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Waleska Gravena - One of the best experts on this subject based on the ideXlab platform.
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Total mercury and methylmercury in river dolphins (Cetacea: Iniidae: Inia spp.) in the Madeira River Basin, Western Amazon
Environmental Science and Pollution Research, 2021Co-Authors: Melissa S. Barbosa, Dario P. Carvalho, Waleska Gravena, Ronaldo Almeida, Marília H. Mussy, Eduardo A. Sousa, Igor B. B. Holanda, Izidro F. Sousa-filho, Wanderley R. BastosAbstract:In the Amazon, mercury (Hg) contamination comes from ASGM operations along with soil remobilization processes associated with deforestation. The objective of this study was to evaluate the exposure to methylmercury (MeHg) and total mercury (THg) in 88 samples of skin and blubber tissue obtained from live captured river dolphins ( Inia boliviensis , Inia geoffrensis , and Inia spp.) in the Madeira River Basin. THg and MeHg measurements were performed by CV-AAS and GC-AFS, respectively. We also calculated the daily intake rate (DIR) of THg (wet weight) by Inia spp. THg levels in blubber tissue of adult river dolphins ( Inia spp.) ranged from 0.015 to 3.804 mg kg^−1, while MeHg concentrations in blubber tissue varied from 0.04 to 2.65 mg kg^−1 and in skin tissue from 0.09 to 0.66 mg kg^−1. There were no significant differences in MeHg concentration in blubber ( p = 0.616) and skin ( p = 0.498) tissue samples between adult males and females in the different sampling locations. The adult animals showed differences in THg and MeHg concentrations significantly higher than in the calves. The estimate of the DIR of the genus Inia ranged from 1.17 to 12.35 μg kg^−1 day^−1 (bw), from the consumption of fish species with herbivorous to piscivorous habits, respectively. More biological and ecological data, such as the precise determination of age, mediated length, weight, and diet of river dolphins, are necessary to verify the Hg biomagnification. However, our data indicate that bioaccumulation is an active process in the dolphins of the Madeira River Basin. Graphical abstract
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Boto (Inia geoffrensis-Cetacea: Iniidae) aggregations in two provisioning sites in the lower Negro River-Amazonas, Brazil: are they related?
PeerJ, 2019Co-Authors: Waleska Gravena, Tomas Hrbek, Vera M. F. Silva, Izeni Pires FariasAbstract:The Negro River currently has seven floating houses where tourists can feed and interact with botos, each with its own history of how these aggregations were formed. Some keepers say these groups are familial, even reporting individuals being born into the group. However, behavioral studies have shown that botos are solitary, only forming groups at feeding areas and during the mating season. In the present study we used 12 microsatellite and molecular sex markers to characterize relationships within and between two boto aggregations (ten and seven botos each) in the lower Negro River. Molecular sexing revealed that all botos sampled from both aggregations were males. This may be explained by habitat preference, as male botos are primarily found in the main channels of large rivers, whereas females prefer more protected areas, such as flooded forests and its channels and lakes. Most of the animals were unrelated within each aggregation, demonstrating that these aggregations are not normally formed due to kinship bonds, but are exclusively for feeding, as botos learn that these places provide easy access to food. This study provides important information that helps us understand how human interaction is affecting the social structure and behavior of these animals.
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living between rapids genetic structure and hybridization in botos cetacea Iniidae inia spp of the madeira river brazil
Biological Journal of The Linnean Society, 2015Co-Authors: Waleska Gravena, Vera Maria Ferreira Da Silva, Maria Nazareth Ferreira Da Silva, Izeni Pires Farias, Tomas HrbekAbstract:Until the recent construction of hydroelectric dams, a series of 18 rapids divided the upper and lower Madeira River, and these rapids were thought to separate two species of Amazonian freshwater dolphins (boto): Inia boliviensis (above) and I. geoffrensis (below). Some reports and articles, however, mention the occurrence of botos within the rapids region and that they occasionally cross the rapids, but without mentioning the species concerned. Based on our previous studies, it is likely that I. boliviensis occurs in the region of the rapids. To test this supposition, we sampled 18 individuals from this region, and collected mitochondrial (control region, cytochrome b and cytochrome oxidase I) and nuclear (10 microsatellite loci) DNA data, in order to test if there is connectivity between the dolphins that were found within the rapids region and dolphins collected upstream and downstream of the rapids, and investigate population structuring between these localities. All animals in our study were molecularly identified using three mitochondrial markers as belonging to the species I. boliviensis. Animals upstream of the Teotonio waterfall, the main and highest waterfall of the region, had nuclear genome of I. boliviensis, while most dolphins downstream of the waterfall had nuclear genome of I. geoffrensis. Inia boliviensis collected in the rapids region above the Teotonio waterfall belong to a management unit (MU) distinct from the I. boliviensis MU occupying Bolivian rivers. Downstream of Teotonio waterfall most dolphins are I. boliviensis/geoffrensis hybrids, with remaining individuals being migrant I. boliviensis. © 2015 The Linnean Society of London, Biological Journal of the Linnean Society, 2015, 114, 764–777.
