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Exploratory behaviors describe the actions performed by an animal to obtain information on an object, environment, or individual by using its different senses. Exploration is described in some marine mammals, but not yet in manatees. Our study investigated behavioral and acoustic responses of two groups of Antillean manatees (N = 12 and N = 4) housed in zoological parks toward various stimuli involving three sensory modalities: visual, tactile, and auditory. Simultaneous audio and video recordings were collected during three periods of time (i.e., before, during, and after the presentation of all stimuli). Behaviors related to interest, social behaviors, the number and type of calls produced, and their frequency and duration were recorded and analyzed. Manatees reacted more to submerged stimuli than to out-of-water and sound stimuli, with an increase in approach, social contacts, and number of vocalizations. The proportion of squeaks and squeals call types also varied according to stimuli, and call entropy and F0 range varied according to periods. Our results suggest that manatees display sensory preferences when exploring stimuli, with more interest in manipulable stimuli, supporting the importance of their somatic perception. We highlight the need for particular enrichment programs (i.e., involving submerged objects) in zoological facilities. By displaying social contacts and by producing vocalizations, manatees communicate information such as their motivational state. The increase in call rate, harsh calls, and entropy values could be valid indicators of heightened arousal. We encourage further studies to associate acoustic recordings with ethological data collection to increase the understanding of manatees' behaviors andperception. [ABSTRACT FROM AUTHOR]

Copyright of Brazilian Journal of Biology is the property of Instituto Internacional de Ecologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Florida manatees (Trichechus manatus latirostris) are protected as a threatened species, and data are lacking regarding their reproductive physiology. This study aimed to (1) quantify plasma steroid hormones in Florida manatees from two field sites, Crystal River and Indian River Lagoon, at different gestational stages and to (2) identify individual lipids associated with pregnancy status. Ultra-high performance liquid chromatography-tandem mass spectrometric analysis was used to measure plasma steroid hormones and lipids. Pregnant female manatees were morphometrically distinct from male and non-pregnant female manatees, characterized by larger body weight and maximal girth. Progesterone concentrations in manatees were also elevated during early gestation versus late gestation. Cholesterol, an important metabolic lipid, and precursor for reproductive steroids, was not different between groups. Mass spectrometry quantified 949 lipids. Plasma concentrations of glycerophospholipids, glycerolipids, sphingolipids, acylcarnitines, and cholesteryl esters were associated with pregnancy status in the Florida manatee. Most of the lipid species associated with pregnancy were triacylglycerides, phosphatidylethanolamines, and ether-linked phosphatidylethanolamines, which may serve as energy sources for fetal development. This research contributes to improving knowledge of manatee reproductive physiology by providing data on plasma steroid hormones relative to reproductive status and by identifying plasma lipids that may be important for pregnancy. Elucidation of lipid species directly associated with pregnancy has the potential to serve as a diagnostic approach to identify pregnant individuals in fresh and archived samples. These biochemical and morphometric indicators of reproductive status advance the understanding of manatee physiology. Experimental design layout. [Display omitted] • Progesterone, weight, and maximum girth were increased in pregnant female manatees. • A total of 949 lipids, representing 39 different lipid subclasses, were detected. • Triacylglycerides (TAG) and phosphatidylethanolamines (PE) were major subclasses associated to pregnancy status. • TAGs were decreased and PEs were increased in pregnant manatees. [ABSTRACT FROM AUTHOR]

A large-scale oil spill along the northeastern Brazilian coast in 2019–2020 severely impacted primary manatee habitats in Brazil. This study aimed to assess metal and metalloid contamination in a dead manatee calf found following this oil spill. Several elements were detected, including chromium, iron, nickel, lead, and vanadium, which are crude oil components, and thallium, a component of dispersants used to degrade and dissipate crude oil. The presence of these contaminants in the manatee calf is indicative of maternal exposure, metabolism, and newborn transference via placenta and lactation. This is the first report of mother-calf metal transfer in manatees, highlighting the species' vulnerability and potential long-term population dynamics effects, and the first report for several metals and metalloids in these animals, laying the foundation for future research efforts. These findings highlight the urgent need for continued environmental monitoring, ecotoxicological assessments, and conservation initiatives. • The 2019 oil spill severely impacted manatee habitats along the Brazilian coast. • Several metals and metalloids were detected in an infant manatee after the oil spill. • Maternal exposure, metabolism, and newborn placental transference are probable. • This is the first study to report mother-calf metal transfer in manatees. • The findings raise concerns about potential long-term population effects. [ABSTRACT FROM AUTHOR]

