0067-4] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Berón-Vera B, Crespo EA, Raga JA, Pedraza SN. Uncinaria hamiltoni (Nematoda: Ancylostomatidae) in South American Sea Lions, Otaria flavescens, From Northern Patagonia, Argentina. J Parasitol 2004; 90:860-3. [PMID: 15357082 DOI: 10.1645/ge-182r] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Thirty-one South American sea lion pups (Otaria flavescens) found dead in Punta León, Argentina, during the summer of 2002, were examined for hookworms (Uncinaria hamiltoni). Parasite parameters were analyzed in 2 locations of the rookery, i.e., a traditional, well-structured breeding area and an expanding area with juveniles and a lax social structure. Prevalence of hookworms was 50% in both localities, and no difference was observed in prevalence between pup sexes (P > 0.05). Hookworms were concentrated in the small intestine. Transmammary transmission is assumed because only adult hookworms were found in the pups. The mean intensity of hookworms per pup was 135; the mean intensity in females (92.78) was significantly different (P < 0.05) from that of males (230.25). No difference (P > 0.05) in intensity was found between the 2 breeding areas, although prevalence was higher in the traditional breeding area than in the other area. Location was the only factor affecting hookworm prevalence (P log-linear model: 0.9552; chi2: 1.5629). No apparent trend between body condition and intensity of hookworms was observed.
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Affiliation(s)
- B Berón-Vera
- Laboratorio de Mamíferos Marinos, Centro Nacional Patagónico, CONICET, Universidad Nacional de la Patagonia, Boulevard, Brown 3600, 9120 Puerto Madryn, Chubut, Argentina.
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Cassens I, Van Waerebeek K, Best PB, Crespo EA, Reyes J, Milinkovitch MC. The phylogeography of dusky dolphins (Lagenorhynchus obscurus): a critical examination of network methods and rooting procedures. Mol Ecol 2003; 12:1781-92. [PMID: 12803631 DOI: 10.1046/j.1365-294x.2003.01876.x] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We investigated the phylogeography and evolutionary history of dusky dolphins (Lagenorhynchus obscurus) using DNA sequences of the full mitochondrial cytochrome b gene in 124 individuals from the putative stocks off Peru, Argentina and Southwest Africa. While genetic differentiation within oceans is surprisingly low, there is no evidence for recent female gene flow between Atlantic and Pacific waters. Highest genetic variability in terms of sequence divergence and number of haplotypes is found in the Atlantic. Our analyses also indicate that the eastern South Pacific dusky dolphins stock should be considered a separate management unit. Given the high level of mortality experienced by the Peruvian dusky dolphin in local fishery activities, these findings have important implications for an objective management of the species. Furthermore, we analysed our mitochondrial sequence data with several widely used network estimation and rooting methods. The resulting intraspecific gene genealogies and rooting inferences exhibited substantial differences, underlying the limitations of some algorithms. Given that scientific hypotheses and management decisions depend strongly on inferred tree or network topologies, there is a clear need for a systematic comparative analysis of available methods. Finally, the present study indicates that (i) the dusky and the Pacific white-sided dolphins are sister species and (ii) not only the Westwind Drift hypothesis but also other models of dispersion are compatible with the current geographical distribution of dusky dolphins.
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Affiliation(s)
- I Cassens
- Unit of Evolutionary Genetics, Institute of Molecular Biology and Medicine, Free University of Brussels, rue Jeener & Brachet 12, 6041 Gosselies, Belgium
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Crespo EA, Pedraza SN, Dans SL, Koen Alonso M, Reyes LM, García NA, Coscarella M, Schiavini ACM. Direct and Indirect Effects of the Highseas Fisheries on the Marine Mammal Populations in the Northern and Central Patagonian Coast. ACTA ACUST UNITED AC 1997. [DOI: 10.2960/j.v22.a15] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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