146 results on '"Sotalia Fluviatilis"'
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2. ÁREAS PREFERENCIAIS DE PESCA E DIETA DO ECÓTIPO MARINHO DO BOTO-CINZA (Sotalia fluviatilis ) NA BAÍA DE SEPETIBA, RJ
- Author
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Sheila Marino Simão and Fabiana Rios Poletto
- Subjects
Uso do Habitat ,Sotalia fluviatilis ,baía de Sepetiba ,Forestry ,SD1-669.5 - Abstract
RESUMO Os botos da baía de Sepetiba apresentam preferência por determinadas áreas para a pesca. Estas têm profundidade ≥10 m, sendo que durante o verão e o outono as áreas preferenciais são mais profundas do que durante o inverno e a primavera. Das ocorrências de pesca, 80,8% se deram dentro de uma faixa que se estende por 2,8 km para cada lado do canal dragado pelo Porto de Sepetiba. No inverno, outono e verão a ocorrência fora desta faixa foi baixa, mas durante a primavera esta foi de 73,3%. Tais preferências podem ser explicadas pelo hábito e padrão de distribuição das presas e por fatores climáticos.
- Published
- 2023
3. Fishers' knowledge indicates that collective benefits outweigh the individual costs of coexisting with dolphins.
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Hallwass, Gustavo, Pereyra, Paula Evelyn Rubira, Vieira, Kaluan C., Lopes, Priscila F.M., Schiavetti, Alexandre, and Silvano, Renato A.M.
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KEYSTONE species ,WILDLIFE conservation ,SMALL-scale fisheries ,FISHING nets ,PERCEIVED benefit - Abstract
• Fishers identify morphological and behavioral characteristics of river dolphins. • There is a partial overlap in fish species harvested by fishers and eaten by dolphins. • Costs of interaction with dolphins are estimated to three days of fishing income. • Most of interviewed fishers considered the dolphins to be beneficial for fisheries. • River dolphins are recognized for reducing fishing effort and protecting fishes. Understanding interactions between small-scale fishers and endangered dolphins is crucial for informing coexistence strategies. We investigated the perceptions and encounters of 123 Amazonian fishers in the Tapajós River (Brazil) with two endangered freshwater dolphins, Sotalia fluviatilis and Inia geoffrensis. Furthermore, 51 fishers self-documented 2,013 fish landings over one year. All interviewed fishers reported regular encounters with dolphins during fishing activities, with landings and interviews showing a partial overlap in fish species caught by fishers and cited as consumed by dolphins. Fishers highlighted that only I. geoffrensis disrupts fishing activities, causing gillnet damage and stealing fish from nets. To avoid interaction, fishers refrain from fishing an average of 3.7 times per month, potentially leading to 14.8 to 18.5 % decrease in total fish harvest. Economic losses were reported by 63 fishers, totaling an estimated US$ 50.3 ± 30.1 per month per fisher, which is equivalent to three days of fishing income. The estimated bycatch of dolphins was 10 per year across the studied area (71 % from I. geoffrensis). While 86 fishers considered dolphins beneficial, 62 viewed them as harmful. Fishers who fish more frequently are more likely to consider dolphins "good". The results revealed dolphins' positive contribution to fisheries by reducing efforts and safeguarding fish, while causing harm through gillnet damage. Negative perceptions are linked to individual economic losses, while positive perceptions stem from perceived collective benefits. By emphasizing dolphins' collective advantages in riverine communities, they can be a flagship species for conservation, leveraging their appeal and function as umbrella species for maintaining ecosystem functions, such as healthy fish stocks. [ABSTRACT FROM AUTHOR]
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- 2024
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4. Effectiveness of unmanned aerial vehicles to detect Amazon dolphins.
- Author
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Oliveira-da-Costa, Marcelo, Marmontel, Miriam, da-Rosa, Daiane S. X., Coelho, André, Wich, Serge, Mosquera-Guerra, Federico, and Trujillo, Fernando
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RIVER dolphins , *WILDLIFE conservation , *WATERSHEDS , *AERIAL surveys - Abstract
Quantifying the abundance of species is essential for their management and conservation. Much effort has been invested in surveys of freshwater dolphins in the Amazon basin but river dimensions and complex logistics limit replication of such studies across the region. We evaluated the effectiveness of using unmanned aerial vehicles (UAVs) for surveying two Amazon dolphin species, the tucuxi Sotalia fluviatilis and pink river dolphin Inia geoffrensis, in tropical rivers. In 2016 we conducted drone and visual surveys over 80 km of the Juruá River in Brazil. The aerial surveys provided higher accuracy than human observers in counting individuals detected in groups. Compared to estimates derived from visual surveys, the use of UAVs could provide a more feasible, economical and accurate estimate of Amazon river dolphin populations. The method could potentially be replicated in other important areas for the conservation of these species, to generate an improved index of river dolphin populations in the Amazon. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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5. Population Structure of Riverine and Coastal Dolphins Sotalia fluviatilis and Sotalia guianensis: Patterns of Nuclear and Mitochondrial Diversity and Implications for Conservation.
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Caballero, Susana, Hollatz, Claudia, Rodríguez, Sebastián, Trujillo, Fernando, and Baker, C Scott
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DOLPHINS , *MITOCHONDRIAL DNA , *MICROSATELLITE repeats , *POPULATION genetics , *ENDANGERED species - Abstract
Coastal and freshwater cetaceans are particularly vulnerable due to their proximity to human activity, localized distributions, and small home ranges. These species include Sotalia guianensis, found in the Atlantic and Caribbean coastal areas of central and South America, and Sotalia fluviatilis, distributed in the Amazon River and tributaries. We investigated the population structure and genetic diversity of these 2 species by analyses of mtDNA control region and 8–10 microsatellite loci. MtDNA analyses revealed strong regional structuring for S. guianensis (i.e. Colombian Caribbean vs. Brazilian Coast, F ST = 0.807, ΦST = 0.878, P < 0.001) especially north and south of the Amazon River mouth. For S. fluviatilis, population structuring was detected between the western and eastern Amazon (i.e. Colombian Amazon vs. Brazilian Amazon, F ST = 0.085, ΦST = 0.277, P < 0.001). Haplotype and nucleotide diversity were higher for S. fluviatilis. Population differentiation was supported by analysis of the microsatellite loci (S. guianensis, northern South America vs. southern South America F ST = 0.275, Jost's D = 0.476, P < 0.001; S. fluviatilis, western and eastern Amazon F ST = 0.197, Jost's D = 0.364, P < 0.001). Most estimated migration rates in both species overlapped with zero, suggesting no measurable migration between most of the sampling locations. However, for S. guianensis, there was measurable migration in neighboring sampling locations. These results indicate that the small home ranges of these species may act to restrict gene flow between populations separated by relatively short distances, increasing the risk of extirpation of some localized populations in the future if existing threats are not minimized. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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6. Abundance estimate of the Amazon River dolphin (Inia geoffrensis) and the tucuxi (Sotalia fluviatilis) in southern Ucayali, Peru.
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Campbell, Elizabeth, Alfaro-Shiguet, Joanna, Godley, Brendan J., and Mangel, Jeffrey C.
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BOTO , *TUCUXI , *LAGOONS , *RIVER dolphins , *CETACEAN behavior - Abstract
We present results of the first simultaneous visual and acoustic surveys for Amazon River dolphins (Inia geoffrensis) and tucuxi (Sotalia fluviatilis), undertaken in Yarinacocha Lagoon, Ucayali, Peru (length = 20 km, area = 12 km2). A total of 324 Sotalia observations and 44 Inia observations were recorded in boat-based transects. Based upon total survey effort, we estimated Sotalia had a mean density ± SE of 1.98 ± 4.6 ind km-2 and an overall abundance of 34 individuals (95% CI: 28 to 40). Average density for Inia was 0.2 ± 1.2 ind km-2 with overall abundance estimated at 3 individuals (95% CI: 0 to 8). Visual surveys observed more Sotalia individuals during earlier hours of the day and during the dry season. Preliminary acoustic surveys undertaken with C-POD passive acoustic monitoring devices indicated a diel pattern in detections of cetacean vocalization with more diurnal activity and with detections ceasing from midnight until 10:00 AM. This work highlights the possibility of monitoring both river dolphin species through visual and acoustic surveys to generate baseline information on abundance trends and distribution patterns in the Ucayali region, an area with high levels of human disturbance. [ABSTRACT FROM AUTHOR]
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- 2017
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7. Sotalia fluviatilis (Tucuxi) - LACM-019594
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Moore, Michael J., Taylor, David B., Moore, Michael J., and Taylor, David B.
- Abstract
Sotalia fluviatilis (Tucuxi) - LACM-019594 - female - unknown length - Pelvic location - LA County Museusm
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- 2022
8. Social Behavior of Sotalia Fluviatilis (Gervais & Deville, 1853) (Cetacea, Delphinidae), in the Northern Channel of the Amazon River, Amapá, Brazil
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Andréa Soares Araújo, Artur Lagoia Fonseca de Miranda, and Carlos Eduardo Costa Campos
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Fishery ,Geography ,biology ,Amazon rainforest ,Applied Mathematics ,General Mathematics ,biology.animal ,Aquatic mammal ,Cetacea ,Channel (broadcasting) ,biology.organism_classification ,Sotalia fluviatilis - Abstract
Sotalia fluviatilis is known as “tucuxi” is endemic to the rivers of the Amazon basin, with aggregations of individuals at the mouths of rivers and canals, it is an almost endangered species and information about it is lacking in the state of Amapá. This study was aimed at monitoring the social behavior of S. fluviatilis in the northern channel of the Amazon River, Amapá, Brazil. Monitoring was carried out from a fixed point on the bank of the northern channel of the Amazon River, located in a Private Reserve of Natural Heritage. Ninety-six days of monitoring were carried out from a fixed point of observation, totaling 480 hours of sample effort. S. fluviatilis was frequently observed throughout the year in predominantly small groups formed mostly by two to three adult animals. Young individuals were observed in larger groups of four to six individuals, formed during activities such as feeding or for protection. Behavioral activities included slow and fast travel, which were in most cases associated with other behaviors, mainly foraging and socializing. The largest number of sightings of socialization occurred in the months of January and February, when river water levels are high. Studies on key species are essential for decision making, in order to optimize conservation strategies for this aquatic mammal in the Amapá. As a suggestion for conservation measures, it would be the distancing of vessels when they perceive a group of porpoises using the region, thus stimulating the conservation of the species.
- Published
- 2021
9. Molecular Identification and Historic Demography of the Marine Tucuxi (Sotalia guianensis) at the Amazon River’s Mouth by Means of Mitochondrial Control Region Gene Sequences and Implications for Conservation
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Joseph Mark Shostell, Daniela Tejada-Martínez, Pablo Escobar-Armel, David Mejia, and Manuel Ruiz-García
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Sotalia guianensis ,Sotalia fluviatilis ,Steno brenadensis ,Ver-ao-Peso market ,mitochondrial control region gene ,Amazon River mouth ,population expansion ,Pleistocene ,Biology (General) ,QH301-705.5 - Abstract
In 2005, three fishermen, with artisan fishing vessels and drift gillnets, accidentally captured around 200 dolphins between Vigia and Salinópolis in the Amazon River estuary. The dolphins died and they then prepared their vaginas and penises in order to sell them in the Ver-ao-Peso market in the city of Belem within the Brazilian state of Pará. We randomly sampled a minimal quantity of tissue of these sexual organs from 78 of these 200 dolphins and we determined the following results after sequencing 689 base pairs (bp) from the mitochondrial control region gene: (1) 96.15% (75/78) of these dolphins belonged to the species Sotalia guianensis. The other species detected were Steno brenadensis, Stenella coeruleoalba and Tursiops truncatus; (2) The levels of gene diversity found in this sample of S. guianensis were high (33 haplotypes, haplotype diversity of 0.917 and nucleotide diversity of 0.0045) compared to gene diversities found in other Brazilian S. guianensis locations; (3) All the population genetics methods employed indicated a clear population expansion in this population. This population expansion could have begun 400,000 years ago; (4) The haplotype divergence within this population could have begun around 2.1 millions of years ago (MYA), with posterior splits around 2.0–1.8 MYA, 1.7–1.8 MYA, 1–1.5 MYA, 0.6–0.8 MYA, 0.4–0.2 MYA and 0.16–0.02 MYA, all during the Pleistocene.