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Looking to the past and the future: were the Madeira River rapids a geographical barrier to the boto (Cetacea: Iniidae)?
Conservation Genetics, 2014Co-Authors: Waleska Gravena, Izeni P. Farias, Maria N. F. Silva, Vera M. F. Silva, Tomas HrbekAbstract:In the present study we tested if a series of 18 rapids on the upper Madeira River form an effective barrier to gene flow, and in particular if they delimit the distribution of the boto Inia boliviensis— which it is believed to occurs only in the Bolivian sub-basin, above the rapids—and I . geoffrensis, which occurs throughout the Amazon basin and below the upper Madeira River rapids. We analyzed 125 individuals from the Madeira River basin sampled from upstream and downstream of the rapids. As the two species are morphologically similar, we used diagnostic molecular characters from known reference specimens to assign individuals to species. We observed that all individuals of Inia from the Bolivian sub-basin up to almost the mouth of the Madeira River belong to the species I . boliviensis . Therefore we concluded that the rapids do not delimit the distribution of I. boliviensis upstream and I. geoffrensis downstream of the rapids as previously hypothesized. Since we registered I. boliviensis along almost the entire length of the Madeira River, we estimated gene flow, time of divergence and effective population sizes of the upstream (Bolivian) and downstream (Madeira River) groups of I. boliviensis using IMa2. We concluded that gene flow is uni-directional from the upstream to the downstream group. Divergence time between the two groups was estimated to have occurred ~122 thousand years ago. The coalescent effective population size for the upstream group was estimated at ~131 thousand individuals, while for the downstream group it was estimated at ~102 thousand individuals. Recently two dams have been constructed in the region of the rapids; neither has a mechanism that will maintain connectivity between the upstream and downstream regions, and together with anthropogenic alterations to the hydrodynamic regime and ecology of the river will likely pose serious long-term and short-term consequences for I . boliviensis and other aquatic taxa.
Josep Mark Shostell - One of the best experts on this subject based on the ideXlab platform.
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Biodiversity in the Amazon: Origin Hypotheses, Intrinsic Capacity of Species Colonization, and Comparative Phylogeography of River Otters (Lontra longicaudis and Pteronura brasiliensis, Mustelidae, Carnivora) and Pink River Dolphin (Inia sp., Iniidae
Journal of Mammalian Evolution, 2018Co-Authors: Manuel Ruiz-garcía, Pablo Escobar-armel, Benoit Thoisy, Maria Martínez-agüero, Myreya Pinedo-castro, Josep Mark ShostellAbstract:We sequenced mitochondrial genes of otter ( Lontra longicaudis and Pteronura brasiliensis ) and dolphin ( Inia sp.) species to provide new systematics data and to test hypotheses that offer explanations as to the Amazon’s biodiversity. Four of the 11 hypotheses tested --Paleogeography (PH), Recent Lagoon (RLH), Hydrogeological Recent Change (HRCH), and Refugia (RH)-- support the evolution of these three species. As part of this comparative phylogenetic study, we also considered the degree of water dependence of each species. For the least water dependent of the three species, L. longicaudis , only HRCH and RH had an influence on genetic structure, although it was relatively minor. For the more water dependent otter species, P. brasiliensis , our analyses stressed the significance of a single PH event along with two lesser important PH events. However, its gene diversification basically occurred during the Pleistocene and our analyses did detect a relatively small influence of HRCH and RH. For the completely water dependent species, Inia , we detected two significant PH events. Its genetic structure was considerably more developed than in either otter species, although the Pleistocene was a very important period of genetic diversification for the pink river dolphins (HRCH and RLH). Each species has ancestors with different geographical origins and genomes with different capacities to colonize—making it difficult to rely on a generalized hypothesis to understand the origins of the Amazon’s extremely rich biodiversity.
