Latin American Journal of Aquatic Mammals (LAJAM)
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Perceptions on the distribution, threats, strandings, and conservation of the Antillean manatee (Trichechus manatus manatus) in the Río Dulce National Park, Izabal, Guatemala
No full textThe Antillean manatee in Guatemala faces multiple threats resulting from habitat loss and human interactions such as motorboat collisions and poaching. While some conservation efforts have been initiated in Río Dulce National Park (RDNP), there is a lack of studies examining the current perceptions of threats to the species. This knowledge gap may hinder the development of effective conservation strategies that consider both the species and local communities. Our objective was to analyze the perceptions of key local stakeholders concerning the Antillean manatee, including its distribution, threats, attention to strandings, and the current status of conservation in the protected area of RDNP. From July to October 2019, we conducted 50 semi-structured interviews with technicians and river users, such as fishermen and boat captains. Additionally, we held two workshops: one aimed at developing a participatory mapping exercise and another to validate the information. Each workshop was divided into two groups: one for technicians and another for river users. A total of 68 people participated in the workshops, the majority of respondents were male (n = 47), ranging in age from 19 to 71, and predominantly local to the area. Their activities in the river included fishing, biological monitoring, transportation, and providing tourism services. Perceived threats to the Antillean manatee included motorboat collisions, poaching, bycatch, habitat degradation, and water pollution. The focus groups also identified key observations, such as mother-calf sightings, specific areas of risk for manatee-boat collisions, areas with a higher presence of aquatic vegetation, and additional threats such as habitat degradation and poaching. Our results demonstrate that stakeholders possess a fundamental understanding of the manatee, its threats, and its distribution. They also highlight a noticeable lack of knowledge, specifically regarding the attention given to manatee strandings. It is recommended that conservation strategies include environmental education adapted to local conditions, as well as the promotion of manatee studies and their dissemination at the local level, including attention to strandings in the area
Downsweep calls attributed to sei whales, Balaenoptera borealis, in Ilhabela, São Paulo, Brazil
No full textArtificial intelligence improves the identification of fur seals recorded at Southern Brazilian coast
No full textThe genus Arctocephalus represents the group of fur seals that mainly inhabit the Southern Hemisphere. In general, Arctocephalus species are extremely similar in appearance, often making it very difficult to impossible to distinguish them only by characteristics of their external morphology. In this context, it is important to find new tools to differentiate them, especially in locations outside of their traditional distribution area, such as Brazilian waters, in order to take appropriate actions for their management. This study proposes the use of an artificial intelligence method, based on machine learning and convolutional neural networks, to classify and identify three species of southern fur seals by analysing 121 facial images from living specimens of Arctocephalus australis, A. gazella, and A. tropicalis found on the Brazilian coast. The image database
Keywords:
citizen science convolutional neural networks, machine learning, pinnipeds
Pseudomonas aeruginosa sepsis in a neonate Franciscana dolphin (Pontoporia blainvillei): clinical approach and laboratory findings
No full textA neonate (4,2 kg and 71 cm total body length) female Franciscana dolphin, Pontoporia blainvillei, was found stranded alive on a beach in Santa Catarina, Southern Brazil, with respiratory signs (dyspnea, crackles during thoracic auscultation and changes in buoyancy) suggestive of pneumonia. Hand-rearing and rehabilitation efforts were unsuccessful, and the neonate died three days after it was rescued. Postmortem investigation was conducted using diagnostic imaging techniques, such as endoscopy and computed tomography. A complete necropsy and histopathology were performed, revealing bronchopneumonia as well as neutrophilic and discrete otitis media. A pure Pseudomonas aeruginosa culture was obtained from the blowhole, bronchoalveolar lavage, and blood using the API NE System. Our results indicate the cause of death to be related to bacterial sepsis. Further understanding of the main causes of death of Franciscana dolphin calves is warranted for conserving this threatened and understudied species.