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- 2013
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10. Passive acoustic monitoring of river dolphin (Inia geoffrensis and Sotalia fluviatilis) presence
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Charles A. Muirhead
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Fishery ,Inland port ,Geography ,biology ,Inia geoffrensis ,Range (biology) ,Amazon rainforest ,biology.animal ,Species distribution ,River dolphin ,Context (language use) ,biology.organism_classification ,Sotalia fluviatilis - Abstract
All river dolphin species are in decline as a direct result of intensified anthropogenic activity along river systems. In South America, the size and geographical complexity of their range pose a challenge to status assessment. Passive acoustic monitoring offers a cost-effective, scalable, and readily standardized method for determining species distribution and can augment the spatiotemporal coverage of visual survey efforts currently underway. A passive acoustic survey of dolphin presence was conducted in two areas of the Amazon River subject to different degrees of human use; the inland port city Iquitos and the Pacaya-Samiria National Reserve, in Peru. Surveys were based on acoustic detection of biosonar activity. Recorders were distributed at 17 sites along 61 linear km of river habitat for durations of 46 to 148 h. Dolphin presence was 45% lower near the city than in the reserve. This study demonstrates the efficacy of acoustic monitoring as a method for testing dolphin redistribution and/or decline hypotheses in the context of anthropogenic development. The methods are applicable to continuous future monitoring and status assessment of river dolphins in South America as well as in Asia.
- Published
- 2021
11. Feeding habits of Sotalia fluviatilis in the Amazonian Estuary = Hábitos alimentares de Sotalia fluviatilis no estuário amazônico
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Sandra Beltrán-Pedreros and Tatyanna Mariucha de Araújo Pantoja
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Sotalia fluviatilis ,amazonian estuary ,feeding habits of dolphins ,estuário amazônico ,hábitos alimentares de golfinhos ,Biology (General) ,QH301-705.5 ,Microbiology ,QR1-502 - Abstract
In this paper we present an analysis of the fifty S. fluviatilis feeding habits in the Amazonian Estuary. Animals were bycaught by the artisanal fishing fleet between 1996 and 2001. Feeding habits were analyzed by prey occurrence frequency (%F) and number percentage and stomachs contents preys similarity between marine and freshwater fishspecies present in the Amazonian Estuary. Thirteen fish species were identified (%F= 86.6), the most significant families were Sciaenidae (32%), Trichiuridae (26%) e Ariidae (16%), and four crustaceans species (%F=26). S. fluviatilis feeding habits did not differ bygender and in general, calves had higher prey diversity than juveniles and adults. The similarity was high (0.89) between estuarine S. fluviatilis feeding habits and the fishes speciespresent in the Amazonian Estuary when the environment is mostly marine.Objetivou-se descrever e analisar os hábitos alimentares de 50 golfinhos Sotalia fluviatilis capturados acidentalmente na frota pesqueira artesanal do Estuário Amazônico entre 1996 e 2001. As presas foram identificadas e calculadas a freqüência de ocorrência e numérica; testada a similaridade entre a diversidade de presas dos conteúdos e a diversidade de peixes marinhos e de água doce do estuário e, comparados os hábitos alimentares por sexo e categoria de maturidade. Ocorreram 13 espécies de peixes (86,6%) onde as famíliasSciaenidae (32%), Trichiuridae (26%) e Ariidae (16%) foram mais representativas e, quatro espécies de crustáceos (26%). A espécie não apresentou diferenças nos hábitos alimentares entre sexos, mas, os filhotes tiveram maior diversidade de presas que jovens e adultos.Finalmente, houve maior similaridade (0.89) entre a diversidade de presas de S. fluviatilis e as espécies de peixes quando o estuário apresenta características marinhas.
- Published
- 2006
12. Helminths of the marine tucuxi, Sotalia fluviatilis (Gervais, 1853) (Cetacea: Delphinidae), in northern Rio de Janeiro State, Brazil
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Osana Prado Melo, Renata Maria Arruda Ramos, and Ana Paula Madeira Di Beneditto
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Sotalia fluviatilis ,marine tucuxi ,helminths ,Rio de Janeiro State ,Brazil ,Biotechnology ,TP248.13-248.65 - Abstract
The objectives of this work were to reporte the helminths of the marine tucuxi, Sotalia fluviatilis (Cetacea: Delphinidae) in northern Rio de Janeiro State; and to check if the infestation rate varied with the host characteristics (sex and maturity) and year seasons. From 1989 to 2002, 80 marine tucuxis that were by-caught in fisheries were examined and four parasites were recorded: Braunina cordiformis, Anisakis typica, Halocercus brasiliensis and Nasitrema sp. The parasitism in the marine tucuxi corroborated its feeding habits and there were no infestation rate differences between males and females, youngs and adults, as well as between year seasons. This work reports for the first time the occurrence of the genus Nasitrema in the marine tucuxi.Os objetivos deste trabalho foram reportar os helmintos parasitas do tucuxi marinho, Sotalia fluviatilis, na costa norte do Estado do Rio de Janeiro; e checar se a taxa de infestação varia com as características do hospedeiro (sexo e maturidade) e estações do ano. Entre 1989 e 2002, 80 tucuxis marinhos capturados acidentalmente em pescarias foram examinados e quatro espécies de parasitas foram registradas: Braunina cordiformis, Anisakis typica, Halocercus brasiliensis e Nasitrema sp. O parasitismo no tucuxi marinho corrobora seu hábito alimentar e não foram constatadas diferenças nas taxas de infestação entre machos e fêmaes, jovens e adultos, assim como entre as estações do ano. Este trabalho reporta pela primeira vez a ocorrência do gênero Nasitrema no tucuxi marinho.
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- 2006
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13. Analysis of whistles produced by the Tucuxi Dolphin Sotalia fluviatilis from Sepetiba Bay, Brazil
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Erber Claudia and Simão Sheila M.
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Sotalia fluviatilis ,Cetacea ,Delphinidea ,vocal repertoire ,whistles ,behavior ,Science - Abstract
From July 2001 to June 2002, we recorded a total of 2h55min of Tucuxi Dolphin Sotalia fluviatilis vocalizations from Sepetiba Bay, Brazil (22º35'S-44º03'W). A total of 3350 whistles were analyzed quantitative and qualitatively and were divided into 124 types, by visual inspection of sonograms. The following parameters were measured: Initial Frequency, Final Frequency, Minimum Frequency, Maximum Frequency, Duration, Number of Inflections, Frequency at the Inflection Points, Frequency at 1/2, 1/4, and 3/4 of whistle duration, Presence of Frequency Modulation and Harmonics. Ascending type whistles (N=2719) were most common, representing 82% of the total. Dolphin behavior and average group size observed during recording influenced the whistle's quantitative and qualitative parameters. The results demonstrate the great diversity of whistles emitted and indicate a functional role of these vocalizations during the observed behaviors.
- Published
- 2004
14. Density, abundance and group size of river dolphins (Inia geoffrensis and Sotalia fluviatilis) in Central Amazonia, Brazil
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Nathali G. Ristau, Mariana Paschoalini, Danielle dos Santos Lima, C.Gomez Salazar, Heloise Julião Pavanato, and Miriam Marmontel
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Inia geoffrensis ,biology ,Amazon rainforest ,Aquatic Science ,Structural basin ,biology.organism_classification ,Sotalia fluviatilis ,Fishery ,Geography ,Abundance (ecology) ,biology.animal ,Citizen science ,Animal Science and Zoology ,Bathymetry ,Ecology, Evolution, Behavior and Systematics ,Strengths and weaknesses - Abstract
Given the difficulties and costs often associated with surveying cetaceans, enlisting members of the public to collect data offers a promisingalternative approach. Comparison of cetacean ‘participatory science’ (also known as ‘citizen science’) data with data collected during traditionalscientific studies helps reveal the strengths and weaknesses of a participatory science approach. With a large number of vessel operators on thewater throughout the year, including dolphin-oriented tour boats, the Hawaiian Islands offer an ideal study site to employ such a dual-methodcomparison. The study aimed to enhance understanding of nearshore dolphin distributions relative to bathymetry. Operators of tour and fishingvessels within the shallow Maui Nui basin of the Hawaiian Islands were recruited to report delphinid sightings. Researchers conducted standarddolphin surveys within the same region. The participatory science approach was successful in generating a large sample size of sightings from fivedifferent species. Findings here demonstrate the potential value of participatory science and of using a multimethod approach to infer odontocetedistribution trends relative to bathymetry in areas where both methods are feasible. Important refinements for future projects are highlighted.
- Published
- 2019
15. Sightings of Pontoporia blainvillei (Gervais & D' Orbigny, 1844) and Sotalia fluviatilis (Gervais, 1853) (Cetacea) in South-eastern Brazil
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Ana Paula M. Di Beneditto, Renata Maria A. Ramos, and Neuza Rejane W. Lima
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Pontoporia blainvillei ,Sotalia fluviatilis ,sightings ,South-eastern Brazil ,Biotechnology ,TP248.13-248.65 - Abstract
Pontoporia blainvillei (Gervais & D' Orbigny, 1844) and Sotalia fluviatilis (Gervais, 1853) have typically coastal habits and are sympatric in South-eastern Brazil. The purpose of this work was to record sightings and describe aspects concerning the behaviour of both species in this region, between 1993 and 1998. The sightings were accomplished by cruises and from a fixed point. Information provided by fishermen were also considered. In general, P. blainvillei was observed in all seasons of the year, up to five nautical miles away from the coast, up to 15 m deep and the groups comprised up to five specimens. The most part of the groups of S. fluviatilis, were observed in autumm and winter times and comprised up to 10 specimens. In about half of the sightings, the presence of calves and/or juveniles was noted. The cooperative (group) fishing was the foranging behaviour most frequently noted for S. fluviatilis.Pontoporia blainvillei (Gervais & D’Orgigny, 1844) e Sotalia fluviatilis (Gervais, 1853) possuem hábitos tipicamente costeiros e são simpátricas no Sudeste do Brasil. O objetivo deste trabalho foi registrar avistagens e descrever aspectos relacionados ao comportamento de ambas as espécies na região, entre 1993 e 1998. As avistagens foram realizadas através de cruzeiros e ponto fixo. Informações fornecidas por pescadores também foram consideradas. Em geral, P. blainvillei foi observada em todas as estações do ano, a até cinco milhas náuticas de distância da linha da costa e 15 m de profundidade e, os grupos eram formados por até cinco espécimens. A maior parte dos grupos de S. fluviatilis foi observada no período de outono e inverno e, era formada por até 10 espécimens. Em metade das avistagens, a presença de filhotes e/ou juvenis foi verificada. A pesca cooperativa (em grupo) foi o comportamento alimentar observado com maior freqüência para S. fluviatilis.
