Manatee Research Articles

First abundance estimate of the Antillean manatee (Trichechus manatus manatus) in Brazil by aerial survey

We estimated the abundance of Antillean manatees (Trichechus manatus manatus) through a large-scale project conducted in 2010 in north-eastern Brazil and evaluated the efficacy of an aerial survey for conservation purposes. Two observers conducted the survey via flights that maintained an altitude of 150 m and an air speed of 140 km h−1, covering over 2590.2 km2of the coastline. Strip transects were flown in a zigzag pattern. A total of 67 manatees (on- and off-effort) were recorded in 55 sightings. Historical published records of occurrence were formally incorporated using a Bayesian approach. We estimated the manatee population for north-eastern Brazil in the form of a posterior distribution with a mean of 1104 individuals and a 95% posterior probability interval ranging from 485 to 2221 individuals, which indicates high uncertainty. More large-scale studies in the region are warranted to understand temporal trends, in addition to further studies in hotspot areas, with smaller spatial scales, to reduce the coefficient of variation and to allow the use of improved techniques for monitoring the manatees. A greater emphasis on species-specific characteristics and methods to enhance detection probability (e.g. dual observers) are also recommended. The conditions prevailing along the study area were not conducive to aerial surveillance; thus, the results are not a precise estimate of the manatee population. However, these highlight the importance of conservation efforts for the Antillean manatee, considered the most endangered aquatic mammal in Brazil.

A combined inverse method and multivariate approach for exploring population trends of Florida manatees

AbstractGiven the expense and time required to monitor marine mammal populations effectively, approaches that fully exploit the resulting data certainly are warranted. We employed a two‐step modeling approach to estimate key demographic parameters, including immigration, from aerial surveys of manatees (Trichechus manatus latirostris) in the Northwest management unit of Florida. Abundances of adults and calves were predicted by multivariate adaptive regression spline (MARS) models, after accounting for heterogeneous detection rates caused by variable environmental conditions. The resulting predictions were incorporated into a stage‐structured, deterministic model that used an inverse method to estimate parameters with and without immigration. The model without immigration estimated mean survival probabilities of 0.966, 0.923, and 0.794 for adults, subadults and calves, respectively, with a per capita reproductive rate of 0.135. These parameter estimates yielded an overall mean population growth rate of approximately 1.037, which is comparable to rates from mark‐recapture studies. When we added an immigration term that accounted for the greater slope in adult counts since 1999, as identified by the MARS model, the estimated per capita reproductive rate was 0.122, with survival probabilities for adults, subadults and calves of 0.926, 0.920, and 0.833, respectively. These rates were coupled with an estimated mean winter immigration rate corresponding to roughly 5.2% of the adult and subadult population. In this latter scenario, the number of manatees in the core population of the Northwest management unit was predicted to remain constant, with a population growth rate near one, and additional manatees counted during aerial surveys were deemed to be immigrants. While further studies could certainly expound on the potential effects of migrants on population indices, we present this first published immigration estimate for wintering manatees in northwest Florida.

Mamíferos del departamento del Chocó, depositados en las tres colecciones científicas más importantes de los Estados Unidos

Objective: To complete the available information on biodiversity of the department of Choco. Methods: We analyzed museological records of Chocoan specimens deposited in the three main collections of the United States: American Museum of Natural History de Nueva York (AMNH, 39 spp/127 records); Field Museum of Natural History de Chicago (FMNH, 53 spp/374 records); y el United State National Museum of the Smithsonian Institution de Washington DC (USNM, 19 spp/65 records). To evaluate the importance of of the analyzed material we contrasted the recovered records with Chocoan records deposited at the collection of the Instituto de Ciencias Naturales of the Universidad Nacional de Colombia (ICN, 52 spp/721 registros). Results: As product of our analyses we generated a database of 566 records representing a total of 82 Chocoan mammalian species deposited in scientific collections of the United States. The analyzed records require an urgent revision of their taxonomic status, in order to make them a useful source of information for local decision makers. We highlight the presence of the Colombian endemic primate Saguinus oedipus, for department of Choco, supported by material deposited at the AMNH. In the same manner we report the presence of the emballonurid bat Cormura brevirostris, and the slot Choloepus didactylus, that if taxonomically confirmed will represent significant distribution extensions and first confirmed records in collections of these taxa for the department. We also highlight the records of the nectarivorous bat Hylonycteris underwoodi and the coati Nasua narica candace, both species known from Central America and potentially present in the department. Finally, called our attention the presence of a mandible of the manatee (Trichechus manatus) from the municipio of Unguia deposited at the FMNH; this represents the only museum voucher material of the species from this portion of the Colombian territory.