Keywords: bacterial septicemia, cetacean, otitis, pneumonia, Pseudomonas aeruginosa, rehabilitation, stranding even
Antillean manatee (Trichechus manatus manatus) occurrence and grazing spots in three protected areas of Costa Rica
No full textThe Antillean manatee is a poorly studied marine mammal in Costa Rica. Its distribution covers the entire Caribbean coast, but sighting reports are scarce. This research was conducted in three protected areas (PA) where the species is primarily observed. The objectives were to determine the density patterns of sightings and grazing spots; to explore the relationship between grazing spots and sightings with geographic and temporal variables, for PA separately; to study the frequency of sightings and grazing spots according to season, month, and period of the day, for PA together; and to determine the pertinence of using a marine ecology application MarEco to register manatee sightings by the public. Data on manatee sightings and grazing spots gathered with the MarEco app, under a citizen science mechanism, were complemented with data obtained by the Tortuguero Conservation Area Administration (TCAA) through other means. The number of sighting records registered through MarEco during nine months was alike to the number of records reported to the TCAA over six years in two of the PA studied. The areas with the highest density of grazing spots and sightings matched with studies conducted 10 to 20 years ago. In two of the PA, sightings were most often associated with the rainy season, while fresh grazing spots were specially counted from 6:00 h to 8:59 h. The results suggest that manatees exhibit high site fidelity in the three PA, that their increased presence during the rainy season is likely due to increased availability of food, and that they perform feeding activity predominantly at night
First record of humpback whales in the Caribbean coast of Costa Rica
No full textKeywords: population dynamics, breeding areas, migration patterns, sightings, threats
Site fidelity and population parameters of short-finned pilot whales (Globicephala macrorhynchus ) in the Eastern Caribbean through photographic identification
No full textThe short-finned pilot whale (Globicephala macrorhynchus) is distributed throughout the Caribbean and within the Agoa Sanctuary, where it is protected. This top predator is overlooked in the Caribbean, and no data is available on the variability of the degree of fidelity to the islands, or even on the demographic parameters and social structure of this species, which is essential for its conservation and the understanding of its behavior. This study focuses on the islands of Guadeloupe and Martinique and is based on 24,374 photos collected between 2014 and 2022. This data was analyzed using the CMR method via photo-identification, then open population modeling under the POPAN formulation and via SOCPROG for the study of social links. This revealed two interconnected populations. Within each of these populations, there are three patterns of residence: core residents, residents, and visitors. A total of 193 core residents and residents were estimated in Guadeloupe, and 565 core residents, residents, and visitors in Martinique. Survival rates for both populations were high. Abundance was constant in Guadeloupe for core residents and residents, but a decline has been observed for the three patterns of residencies in Martinique - special attention must be given to this population. International collaboration throughout the Lesser Antilles is essential in order to estimate the number of populations and understand the behavior of the short-finned pilot whale in the Caribbean Sea.
Keywords: catch-mark-release, pattern of residence, photo-identification, short-finned pilot whale, site fidelity, social link
Stranding reports of the Antillean manatee in the middle Magdalena Basin, Colombia 2011 to 2023
No full textThe aim of this study was to conduct an analysis of reported events concerning Antillean manatee (Trichechus manatus manatus) strandings in the middle Magdalena Basin region of Colombia from January 2011 to December 2023. To achieve this, a literature search was conducted in newspapers, news broadcasts, as well as gray and published reports, complemented by interviews and workshops with various governmental and non-governmental organizations. This search resulted in reliable information regarding past experiences involving stranded manatees over the years. Cases attended to by the environmental authority and its partners were also considered. Forty-four stranding events were recorded, with 34 deaths and 10 live manatees. Of the cases discovered, 79.5% of the reported cases were addressed. This effort highlighted the current lack of an official database that would provide firsthand knowledge of Antillean manatee stranding events in Colombia, thereby hindering timely and appropriate territorial management during response to the challenges faced by this species in the region. Furthermore, it underscores the need to implement a standardized response pathway for manatee cases, following appropriate protocols, and promoting the coordination of stakeholders within the regional stranding network in the middle Magdalena Basin. This approach, in addition to supporting the capacity building of communities, institutions, and organizations for improving response knowledge, conservation, and manatee recovery, is of paramount importance for the long-term sustainability of manatee populations in the region
Oral cleft in an Amazonian manatee (Trichechus inunguis) (Mammalia, Sirenia)
No full textSince 1976, Amazonian manatees have been examined either alive or through necropsies as part of a long-term program to rescue and rehabilitate orphan manatee calves whose mothers were either victims of illegal hunting or accidental catch in fishing nets in the Brazilian Amazon region. Rescued manatees have been found to have several types of diseases, but to our knowledge, there is no record of a congenital anomaly of the face, known as an oral cleft, in Amazonian manatees. In this paper, we report the occurrence of an oral cleft in an Amazonian manatee calf, describing the clinical evaluation and discussing the potential causes