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- 2001
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16. Sightings of Pontoporia blainvillei (Gervais & D' Orbigny, 1844) and Sotalia fluviatilis (Gervais, 1853) (Cetacea) in South-eastern Brazil
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Di Beneditto Ana Paula M., Ramos Renata Maria A., and Lima Neuza Rejane W.
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Pontoporia blainvillei ,Sotalia fluviatilis ,sightings ,South-eastern Brazil ,Biotechnology ,TP248.13-248.65 - Abstract
Pontoporia blainvillei (Gervais & D' Orbigny, 1844) and Sotalia fluviatilis (Gervais, 1853) have typically coastal habits and are sympatric in South-eastern Brazil. The purpose of this work was to record sightings and describe aspects concerning the behaviour of both species in this region, between 1993 and 1998. The sightings were accomplished by cruises and from a fixed point. Information provided by fishermen were also considered. In general, P. blainvillei was observed in all seasons of the year, up to five nautical miles away from the coast, up to 15 m deep and the groups comprised up to five specimens. The most part of the groups of S. fluviatilis, were observed in autumm and winter times and comprised up to 10 specimens. In about half of the sightings, the presence of calves and/or juveniles was noted. The cooperative (group) fishing was the foranging behaviour most frequently noted for S. fluviatilis.
- Published
- 2001
17. When You Get What You Haven't Paid for: Molecular Identification of "Douradinha" Fish Fillets Can Help End the Illegal Use of River Dolphins as Bait in Brazil.
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Cunha, Haydée A., da Silva, Vera M. F., Santos, Teresa E. C., Moreira, Stella M., do Carmo, Nivia A. S., and Solé-Cava, Antonio M.
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FISH fillets , *RIVER dolphins , *FISHING baits , *CATFISHES , *FISHERIES - Abstract
The fishery for Calophysus macropterus, an Amazonian necrophagous catfish, is highly detrimental to river dolphins and caimans, which are deliberately killed for use as bait. In the Brazilian Amazon, this fishery has increased over the last decade, in spite of the rejection of scavenger fishes by Brazilian consumers. It was suspected that C. macropterus fillets were being sold in Brazilian markets, disguised as a fictitious fish (the "douradinha"). We collected 62 fillets from "douradinha" and other suspiciously named fish from 4 fish-processing plants sold at 6 markets in Manaus, in the Brazilian Amazon, and sequenced the cytochrome b gene to identify fillets to species. Sixty percent of fillets labeled "douradinha" or with other deceptive names were actually C. macropterus. Six other fish species of low commercial value were also found. The presence of dolphin tissue in the stomach contents of C. macropterus was confirmed by mtDNA control region sequencing. Our results formed the scientific basis for a moratorium on the fishing and fraudulent selling of C. macropterus, issued by the Brazilian Ministries of the Environment and Fisheries. Exposure of this fraud via the mass media can help end the illegal use of dolphins as bait in Brazil. [ABSTRACT FROM AUTHOR]
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- 2015
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18. The dammed river dolphins of Brazil: impacts and conservation.
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Araújo, Claryana C. and Wang, John Y.
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DOLPHINS , *FRAGMENTATION reactions , *HYDROELECTRIC power plants , *WATERSHED ecology - Abstract
A major threat to river dolphins in Brazil is habitat loss and fragmentation as a result of the construction of hydroelectric dams. We examine the degree of overlap between the distributions of two river dolphin species (boto Inia geoffrensis and tucuxi Sotalia fluviatilis) and hydroelectric projects and provide an initial quantification of impacts. The locations of dams were overlaid onto a map of the known distributions of the dolphins. Two types of impacts were evaluated: population fragmentation and effects on prey. For each of these a binary score (for absence or presence) was assigned for each dam. The sum of all impact scores for each dam, in each of the three watersheds in which dolphins are found, including realized and potential impacts, was calculated as the impact index. Thirteen dams affect the distribution of I. geoffrensis (as could a further three dams under construction and seven planned), and three dams affect S. fluviatilis (as could three under construction and two planned). Overall, the impact index was higher for I. geoffrensis than for S. fluviatilis. The Araguaia–Tocantins and North Atlantic watersheds have higher impact index values than the Amazon watershed. Although some impacts of damming could not be considered in this study, our approach was a rapid initial risk assessment that provided an overall understanding of how river dolphins are and may be affected by hydroelectric projects in Brazil. Our method may be applicable to other freshwater cetaceans and species facing similar threats when information about impacts is incomplete. [ABSTRACT FROM PUBLISHER]
- Published
- 2015
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19. Aquatic Mammals of the Amazon: A Review of Gene Diversity, Population Structure and Phylogeography Applied to Conservation
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Israela da Silva de Souza, Waleska Gravena, and Mario Da Silva Nunes
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River otter ,geography.river ,Near-threatened species ,biology ,Ecology ,biology.organism_classification ,Otter ,Sotalia fluviatilis ,Phylogeography ,Geography ,Trichechus inunguis ,biology.animal ,IUCN Red List ,Amazonian manatee - Abstract
There are five types of aquatic mammals in the Amazon river basin. Two are semi-aquatic: the giant river otter (Pteronura brasiliensis) and the Neotropical otter (Lontra longicaudis); and three are fully aquatic: the Amazonian manatee (Trichechus inunguis), the tucuxi (Sotalia fluviatilis) and the boto (Inia spp.). This chapter reviews literature published over the past two decades on the genetic diversity and population genetics of these five groups. The results indicate a huge increase in the amount of published studies regarding these animals, but significant gaps in data from different localities impairs proper evaluation of how their populations are structured. This is a problem for scientists to correctly assess conservation and taxonomic statuses, as well as elaborate management plans for the conservation of these species. This information is critical, particularly since four species in this group are classified in a threaten category by the IUCN, and the other is categorized as near threatened. The following text will present an overview of what has been accomplished in the field of genetics over the past couple of decades and will discuss what are some of the problems and possible solutions to improve data in this field in future studies.
- Published
- 2021
20. On the brink of isolation: Population estimates of the Araguaian river dolphin in a human-impacted region in Brazil
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Miriam Marmontel, Nathali G. Ristau, Gabriel Melo-Santos, Alexandre N. Zerbini, Federico Guerra, Heloise Julião Pavanato, Mariana Paschoalini, Fernando Trujillo, and Rafael M. Almeida
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0106 biological sciences ,Topography ,Drainage basin ,Marine and Aquatic Sciences ,01 natural sciences ,Inia araguaiaensis ,Geographical locations ,Mammals ,Islands ,education.field_of_study ,Multidisciplinary ,geography.geographical_feature_category ,biology ,Inia geoffrensis ,Geography ,River dolphin ,Eukaryota ,Sotalia fluviatilis ,Habitats ,Vertebrates ,Medicine ,Channel (geography) ,Brazil ,Research Article ,Freshwater Environments ,Conservation of Natural Resources ,Dolphins ,Science ,Population ,Fisheries ,Marine Biology ,Extinction, Biological ,010603 evolutionary biology ,Rivers ,Population Metrics ,Surface Water ,biology.animal ,Animals ,education ,Marine Mammals ,Ecosystem ,Population Density ,geography ,Landforms ,Population Biology ,010604 marine biology & hydrobiology ,Ecology and Environmental Sciences ,Endangered Species ,Organisms ,Aquatic Environments ,Biology and Life Sciences ,Geomorphology ,Bodies of Water ,South America ,biology.organism_classification ,Bolivian river dolphin ,Fishery ,Lakes ,Amniotes ,Earth Sciences ,Hydrology ,People and places - Abstract
Populations of freshwater dolphins are declining in response to increased human pressure, including habitat degradation, overfishing, bycatch, poaching and obstruction of free-flowing river corridors by dams. At least three river dolphin species occur in South America: the Amazonian river dolphin, or boto (Inia geoffrensis), the Bolivian river dolphin (Inia boliviensis) and the tucuxi (Sotalia fluviatilis). A fourth species, the Araguaian boto (Inia araguaiaensis), been proposed for the Tocantins-Araguaia, a large river basin in northern Brazil. Here we show that the Araguaian boto population in the Tocantins River is relatively small (N = 1083, CV = 0.52). During a survey to estimate density and abundance, 138 groups (198 individuals) of botos were observed along a ~600 km stretch of the Tocantins River in five different habitats (river margin, river channel, channel, island margin, and a dam reservoir). Overall, lower densities of the Araguaian boto were registered downstream of the Tucurui dam, the world's fifth largest hydropower dam. Density was 68% lower in the river margin habitat downstream (0.23 ind./km2, CV = 0.92) than upstream (0.72 ind./km2, CV = 0.53). In addition, density within the Tucurui reservoir decreases from upstream areas towards the dam. Geographic post-stratification of data into sub-regions (downstream, reservoir, upstream) in relation to the Tucurui dam helped to reduce CV by ~70%, which illustrates the high variability in the encounter rate in these areas. Our findings suggest that the Araguaian boto population has been impacted by the construction of the Tucurui dam. The construction of other dams proposed for the Tocantins-Araguaia basin should be planned strategically to minimize overlapping with the Araguaian boto distribution. Coordinated conservation actions are imperative to prevent the Araguaian boto from reaching extinction or near-extinction as some of their Asian counterparts such as the Yangtze, Ganges, and Indus river dolphins.
- Published
- 2020
21. Molecular Identification and Historic Demography of the Marine Tucuxi (Sotalia guianensis) at the Amazon River's Mouth by Means of Mitochondrial Control Region Gene Sequences and Implications for Conservation.
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Ruiz-García, Manuel, Mejia, David, Escobar-Armel, Pablo, Tejada-Martínez, Daniela, and Shostell, Joseph Mark
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- *
TUCUXI , *DOLPHINS , *HAPLOTYPES , *ESTUARINE fishes , *STATISTICAL sampling , *PLEISTOCENE Epoch - Abstract
In 2005, three fishermen, with artisan fishing vessels and drift gillnets, accidentally captured around 200 dolphins between Vigia and Salinópolis in the Amazon River estuary. The dolphins died and they then prepared their vaginas and penises in order to sell them in the Ver-ao-Peso market in the city of Belem within the Brazilian state of Pará. We randomly sampled a minimal quantity of tissue of these sexual organs from 78 of these 200 dolphins and we determined the following results after sequencing 689 base pairs (bp) from the mitochondrial control region gene: (1) 96.15% (75/78) of these dolphins belonged to the species Sotalia guianensis. The other species detected were Steno brenadensis, Stenella coeruleoalba and Tursiops truncatus; (2) The levels of gene diversity found in this sample of S. guianensis were high (33 haplotypes, haplotype diversity of 0.917 and nucleotide diversity of 0.0045) compared to gene diversities found in other Brazilian S. guianensis locations; (3) All the population genetics methods employed indicated a clear population expansion in this population. This population expansion could have begun 400,000 years ago; (4) The haplotype divergence within this population could have begun around 2.1 millions of years ago (MYA), with posterior splits around 2.0-1.8 MYA, 1.7-1.8 MYA, 1-1.5 MYA, 0.6-0.8 MYA, 0.4-0.2 MYA and 0.16-0.02 MYA, all during the Pleistocene. [ABSTRACT FROM AUTHOR]
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- 2013
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22. Effectiveness of unmanned aerial vehicles to detect Amazon dolphins
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Miriam Marmontel, André Giovanni de Almeida Coelho, Daiane S. X. da-Rosa, Federico Mosquera-Guerra, Serge A. Wich, Marcelo Oliveira-da-Costa, and Fernando Trujillo
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0106 biological sciences ,biology ,Aerial survey ,Inia geoffrensis ,Amazon rainforest ,010604 marine biology & hydrobiology ,Wildlife ,River dolphin ,biology.organism_classification ,010603 evolutionary biology ,01 natural sciences ,Sotalia fluviatilis ,Fishery ,Geography ,Abundance (ecology) ,biology.animal ,Ecology, Evolution, Behavior and Systematics ,Nature and Landscape Conservation ,Amazon River Dolphins - Abstract
Quantifying the abundance of species is essential for their management and conservation. Much effort has been invested in surveys of freshwater dolphins in the Amazon basin but river dimensions and complex logistics limit replication of such studies across the region. We evaluated the effectiveness of using unmanned aerial vehicles (UAVs) for surveying two Amazon dolphin species, the tucuxi Sotalia fluviatilis and pink river dolphin Inia geoffrensis, in tropical rivers. In 2016 we conducted drone and visual surveys over 80 km of the Juruá River in Brazil. The aerial surveys provided higher accuracy than human observers in counting individuals detected in groups. Compared to estimates derived from visual surveys, the use of UAVs could provide a more feasible, economical and accurate estimate of Amazon river dolphin populations. The method could potentially be replicated in other important areas for the conservation of these species, to generate an improved index of river dolphin populations in the Amazon.