Yeast microbiota of natural cavities of manatees (Trichechus inunguis and Trichechus manatus) in Brazil and its relevance for animal health and management in captivity.

The aim of this study was to characterize the yeast microbiota of natural cavities of manatees kept in captivity in Brazil. Sterile swabs from the oral cavity, nostrils, genital opening, and rectum of 50 Trichechus inunguis and 26 Trichechus manatus were collected. The samples were plated on Sabouraud agar with chloramphenicol and incubated at 25 °C for 5 days. The yeasts isolated were phenotypically identified by biochemical and micromorphological tests. Overall, 141 strains were isolated, of which 112 were from T. inunguis (Candida albicans, Candida parapsilosis sensu stricto, Candida orthopsilosis, Candida metapsilosis, Candida guilliermondii, Candida pelliculosa, Candida tropicalis, Candida glabrata, Candida famata, Candida krusei, Candida norvegensis, Candida ciferri, Trichosporon sp., Rhodotorula sp., Cryptococcus laurentii) and 29 were from T. manatus (C. albicans, C. tropicalis, C. famata, C. guilliermondii, C. krusei, Rhodotorula sp., Rhodotorula mucilaginosa, Rhodotorula minuta, Trichosporon sp.). This was the first systematic study to investigate the importance of yeasts as components of the microbiota of sirenians, demonstrating the presence of potentially pathogenic species, which highlights the importance of maintaining adequate artificial conditions for the health of captive manatees.

Seasonal differences in the feeding habits of the Antillean manatee population (Trichechus manatus manatus) in the fluvial-lagoon systems of Tabasco, Mexico

Seasonal differences in the feeding habits of the Antillean manatee population (<i>Trichechus manatus manatus</i>) in the fluvial-lagoon systems of Tabasco, Mexico

Transposon-mediated death of an ancestral A-23-like allele: evolution of TCR-positioning motifs in the HLA-A lineage.

HLA-A alleles are characterized by tandem arginine and histidine/arginine motifs (i.e., R65 and H151R motifs) present on the α1- and α2-helix, respectively. In crystallographic structures, α/β T-cell receptors (TCR) contact both motifs and appear to be geometrically positioned for alloreactivity. Herein, bioinformatics of "dual-motif" MHC A-like alleles were investigated across phylogeny. While A-like alleles with the R65 motif are widespread, the H151R motif has segregated out of most species. Surprisingly, an uncharacterized orf in tarsiers (Loc-103275158) encodes R151 within a truncated A-23-like gene, which is in frame with short footprints of Tc5 and Tigger transposons (TE); the extant tarsier A-23 allele is totally missing exon-3 and part of exon-4; together, suggesting TE-mediated inactivation of an intact/ancestral A-23 allele. Since the only other (non-human) dual-motif A-like alleles are in gorilla, chimpanzee, and the Florida manatee, we speculate that dual-motif A alleles first emerged in the Afrotherian lineage and reappeared during the evolution of higher primates.

Circadian and ultradian activity rhythms in manatee (Trichechus manatus manatus) in captivity

In this study, we show temporal organization of activity patterns in larger temporal series recording. The objective of this study was to determine the temporal pattern of the rest-activity rhythm in manatee (Trichechus manatus manatus) in captivity. Activity recordings were programmed from August 2010 to September 2011 with actimetry devices, and behavior recordings were conducted in dry and rainy seasons. We showed that the marine manatee presents a complex temporal organization, in which the rest-activity rhythm comprises several frequencies with a predominant circadian component and multiple ultradian components. Our results indicate that the animals were more active during the day with respect to the night. The temporal organization of this cycle entails multiple frequencies that include ultradian rhythms, which may be expressions generated by physiological needs, such as food availability and thermoregulatory requirements. These patterns should be taken into consideration for future studies of biological rhythms in manatee.

