Miriam Marmontel

Instituto de Desenvolvimento Sustentável Mamirauá | MAMIRAUA · Science

For many species at risk, monitoring challenges related to low visual detectability and elusive behavior limit the use of traditional visual surveys to collect critical information, hindering the development of sound conservation strategies. Passive acoustics can cost‐effectively acquire terrestrial and underwater long‐term data. However, to extrac...

In 2023, an unprecedented drought and heatwave severely impacted Amazon waters, leading to high mortality of fishes and river dolphins. Five of 10 lakes monitored showed exceptionally high daytime temperatures (>37°C), with one large lake reaching up to 41°C in the entire ~2-m deep water column, with up to 13°C of diel variation. Modeling show that...

1. While cetaceans are known to produce large and complex acoustic repertoires, the challenges of exhaustively sampling sounds at sea and counting relevant signals has precluded an understanding of their true repertoire diversity. 2. Here we quantify and compare the whistle repertoires of 16 populations in the genus Sotalia, belonging to two sister...

From September-December 2023, a unprecedent, unusual mortality event (UME) affecting Amazon River Dolphins (Inia geoffrensis) and tucuxis (Sotalia fluviatillis) was registered in Lake Tefé (n = 155) and Lake Coari (n = 121) (Amazonas State, Brazil). To respond to this UME, an emergency was installed by the Chico Mendes Institute for Biodiversit...

Trichechus manatus is one of 3 recognized extant species of manatees of the mammalian Order Sirenia. Currently, it is known by various vernacular names, none of which are descriptive of its biology and known distribution. This lack of standardization has led to confusion and miscommunication, hindering conservation efforts for this species. We prop...

We conducted a study to characterize the nutritional composition of the main aquatic herbaceous plants in two protected areas within the Central Amazon. Our investigation aimed to evaluate possible nutritional variations in these plant species between two floodplains contrasting in fertility throughout the annual hydrological cycle and to examine i...

The escalating impacts of climate change on river ecosystems have brought unprecedented challenges to the survival of river dolphins, exemplified by the devastating Tefe, Brazil drought, which claimed the lives of over 160 Amazon River and Sotalia dolphins. Amidst these crises, Dolphinaria, equipped with hands-on expertise in veterinary medicine, h...

The investigation of tooth wear and pathology in freshwater dolphins can increase our understanding of their life history, including interactions with the environment and impacts of disease and morbidity. This paper evaluated the occurrence, prevalence and discussed the putative etiology of dental wear and pathology in freshwater dolphins - tucuxi...

Interspecific hybridization has been historically neglected in research and conservation practice, but it is a common phenomenon in nature, and several models have been developed to characterize it genetically. Even though Trichechus inunguis (Amazonian manatee) and T. manatus (West Indian manatee) exhibit large morphological, karyotypic, and molec...

In this chapter, we consider pathways to work for a future for Amazonia where both humans and other mammals flourish and the rainforest is protected. First we briefly review the tens of millions of years it has taken to develop the current diversity of mammalian fauna living in Amazonia. Humans are a very recent mam-malian arrival to Amazonia at ab...

Environmental contamination due to the discard of organic and inorganic chemicals into freshwater systems is currently a worldwide threat to wildlife, including in remote areas of the Amazon basin. Mercury, cadmium, lead, aluminum, arsenic, chromium, copper, iron, manganese, and zinc were evaluated in terms of their toxicity to five genera of Amazo...

The catastrophic heatwave and drought that hit the Amazon at the end of last year (see L. Santos de Lima et al. Nature 622, 697; 2023) has led to the unprecedented mortality of hundreds of its river dolphins. A better understanding of how climate change affects biodiversity in tropical water bodies is needed for more effective management of these s...

Abstract The Antillean manatee occurs discontinuously from the state of Amapá to the state of Alagoas on the coast of Brazil. There is also evidence of reintroduced manatees using the coasts of Sergipe and Bahia, with a preference for calm shallow waters. This study characterized the home range areas of six rehabilitated manatees released in northe...

Bolivian Amazon small-scale fisheries traditionally focus on large migratory fish species. However, in the last decade there has been a trend of increased landings of low-value medium-sized migratory species, such as blanquillo, Calophysus macropterus. This scavenger species is captured using chicken and bovine waste as bait, and occasionally carca...

Freshwater cetaceans play a significant role as sentinel animals, providing important data on animal species and aquatic ecosystem health. They also may serve as potential reservoirs of emerging pathogens and host virulence genes in their microbiota. In this study, we evaluated virulence factors produced by Gram-negative bacteria recovered from ind...

conducted on wild manatees, 21,5% under human care conditions, and the rest a combination of both; the most common topics of study were 'ecology', 'conservation', 'morphology, anatomy and physiology', and 'behavior'. The literature on Antillean manatee has expanded significantly over the last two decades across the region, with most of the research...

We conducted a retrospective bibliometric analysis of the Latin American Journal of Aquatic Mammals (LAJAM), the scholarly publication of the Latin American Society of Specialists of Specialists in Aquatic Mammals (SOLAMAC) for the last 20 years. The goal was to describe the state of the research, trends, changes, and priorities to provide a deeper...