- Published
- 2019
23. Abundance estimate of the Amazon River dolphin (Inia geoffrensis) and the tucuxi (Sotalia fluviatilis) in southern Ucayali, Peru
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Jeffrey C. Mangel, Brendan J. Godley, Joanna Alfaro-Shigueto, and Elizabeth Campbell
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0106 biological sciences ,education.field_of_study ,010504 meteorology & atmospheric sciences ,biology ,Inia geoffrensis ,Amazon rainforest ,Population ,Inia ,River dolphin ,Aquatic Science ,Oceanography ,biology.organism_classification ,010603 evolutionary biology ,01 natural sciences ,Sotalia fluviatilis ,Fishery ,Geography ,Abundance (ecology) ,biology.animal ,education ,Transect ,0105 earth and related environmental sciences - Abstract
We present results of the first simultaneous visual and acoustic surveys for Amazon River dolphins ( Inia geoffrensis ) and tucuxi ( Sotalia fluviatilis ), undertaken in Yarinacocha Lagoon, Ucayali, Peru (length = 20 km, area = 12 km -2 ). A total of 324 Sotalia observations and 44 Inia observations were recorded in boat-based transects. Based upon total survey effort, we estimated Sotalia had a mean density ± SE of 1.98 ± 4.6 ind km -2 and an overall abundance of 34 individuals (95% CI: 28 to 40). Average density for Inia was 0.2 ± 1.2 ind km -2 with overall abundance estimated at 3 individuals (95% CI: 0 to 8). Visual surveys observed more Sotalia individuals during earlier hours of the day and during the dry season. Preliminary acoustic surveys undertaken with C-POD passive acoustic monitoring devices indicated a diel pattern in detections of cetacean vocalization with more diurnal activity and with detections ceasing from midnight until 10:00 AM. This work highlights the possibility of monitoring both river dolphin species through visual and acoustic surveys to generate baseline information on abundance trends and distribution patterns in the Ucayali region, an area with high levels of human disturbance.
- Published
- 2017
24. River Dolphin (Inia geoffrensis, Sotalia fluviatilis) Mortality Events Attributed to Artisanal Fisheries in the Western Brazilian Amazon.
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Iriarte, Verónica and Marmontel, Miriam
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- *
ANIMAL mortality , *BOTO , *TUCUXI , *STRANDING of aquatic animals , *SMALL-scale fisheries , *ANIMAL carcasses , *GILLNETTING - Abstract
In the Western Brazilian Amazon, interactions of boto (Inia geoffrensis) and tucuxi (Sotalia fluviatilis) dolphins with fishing activities are common, but the prevalence of incidental/intentional catches is not known. This article describes incidental mortality events and intentional killing of I. geoffrensis and S. fluviatilis entangled in artisanal fishing gear and the opportunistic use of carcasses as bait. Between October 2010 and November 2011, surveys were conducted in waters of the lower Japurá River, between the Mamirauá and Amanã sustainable development reserves. In order to obtain information on interactions and to try to establish a stranding/entanglement response program (SERP), informal conversations were exchanged with local inhabitants (n = 174). Intense carcass-search surveys (n = 171) along the river in the four hydrological seasons (e.g., low, rising, high, and falling waters) were conducted, comprising a total of 1,197 h of sampling effort. Twenty-five dolphin-fishing interaction events were recorded (11 I. geoffrensis and 14 S. fluviatilis), 19 in 2011 and six in 2012 (through SERP). A total of 11 necropsies (three I. geoffrensis and eight S. fluviatilis) were performed. Four individuals (two I. geoffrensis and two S. fluviatilis) exhibited evidence of physical violence before death, and two (one I. geoffrensis and one S. fluviatilis) died in abandoned gillnets. Two intentional killing events of I. geoffrensis incidentally entangled for bait use in the piracatinga (Calophysus macropterus) fishery were reported by fishermen, while three carcasses (two I. geoffrensis and one S. fluviatilis) with gillnet marks were also used in that activity. At least six of the S. fluviatilis entanglement events occurred in fishing gear used for tambaqui (Colossoma macropomum) and pirapitinga (Piaractus brachypomus) (90/100-mm mesh-size gillnet), two of the most important commercial fish species in the Amazon Basin. As seasonal fishing constitutes the main income for riverine human populations, the negative reactions that cetacean presence causes to people could have a catalyst effect for the transition from "incidental capture" to "intentional capture and competitor removal." Law enforcement and precautionary measures through good fishing practices inside dolphin critical foraging areas should be taken together with fisheries' managers and fishermen to start to develop multiple-species management and ensure sustainable fishing practices. [ABSTRACT FROM AUTHOR]
- Published
- 2013
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25. Survey for Leptospira and Brucella in Amazonian manatees, Amazon river dolphins, and a tucuxi in the Brazilian Amazon.
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Rodrigues TC, Santos AL, Pinheiro ES, Piatti RM, Castro V, Buiatte AB, Lima AM, and Marmontel M
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- Animals, Antibodies, Bacterial blood, Brazil epidemiology, Brucellosis diagnosis, Brucellosis epidemiology, DNA, Bacterial, Leptospirosis diagnosis, Leptospirosis epidemiology, Brucella, Dolphins microbiology, Leptospira genetics, Trichechus inunguis microbiology
- Abstract
Leptospirosis and brucellosis are zoonotic diseases with global distributions that represent severe hazards to humans and animals. We investigated exposure to Leptospira spp. and Brucella spp. in samples from Amazonian manatees Trichechus inunguis, Amazon river dolphins Inia geoffrensis, and a tucuxi Sotalia fluviatilis. The animals were free-ranging or undergoing in situ rehabilitation in the mid-Solimões River region, Brazilian Amazon. Serum samples from 19 Amazonian manatees were tested by microscopic agglutination test, Rose Bengal test, and 2-mercaptoethanol Brucella agglutination test. Antibodies against Leptospira spp. were detected in 63% of the manatees tested and serovar Patoc was considered the infecting serovar in all positive samples. Titers were generally low, indicating chronic exposure, but higher titers indicative of an active infection were detected in 3 animals. Anti-Brucella spp. antibodies were not detected. Tissue and/or body fluid samples from 12 Amazon river dolphins, a tucuxi, and 2 Amazonian manatees were investigated by multiplex PCR and bacteriology for Leptospira spp. and Brucella spp. All samples were negative. However, Enterococcus faecalis was isolated from uterine fluid, lymph node, and lung of 3 Amazon river dolphins. Bacillus spp. were isolated from milk and synovial fluid from 2 Amazon river dolphins and from a milk sample from 1 Amazonian manatee. Knowledge of the pathogens present in Amazonian manatees, Amazon river dolphins, and tucuxis is of great relevance to species conservation and environmental health. Although no clinical signs were noted, further research is needed to elucidate the clinical relevance of infection by Leptospira sp. serovar Patoc in Amazonian aquatic mammals.
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- 2022
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26. Sternum and appendicular skeleton: morphometric differences between the species of genus Sotalia (Cetacea: Delphinidae).
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Fettuccia, D.C., da Silva, V.M.F., Rocha, M.S., and Simões-Lopes, P.C.
- Abstract
Two distinct species have been recently recognized for the genus Sotalia: S. fluviatilis, occurring in the Amazon River basin, and S. guianensis, from Honduras (15°58′N and 85°42′W) to Santa Catarina State (Florianópolis, southern Brazil—27°35′S and 48°34′W). For the first time the sternum and the appendicular skeleton of the two species of the genus Sotalia are compared. A comparative osteological work was performed with marine samples (from the States of Ceará, north-eastern and Santa Catarina, southern regions of Brazil) and riverine samples (Amazonas State) in relation to metric characters (scapula, flipper and sternum). There was a clear distinction of two species in relation to postcranial skeleton in the morphometric analysis (canonical variate analysis) presented. The flipper and the glenoid cavity of the scapula were proportionally wider in the fluvial species. The sternum, however, was smaller in this species in relation to the maximum width of the manubrium. Nevertheless, this structure still needs to be further studied. [ABSTRACT FROM PUBLISHER]
- Published
- 2012
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27. Hábitos alimentares de Sotalia fluviatilis no estuário amazônico - DOI: 10.4025/actascibiolsci.v28i4.173
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Sandra Beltrán Pedreros and Tatyanna Mariucha de Araújo Pantoja
- Subjects
Sotalia fluviatilis ,estuário amazônico ,hábitos alimentares de golfinhos ,Biology (General) ,QH301-705.5 ,Microbiology ,QR1-502 - Abstract
Objetivou-se descrever e analisar os hábitos alimentares de 50 golfinhos Sotalia fluviatilis capturados acidentalmente na frota pesqueira artesanal do Estuário Amazônico entre 1996 e 2001. As presas foram identificadas e calculadas a freqüência de ocorrência e numérica; testada a similaridade entre a diversidade de presas dos conteúdos e a diversidade de peixes marinhos e de água doce do estuário e, comparados os hábitos alimentares por sexo e categoria de maturidade. Ocorreram 13 espécies de peixes (86,6%) onde as famílias Sciaenidae (32%), Trichiuridae (26%) e Ariidae (16%) foram mais representativas e, quatro espécies de crustáceos (26%). A espécie não apresentou diferenças nos hábitos alimentares entre sexos, mas, os filhotes tiveram maior diversidade de presas que jovens e adultos. Finalmente, houve maior similaridade (0.89) entre a diversidade de presas de S. fluviatilis e as espécies de peixes quando o estuário apresenta características marinhas.
- Published
- 2006
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28. Ecological factors influencing group sizes of river dolphins ( Inia geoffrensis and Sotalia fluviatilis).