Fernando Trujillo - One of the best experts on this subject based on the ideXlab platform.
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valoracion estacional de las amenazas contra la conservacion de inia geoffrensis humboldltiana cetartiodactyla Iniidae en la cuenca del rio meta colombia
THERYA, 2015Co-Authors: Federico Mosqueraguerra, Fernando Trujillo, Carlos Parra, Alex Mauricio Jimenezortega, Hugo MantillamelukAbstract:Introduction: As a consequence of population isolation by the presence of geomorphological barriers, dolphins from northern South America are subdivided into three species: I. geoffrensis (Amazon and Orinoco Rivers), I. boliviensis (Madeira River in Bolivia), and the recently described I. araguaiaensis inhabiting the hydrologic complex of the Araguaia –Tocantins Rivers in the northeastern Brazilian Amazon. The importance of pink dolphins at the ecosystems they inhabit is supported by: 1) its position as top predators in the food chain; 2) bioindicators for ecosystem health; 3) its cultural and mythological meaning for the local ethnic groups, such as Sikuanis from the Orinoco, and Ticuna for the Amazon; and 4) their economic value, mainly as a touristic attraction. The conservation status of Orinoquian populations of river dolphins ( i. g. humboldtiana ), has not been fully established. However, we know their populations are threatened by a series of human activities on both aquatic and terrestrial environments, affecting their occurrence across the basin. This research is part of an inter-institutional effort conducted between the Corporacion para el Desarrollo Sostenible del Area de Manejo Especial de la Macarena (CORMACARENA) and Fundacion Omacha, to monitor pink dolphin populations inhabiting the rivers: Meta, Manacacias, Yucao, and Cusiana, in order to identify conservation tensors affecting the species in the study area. Methods: We conducted a multitemporal study to determine anthropogenic threats affecting dolphin populations during two hydrologic periods along 317.2 km -1 across the middle Meta River basin. We calculated the degradation index for streams of continental waters and density of the river dolphins, developed by Gomez-Salazar et al. (2012). Water quality, habitat transformation, species exploitation, and the increment in number of human settlements were identified as the main conservation tensors in the analyzed area. Results: We obtained a high value in the index of degradation, with a potential increment in value through time. River confluences were identified as priority areas for the conservation of the species. The development of infrastructure projects on the main streams was identified as a future threat on freshwater ecosystems in the basin. Differences in hydrologic periods were identified as an important variable, not only affecting the ecological dynamic of the species, but also determining the anthropogenic tensors through time. Water quality, habitat modification, and species exploitation were particularly intense at low water level periods, while boat traffic, and fishing activities are more frequent at periods of high water levels in the region. Discussion and conclusions: For the Meta River, water quality and species exploitation appear to be the major tensors for dolphins and they may explain the low densities recorded for the area in comparison with densities reported for the Amazon basin. Even though, we consider this analysis is not definite and more samplings are necessary to confirm this hypothesis. Finally, river confluences were identified as conservation hot spots for dolphin populations. We point out on the importance of river dolphins as umbrella species, ideal to develop conservation strategies in the region. Key words: Degradation index, Meta River, threats and conservation, Tonina.
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relaciones cultura naturaleza en comunidades riberenas del orinoco colombiano como estrategia para la conservacion de inia geoffrensis humboldtiana cetartiodactyla Iniidae
Momentos de Ciencia, 2015Co-Authors: Monica Paez Vasquez, Fernando Trujillo, Gabriel Rodriguez Ovalle, Federico GuerraAbstract:En esta investigacion, se caracterizaron las relaciones cultura-naturaleza que establecen los pescadores y comunidades riberenas situadas en las zonas de influencia de los rios Orinoco, Meta y Bita en el municipio de Puerto Carreno, Vichada, con el delfin rosado (Inia geoffrensis); para ello, se aplicaron metodologias de investigacion cualitativa y etnografia, en el marco de la conservacion biocultural y la etnoecologia y se establecieron escenarios participativos de ensenanza aprendizaje en las comunidades educativas de las areas anteriormente mencionadas. A partir de ello, se determinaron practicas de uso, percepciones locales y potenciales amenazas para la especie en la region, lo que permitio identificar como prioritario el diseno e implementacion de estrategias y propuestas educativas y participativas contextualizadas, que incorporen dichos elementos y contribuyan a la conservacion de la especie, desde el hacer y saber local.
