Long-Term Monitoring of Dolphins in a Large Estuarine System of Southeastern Brazil

Monteiro‐Filho, Emygdio L. A.; Deconto, Lucimary S.; Louzada, Caio Noritake; Wanderley, Rebeca Pires; Godoy, Daniela Ferro de; Medeiros, Eric

doi:10.1007/978-3-319-56985-7_2

Cited by 6 publications

(7 citation statements)

References 29 publications

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“…The persistence of the species throughout the year indicates that the environment offers sufficient resources for the population (Hardt et al ., 2010; Monteiro-Filho et al ., 2018). Residency is common for this species throughout its distribution, as observed in Caravelas (Rossi-Santos et al ., 2007), Baía de Sepetiba (Campos et al ., 2004), Baía de Babitonga (Hardt et al ., 2010; Cremer et al ., 2011), Costa Rica (Gamboa-Poveda and May-Collado, 2006) and the Gulf of Venezuela (Espinoza-Rodríguez et al ., 2019).…”

Section: Discussionmentioning

confidence: 99%

“…Over the last decades, studies addressing ecological and reproductive parameters, abundance and population density of S. guianensis throughout its distribution have intensified (Borobia et al ., 1991; Lodi and Hetzel, 1998; Geise et al ., 1999; Ramos et al ., 2000; Rollo, 2002; Rosas and Monteiro-Filho, 2002; Rosas et al ., 2003; Di Beneditto and Ramos, 2004; Araújo et al ., 2007; Crespo et al ., 2010; Da Silva et al ., 2010; Hardt et al ., 2010; Santos et al ., 2010 a ; Havukainen et al ., 2011; Lima et al ., 2017; Monteiro-Filho et al ., 2018; Santos et al ., 2019; Tardin et al ., 2020). The distance sampling method has been widely used and recommended for estimating the density and abundance of cetacean species and all sorts of biological populations (Thomas et al ., 2002).…”

Section: Introductionmentioning

confidence: 99%

“…Different populations of the species have been accessed for these data in Brazil, at the Baía do Emboraí (Pará state), Baía de Guanabara and Baía de Sepetiba (Rio de Janeiro state), Cananéia estuary (São Paulo state), Paranaguá and Guaratuba estuaries (Paraná state) and Baía de Babitonga (Santa Catarina state) (Santos et al ., 2010 a ; Azevedo et al ., 2017; Monteiro-Filho et al ., 2018). Population estimates are also available for Venezuela (Gulf of Venezuela), Colombia (Gulf of Morrosquillo) and Nicaragua (Miskito Cayos Reserve) (Santos et al ., 2010 a ; Espinoza-Rodríguez et al ., 2019).…”

Section: Introductionmentioning

confidence: 99%

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Assessing Guiana dolphin abundance and density in the Southwestern Atlantic: insights from conservation areas

Almeida¹,

Percequillo²,

Rollo³

2023

J. Mar. Biol. Ass.

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Accurate demographic data play a critical role in implementing conservation strategies and identifying key areas for species preservation. The population abundance and density of Sotalia guianensis were estimated in the estuarine-lagoon complex of Cananéia, Brazil, using distance sampling. The survey covered 1339.91 km with 83 h 05 min in effort. A half-normal model with cosine adjustments was evaluated as the best fit to estimate an abundance of 193 individuals (95% CI 158–237) and a density of 2.55 ind km−2. The majority of sightings occurred in the Baía de Trapandé (48.72%), followed by the Mar de Cananéia (32.72%) and Mar de Cubatão (18.56%), the three areas surrounding the Ilha de Cananéia. The study confirmed the heterogeneous distribution of the estuary and found that the Mar de Cananéia and the Baía de Trapandé were more densely populated, with 2.76 ind km−2 (95% CI 1.93–3.96) and 2.76 ind km−2 (95% CI 2.07–3.66), respectively, while the Mar de Cubatão was less densely populated, with 1.59 ind km−2 (95% CI 1.04–2.44). The findings support previous research indicating a stable population over the last few decades. The Cananéia estuary is an ecologically diverse region located between protected areas under different categories of environmental protection and harbours a significant population of S. guianensis, providing essential resources for feeding and breeding. Protected areas have proven to be effective tools for preserving both marine and terrestrial environments. Despite the close proximity to humans and constant threats, the study underscores the importance of the area for the conservation of the species.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Assessing Guiana dolphin abundance and density in the Southwestern Atlantic: insights from conservation areas