ESTABLISHMENT OF ECHOCARDIOGRAPHIC PARAMETERS OF CLINICALLY HEALTHY FLORIDA MANATEES (TRICHECHUS MANATUS LATIROSTRIS).

A standardized echocardiographic technique was recently established for the Florida manatee (Trichechus manatus latirostris). There are no available published data on normal echocardiographic parameters in any Sirenian species. The purpose of this study was to report reference parameters for various echocardiographic measurements. These parameters are intended to serve as a comparison for future research into the prevalence of cardiac diseases in the manatee and to aid in diagnosing animals with suspected cardiac disease in rehabilitation facilities. Annual health assessments of free-ranging manatees in Crystal River National Wildlife Refuge, Florida, and pre-release health assessments of rehabilitated manatees at Tampa's Lowry Park Zoo permitted comparison of echocardiographic measurements in adult (n=14), subadult (n=7), and calf (n=8) animals under manual restraint.

Multiple conformations are a conserved and regulatory feature of the RB1 5' UTR.

Folding to a well-defined conformation is essential for the function of structured ribonucleic acids (RNAs) like the ribosome and tRNA. Structured elements in the untranslated regions (UTRs) of specific messenger RNAs (mRNAs) are known to control expression. The importance of unstructured regions adopting multiple conformations, however, is still poorly understood. High-resolution SHAPE-directed Boltzmann suboptimal sampling of the Homo sapiens Retinoblastoma 1 (RB1) 5′ UTR yields three distinct conformations compatible with the experimental data. Private single nucleotide variants (SNVs) identified in two patients with retinoblastoma each collapse the structural ensemble to a single but distinct well-defined conformation. The RB1 5′ UTRs from Bos taurus (cow) and Trichechus manatus latirostris (manatee) are divergent in sequence from H. sapiens (human) yet maintain structural compatibility with high-probability base pairs. SHAPE chemical probing of the cow and manatee RB1 5′ UTRs reveals that they also adopt multiple conformations. Luciferase reporter assays reveal that 5′ UTR mutations alter RB1 expression. In a traditional model of disease, causative SNVs disrupt a key structural element in the RNA. For the subset of patients with heritable retinoblastoma-associated SNVs in the RB1 5′ UTR, the absence of multiple structures is likely causative of the cancer. Our data therefore suggest that selective pressure will favor multiple conformations in eukaryotic UTRs to regulate expression.

Understanding manatee immunogenetics and the implications for conservation (VET1P.1121)

Abstract The completion of the genome draft of the Florida manatee (Trichechus manatus latirostris) in 2012 made immunogenetic exploration of the Sirenia order more feasible. The endangered manatees are sentinel species for coastal ecosystems and their evolutionary origins are complex. It is believed that they evolved from a wading terrestrial mammal that became fully aquatic, which suggests distinctive adaptations for transitioning to a new environment. Discovering the genetic details of their immune system will help understand manatee evolution and allow species-specific diagnostic tools to be developed. Due to bottleneck signatures at other loci, the genetic diversity of the major histocompatibility complex (MHC) is expected to be low. This could pose problems for conservation efforts because low diversity can increase the chance of extirpation. The primary focus of this project is to determine the immune robustness of manatees by looking at their antibody repertoire and MHC polymorphism. Two species will be compared: the West Indian manatee (T. manatus) and the Amazonian manatee (T. inunguis). Using next generation sequencing, we will robustly sample the IgH and IgL rearrangements contributing to the antibody repertoire, and identify dominant MHC alleles and estimate their frequencies. The allelic distribution between the species could reveal clues to their evolutionary relationship and aid conservation efforts to help this species become more stable in their environment.

Automatic manatee count using passive acoustics

The West Indian manatee is a threatened species throughout its known range. To improve its conservation, it is necessary to locate and count the individuals. This is a very difficult task due to the cryptic behavioral characteristics of the species and the environmental constrains, particularly in the Central American region, where muddy waters produce limited visibility. A method to estimate manatee population through vocalizations is a reliable, inexpensive, non-invasive, and novel option in the region. Digital signal processing techniques are proposed to identify individuals in field recordings of manatee vocalizations. The proposed methods for signal denoising and vocalization recognition have produced promising results. Further work needs to be done to identify individuals.