The last relevant work that reviewed the biological and conservation aspects of the Amazonian manatee (Trichechus inunguis) was published almost 30 years ago. In these three decades, scientific knowledge about the species has advanced substantially. This review article updates knowledge about the various biological and conservation aspects of Amazo...

Hemotropic Mycoplasma spp. (hemoplasmas) are uncultivable bacteria that infect mammals, including humans. We detected a potentially novel hemoplasma species in blood samples from wild river dolphins in the Amazon River Basin, Brazil. Further investigation could determine pathogenicity and zoonotic potential of the detected hemoplasma.

The Amazonian manatee has been hunted since antiquity and is part of local culture and tradition. Although protected by law, manatees continue to be hunted for food and trade. In most regions where the species occurs, there are no reliable data on current hunting pressure. In addition, difficulty in determining its abundance prevents the definition...

River cetaceans are particularly vulnerable to anthropogenic impacts due to their constrained ranges in freshwater systems of China, South Asia, and South America. We undertook an exhaustive review of 280 peer-reviewed papers and grey literature reports (1998−2020) to examine the current status of knowledge regarding these cetaceans and their conse...

The Amazon forest has the highest biodiversity on Earth. However, information on Amazonian vertebrate diversity is still deficient and scattered across the published, peer‐reviewed, and gray literature and in unpublished raw data. Camera traps are an effective non‐invasive method of surveying vertebrates, applicable to different scales of time and...

The Amazon forest has the highest biodiversity on Earth. However, information on Amazonian vertebrate diversity is still deficient and scattered across the published, peer-reviewed, and gray literature and in unpublished raw data. Camera traps are an effective non-invasive method of surveying vertebrates, applicable to different scales of time and...

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-ra...

River dolphins from the genus Inia are widely distributed in the Amazon, Orinoco and Tocantins River basins. Current knowledge on the dietary habits of these species is poor and based on stomach contents from stranded animals. We used carbon and nitrogen stable isotopes to evaluate the diet preferences and trophic niche of the boto (Inia geoffrensi...

Sirenian social and reproductive behaviors lack much complexity or diversity. Whereas sirenians are usually sighted as solitary, or as cows with single calves, aggregations of many individuals can occur. Persistent social groupings are unknown. Home ranges are widely overlapping. Mating systems of dugongs (Dugong dugon) have been variously describe...

Sirenians are culturally significant to traditional and contemporary human communities throughout their ranges. They live in tropical and sub-tropical coastal, riverine, and lacustrine habitats, including many sites of high human use. Manatees and dugongs nurse their calves over prolonged periods via axillary teats and their mammary glands have oft...

Threats to aquatic mammals may occur in isolation or in combination, leading to cumulative effects on populations and their ecosystems. Thus, conservation actions must consider the complexity of factors involved in patterns of habitat use, including feeding ecology, such as ontogenetic, spatial and temporal dietary shifts. The Amazonian manatee ( T...

Provisioning food to wildlife is a strategy used to habituate animals to human proximity during tourism activities, but it can contribute to changes in individual behavior and social structure and impacts on the nutritional health status. This article evaluates the presence and relationships of Amazon River dolphins (Inia geoffrensis) in feeding se...

Sirenians have a unique ecological function in coastal ecosystems, deserving special conservation attention. The West Indian manatee (Trichechus manatus) is globally classified as Vulnerable by the IUCN. In Brazil, where the species was intensively hunted in the past and currently faces several threats, it was classified as Endangered during the la...

Abstract The inadequate choice of a diagnostic method or the option for techniques that have low sensitivity and specificity may limit the diagnosis of parasitic agents that affect aquatic mammals. The aim of this study was to evaluate the performance of the FLOTAC technique and compare it with three traditional methods (Willis, sedimentation and c...

The distribution of the Vulnerable West Indian manatee Trichechus manatus is influenced by physical and environmental factors such as water salinity, temperature and depth, freshwater supply and the availability of food resources. In Brazil, information on the habitat use of this species is insufficient for effective conservation. Here, we monitore...

River dolphins are a highly threatened polyphyletic group comprised of four odontocete families: Iniidae, Pontoporiidae, Lipotidae, and Platanistidae, the first two endemic to South America. To address the knowledge gap regarding infectious agents in this cetacean group, we surveyed the presence of herpesviruses by PCR in skin and/or blood samples...

The 2030 Agenda was set in 2015 by the United Nations, with 17 Sustainable Development Goals. The Amazonian riverine people are recognized as traditional communities that have their own culture and use the local natural resources of their territories in an ancestral and traditional way. The Sustainable Development Reserve is a Brazilian protected a...

To optimize the health evaluation of Giant and Neotropical otters in the wild and under human care and to guarantee the quality of the information collected and maximize efforts in research projects, Brazilian veterinarians developed two protocols: 1) Protocol for collection, processing and storage of biological samples from live Giant and Neotropi...

Studies on the microbiota of freshwater cetaceans are scarce and may provide important data on animal and environmental health. This study aimed to evaluate the antimicrobial susceptibility of Gram-negative bacteria recovered from two populations of free-ranging Amazon river dolphins (Inia geoffrensis). Twenty-one animals were captured and released...