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Gomez-Salazar, Catalina, Trujillo, Fernando, and Whitehead, Hal
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RIVER dolphins ,BOTO ,TUCUXI ,GROUP size ,ECOLOGICAL research ,BIOTIC communities - Abstract
Living in groups is usually driven by predation and competition for resources. River dolphins do not have natural predators but inhabit dynamic systems with predictable seasonal shifts. These ecological features may provide some insight into the forces driving group formation and help us to answer questions such as why river dolphins have some of the smallest group sizes of cetaceans, and why group sizes vary with time and place. We analyzed observations of group size for Inia and Sotalia over a 9 yr period. In the Amazon, largest group sizes occurred in main rivers and lakes, particularly during the low water season when resources are concentrated; smaller group sizes occurred in constricted waters (channels, tributaries, and confluences) that receive an influx of blackwaters that are poor in nutrients and sediments. In the Orinoco, the largest group sizes occurred during the transitional water season when the aquatic productivity increases. The largest group size of Inia occurred in the Orinoco location that contains the influx of two highly productive whitewater rivers. Flood pulses govern productivity and major biological factors of these river basins. Any threats to flood pulses will likely have an effect on the functionality of these ecosystems and the species living in them. [ABSTRACT FROM AUTHOR]
- Published
- 2012
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29. Purification and Characterization of a Liver-derived β-N-Acetylhexosaminidase from Marine Mammal Sotalia fluviatilis.
- Author
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Júnior, J. E. Gomes, Souza, D. S. L., Nascimento, R. M., Lima, A. L. M., Melo, J. A. T., Rocha, T. L., Miller, R. N. G., Franco, O. L., Grossi-de-Sa, M. F., and Abreu, L. R. D.
- Subjects
- *
TUCUXI , *MARINE mammals , *ENZYMES , *CHROMATOGRAPHIC analysis , *HYDROXYAPATITE - Abstract
A β-N-Acetylhexosaminidase (EC 3.2.1.52) was purified from hepatic extracts of Sotalia fluviatilis, order Cetacea. The protein was purified by using ammonium sulfate fractionation and four subsequent chromatographies (Biogel A 1.5 m, Chitin, Deae-Biogel and hydroxyapatite resins). After these purification steps, the enzyme was purified 380.5-fold with an 8.4% yield. The molecular mass (10 kDa) was estimated by SDS–PAGE and MALDI-TOF analysis. A Km of 2.72 mM and Vmax 9.5 × 10−6 μmol/(min.mg) were found for this enzyme, determined by p-nitrophenyl-β- d-hexosaminide substrate digestion. Optimal pH and temperature for β-N-Acetylhexosaminidase activity were 5.0 and 60 °C, respectively. Enzyme activity was inhibited by sodium selenate (Na2SeO4), mercuric chloride (HgCl2) and sodium dodecyl sulfate (C12H25SO4Na), and activated by zinc, calcium, barium and lithium ions. Characterization of the β-N-Acetylhexosaminidase in Sotalia fluviatilis can be a basis for physiological studies in this species. [ABSTRACT FROM AUTHOR]
- Published
- 2010
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30. TAXONOMIC STATUS OF THE GENUS SOTALIA: SPECIES LEVEL RANKING FOR “TUCUXI” ( SOTALIA FLUVIATILIS) AND “COSTERO” ( SOTALIA GUIANENSIS) DOLPHINS.
- Author
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Caballero, S., Trujillo, F., Vianna, J. A., Barrios-Garrido, H., Montiel, M. G., Beltrán-Pedreros, S., Marmontel, M., Santos, M. C., Rossi-Santos, M., Santos, F. R., and Baker, C. S.
- Subjects
DOLPHINS ,SOTALIA ,TUCUXI ,ANIMAL classification ,MITOCHONDRIAL DNA ,SPECIES - Abstract
Dolphins of the genus Sotalia are found along the Caribbean and Atlantic coasts of Central and South America and in the Amazon River and most of its tributaries. At present, the taxonomy of these dolphins remains unresolved. Although five species were described in the late 1800s, only one species is recognized currently ( Sotalia fluviatilis) with two ecotypes or subspecies, the coastal subspecies ( Sotalia fluviatilis guianensis) and the riverine subspecies ( Sotalia fluviatilis fluviatilis). Recent morphometric analyses, as well as mitochondrial DNA analysis, suggested recognition of each subspecies as separate species. Here we review the history of the classification of this genus and present new genetic evidence from ten nuclear and three mitochondrial genes supporting the elevation of each subspecies to the species level under the Genealogical/Lineage Concordance Species Concept and the criterion of irreversible divergence. We also review additional evidence for this taxonomic revision from previously published and unpublished genetic, morphological, and ecological studies. We propose the common name “costero” for the coastal species, Sotalia guianensis ( Van Bénéden 1864 ), and accept the previously proposed “tucuxi” dolphin, Sotalia fluviatilis (Gervais, 1853), for the riverine species. [ABSTRACT FROM AUTHOR]
- Published
- 2007
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31. Chlorinated pesticides and polychlorinated biphenyls in marine tucuxi dolphins (Sotalia fluviatilis) from the Canane´ia estuary, southeastern Brazil
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Yogui, Gilvan Takeshi, de Oliveira Santos, Marcos César, and Montone, Rosalinda Carmela
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- *
PESTICIDES , *ESTUARIES , *TUCUXI - Abstract
The Canane´ia estuary is an important biological area on the southeast coast of Brazil. In the past, it was impacted by both chlorinated pesticides and polychlorinated biphenyls (PCBs) due to its natural location. The marine tucuxi dolphin (Sotalia fluviatilis) is a top predator in this ecosystem and can be found year round in Canane´ia estuarine waters that represent an important nursing area for the species. This work investigated chlorinated compounds in the blubber of nine individuals from the Canane´ia estuary. Residue levels of DDTs (0.541–125 μg g−1 lipid wt.) were the highest, followed by PCBs (0.2–9.22 μg g−1 lipid wt.), mirex (0.014–0.312 μg g−1 lipid wt.), chlordanes (0.001–0.047 μg g−1 lipid wt.), HCHs (<0.003–0.044 μg g−1 lipid wt.), and HCB (n.d.−0.024 μg g−1 lipid wt.). The mean p,p′-DDE/Σ DDT ratio was approximately 0.8 and is indicative of the former DDT application in the study area. PCB contamination is suggested to be associated with atmospheric transport and relative proximity to the Cubata˜o industrial complex—the most important along the Brazilian coast. Low levels of HCHs and HCB can be attributed to their high volatility in tropical environments. Concentrations of organochlorines in the blubber of marine tucuxis from the Canane´ia estuary were lower than levels found in small cetacean species from developed countries, where the input of these compounds was considerably greater than in Brazil. At extremes, male dolphins can present DDT burden several orders of magnitude higher than females. Despite the high levels of total DDT found in males, the major detected compound was p,p′-DDE which is considered to be of low toxicity. [Copyright &y& Elsevier]
- Published
- 2003
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32. Concentrations of heavy metals in Sotalia fluviatilis (Cetacea: Delphinidae) off the coast of Ceará, northeast Brazil.
- Author
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Monteiro-Neto, Cassiano, Itavo, Renata Vinhas, and Moraes, Luiz Eduardo de Souza
- Published
- 2003
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33. Lesões ósseas em Sotalia fluviatilis (Cetacea) como conseqüência de enredamento: Relato de caso
- Author
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Renata Maria Arruda Ramos, Ana Paula Madeira Di Beneditto, and Sheila Mendonça de Souza
- Subjects
Sotalia fluviatilis ,Lesões na pele e óssea ,Enredamento ,Sudeste do Brasil ,Animal culture ,SF1-1100 - Abstract
O objetivo do presente estudo foi descrever um grupo de lesões causadas por enredamento em Sotalia fluviatilis capturado acidentalmente por rede de pesca em 23 de julho de 1995 no Norte do Estado do Rio de Janeiro (21º37'S-041º01'W), Sudeste do Brasil. O espécime apresentou lesões laceradas na pele e no tecido subcutâneo ao redor da extremidade posterior do rostro. Fios de náilon foram encontrados associados às lesões. Lesões ósseas e nos dentes foram também observadas na área subjacente e afetaram as maxilas, pré-maxilas e mandíbulas. As lesões provavelmente foram causadas por enredamento não-letal em aparelho de pesca. Anomalias no padrão de camadas de crescimento dos dentes lesados, entre a terceira e a sexta camada, sugerem que esta lesão ocorreu aos três anos de idade. Os dados indicam que encontros não-letais com redes de pesca podem causar sérios problemas de saúde em pequenos cetáceos. Esta é a primeira descrição de lesão crônica em S. fluviatilis relacionada a pescarias.