Although red tides are a common and natural occurrence around the coast of Florida, within the last few decades they have intensified and become much more deadly. Several identifiable human-caused factors exacerbate the size, concentration, and duration of the harmful algae bloom and disturb the environment's natural balance. The Florida Gulf Coast provides all the algae 's necessary requirements for survival, the perfect storm to create a resilient super bloom that annihilates its host ecosystem. This article explains the plight of Florida manatees who, like other marine animals and plants, are being injured or killed by this algae crisis. It also provides background information about Florida red tides, including how they are formed and the human activities that are to blame for this disruption in the ecosystem's natural balance. It suggests current laws protecting both manatees and water quality are inadequate or ineffective as they do not directly address nonpoint nutrient pollution, the root cause of these massive super blooms. Using a multifactorial approach, it proposes several simple solutions to mitigate the harmful effects of red tide super blooms and save the manatees along with other marine life. [ABSTRACT FROM AUTHOR]

This article explores caring relations between child characters and sentient animals in two tales by Australian author-illustrator Shaun Tan. Each of Tan's 15 Tales from Outer Suburbia are set in an "outer" suburban world replete with curious critters. These include a silent and stoic water buffalo, an unmoving dugong (manatee), and other surprising companion species. In this article, the author unpacks the caring relationships between child protagonists and the sentient creatures they encounter in two selected tales by focusing specifically on those processes that bring these characters together in curious encounters: that is, processes of embodied mapping. Emphasis is placed on enchantment and movement, and, in particular, moments given to pausing, lingering, and reflection. The author argues that both the fields of human-animal studies and the social studies of childhood can gain from exploration of the subtleties of these moments. [ABSTRACT FROM AUTHOR]

Serum iron concentration is usually decreased in true iron deficiency and with inflammatory disease in man and domestic animals. Serum total iron binding capacity (TIBC) may be increased in true iron deficiency and decreased with inflammatory disease. This prospective study was designed to measure serum iron analytes in healthy free-ranging and housed Florida manatees (Trichechus manatus latirostris) of both sexes and various ages and to evaluate the effects of diseases common to manatees on these analytes. Blood samples were collected without anticoagulant from 137 healthy free-ranging manatees, 90 healthy housed manatees and 74 free-ranging diseased manatees, and serum was prepared by centrifugation. Serum iron concentration and unsaturated iron binding capacity were measured colourimetrically, and TIBC and percent transferrin saturation with iron were calculated. Serum amyloid A (SAA) was measured to assist in the health assessment of manatees and provide evidence of inflammation in diseased manatees. Based on the serum iron analytes, iron availability was lower in immature manatees compared with adults, and it was lower in housed manatees compared with free-ranging manatees. In contrast to other mammals studied, serum iron concentration was elevated rather than depressed in late pregnancy. Serum iron concentrations and transferrin saturation with iron percentages were significantly lower, and SAA concentrations were significantly higher, in diseased (ill and injured) manatees compared with healthy manatees. Serum iron concentration and transferrin saturation with iron values were negatively correlated with SAA concentrations, and manatees with the highest SAA concentrations had lower serum TIBC values. These findings indicate that inflammation is the major factor responsible for alterations in iron analytes in diseased manatees. Consequently, hypoferraemia may be used as supportive evidence of inflammatory disease in manatees (unless haemorrhage is also present). A decision threshold of ≤13.8 μmol/l was determined for hypoferraemia using receiver operating curve analysis. Based on studies in man and domestic animals, iron therapy is unnecessary for manatees with hypoferraemia associated with inflammation and has the potential for causing tissue damage and increased susceptibility to bacterial infections. [ABSTRACT FROM AUTHOR]