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seasonal assessment of threats against conservation of inia geoffrensis humboldltiana cetartiodactyla Iniidae middle river basin meta colombia valoracion estacional de las amenazas contra la conservacion de inia geoffrensis humboldltiana cetartiodact
2015Co-Authors: Federico Mosqueraguerra, Fernando Trujillo, Carlos Parra, Alex Mauricio Jimenezortega, Hugo MantillamelukAbstract:across the middle Meta River basin. We calculated the degradation index for streams of continental waters and density of the river dolphins, developed by Gomez-Salazar et al. (2012). Water quality, habitat transformation, species exploitation, and the increment in number of human settlements were identified as the main conservation tensors in the analyzed area. Results: We obtained a high value in the index of degradation, with a potential increment in value through time. River confluences were identified as priority areas for the conservation of the species. The development of infrastructure projects on the main streams was identified as a future threat on freshwater ecosystems in the basin. Differences in hydrologic periods were identified as an important variable, not only affecting the ecological dynamic of the species, but also determining the anthropogenic tensors through time. Water quality, habitat modification, and species exploitation were particularly intense at low water level periods, while boat traffic, and fishing activities are more frequent at periods of high water levels in the region.
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indicios de biomagnificacion de mercurio total hg en las especies del genero inia cetartiodactyla Iniidae en los rios amazonas y orinoco colombia
Momentos de Ciencia, 2015Co-Authors: Federico Mosquera Guerra, Fernando Trujillo, Dalila Caicedo Herrera, Sindy Martinez CallejasAbstract:Los depredadores tope como delfines de rio, nutrias y grandes bagres, son considerados buenos bioindicadores para medir el estado de salud de las cuencas hidrograficas donde se distribuyen. En la actualidad estan siendo empleados para evaluar la presencia y concentracion de contaminantes al interior de la dinamica trofica en los ecosistemas acuaticos de la Amazonia y Orinoquia. En estas ecorregiones historicamente se han desarrollado fuertes procesos intervencion a escala de cuenca, actividades extractivas como la mineria aurifera y deforestacion por implementacion de actividades agropecuarias y comercializacion de madera, han liberado de forma artificial o natural grandes cantidades de este metal a los cuerpos de agua. Se evaluo de forma preliminar el proceso de biomagnificacion del Mercurio total (Hg) en las redes troficas acuaticas para los rio Amazonas y Orinoco (Colombia), a traves de la determinacion de la concentracion de Mercurio total (Hg) en tejido de muestras obtenidas de dos individuos varados, el primer especimen correspondio a un adulto de Inia humboltiana ubicado en el rio Arauca que registro 3,51 mg.kg-1 Hg y la segunda muestra correspondio a un neonato, encontrado en la localidad de Puerto Narino (Amazonas) registrando 0,16 mg.kg-1 Hg. Los valores obtenidos, presentaron niveles de Mercurio total (Hg) por encima de la normatividad nacional y lo establecido por la organizacion mundial de la salud (OMS), infiriendo de forma preliminar la existencia de procesos de biomagnificacion de Mercurio total (Hg) en las redes troficas para los sistemas hidricos de la Amazonia y Orinoquia.
Tomas Hrbek - One of the best experts on this subject based on the ideXlab platform.
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Boto (Inia geoffrensis-Cetacea: Iniidae) aggregations in two provisioning sites in the lower Negro River-Amazonas, Brazil: are they related?
PeerJ, 2019Co-Authors: Waleska Gravena, Tomas Hrbek, Vera M. F. Silva, Izeni Pires FariasAbstract:The Negro River currently has seven floating houses where tourists can feed and interact with botos, each with its own history of how these aggregations were formed. Some keepers say these groups are familial, even reporting individuals being born into the group. However, behavioral studies have shown that botos are solitary, only forming groups at feeding areas and during the mating season. In the present study we used 12 microsatellite and molecular sex markers to characterize relationships within and between two boto aggregations (ten and seven botos each) in the lower Negro River. Molecular sexing revealed that all botos sampled from both aggregations were males. This may be explained by habitat preference, as male botos are primarily found in the main channels of large rivers, whereas females prefer more protected areas, such as flooded forests and its channels and lakes. Most of the animals were unrelated within each aggregation, demonstrating that these aggregations are not normally formed due to kinship bonds, but are exclusively for feeding, as botos learn that these places provide easy access to food. This study provides important information that helps us understand how human interaction is affecting the social structure and behavior of these animals.