- Published
- 2001
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34. Risks of dam construction for South American river dolphins: a case study of the Tapajós River
- Author
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Danielle dos Santos Lima, Heloise Julião Pavanato, Miriam Marmontel, Federico Mosquera, Marcela Portocarrero-Aya, Fernando Trujillo, Gabriel Melo-Santos, Cláudio Maretti, Rafael Freitas Meneses, Mariana Paschoalini, University of St Andrews. School of Biology, and University of St Andrews. Scottish Oceans Institute
- Subjects
Cetacean abundance ,0106 biological sciences ,Population fragmentation ,Population ,NDAS ,Inia geoffrensis ,IUCN Red List Category ,Marine mammal ,010603 evolutionary biology ,01 natural sciences ,Distance sampling ,Population modeling ,biology.animal ,lcsh:Botany ,lcsh:Zoology ,SDG 14 - Life Below Water ,lcsh:QL1-991 ,education ,Nature and Landscape Conservation ,education.field_of_study ,Ecology ,biology ,010604 marine biology & hydrobiology ,Population size ,Sotalia fluviatilis ,Extinction ,biology.organism_classification ,lcsh:QK1-989 ,Fishery ,Geography ,Habitat - Abstract
Funding: This study was funded by the Ministério da Ciência, Tecnologia e Inovação (MCTI) through Mamirauá Institute for Sustainable Development, with support from the Omacha Foundation (Colombia) and Whitley Fund for Nature. River dolphins are strongly affected by the construction of hydroelectric dams. Potential isolation in subpopulations above and below such dams and the resulting low genetic variability of these subpopulations can cause extinction at a local level. Here we aimed to estimate density and population size of South American river dolphins (boto Inia geoffrensis and tucuxi Sotalia fluviatilis), map their distribution, and estimate potential biological removal (PBR) limits in order to evaluate the effects of population fragmentation between planned dams in the Tapajós River, Amazonian basin, Brazil. Boat-based surveys were conducted following a line transect sampling protocol covering different dolphin habitats in 2 stretches of the river divided by rapids. The mark-recapture distance sampling method was applied to account for animals missed on the trackline. After the estimation of population sizes by habitat, PBR was calculated. The farthest upriver sighting of tucuxis was close to the São Luiz do Tapajós rapids, whereas the farthest upriver sighting of botos was upstream of the rapids, suggesting that botos move upstream through the rapids. Estimated abundance of tucuxis (3372 ind., CV = 0.38) was twice as high as that estimated for botos (1815 ind., CV = 0.4). The PBR ranged from 11 to 18 ind. for boto and 21 to 34 for tucuxi. Throughout this study, we identified low abundances of river dolphins compared to other Amazon rivers. Boto may not be sustainable at a population level, due primarily to population fragmentation which would result from the construction of the proposed dams. Precautionary measures are urgently needed before construction of dams begins in the Tapajós River. Publisher PDF
- Published
- 2016
35. Padrão Comportamental e Percepção dos Barqueiros Sobre o Boto Tucuxi, Sotalia fluviatilis (Odontoceti: Delphinidae) em Área do Entorno da Ilha de Santana, Amapá, Brasil
- Author
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Carlos Eduardo Costa Campos, Luana Caroline de Souza Barroso, and Andréa Soares Araújo
- Subjects
biology ,Amazon rainforest ,Ecology ,Foraging ,Pharmaceutical Science ,High tide ,Sotalia fluviatilis ,Fishery ,Geography ,lcsh:Biology (General) ,Complementary and alternative medicine ,biology.animal ,Slow Movement ,%22">Fish ,Pharmacology (medical) ,lcsh:QH301-705.5 - Abstract
A espécie Sotalia fluviatilis é pouco conhecida na região amazônica, principalmente no estado do Amapá, onde estudos são bastante escassos. O presente estudo tem por objetivo contribuir para o aumento do conhecimento sobre o padrão comportamental e percepção dos barqueiros sobre S. fluviatilis no porto do açaí. Este trabalho foi realizado em um ponto fixo localizado no Porto do Açaí. As observações foram feitas mensalmente no período de julho de 2013 a dezembro de 2013 em período matutino, junto às entrevistas com os barqueiros presentes no porto com a aplicação de um questionário de pesquisa com TCLE. Os padrões comportamentais mais frequentes observados pelo tucuxi foram deslocamento lento, deslocamento rápido e forrageio. Com relação a percepção dos barqueiros quando perguntados a maior parte dos barqueiros afirmou ver o boto tucuxi com frequência no porto, em grupos de dois a três indivíduos, realizando atividade de alimentação/forrageio. A presença maior da espécie no período de maré alta foi afirmada pelos entrevistados, corroborando com os dados de observação in loco. Segundo os entrevistados o tucuxi quando avistado localiza-se as margens do rio e que a presença da espécie é atribuída à alimentação descartada pelos vendedores de peixe do local e que hoje há menos animais em relação à 5 anos. Nesse sentido, espera-se o presente estudo contribua para informações sobre áreas de ocorrência de S. fluviatilis e futuramente subsidiar medidas de conservação para a espécie, tendo em vista a iminência da construção de um porto de escoamento de soja nas proximidades da área. Palavras-chave: Conhecimento popular, Etologia, região norte, cetáceos. DOI: http://dx.doi.org/10.18561/2179-5746/biotaamazonia.v5n4p119-124
- Published
- 2015
36. Retrospective pathological survey of pulmonary disease in free-ranging Amazon river dolphin Inia geoffrensis and tucuxi Sotalia fluviatilis
- Author
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José Luiz Catão-Dias, Júlia da Luz Carvalho, Josué Díaz-Delgado, Thaís Carneiro S Rodrigues, and Miriam Marmontel
- Subjects
0301 basic medicine ,Male ,040301 veterinary sciences ,Lung Diseases, Parasitic ,Dolphins ,Population ,Zoology ,Environmental pollution ,Aquatic Science ,Pneumonia, Aspiration ,0403 veterinary science ,03 medical and health sciences ,biology.animal ,STREPTOCOCCUS ,medicine ,Pneumonia, Bacterial ,Animals ,education ,Lung ,Ecology, Evolution, Behavior and Systematics ,Retrospective Studies ,Data deficient ,education.field_of_study ,Inia geoffrensis ,biology ,Mortality rate ,River dolphin ,04 agricultural and veterinary sciences ,030108 mycology & parasitology ,biology.organism_classification ,medicine.disease ,Sotalia fluviatilis ,Female ,Pneumonia (non-human) ,Brazil - Abstract
The Amazon river dolphin Inia geoffrensis and tucuxi Sotalia fluviatilis are classified as Data Deficient species. Despite very limited knowledge on health and disease aspects of these species, the main threats to their conservation include incidental mortality in fishing gear, population fragmentation, habitat loss and environmental pollution. It is also suggested that underlying diseases may contribute to their mortality rates. Herein, we retrospectively describe gross and microscopic pulmonary lesions in free-ranging I. geoffrensis (n = 24) and S. fluviatilis (n = 28) found dead. Nearly 85% of the examined animals presented some kind of primary lung disease, wherein the main etiological diagnoses were verminous pneumonia by Halocercus brasiliensis (25%), bacterial pneumonia (25%) and a single case of meconium aspiration syndrome (1.9%). An etiology was not determined in 36.5% (19/52) of animals. These results indicate a high incidence of pulmonary pathology in these species, raising concerns about population impacts and potential zoonotic implications in some instances. These data may provide a scientific basis for future medical and conservation efforts focused on Amazonian dolphins.
- Published
- 2018
37. Population Structure of Riverine and Coastal Dolphins Sotalia fluviatilis and Sotalia guianensis: Patterns of Nuclear and Mitochondrial Diversity and Implications for Conservation
- Author
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Sebastián Cisternas Rodríguez, Susana Caballero, C. Scott Baker, Claudia Hollatz, and Fernando Trujillo
- Subjects
0106 biological sciences ,Conservation of Natural Resources ,Sotalia guianensis ,Dolphins ,Population ,Fresh Water ,010603 evolutionary biology ,01 natural sciences ,DNA, Mitochondrial ,Nucleotide diversity ,Gene flow ,Species Specificity ,biology.animal ,parasitic diseases ,Genetics ,Animals ,Seawater ,14. Life underwater ,education ,Molecular Biology ,Genetics (clinical) ,mtDNA control region ,Cell Nucleus ,education.field_of_study ,Genetic diversity ,biology ,Ecology ,Amazon rainforest ,010604 marine biology & hydrobiology ,Genetic Variation ,15. Life on land ,biology.organism_classification ,Sotalia fluviatilis ,Phylogeography ,Haplotypes ,geographic locations ,Biotechnology ,Microsatellite Repeats - Abstract
Coastal and freshwater cetaceans are particularly vulnerable due to their proximity to human activity, localized distributions, and small home ranges. These species include Sotalia guianensis, found in the Atlantic and Caribbean coastal areas of central and South America, and Sotalia fluviatilis, distributed in the Amazon River and tributaries. We investigated the population structure and genetic diversity of these 2 species by analyses of mtDNA control region and 8-10 microsatellite loci. MtDNA analyses revealed strong regional structuring for S. guianensis (i.e., Colombian Caribbean vs. Brazilian Coast, FST = 0.807, ΦST = 0.878, P < 0.001) especially north and south of the Amazon River mouth. For S. fluviatilis, population structuring was detected between the western and eastern Amazon (i.e., Colombian Amazon vs. Brazilian Amazon, FST = 0.085, ΦST = 0.277, P < 0.001). Haplotype and nucleotide diversity were higher for S. fluviatilis. Population differentiation was supported by analysis of the microsatellite loci (S. guianensis, northern South America vs. southern South America FST = 0.275, Jost's D = 0.476, P < 0.001; S. fluviatilis, western and eastern Amazon FST = 0.197, Jost's D = 0.364, P < 0.001). Most estimated migration rates in both species overlapped with zero, suggesting no measurable migration between most of the sampling locations. However, for S. guianensis, there was measurable migration in neighboring sampling locations. These results indicate that the small home ranges of these species may act to restrict gene flow between populations separated by relatively short distances, increasing the risk of extirpation of some localized populations in the future if existing threats are not minimized.
- Published
- 2017
38. Ba/Ca ratios in teeth reveal habitat use patterns of dolphins
- Author
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Ana Paula Madeira Di Beneditto, Vera M. F. da Silva, Carolina P. Bertozzi, Silvina Botta, Marcos César de Oliveira Santos, Norbert Miekeley, Aleta A. Hohn, C. Meirelles, Marta Jussara Cremer, Lupércio A. Barbosa, Cristiano Queiroz de Albuquerque, Valentina Franco-Trecu, Eduardo R. Secchi, and Renata Maria Arruda Ramos
- Subjects
Strontium ,geography ,geography.geographical_feature_category ,Ecology ,Inia geoffrensis ,Aquatic ecosystem ,chemistry.chemical_element ,Barium ,Estuary ,Aquatic Science ,Biology ,biology.organism_classification ,Sotalia fluviatilis ,Salinity ,medicine.anatomical_structure ,chemistry ,Environmental chemistry ,biology.animal ,medicine ,Ecology, Evolution, Behavior and Systematics ,Otolith - Abstract
Teeth and otoliths are metabolically inert structures that preserve a chronology of chemical variations that may be related to the environmental histories experienced by each organism. Because of the natural decrease of barium (Ba) and increase of strontium (Sr) bioavail- ability in water with increasing salinity, these elements may be especially useful to track habitat use in aquatic organisms. Therefore, we tested whether the Ba/Ca and Sr/Ca ratios in the teeth of dolphins represent a salinity gradient. The main aim was to determine whether these elements can be used as a natural tag for different aquatic environments. Teeth from 2 freshwater dolphins (Inia geoffrensis and Sotalia fluviatilis) and 2 marine species (S. guianensis and Pontoporia blainvillei) from Brazil and Uruguay were analyzed using a Laser Ablation Inductively Coupled Plasma-Mass Spectrometer. Intensity ratios of 138 Ba/ 43 Ca and 86 Sr/ 43 Ca were measured along a line that covered all growth increments in the dentin from the second year of life onwards. Teeth from the freshwater species had mean Ba/Ca values tenfold higher than marine dolphins, confirm- ing the inverse relationship between salinity (and thus ambient Ba/Ca) and elemental ratios in teeth. Furthermore, Ba/Ca ratios could also differentiate dolphins from lower-salinity estuarine areas from those in areas with minimal freshwater discharge. No significant differences were found for Sr/Ca values. Results presented encouraging indications for the application of this tech- nique as a potential new tool for studying habitat use in aquatic mammals.
- Published
- 2015
39. When You Get What You Haven’t Paid for: Molecular Identification of 'Douradinha' Fish Fillets Can Help End the Illegal Use of River Dolphins as Bait in Brazil
- Author
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Antonio M. Solé-Cava, Stella M. Moreira, Teresa E. C. Santos, Vera Maria Ferreira da Silva, Nivia A. S. do Carmo, and Haydée A. Cunha
- Subjects
Dolphins ,Fishing ,Fisheries ,DNA, Mitochondrial ,Rivers ,biology.animal ,Genetics ,Animals ,Food Industry ,Calophysus macropterus ,Molecular Biology ,Catfishes ,Genetics (clinical) ,mtDNA control region ,biology ,Inia geoffrensis ,Amazon rainforest ,Fraud ,Sequence Analysis, DNA ,biology.organism_classification ,Gastrointestinal Contents ,Haven ,Sotalia fluviatilis ,Fishery ,Seafood ,Brazil ,Food Analysis ,Biotechnology ,Catfish - Abstract
The fishery for Calophysus macropterus, an Amazonian necrophagous catfish, is highly detrimental to river dolphins and caimans, which are deliberately killed for use as bait. In the Brazilian Amazon, this fishery has increased over the last decade, in spite of the rejection of scavenger fishes by Brazilian consumers. It was suspected that C. macropterus fillets were being sold in Brazilian markets, disguised as a fictitious fish (the "douradinha"). We collected 62 fillets from "douradinha" and other suspiciously named fish from 4 fish-processing plants sold at 6 markets in Manaus, in the Brazilian Amazon, and sequenced the cytochrome b gene to identify fillets to species. Sixty percent of fillets labeled "douradinha" or with other deceptive names were actually C. macropterus. Six other fish species of low commercial value were also found. The presence of dolphin tissue in the stomach contents of C. macropterus was confirmed by mtDNA control region sequencing. Our results formed the scientific basis for a moratorium on the fishing and fraudulent selling of C. macropterus, issued by the Brazilian Ministries of the Environment and Fisheries. Exposure of this fraud via the mass media can help end the illegal use of dolphins as bait in Brazil.
