The coastal zone of Belize is home to the largest recorded number of the threatened Antillean manatee (Trichechus manatus manatus) within the species' Caribbean range. The objectives of my study were: (1) to determine long-term trends in aerial survey counts and indices of the manatee population in the coastal zone of Belize; and (2) to examine the seasonal change in manatee distribution among habitats in the coastal zone. Standardized extended-area aerial surveys were conducted along the entire coastline of Belize in the dry and wet seasons of 1997, and 1999 - 2002. Manatees were counted in five habitat categories: cay, coast, estuary, lagoon, and river. Total sightings per survey ranged from 90 to 338; the greatest number was counted in the 2002 wet season. Calf percentage ranged from 5 to 13. A slight negative trend in total counts was significant for dry-season, not wet-season surveys, indicating an interactive effect of season and year. Based on analysis of variance, the Abundance Index (transformed manatee sightings per hour) did not differ significantly among years, although it varied significantly within year by season and habitat by season. In applying a spatial approach, the general survey route was buffered 1 km on both sides, and 1 km grids were overlaid and classified by habitat type. The presence or absence of each cell for each survey was used in likelihood ratio tests of the single and interactive effect of season and habitat. The Index for river habitat was higher in the dry season, while cay habitat was higher in the wet season. Overall, near-shore habitat (estuary, lagoon, and river) showed a higher Index than did the offshore habitat (cay and coast) although the total number of sightings was higher offshore. Considering the interactive effect of year, season, and habitat, long-term studies are needed, in both seasons, and among all habitats to account for variation. Continued broad-scale surveys, along with metapopulation analysis would fine-tune the understanding of specific sites, enhancing integrated coastal zone management for protected species and their habitat systems.

The coastal zone of Belize is home to the largest recorded number of the threatened Antillean manatee (Trichechus manatus manatus) within the species' Caribbean range. The objectives of my study were: (1) to determine long-term trends in aerial survey counts and indices of the manatee population in the coastal zone of Belize; and (2) to examine the seasonal change in manatee distribution among habitats in the coastal zone. Standardized extended-area aerial surveys were conducted along the entire coastline of Belize in the dry and wet seasons of 1997, and 1999 - 2002. Manatees were counted in five habitat categories: cay, coast, estuary, lagoon, and river. Total sightings per survey ranged from 90 to 338; the greatest number was counted in the 2002 wet season. Calf percentage ranged from 5 to 13. A slight negative trend in total counts was significant for dry-season, not wet-season surveys, indicating an interactive effect of season and year. Based on analysis of variance, the Abundance Index (transformed manatee sightings per hour) did not differ significantly among years, although it varied significantly within year by season and habitat by season. In applying a spatial approach, the general survey route was buffered 1 km on both sides, and 1 km grids were overlaid and classified by habitat type. The presence or absence of each cell for each survey was used in likelihood ratio tests of the single and interactive effect of season and habitat. The Index for river habitat was higher in the dry season, while cay habitat was higher in the wet season. Overall, near-shore habitat (estuary, lagoon, and river) showed a higher Index than did the offshore habitat (cay and coast) although the total number of sightings was higher offshore. Considering the interactive effect of year, season, and habitat, long-term studies are needed, in both seasons, and among all habitats to account for variation. Continued broad-scale surveys, along with metapopulation analysis would fine-tune the understanding of specific sites, enhancing integrated coastal zone management for protected species and their habitat systems.

Florida manatees (Trichechus manatus latirostris) live in the shallow, often turbid inland and coastal waters of the southeastern United States. Since their vision is poor (Bauer et al., 2003), other senses probably guide orientation. Previous studies have found that manatees can hear over 40 kHz (Gerstein et al., 1999) and have the capacity for rapid auditory temporal processing (Mann et al., 2005). However, it is not known if manatees have the ability to localize underwater sounds. Two Florida manatees were trained to identify underwater sound source locations using a four-choice discrimination paradigm. Three broad-band signals ( 0.2 - 20, 6 - 20, and 0.2 2kHz) were tested at four durations (3,000, 1,000, 500, and 200ms) and two tonal signals (4 and 16kHz) were tested with a 3,000ms duration. A total of 1,008 test trials were analyzed per subject. Both manatees learned the task easily, and could localize all of the test signals at a performance rate well above the 25% chance level. Within all of the broad-band conditions, performance accuracy ranged from 93% - 79% for Buffett, and 93% - 51% for Hugh. Broad-band signal duration did not have an effect on performance accuracy with Buffett who ranged from 89% to 87%, but did with Hugh who ranged from 87% - 58%. Broad-band frequency type did not have an effect on performance accuracy with Buffett who averaged 90%, 86%, and 89%, but may have with Hugh who averaged from 76%, 68%, and 65% at the 0.2 20, 6 20, and 0.2 2 kHz conditions. Both animals performed above chance levels with the pure tone signals, but at a much lower accuracy rate with Hugh at 49% and 32% and Buffett at 44% and 33% with the 4 kHz and 16 kHz conditions. Results from this experiment provide information about the manatees ability to localize different types of sounds in a controlled environment. This knowledge is important for understanding how manatees detect and localize noise generated from conspecifics and boat engines and contributes to making competent conservation management decisions about these endangered marine mammals.