Three New Species of Tursiocola (Bacillariophyta) from the Skin of the West Indian Manatee (Trichechus manatus)

Three new species of Tursiocola are described from the skin of the West Indian manatee bringing the total number of known species in the genus to seven. The range of morphological diversity within the genus is greatly expanded. The number of poroid rows on the copulae is no longer a valid characteristic for the separation of Tursiocola from the ceticolous genus Epiphalaina. The presence of a butterfly-like structure in the central area of the former is at present the best criterion for separating the 2 genera. The 3 new Tursiocola species accounted for nearly 90% of all diatom valves on the manatee skin. No other diatom taxa previously described as new from the skin of cetaceans were present on the manatee.

Combining information for monitoring at large spatial scales: First statewide abundance estimate of the Florida manatee

Monitoring abundance and distribution of organisms over large landscapes can be difficult. Because of challenges associated with logistics and data analyses uncorrected counts are often used as a proxy for abundance. We present the first statewide estimate of abundance for Florida manatees (Trichechus manatus latirostris) using an innovative approach that combines multiple sources of information. We used a combination of a double-observer protocol, repeated passes, and collection of detailed diving behavior data to account for imperfect detection of animals. Our estimate of manatee abundance was 6350 (95%CI: 5310–7390). Specifically, we estimated 2790 (95%CI: 2160–3540) manatees on the west coast (2011), and 3560 (95%CI: 2850–4410) on the east coast (2012). Unlike uncorrected counts conducted since 1991, our estimation method considered two major sources of error: spatial variation in distribution and imperfect detection. The Florida manatee is listed as endangered, but its status is currently under review; the present study may become important for the review process. Interestingly, we estimated that 70% (95%CI: 60–80%) of manatees on the east coast of Florida were aggregated in one county during our survey. Our study illustrates the value of combining information from multiple sources to monitor abundance at large scales. Integration of information can reduce cost, facilitate the use of data obtained from new technologies to increase accuracy, and contribute to encouraging coordination among survey teams from different organizations nationally or internationally. Finally, we discuss the applicability of our work to other conservation applications (e.g., risk assessment) and to other systems.

Comment on “Insulative capacity of the integument of the dugong (Dugong dugon): thermal conductivity, conductance and resistance measured by in vitro heat flux” by Horgan, Booth, Nichols and Lanyon (2014)

Cold stress syndrome is an incompletely understood but clearly very complicated, multisystemic entity that has been described as affecting Florida manatees chronically exposed to cold water (Bossart et al. 2002). Florida and south-east Queensland (QLD) are very similar in climate, species composition and marine environment. In 2013, our group published an article comparing the lesions described in manatees with those we were seeing in many of the dugongs presenting to our post-mortem room during the colder months of the year in Queensland. This description was combined with presentation of supporting environmental data (Owen et al. 2013). Horgan, Booth, Nichols and Lanyon have made statements contradicting our argument in their article, namely: “with no credible pathological evidence of CSS (cf. Owen et al. 2013)” and “Skin lesions suggested as characteristic of cold stress and reported for dugongs by Owen et al. (2013) are grossly and histologically different to those reported for the Florida manatee, are found in dugongs throughout the tropics (Woolford and Lanyon unpublished data) and are also found in dugongs in cooler waters outside the winter period (the latter point also reported by Owen et al. 2013). Each of these factors casts serious doubt as to these skin characteristics being thermally related”. These statements are not based on sound scientific principles. In the former instance, this statement has been made without offering any supporting or qualifying evidence and is therefore an unsubstantiated opinion. The dugong samples used for Owen et al. (2013) were assessed and compared by experienced pathologists and experts in marine population health, one of whom (MF) is in the unique position of having first-hand experience with disease in both manatees in Florida and dugongs in southeast QLD. Data and the resulting interpretations in this article were also deemed as credible by multiple reviewers. The qualifying This article presents original research to investigate the relationship between integumentary composition and predictive thermal capacity. The authors suggest that cold stress syndrome (CSS) is unlikely to occur in dugongs, a claim that is at odds with a recent study from our group where we described the local appearance of mortality cases consistent with this syndrome. Horgan et al. (2014) made two statements, in particular, which disregarded a diagnosis following observations by specialist veterinary pathologists, yet without, to our knowledge, accessing the material themselves and instead quoting ‘unpublished data’ to support their conclusions. Further, and importantly, Horgan et al. (2014) ignore the pathological changes we described in other organ systems, which were consistent with changes noted during CSS in manatees and led to our diagnosis.