- Published
- 2015
40. Posterior respiratory apparatus of Inia geoffrensis and Sotalia fluviatilis: structure and ultrastructure
- Author
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Maria Angélica Miglino, Yuri Karaccas de Carvalho, Rose Eli Grassi Rici, Miriam Marmontel, Francisco Glauco de Araújo Santos, and Luzivaldo Castro dos Santos Júnior
- Subjects
Tucuxi ,Inia geoffrensis ,biology.animal ,Amazon river dolphin ,Ultrastructure ,Zoology ,respiratory system ,Anatomy ,Respiratory system ,Biology ,biology.organism_classification ,Sotalia fluviatilis ,ANATOMIA ANIMAL - Abstract
SUMMARY: This study aimed to characterize the structures of the posterior respiratory system of two species of river dolphins: Inia geoffrensis and Sotalia fluviatilis. The respiratory tract of both species was evaluated using macro and microscopic techniques. Four macroscopic anatomical structures were identified: Trachea, main bronchus, tracheal bronchus and lung. The presence of the exuberant tracheal bronchus suggested ease of gas exchanges. Histological analysis revealed the presence of alveolar ducts and myoelastic sphincter in these Amazonian cetaceans. The posterior respiratory portion of the Amazonian dolphins presents similarity with other odontocetes and the knowledge of this structure can also help contribute to the understanding of the physiology of diving and how these species are adapted to their habitat.
- Published
- 2017
41. The dammed river dolphins of Brazil: impacts and conservation
- Author
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John Y. Wang and Claryana C. Araújo
- Subjects
Population fragmentation ,Watershed ,biology ,Inia geoffrensis ,Amazon rainforest ,Ecology ,River dolphin ,biology.organism_classification ,Sotalia fluviatilis ,Fishery ,Habitat destruction ,Geography ,Hydroelectricity ,biology.animal ,Ecology, Evolution, Behavior and Systematics ,Nature and Landscape Conservation - Abstract
A major threat to river dolphins in Brazil is habitat loss and fragmentation as a result of the construction of hydroelectric dams. We examine the degree of overlap between the distributions of two river dolphin species (boto Inia geoffrensis and tucuxi Sotalia fluviatilis) and hydroelectric projects and provide an initial quantification of impacts. The locations of dams were overlaid onto a map of the known distributions of the dolphins. Two types of impacts were evaluated: population fragmentation and effects on prey. For each of these a binary score (for absence or presence) was assigned for each dam. The sum of all impact scores for each dam, in each of the three watersheds in which dolphins are found, including realized and potential impacts, was calculated as the impact index. Thirteen dams affect the distribution of I. geoffrensis (as could a further three dams under construction and seven planned), and three dams affect S. fluviatilis (as could three under construction and two planned). Overall, the impact index was higher for I. geoffrensis than for S. fluviatilis. The Araguaia–Tocantins and North Atlantic watersheds have higher impact index values than the Amazon watershed. Although some impacts of damming could not be considered in this study, our approach was a rapid initial risk assessment that provided an overall understanding of how river dolphins are and may be affected by hydroelectric projects in Brazil. Our method may be applicable to other freshwater cetaceans and species facing similar threats when information about impacts is incomplete.
- Published
- 2014
42. River Dolphin (Inia geoffrensis, Sotalia fluviatilis) Mortality Events Attributed to Artisanal Fisheries in the Western Brazilian Amazon
- Author
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Miriam Marmontel and Verónica Iriarte
- Subjects
Piaractus brachypomus ,Inia geoffrensis ,biology ,Amazon rainforest ,Ecology ,Fishing ,River dolphin ,Artisanal fishing ,Aquatic Science ,biology.organism_classification ,Sotalia fluviatilis ,Fishery ,Geography ,biology.animal ,Animal Science and Zoology ,Calophysus macropterus ,Nature and Landscape Conservation - Abstract
In the Western Brazilian Amazon, interactions of boto (Inia geoffrensis) and tucuxi (Sotalia fluviatilis) dolphins with fishing activities are common, but the prevalence of incidental/intentional catches is not known. This article describes incidental mortality events and intentional killing of I. geoffrensis and S. fluviatilis entangled in artisanal fishing gear and the opportunistic use of carcasses as bait. Between October 2010 and November 2011, surveys were conducted in waters of the lower Japura River, between the Mamiraua and Amana sustainable development reserves. In order to obtain information on interactions and to try to establish a stranding/entanglement response program (SERP), informal conversations were exchanged with local inhabitants (n = 174). Intense carcasssearch surveys (n = 171) along the river in the four hydrological seasons (e.g., low, rising, high, and falling waters) were conducted, comprising a total of 1,197 h of sampling effort. Twenty-five dolphin– fishing interaction events were recorded (11 I. geoffrensis and 14 S. fluviatilis), 19 in 2011 and six in 2012 (through SERP). A total of 11 necropsies (three I. geoffrensis and eight S. fluviatilis) were performed. Four individuals (two I. geoffrensis and two S. fluviatilis) exhibited evidence of physical violence before death, and two (one I. geoffrensis and one S. fluviatilis) died in abandoned gillnets. Two intentional killing events of I. geoffrensis incidentally entangled for bait use in the piracatinga (Calophysus macropterus) fishery were reported by fishermen, while three carcasses (two I. geoffrensis and one S. fluviatilis) with gillnet marks were also used in that activity. At least six of the S. fluviatilis entanglement events occurred in fishing gear used for tambaqui (Colossoma macropomum) and pirapitinga (Piaractus brachypomus) (90/100-mm mesh-size gillnet), two of the most important commercial fish species in the Amazon Basin. As seasonal fishing constitutes the main income for riverine human populations, the negative reactions that cetacean presence causes to people could have a catalyst effect for the transition from “inciden- tal capture” to “intentional capture and competi- tor removal.” Law enforcement and precautionary measures through good fishing practices inside dolphin critical foraging areas should be taken together with fisheries’ managers and fishermen to start to develop multiple-species management and ensure sustainable fishing practices.
- Published
- 2013
43. Fishing activity in Northern Rio de Janeiro State (Brazil) and its relation with small cetaceans
- Author
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Ana Paula Madeira Di Beneditto, Renata Maria Arruda Ramos, and Neuza Rejane Wille Lima
- Subjects
Fishery ,Accidental capture ,Pontoporia blainvillei ,Sotalia fluviatilis ,Biotechnology ,TP248.13-248.65 - Abstract
Research on fishing activity at Atafona village, in Northern Rio de Janeiro, Brazil (21°35'S), was carried out between 1987-96 for the purpose of relating it to the accidental capture of small cetaceans and of estimating the relationship between fishing activity and the diet of small cetaceans. Data on fishing operations were obtained at the cold storage plants management, from interviews with fishermen and personal observations. The most representative fishing resources were Xyphopenaeus kroyeri, Micropogonias furnieri, Carcharhinus plumbeus, C. acronotus,and Rhizoprionodon porosus. Gillnets are responsible for the accidental capture of small cetaceans in the region, mainly Pontoporia blainvillei and Sotalia fluviatilis (marine form). Four types of gillnets that are used on the region ("minjuada", "sarda", "caçoá" and "pescadinha") were dangerous to these species because they are placed in their preferred habitat. There is no competition between fishermen and small cetaceans due to the selection in the capture of commercialized fishesInvestigação sobre a atividade pesqueira na localidade de Atafona, Norte do Rio de Janeiro, Brasil (21º25`S), foi conduzida entre 1987-96 com o objetivo de relacioná-la com a captura acidental e a dieta dos pequenos cetáceos. Dados sobre as operações pesqueiras foram obtidos na administração dos entrepostos de pesca, através de entrevistas com pescadores e observações pessoais. Os recursos pesqueiros mais representativos foram Xyphopenaeus kroyeri, Micropogonias furnieri, Carcharhinus plumbeus, C. acronotus, and Rhizoprionodon porosus. As redes de espera são responsáveis pela captura acidental de pequenos cetáceos na região, principalmente de Pontoporia blainvillei e Sotalia fluviatilis (forma marinha). Quatro tipos de redes de espera que são usadas na região ("minjuada", "sarda", "caçoá" and "pescadinha") foram mais perigosas para essas espécies pois são colocadas no seu hábitat preferencial. Não existe competição entre pescadores e pequenos cetáceos devido à seleção na captura dos peixes comercializados.
- Published
- 1998
- Full Text
- View/download PDF
44. Situación actual de los delfines de río en cuencas hidrográficas amazónicas con presencia de represas
- Author
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González Borasca, Valeria Elena, Trujillo, Fernando, and Portocarrero Aya, Marcela
- Subjects
Sotalia fluviales ,Density estimates ,Inia ,Sub-cuenca ,Nivel de afectación ,Level of concern ,Sotalia fluviatilis ,Cuencas hidrográficas ,Maestría en conservación y uso de biodiversidad - Tesis y disertaciones académicas ,Delfines de río ,Densidades estimadas ,Sub-basin - Abstract
En la actualidad, las hidroeléctricas ubicadas en la cuenca amazónica están afectando a las poblaciones de delfines de distintas formas (transformación del hábitat, reducción de la oferta de alimento y fragmentación de sus poblaciones). En el presente trabajo, se emplearon los resultados obtenidos en las estimaciones de densidad realizadas en distintos ríos amazónicos e información relacionada con la ubicación de represas para la cuenca del Amazonas. Esto permitió conocer dónde están las poblaciones más saludables de los géneros Inia y Sotalia. Se creó un índice para detectar el nivel de afectación para las sub-cuencas que tienen represas en condiciones presentes y/o futuras. Para este análisis se consideraron cuatro variables: distribución y número de especies afectadas, número de represas y el área de inundación. Según el nivel de afectación, la sub-cuenca Tocantins se ubica en primer lugar con una afectación alta, donde habita I. araguaiaensis, en segundo lugar se ubican las subcuencas Madeira (donde habita I. boliviensis), Urucara (donde habita I. geoffrensis) y Amazonas Estuario (donde habitan I. geoffrensis y S. fluviatilis) con una afectación media, en tercer lugar la sub-cuenca Curua- Una con una afectación baja, donde habita I. geoffrensis. Los resultados obtenidos permiten proyectar que la situación para las diferentes especies de delfines de río y sus hábitats continuará empeorando si las represas planeadas ingresan a una fase constructiva debido al creciente aumento en la demanda de energía. Currently, populations of Amazon river dolphins are been affected by hydroelectric projects in several ways (habitat transformation, reduction of food, and population fragmentation). In this article, dolphin density estimates were used from several Amazon rivers and their dams into the Amazon basin. This allowed us to know the healthiest dolphin population of Inia and Sotalia. A health index was created to quantify the level of concern of several sub-basins with present and/or future dams. For this study four variables were considered: (1) distribution of species, (2) the number of affected species, (3) the number of dams and (4) the location of flooded areas. According to the level of concern, Tocantins sub-basin is considered of high concern, where I. araguaiaensis inhabit, it is followed by the sub-basins Madeira (where I. boliviensis inhabit), Urucura (where I. geoffrensis inhabit) and Estuario Amazon (where I. geoffrensis and S. fluviatilis inhabit) which are considered at a level of medium concern. Finally, the sub-basin Curua-Una, where I. geoffrensis inhabit, is considered at a level of low concern. The results obtained allow us to project the potential situation for each species if their habitats continue in their current states. Magíster en Conservación y Uso de la Biodiversidad Maestría