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living between rapids genetic structure and hybridization in botos cetacea Iniidae inia spp of the madeira river brazil
Biological Journal of The Linnean Society, 2015Co-Authors: Waleska Gravena, Vera Maria Ferreira Da Silva, Maria Nazareth Ferreira Da Silva, Izeni Pires Farias, Tomas HrbekAbstract:Until the recent construction of hydroelectric dams, a series of 18 rapids divided the upper and lower Madeira River, and these rapids were thought to separate two species of Amazonian freshwater dolphins (boto): Inia boliviensis (above) and I. geoffrensis (below). Some reports and articles, however, mention the occurrence of botos within the rapids region and that they occasionally cross the rapids, but without mentioning the species concerned. Based on our previous studies, it is likely that I. boliviensis occurs in the region of the rapids. To test this supposition, we sampled 18 individuals from this region, and collected mitochondrial (control region, cytochrome b and cytochrome oxidase I) and nuclear (10 microsatellite loci) DNA data, in order to test if there is connectivity between the dolphins that were found within the rapids region and dolphins collected upstream and downstream of the rapids, and investigate population structuring between these localities. All animals in our study were molecularly identified using three mitochondrial markers as belonging to the species I. boliviensis. Animals upstream of the Teotonio waterfall, the main and highest waterfall of the region, had nuclear genome of I. boliviensis, while most dolphins downstream of the waterfall had nuclear genome of I. geoffrensis. Inia boliviensis collected in the rapids region above the Teotonio waterfall belong to a management unit (MU) distinct from the I. boliviensis MU occupying Bolivian rivers. Downstream of Teotonio waterfall most dolphins are I. boliviensis/geoffrensis hybrids, with remaining individuals being migrant I. boliviensis. © 2015 The Linnean Society of London, Biological Journal of the Linnean Society, 2015, 114, 764–777.
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Looking to the past and the future: were the Madeira River rapids a geographical barrier to the boto (Cetacea: Iniidae)?
Conservation Genetics, 2014Co-Authors: Waleska Gravena, Izeni P. Farias, Maria N. F. Silva, Vera M. F. Silva, Tomas HrbekAbstract:In the present study we tested if a series of 18 rapids on the upper Madeira River form an effective barrier to gene flow, and in particular if they delimit the distribution of the boto Inia boliviensis— which it is believed to occurs only in the Bolivian sub-basin, above the rapids—and I . geoffrensis, which occurs throughout the Amazon basin and below the upper Madeira River rapids. We analyzed 125 individuals from the Madeira River basin sampled from upstream and downstream of the rapids. As the two species are morphologically similar, we used diagnostic molecular characters from known reference specimens to assign individuals to species. We observed that all individuals of Inia from the Bolivian sub-basin up to almost the mouth of the Madeira River belong to the species I . boliviensis . Therefore we concluded that the rapids do not delimit the distribution of I. boliviensis upstream and I. geoffrensis downstream of the rapids as previously hypothesized. Since we registered I. boliviensis along almost the entire length of the Madeira River, we estimated gene flow, time of divergence and effective population sizes of the upstream (Bolivian) and downstream (Madeira River) groups of I. boliviensis using IMa2. We concluded that gene flow is uni-directional from the upstream to the downstream group. Divergence time between the two groups was estimated to have occurred ~122 thousand years ago. The coalescent effective population size for the upstream group was estimated at ~131 thousand individuals, while for the downstream group it was estimated at ~102 thousand individuals. Recently two dams have been constructed in the region of the rapids; neither has a mechanism that will maintain connectivity between the upstream and downstream regions, and together with anthropogenic alterations to the hydrodynamic regime and ecology of the river will likely pose serious long-term and short-term consequences for I . boliviensis and other aquatic taxa.