The West Indian manatee (Trichechus manatus manatus), a subspecies that inhabits coastal areas of Central and South America, has been listed as a vulnerable species because of the rapid decline in its population. Commercially available immunologic reagents specific for sirenians are lacking, limiting the development of sensitive immunodiagnostic assays. We observed the affinity of the microbial proteins A and G to T. m. manatus immunoglobulins. Manatee serum pools were analyzed using enzyme-linked immunosorbent assay (ELISA) to determine the affinity intensity followed by western blotting to confirm the specific binding of proteins A and G to immunoglobulins. The ELISA demonstrated maximum affinity of both proteins until the serum dilution of 1:12,800, with a similar affinity for both proteins. Because both A and G proteins exhibited affinity to manatee immunoglobulins, they can be used to develop sensitive immunodiagnostic assays for this species, contributing to manatee conversation procedures. [ABSTRACT FROM AUTHOR]

Abstract The effects of underwater noise pollution on marine life are of increasing concern. Research and management have focussed on the strongest underwater sound sources. Aerial sound sources have understandably been ignored as sound transmits poorly across the air-water interface. However, there might be situations when air-borne noise cannot be dismissed. Commercial passenger airplanes were recorded in a coastal underwater soundscape exhibiting broadband received levels of 84–132 dB re 1 μPa rms. Power spectral density levels of airplane noise underwater exceeded ambient levels between 12 Hz and 2 or 10 kHz (depending on site) by up to 36 dB. Underwater noise from airplanes is expected to be audible to a variety of marine fauna, including seals, manatees, and dolphins. With many of the world's airports lying close to the coast, it is cautioned that airplane noise not be ignored, in particular in the case of at-risk species in small, confined habitats. Highlights • Major airports around the globe exist on the water edge. • Underwater noise from airplanes was detectable at 12 Hz–10 kHz. • It exceeded ambient levels by up to 36 dB (received levels 84–132 dB re 1 μPa). • While underwater noise from individual planes was low, overflights may be frequent. • Impacts may be non-negligible for at-risk species in confined habitats. [ABSTRACT FROM AUTHOR]

[Display omitted] The Hondo River is the natural border between Mexico and Belize, and it is part of the distribution area of the Endangered Antillean manatee Trichechus manatus manatus. Currently, the Hondo River does not have any special protection. Employing qualitative research methods, we documented the social perception and local knowledge from riverside communities to assess conservation status and trends of manatees in the area. Fifty semi-structured interviews were carried out to river users in 16 Mexican communities, distributed in six segments along the riverbed. The claims of the inhabitants agree with boat-based surveys: most of the current and historical manatee sightings were reported in segments of the main watercourses, but also in small tributaries, which are usually shallow and rich in aquatic vegetation. Additionally, the local perception about manatee conservation status can be helpful to understand population trends and threats: 48 % of the interviewees claimed that nowadays the number of sighted manatees is less than that observed 10 years ago. The responders identified water pollution due to cane cultivation practices, motorized vessels traffic, and presence of fishing nets as potential threats to manatees. This study provides evidence of relevant local knowledge about the manatee ecology and its habitat, critical in the construction of binational conservation strategies for the species. Therefore, local resources users may play an increasingly significant role in manatee management and monitoring. Although manatees are poached for their meat in several areas of their distribution, the most common value attributed to manatees in Hondo River was non-use existence values. Local people recognize the challenges to observe this cryptic species in this river, but also identified manatees as potential flag species, suggesting that it may represent a valuable resource for ecotourism. We suggest that the non-extractive use of manatees has the potential for promoting species conservation and local economic growth. [ABSTRACT FROM AUTHOR]

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 last national assessment published in 2014. Here, we generated information based on available data to assess the species extinction risk in Brazil using IUCN regional guidelines, applying all criteria, and choosing the highest category of risk. Abundance at the national level was projected considering the density estimated in Ceará and Rio Grande do Norte states and the Criterion B EOO (Extent of Occurrence) estimated in this study (34,899 km2) and resulted in 1,047 individuals (95% CI: 538–2,038). Six scenarios of annual mortality were inferred and suspected based on evidence. We adopted a simple discrete logistic growth model to project population reduction in the past and future (three generations − 69 years) in 18 scenarios. Among the 18 projected scenarios, four resulted in extinction, six in decline and eight in population growth. Considering the low abundance bound, all scenarios indicate a reduction larger than 80% in population size, classifying the species as 'Critically Endangered' based on A4de. Reduction in EOO and abundance in the past classify the species as 'Endangered' based on A2c. The suspected number of mature animals (607;95% CI: 312–1,182) and the projected decline higher than 20% in two generations also classify the species as 'Endangered' based on C1 and 'Vulnerable' under D1. Our results indicate that information can be generated to produce more accurate assessments based on available data. The species national extinction risk needs to be reassessed, and the National Action Plan effectiveness evaluated. [ABSTRACT FROM AUTHOR]