Almeida¹,

Percequillo²,

Rollo³

2023

J. Mar. Biol. Ass.

View full text Add to dashboard Cite

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“…Finally, we recommend integrating PAM and visual surveys on habitat use with research on animal activity. Long‐term PAM on cetacean activity has been applied in marine environments (Fang et al, 2015; Munger et al, 2016; Dong et al, 2017; Monteiro‐Filho et al, 2018; Nuuttila et al, 2018). In river environments, the implementation of long‐term PAM can help fill gaps in visual surveys by providing detailed information on the seasonal and diel activities of riverine cetaceans, especially in waters where visual surveys are prone to false‐absence, such as areas where animal activities are low or mainly occur during nighttime.…”

Section: Discussionmentioning

confidence: 99%

Seasonal and diel activities of the Yangtze finless porpoise in natural and highly disturbed habitats: Implications for conservation planning of freshwater cetaceans

Chen

Wang

et al. 2022

Aquatic Conservation

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1. Knowledge of fine-scale seasonal and diel activity patterns of animals provides insights into habitat utilization dynamics and informs conservation action planning against potential human impacts. Such information is particularly important for riverine cetaceans, such as the Yangtze finless porpoise, which is threatened by habitat loss and disturbances by a variety of human activities.2. Passive acoustic monitoring (PAM) techniques were used to survey the seasonal and diel activities of the Yangtze finless porpoise in two natural habitat patches of the Anqing Yangtze Finless Porpoise Natural Reserve, and in one highly disturbed area adjacent to the reserve.3. In the two natural habitat patches, significantly higher detection rates of porpoises were observed during autumn and winter. The detection rates during

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“…Estuaries are ecologically significant habitats for many marine mammal species (Harzen, 1998; Jefferson & Hung, 2004; Grigg, 2008; Rodriguez et al, 2013; Hornby et al, 2016). The sheltered nature and high productivity of estuaries has led to many estuaries providing key foraging and nursing habitat for coastal delphinids, such as Guiana dolphin Sotalia guianensis (Berrow et al, 2002; De Oliveira Santos & Rosso, 2008; Monteiro‐Filho et al, 2018), bottlenose dolphin Tursiops truncatus (Gubbins, 2002), and Indo‐Pacific humpback dolphins Sousa chinensis (Jefferson & Hung, 2004; Chen et al, 2016). Estuaries are also important human habitat, with a substantial proportion of the human population living within or near an estuary (including some of the world's largest cities, such as Shanghai, San Francisco, and Hong Kong).…”

Section: Introductionmentioning

confidence: 99%

Monitoring Indo‐Pacific humpback dolphin occurrences in a highly urbanized estuary for informing conservation and management

Fang

Lin

Guo

et al. 2020

Aquatic Conservation

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The estuaries within the Pearl River Delta are sites for large‐scale urban development and offshore construction. These projects have conservation stakeholders calling for more protection for the Indo‐Pacific humpback dolphins whose habitat overlaps with current and proposed construction sites. Efforts to improve impact assessments are hindered by the lack of baseline data and comprehensive understanding of how often the dolphins are present in areas near or within locations targeted for further development. The Modaomen Estuary within the Pearl River Delta is a good example of this, with little consideration for the dolphins as no data on their diurnal and seasonal occurrences within the estuary exist. A passive acoustic monitoring system was deployed over a calendar year from October 2016 to September 2017 to monitor the presence of humpback dolphins in the Modaomen Estuary. Results indicated that the estuary is an important area for humpback dolphins, with regular diel rhythms and seasonality in detection rates. For example, higher detections were seen during the wet season than during the dry season. However, there was no significant difference in detection rates between the flood and ebb tides, or between high and low tidal phases. Since the Modaomen Estuary is targeted for further development in the near future, these data provide the rationale for resource management and consent processes to consider potential impacts on the dolphins, as well as to aid marine spatial planning and conservation measures.

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Long-Term Monitoring of Dolphins in a Large Estuarine System of Southeastern Brazil

Cited by 6 publications

References 29 publications

Assessing Guiana dolphin abundance and density in the Southwestern Atlantic: insights from conservation areas

Assessing Guiana dolphin abundance and density in the Southwestern Atlantic: insights from conservation areas

Seasonal and diel activities of the Yangtze finless porpoise in natural and highly disturbed habitats: Implications for conservation planning of freshwater cetaceans

Monitoring Indo‐Pacific humpback dolphin occurrences in a highly urbanized estuary for informing conservation and management

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