Hugo Mantillameluk - One of the best experts on this subject based on the ideXlab platform.
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valoracion estacional de las amenazas contra la conservacion de inia geoffrensis humboldltiana cetartiodactyla Iniidae en la cuenca del rio meta colombia
THERYA, 2015Co-Authors: Federico Mosqueraguerra, Fernando Trujillo, Carlos Parra, Alex Mauricio Jimenezortega, Hugo MantillamelukAbstract:Introduction: As a consequence of population isolation by the presence of geomorphological barriers, dolphins from northern South America are subdivided into three species: I. geoffrensis (Amazon and Orinoco Rivers), I. boliviensis (Madeira River in Bolivia), and the recently described I. araguaiaensis inhabiting the hydrologic complex of the Araguaia –Tocantins Rivers in the northeastern Brazilian Amazon. The importance of pink dolphins at the ecosystems they inhabit is supported by: 1) its position as top predators in the food chain; 2) bioindicators for ecosystem health; 3) its cultural and mythological meaning for the local ethnic groups, such as Sikuanis from the Orinoco, and Ticuna for the Amazon; and 4) their economic value, mainly as a touristic attraction. The conservation status of Orinoquian populations of river dolphins ( i. g. humboldtiana ), has not been fully established. However, we know their populations are threatened by a series of human activities on both aquatic and terrestrial environments, affecting their occurrence across the basin. This research is part of an inter-institutional effort conducted between the Corporacion para el Desarrollo Sostenible del Area de Manejo Especial de la Macarena (CORMACARENA) and Fundacion Omacha, to monitor pink dolphin populations inhabiting the rivers: Meta, Manacacias, Yucao, and Cusiana, in order to identify conservation tensors affecting the species in the study area. Methods: We conducted a multitemporal study to determine anthropogenic threats affecting dolphin populations during two hydrologic periods along 317.2 km -1 across the middle Meta River basin. We calculated the degradation index for streams of continental waters and density of the river dolphins, developed by Gomez-Salazar et al. (2012). Water quality, habitat transformation, species exploitation, and the increment in number of human settlements were identified as the main conservation tensors in the analyzed area. Results: We obtained a high value in the index of degradation, with a potential increment in value through time. River confluences were identified as priority areas for the conservation of the species. The development of infrastructure projects on the main streams was identified as a future threat on freshwater ecosystems in the basin. Differences in hydrologic periods were identified as an important variable, not only affecting the ecological dynamic of the species, but also determining the anthropogenic tensors through time. Water quality, habitat modification, and species exploitation were particularly intense at low water level periods, while boat traffic, and fishing activities are more frequent at periods of high water levels in the region. Discussion and conclusions: For the Meta River, water quality and species exploitation appear to be the major tensors for dolphins and they may explain the low densities recorded for the area in comparison with densities reported for the Amazon basin. Even though, we consider this analysis is not definite and more samplings are necessary to confirm this hypothesis. Finally, river confluences were identified as conservation hot spots for dolphin populations. We point out on the importance of river dolphins as umbrella species, ideal to develop conservation strategies in the region. Key words: Degradation index, Meta River, threats and conservation, Tonina.
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seasonal assessment of threats against conservation of inia geoffrensis humboldltiana cetartiodactyla Iniidae middle river basin meta colombia valoracion estacional de las amenazas contra la conservacion de inia geoffrensis humboldltiana cetartiodact
2015Co-Authors: Federico Mosqueraguerra, Fernando Trujillo, Carlos Parra, Alex Mauricio Jimenezortega, Hugo MantillamelukAbstract:across the middle Meta River basin. We calculated the degradation index for streams of continental waters and density of the river dolphins, developed by Gomez-Salazar et al. (2012). Water quality, habitat transformation, species exploitation, and the increment in number of human settlements were identified as the main conservation tensors in the analyzed area. Results: We obtained a high value in the index of degradation, with a potential increment in value through time. River confluences were identified as priority areas for the conservation of the species. The development of infrastructure projects on the main streams was identified as a future threat on freshwater ecosystems in the basin. Differences in hydrologic periods were identified as an important variable, not only affecting the ecological dynamic of the species, but also determining the anthropogenic tensors through time. Water quality, habitat modification, and species exploitation were particularly intense at low water level periods, while boat traffic, and fishing activities are more frequent at periods of high water levels in the region.