The dolphins Inia geoffrensis-boto and Sotalia fluviatilis-tucuxi are threatened cetaceans inhabiting river ecosystems in South America; population numbers are still lacking for many areas. This paper provides density and abundance estimations of boto and tucuxi in 15 rivers sampled during the past nine years as part of a multinational research all...

Supplementary Castelblanco-Martínez, D. N., Slone, D. H., Landeo-Yauri, S. S., Ramos, E. A., Alvarez-Alemán, A., Attademo, F. L. N., Beck, C. A., Bonde, R. K., Butler, S. M., Cabrias-Contreras, L. J., Caicedo-Herrera, D., Galves, J., Gómez-Camelo, I. V., González-Socoloske, D., Jiménez-Domínguez, D., Luna, F. O., Mona-Sanabria, Y., Morales-Vela, J...

Studying the variables that describe the spatial ecology of threatened species allows us to identify and prioritize areas that are critical for species conservation. To estimate the home range and core area of the Endangered (EN) Amazon river dolphin Inia geoffrensis , 23 individuals (6♀, 17♂) were tagged during the rising water period...

Estuaries in Brazil are highly threatened environments and habitat loss is the main influential factor for the increase in the number of strandings of Antillean manatee (Trichechus manatus) calves in the north-eastern region of the country. The aim of the present study was to analyse and quantify the spatiotemporal dynamics of mangroves in the stat...

Stranded cetaceans (whales, dolphins, and porpoises) are frequently used to obtain data on species occurrence and demographic trends. Accurate species-level identification of these individuals is crucial, but often challenging or impossible when relying solely on morphological features (e.g., for highly decayed specimens). To aid in the development...

The manatee family encompasses three extant congeneric species: Trichechus senegalensis (African manatee), T. inunguis (Amazonian manatee), and T. manatus (West Indian manatee). The fossil record for manatees is scant, and few phylogenetic studies have focused on their evolutionary history. We use full mitogenomes of all extant manatee species to i...

This study assessed the nutritional composition of 31 food items consumed by Antillean manatees in the estuary of the Mamanguape River Mouth, state of Paraiba, northeastern Brazil. Samples were collected during dry and rainy seasons, and analysed levels of dry matter, crude protein, neutral detergent fiber, acid detergent fiber and mineral matter....

River dolphins in South America face a high number of threats, most of them of anthropogenic origin (Trujillo et al., 2010). Among those, the most worrisome are the negative interactions with fisheries and the illegal capture of individuals for use as bait in piracatinga Calophysus macropterus fishing (Estupiñán et al., 2003; Flores et al., 2008; G...

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 dolp...

Araguaian botos (Inia araguaiaensis) are known to produce pulsed as well as tonal sounds. This study documents the first evidence for repetitive sequences of downsweep whistles in botos that appear to be shared between individuals, and the context of their occurrence is investigated. Boat surveys were conducted along the Tocantins River located in...

Side-scan sonar (SSS) has been successfully used to detect West Indian and African manatees, however confirmed sonar images of Amazonian manatees have not been obtained yet. One potential difficulty is differentiating manatee images from other large aquatic vertebrates. The Amazonian manatee shares most of its habitat with two cetaceans, the Amazon...

Manatees (Trichechus spp.) are herbivorous aquatic mammals found in warm waters. At maturity, they possess only supernumerary molars (SM), with 5-8 in occlusion in each quadrant. Manatees exhibit a dental replacement system in which they shed old teeth anteriorly and erupt new teeth posteriorly. This adaptation is thought to have arisen to deal wit...

In the Amazon and Orinoco basins, mercury has been released from artisanal and industrial gold mining since the Colonial time, as well as a result of deforestation and burning of primary forest, that release natural deposits of methyl mercury, affecting the local aquatic vertebrate fauna. This study reports the presence of mercury in river dolphins...

Humpback whales have a cosmopolitan distribution and undertake annual migrations between low and high latitudes where breeding and feeding takes place, respectively. In Brazil, the main breeding area encompasses the Abrolhos Bank at the Eastern Brazilian Coast and the feeding area of this population is located in South Georgia and South Sandwich Is...

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 surve...

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 surve...

The West Indian (Trichechus manatus) and Amazonian (T. inunguis) manatees have a sympatric occurrence at the mouth of the Amazon River. A result of this interspecific encounter is the occurrence of hybrids, which are frequently found along the coasts of Amapá state in Brazil, French Guiana and Guyana. Here we present new genetic evidence indicating...

The recent discovery of the Araguaian river dolphin (Inia araguaiaensis) highlights how little we know about the diversity and biology of river dolphins. In this study, we described the acoustic repertoire of this newly discovered species in concert with their behaviour. We analysed frequency contours of 727 signals (sampled at 10 ms temporal resol...

Tonal whistle produced by an Araguaian boto and the longest sound in our recordings

Short call with no non-linear phenomena produced by an Araguaian boto

Short two-component calls produced by an Araguaian boto calf

Short calls with subharmonics produced by an Araguaian boto