- Published
- 2016
45. Conflicts between river dolphins (Cetacea: Odontoceti) and fisheries in the Central Amazon: a path toward tragedy?
- Author
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Artur Andriolo, Luiz Cláudio Pinto de Sá Alves, and Camilah Antunes Zappes
- Subjects
biology ,Inia geoffrensis ,Amazon rainforest ,Fishing ,Cetacea ,biology.organism_classification ,Sotalia fluviatilis ,Fishery ,Geography ,biology.animal ,piracatinga ,lcsh:Zoology ,Amazon river dolphins ,fisheries interactions ,%22">Fish ,Tragedy (event) ,Animal Science and Zoology ,lcsh:QL1-991 ,Calophysus macropterus - Abstract
Dolphin interactions with fishermen have increased significantly and pose potential risks to the boto, Inia geoffrensis (Blainville, 1817), and the tucuxi, Sotalia fluviatilis (Gervais & Deville, 1853). The main objective of the present paper was to describe the existing conflicts between river dolphins and fishermen in the municipality of Manacapuru region. Sixteen fishermen were interviewed in Manacapuru, state of Amazonas, Brazil who described a situation of ongoing conflict that may be unsustainable. Two merchants from Manacapuru made unconfirmed reports on a boto carcass trade. Data collection for this study occurred between April 20th and April 25th, 2009, but the first author had been conducting research on river dolphins and fisheries in Manacapuru and nearby cities since the beginning of 2008, in order to gain the trust of the fishermen interviewed. The hunting and deliberate killing of the species is probably more threatening to botos than their incidental capture in fishing gears in the Manacapuru region. This practice may result from the fact that dolphins are prone to damaging fishing equipment, and stealing (and possibly damaging) fish from the nets. They are portrayed negatively in numerous myths and superstitions of traditional Amazonian folklore, making them extremely undesired or even hated, seen as pests, and used in the piracatinga, Calophysus macropterus (Lichtenstein, 1819) fishery as bait. For tucuxis, incidental capture still represents the major threat to their conservation in the region evaluated here.
- Published
- 2012
46. Sternum and appendicular skeleton: morphometric differences between the species of genus Sotalia (Cetacea: Delphinidae)
- Author
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Marcelo José Sanches da Rocha, V. M. F. da Silva, Daniela de Castro Fettuccia, and Paulo C. Simões-Lopes
- Subjects
Osteology ,biology ,Appendicular skeleton ,Sotalia guianensis ,Postcrania ,Zoology ,Anatomy ,Aquatic Science ,Sternum (arthropod anatomy) ,biology.organism_classification ,Sotalia fluviatilis ,medicine.anatomical_structure ,Genus ,biology.animal ,medicine ,Flipper - Abstract
Two distinct species have been recently recognized for the genus Sotalia: S. fluviatilis, occurring in the Amazon River basin, and S. guianensis, from Honduras (15°58′N and 85°42′W) to Santa Catarina State (Florianópolis, southern Brazil—27°35′S and 48°34′W). For the first time the sternum and the appendicular skeleton of the two species of the genus Sotalia are compared. A comparative osteological work was performed with marine samples (from the States of Ceará, north-eastern and Santa Catarina, southern regions of Brazil) and riverine samples (Amazonas State) in relation to metric characters (scapula, flipper and sternum). There was a clear distinction of two species in relation to postcranial skeleton in the morphometric analysis (canonical variate analysis) presented. The flipper and the glenoid cavity of the scapula were proportionally wider in the fluvial species. The sternum, however, was smaller in this species in relation to the maximum width of the manubrium. Nevertheless, this structure still needs to be further studied.
- Published
- 2012
47. Ecological factors influencing group sizes of river dolphins (Inia geoffrensis and Sotalia fluviatilis)
- Author
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Catalina Gomez-Salazar, Fernando Trujillo, and Hal Whitehead
- Subjects
geography.geographical_feature_category ,Inia geoffrensis ,biology ,Flood myth ,Ecology ,Inia ,Drainage basin ,Aquatic Science ,biology.organism_classification ,Sotalia fluviatilis ,Fishery ,Geography ,Productivity (ecology) ,biology.animal ,parasitic diseases ,Tributary ,Ecosystem ,Ecology, Evolution, Behavior and Systematics - Abstract
Living in groups is usually driven by predation and competition for resources. River dolphins do not have natural predators but inhabit dynamic systems with predictable seasonal shifts. These ecological features may provide some insight into the forces driving group formation and help us to answer questions such as why river dolphins have some of the smallest group sizes of cetaceans, and why group sizes vary with time and place. We analyzed observations of group size for Inia and Sotalia over a 9 yr period. In the Amazon, largest group sizes occurred in main rivers and lakes, particularly during the low water season when resources are concentrated; smaller group sizes occurred in constricted waters (channels, tributaries, and confluences) that receive an influx of blackwaters that are poor in nutrients and sediments. In the Orinoco, the largest group sizes occurred during the transitional water season when the aquatic productivity increases. The largest group size of Inia occurred in the Orinoco location that contains the influx of two highly productive whitewater rivers. Flood pulses govern productivity and major biological factors of these river basins. Any threats to flood pulses will likely have an effect on the functionality of these ecosystems and the species living in them.
- Published
- 2011
48. Population, density estimates, and conservation of river dolphins (Inia and Sotalia) in the Amazon and Orinoco river basins
- Author
-
Hal Whitehead, Catalina Gomez-Salazar, Marcela Portocarrero-Aya, and Fernando Trujillo
- Subjects
education.field_of_study ,geography.geographical_feature_category ,biology ,Inia geoffrensis ,Amazon rainforest ,Inia ,Population ,Drainage basin ,River dolphin ,Aquatic Science ,biology.organism_classification ,Sotalia fluviatilis ,Fishery ,Geography ,biology.animal ,Tributary ,education ,Ecology, Evolution, Behavior and Systematics - Abstract
This study is part of an on-going effort to evaluate and monitor river dolphin populations in South America. It comprises the largest initiative to estimate population size and densities of Inia and Sotalia dolphins using statistically robust and standardized methods. From May 2006 to August 2007, seven visual surveys were conducted in selected large rivers of Bolivia, Colombia, Brazil, Ecuador, Peru, and Venezuela in the Amazon and Orinoco river basins. Population sizes of Inia and Sotalia were estimated for different habitats (main river, tributary, lake, island, confluence, and channel). A total of 291 line and 890 strip transects were conducted, covering a distance of 2,704 linear kilometers. We observed 778 Inia geoffrensis ,1 ,323Inia boliviensis ,a nd 764Sotalia fluviatilis .H igh-density areas were identified (within 200 m from the river banks, confluences, and lakes) and we propose that these constitute critical habitat for river dolphins. High densities of river
- Published
- 2011
49. Frequência de Avistamentos do Boto Tucuxi, Sotalia fluviatilis (Odontoceti: Delphinidae) em Área de Entorno da Ilha de Santana, Macapá, Amapá, Brasil
- Author
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Carlos Eduardo Costa Campos, Andréa Soares Araújo, and Luana Caroline de Souza Barroso
- Subjects
Frequency of occurrence ,biology ,Tucuxi Dolphins ,Ecology ,Pharmaceutical Science ,Zoology ,Sotalia fluviatilis ,Geography ,lcsh:Biology (General) ,Complementary and alternative medicine ,biology.animal ,Pharmacology (medical) ,lcsh:QH301-705.5 ,Amazon basin - Abstract
Sotalia fluviatilis conhecido como boto tucuxi é considerado o único delfinídeo exclusivamente fluvial e de acordo com o IBAMA, é classificada como espécie de “Dados insuficientes”. O objetivo do presente trabalho é descrever a frequência de ocorrência da espécie S. fluviatilis no Porto do Açaí, em Santana, Amapá. O estudo foi realizado através de observações in loco e contagem de observações dos indivíduos. Durante três meses de atividade em campo por 4 horas semanais, houve 102 avistamentos, o que sugere uma preferência de habitat desses animais na referida área de estudo. Palavras-chave: Sotalia fluviatilis; Delphinidae; bacia Amazônica. DOI: http://dx.doi.org/10.18561/2179-5746/biotaamazonia.v4n1p143-145
- Published
- 2014
50. Both cetaceans in the Brazilian Amazon show sustained, profound population declines over two decades
- Author
-
Anthony R. Martin, Vera M. F. da Silva, Rodrigo L. Dias, and Carlos Edwar de Carvalho Freitas
- Subjects
0106 biological sciences ,Population Dynamics ,Marine and Aquatic Sciences ,lcsh:Medicine ,Fresh Water ,01 natural sciences ,Geographical locations ,IUCN Red List ,lcsh:Science ,Mammals ,Animalss ,Data deficient ,education.field_of_study ,Multidisciplinary ,Ecology ,Geography ,biology ,Inia geoffrensis ,Amazon rainforest ,Statistical Model ,River dolphin ,Eukaryota ,Agriculture ,Sotalia fluviatilis ,Freshwater Fish ,Survival Rate ,Vertebrates ,Brazil ,Research Article ,Freshwater Environments ,Dolphins ,Population ,Fisheries ,Marine Biology ,Environment ,010603 evolutionary biology ,Rivers ,Surface Water ,biology.animal ,Pressure ,Animals ,Toothed Whale ,Marine Mammals ,Population Growth ,education ,Population Density ,Models, Statistical ,Brasil ,010604 marine biology & hydrobiology ,Ecology and Environmental Sciences ,lcsh:R ,Organisms ,Biology and Life Sciences ,Aquatic Environments ,Bodies of Water ,South America ,Nonhuman ,biology.organism_classification ,Fishery ,Lakes ,Fish ,Amniotes ,Earth Sciences ,Conservation status ,lcsh:Q ,Cetacea ,People and places ,Hydrology ,human activities - Abstract
Obligate river dolphins occur only in the rivers of Asia and South America, where they are increasingly subject to damaging pressures such as habitat degradation, food competition and entanglement in fishing gear as human populations expand. The Amazon basin hosts two, very different, dolphins—the boto or Amazon river dolphin (Inia geoffrensis) and the smaller tucuxi (Sotalia fluviatilis). Both species have wide geographical ranges and were once considered to be relatively abundant. Their IUCN Red List conservation status of Data Deficient (DD), due to limited information on threats, ecology, population numbers and trends, did not initially cause alarm. However, the development of dolphin hunting to provide fish bait at around the beginning of this millennium broadly coincided with the onset of a widespread perception that numbers of both species were in decline. Consequently, the need for population trend data to inform conservation advice and measures became urgent. This paper presents a 22-year time series of standardised surveys for both dolphins within the Mamirauá Reserve, Amazonas State, Brazil. Analysis of these data show that both species are in steep decline, with their populations halving every 10 years (botos) and 9 years (tucuxis) at current rates. These results are consistent with published, independent information on survival rates of botos in this area, which demonstrated a substantial drop in annual survival, commencing at around the year 2000. Mamirauá is a protected area, and is subject to fewer environmental pressures than elsewhere in the region, so there is no reason to suspect that the decline in dolphins within the Reserve is more pronounced than outside it. If South America’s freshwater cetaceans are to avoid following their Asian counterparts on the path to a perilous conservation status, effective conservation measures are required immediately. Enforcement of existing fishery laws would greatly assist in achieving this. © 2018 F. da Silva et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
- Published
- 2018
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