Sublethal red tide toxin exposure in free-ranging manatees (Trichechus manatus) affects the immune system through reduced lymphocyte proliferation responses, inflammation, and oxidative stress

The health of many Florida manatees (Trichechus manatus latirostris) is adversely affected by exposure to blooms of the toxic dinoflagellate, Karenia brevis. K. brevis blooms are common in manatee habitats of Florida’s southwestern coast and produce a group of cyclic polyether toxins collectively referred to as red tide toxins, or brevetoxins. Although a large number of manatees exposed to significant levels of red tide toxins die, several manatees are rescued from sublethal exposure and are successfully treated and returned to the wild. Sublethal brevetoxin exposure may potentially impact the manatee immune system. Lymphocyte proliferative responses and a suite of immune function parameters in the plasma were used to evaluate effects of brevetoxin exposure on health of manatees rescued from natural exposure to red tide toxins in their habitat. Blood samples were collected from rescued manatees at Lowry Park Zoo in Tampa, FL and from healthy, unexposed manatees in Crystal River, FL. Peripheral blood leukocytes (PBL) isolated from whole blood were stimulated with T-cell mitogens, ConA and PHA. A suite of plasma parameters, including plasma protein electrophoresis profiles, lysozyme activity, superoxide dismutase (SOD) activity, and reactive oxygen/nitrogen (ROS/RNS) species, was also used to assess manatee health. Significant decreases (p<0.05) in lymphocyte proliferation were observed in ConA and PHA stimulated lymphocytes from rescued animals compared to non-exposed animals. Significant correlations were observed between oxidative stress markers (SOD, ROS/RNS) and plasma brevetoxin concentrations. Sublethal exposure to brevetoxins in the wild impacts some immune function components, and thus, overall health, in the Florida manatee.

Eight-choice sound localization by manatees: performance abilities and head related transfer functions.

Two experiments investigated the ability and means by which two male Florida manatees (Trichechus manatus latirostris) may determine the direction of a sound source. An eight-choice discrimination paradigm was used to determine the subjects' sound localization abilities of five signal conditions covering a range of frequencies, durations, and levels. Subjects performed above the 12.5% chance level for all broadband frequencies and were able to localize sounds over a large level range. Errors were typically located to either side of the signal source location when presented in the front 180° but were more dispersed when presented from locations behind the subject. Front-to-back confusions were few and accuracy was greater when signals originated from the front 180°. Head-related transfer functions were measured to determine if frequencies were filtered by the manatee body to create frequency-specific interaural level differences (ILDs). ILDs were found for all frequencies as a function of source location, although they were largest with frequencies above 18 kHz and when signals originated to either side of the subjects. Larger ILDs were found when the signals originated behind the subjects. A shadowing-effect produced by the body may explain the relatively low occurrence of front-back confusions in the localization study.

Issues and opportunities associated with using manatee mortality data to evaluate the effectiveness of manatee protection efforts in Florida