We illustrate how the application of a traditional marketing approach can be used to address conservation problems. The conservation challenge at hand relates to the low number of reported boat strikes of the Florida manatee (Trichechuslatirostris), an endangered marine mammal that inhabits coastal Florida. Our objective was to assess why boaters do or do not call the authorities after their boat strikes a manatee and what can be done to increase the rate of reporting. Results of our online survey indicated that over 90% of subjects expressed a willingness to call the authorities if they strike a manatee with their boat. However, this self-reported sentiment has not resulted in frequent calls to the authorities by boaters involved in a collision with a manatee since records have been kept. The outcome of subsequent personal in-depth interviews suggested that most boaters do not know who to call or do not have the proper contact number. Based on our findings, we suggest the implementation of a decal to be positioned in a vessel's cockpit displaying the proper number to call to report a manatee incident. We also recommend including numbers for other marine emergencies on the decal. We discuss barriers to success that need to be considered and caution as to potential market failures. [ABSTRACT FROM AUTHOR]

Highlights: [•] Florida fishery gear interactions were reviewed for three megafauna from 1997 to 2009. [•] Overall gear interactions were 75.3% hook/line, 18.2% trap pot and 4.8% fishing net. [•] Gear cases increased for manatees, dolphins, loggerheads and green sea turtles. [•] Dolphin, manatee and sea turtle hook/line gear interactions were stable over time. [•] No significant trends in trap pot gear interactions strandings relative to total strandings were observed. [ABSTRACT FROM AUTHOR]

Copyright of Ocean & Coastal Management is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Universidad & Ciencia is the property of Universidad Juarez Autonoma de Tabasco and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Brazilian Journal of Biology is the property of Instituto Internacional de Ecologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The West Indian manatee, Trichechus manatus, is currently listed as an endangered species throughout its range. Threats to the subspecies in Florida include watercraft collisions, the potential loss of warm water refuges, exposure to harmful algal blooms, entanglement in fishery gear, habitat degradation, freshwater diversions and withdrawals, and the crushing or isolation caused by water control structures. A study was initiated in 2001 to investigate several of these threats and develop methods to aid in endangered species recovery needs by exploring the feasibility of using CRITTERCAM, an animal-borne imaging and data-collection device, on Florida manatees. While the actual CRITTERCAM technology was appropriate for the goals of this study, the unique morphology of the species and its variable habitat made finding a method of attachment extremely challenging. An appropriate and reliable method of attachment to the manatee is necessary for the successful application of animal-borne imaging data collection. Methods previously used successfully on other species were explored, including various combinations of suction cups and adhesives, a nylon harness and a peduncle belt with a trailing tether. Over a span of several years, captive trials and field testing determined that the peduncle belt with connecting tether was the most appropriate method of attachment. Several iterations of this design were made in order to provide the necessary functionality for ensuring productive research with the CRITTERCAM on wild manatees. [ABSTRACT FROM AUTHOR]

The article focuses on the estimation of manatee (Trichechus manatus latirostris) places and movement corridors. The researchers developed a raster-based spatial model that transformed radio-telemetry point data to surfaces illustrating the areas manatees visited frequently for relatively long periods, called places and areas visited frequently for short periods, called movement corridors. The article involves simulating manatee movement paths between sequential telemetry points using a cost surface based on manatee bathymetric preferences that were derived from empirical associations between telemetry locations and water depth, distributing movement time to cells that were crossed by the simulated movement path, and extracting cells from the movement-path map that qualified as places and those that qualified as corridors. Movement characteristics of wild and rehabilitated animals were similar. Movement rates of males were significantly greater than those of either females with calves or females without calves. Mean number of visits per cell and mean time per visit for the three adult classes were not significantly different.

The article presents an analysis of 19 years of photo-identification data of endangered Florida manatee (Trichechus manatus latirostris) in 2003. The annual variation detected in adult survival of manatee coincided with years when major winter storm and intense hurricanes occurred in the northern Gulf of Mexico. The decreases in survival in manatee could be due to indirect mortality, direct mortality and/or emigration from the region due to storms.