ESR Endangered Species Research Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials ESR 26:127-136 (2014) - DOI: https://doi.org/10.3354/esr00638 Issues and opportunities associated with using manatee mortality data to evaluate the effectiveness of manatee protection efforts in Florida C. Scott Calleson* Florida Fish and Wildlife Conservation Commission, Imperiled Species Management Section, 620 South Meridian Street, Tallahassee, FL 32399, USA *Corresponding author: scott.calleson@myfwc.com ABSTRACT: Protection zones to reduce risks to Florida manatees Trichechus manatus latirostris associated with boat operation have been in place since the 1990s or earlier in most areas considered important for the species. Despite the relatively long period of time protections have been in place, evaluating the effectiveness of these efforts has proven to be difficult. This paper discusses manatee mortality data, which is one of the most long-term sources of data available for analysis, and some of the difficulties associated with using these data to evaluate effectiveness. It then explores the concept of using differences in rates of change in mortality during three 10 yr periods as an evaluation metric. Rates were calculated for the state of Florida as a whole and for Treatment and No Treatment groups, with the Treatment group including all counties where comprehensive protection zones have been established. The only rates of change that were statistically different from one another were for boat-related deaths, both statewide and for the Treatment group, between the 1981-1990 and 2001-2010 periods. Statewide, the average rate of increase fell from 11.2 to 1.0% yr-1, while, within the Treatment group, the rate fell from 12.4 to 1.2% yr-1. These results provide evidence that protection efforts have likely helped to reduce boat-related mortality risks; however, the analysis does not account for some uncertainties associated with the mortality data, and the confidence intervals are fairly wide. Additional research and analyses should be pursued to account for these issues and also to consider risks related to non-lethal manatee-boat collisions. KEY WORDS: Florida manatee · Trichechus manatus latirostris · Boat speed zones · Mortality · Risk reduction · Effectiveness Full text in pdf format PreviousNextCite this article as: Calleson CS (2014) Issues and opportunities associated with using manatee mortality data to evaluate the effectiveness of manatee protection efforts in Florida. Endang Species Res 26:127-136. https://doi.org/10.3354/esr00638 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in ESR Vol. 26, No. 2. Online publication date: December 10, 2014 Print ISSN: 1863-5407; Online ISSN: 1613-4796 Copyright © 2014 Inter-Research.

Diatoms in cytologic specimens of aquatic animals--Part II, dermal, respiratory, and gastric samples.

Figure 1. Diatoms in cytologic samples of Florida manatees (Trichechus manatus latirostris) in A, C, D, F, G, J–L, bottlenose dolphins (Tursiops truncatus) in B, E, I, and a seahorse (Hippocampus erectus) in H. Wright–Giemsa stain.9100 objective (except F;920). (A) naviculoid benthic diatom; skin contamination of urine sediment; wet mount. (B) Nitzschia sp.; gastric fluid direct smear. (C) Navicula sp.; nasal swab. (D) Tursiocola spp. in teat fluid cytospin preparation with heterophilic inflammation, diatom phagocytized by heterophil consistent with incidental finding. (E) Nitzschia sp.; gastric fluid direct smear. (F) Tursiocola spp. and pennate diatoms; skin scraping. (G) Amphora sp.; nasal swab. (H) pennate diatom; skin scraping. (I) centric diatom; gastric fluid direct smear. (J) Tursiocola sp.; skin scraping. (K) Tursiocola sp.; skin scraping (cleaned). (L) Tursiocola sp.; skin scraping (SEM).

Sulfur isotopes show importance of freshwater primary production for Florida manatees

Table S1. Sulfur stable isotope data for manatee with sex, bone type sampled, and location. δ34S values are relative CDT. ID number is that of the marine mammal stranding response team of southern Florida. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

Características del hábitat del Manatí antillano (Trichechus manatus manatus) en sistemas fluvio-lagunares del sur del Golfo de México

Introduction : Studying a species habitat is a tool for researchers and stake holders to find key ecological characteristics to be used in management actions. Freshwater systems comprises most of the habitat of Antillean manatees, however the habitat features of these systems are still poorly understood. The objective of this study was to explore habitat variables related most to the use of freshwater systems by the Antillean manatees on the low basin of Usumacinta river. Methods: We built generalized linear models using data on presence/absence and from sightings, achieved by direct and indirect sources on 62 navigations, between March 2006 and November 2007. For the models we used four types of variables: biological, physical, anthropic and from landscape, all previously reported as important in the habitat use of Antillean manatee. Results: In general, the area had warm and shallow waters (2 to 4 m) with low transparency; waters are mostly lentic except for secondary and main rivers; vegetation was mostly of bank grasses and shrubs and boat traffic was medium. From the 19 initial habitat variables evaluated here, the best presence-absence model included transparency, distance to confluence and submerged vegetation. The best sightings model was built with current and distance to streams . Discussion and conclusions: On the study area, manatees use deeper lentic environments near to feeding areas, like streams or confluences, where they find shelter. Connectivity is important in the habitat of manatees, they could be using shallow lakes to feeding in times of the day not comprised in this study, but then traveled to deeper watercourses using confluences. Manatees have also been reported to use these environments in Central and South America. Along freshwater systems associated to Usumacinta River, manatee is still abundant, confirming this region as a key area for manatee conservation in Mexico. Results of this study had been use to classify the region and to prioritize research and conservation actions in a landscape scale.