Submitted by Celso Magalhaes (celsomagalhaes@ufrrj.br) on 2017-06-07T11:15:45Z No. of bitstreams: 1 2015 - Uiara Hanna Ara?jo Barreto.pdf: 2769988 bytes, checksum: cebc9db54d83f27429944a782944b7d6 (MD5) / Made available in DSpace on 2017-06-07T11:15:45Z (GMT). No. of bitstreams: 1 2015 - Uiara Hanna Ara?jo Barreto.pdf: 2769988 bytes, checksum: cebc9db54d83f27429944a782944b7d6 (MD5) Previous issue date: 2015-06-22 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / The study of the wildlife has increased because many species find themselves threatened with extinction, the Amazonian manatee (Trichechus inunguis) is classified as vulnerable. The main factors that aggravate this situation is the slow reproduction of these animals, as well as poaching, which still occurs in the Amazon region, increased the need for preservation. The study of this kind is crucial to generate knowledge about the same, contributing in an attempt to reverse your current frame. Research on diagnostic imaging for manatees are rare, especially when directed ultrasound, it is an excellent technique to be carried out in wild animals, for not being invasive and provide real time information of each body. This abdominal ultrasound research will generate normal data, in the future we can diagnose diseases. The aim of this study was to standardize the examination technique and describe the abdominal ultrasound findings in inunguis Trichechus bred in captivity, increasing knowledge about the species and consequently aid in the diagnosis of diseases. The survey was conducted with 18 animals to describe the normal sonographic anatomy in the abdominal cavity of Amazonian manatee. During abdominal scan was viewed homogeneous liver, hyperechoic contoured edges and regular; the gallbladder showed anechoic content with regular and thin wall; stomach was present gas content, hypoechoic and thin wall. In the caudal abdomen visibilizou urinary bladder in piriformis format, bit full, hyperechoic wall and content ranging from anechoic and hypoechoic. Evaluated the subcutaneous tissue, which can differentiate the layer of skin, fat, muscle and peritoneum. The ultrasound examination obtained satisfactory results in this study, concluding that an efficient technique for evaluation in Amazonian manatee / O estudo com a fauna silvestre vem crescendo devido muitas esp?cies encontrarem-se amea?adas a extin??o, como o peixe-boi amaz?nico (Trichechus inunguis) que est? classificado como vulner?vel. Os principais fatores que agravam esse quadro ? a reprodu??o lenta destes animais, al?m da ca?a predat?ria, que ainda ocorre na regi?o amaz?nica, aumentando a necessidade de preserva??o. O estudo desta esp?cie ? fundamental para gerar conhecimento sobre a mesma, contribuindo na tentativa de reverter o seu quadro atual. Pesquisas sobre diagn?stico em imagem em peixe-boi s?o raras, principalmente quando direcionada a ultrassonografia, trata-se de uma excelente t?cnica para ser realizada em animais silvestres, por n?o ser invasiva e fornecer informa??es em tempo real de cada ?rg?o. Esta pesquisa de ultrassonografia abdominal ir? gerar dados de normalidade, para no futuro conseguirmos diagnosticar patologias. O objetivo do presente estudo foi padronizar a t?cnica de exame e descrever os achados de ultrassonografia abdominal em Trichechus inunguis criados em cativeiro, aumentando o conhecimento sobre a esp?cie e como consequ?ncia auxiliar no diagn?stico de patologias. A pesquisa foi realizada com 18 animais para descri??o da anatomia ultrassonogr?fica normal em cavidade abdominal de peixe-boi amaz?nico. Durante varredura abdominal foi visualizado f?gado homog?neo, hiperec?ico com contornos e bordos regulares; a ves?cula biliar apresentou conte?do anec?ico com parede regular e fina; no est?mago estava presente conte?do gasoso, parede hipoec?ica e fina. No abd?men caudal visibilizou a ves?cula urin?ria em formato piriforme, pouco repleta, parede hiperec?ica e conte?do variando entre anec?ico e hipoec?ico. Avaliou-se o tecido subcut?neo, onde pode-se diferenciar a camada de pele, gordura, muscular e perit?nio. O exame de ultrassonografia obteve resultados satisfat?rios neste estudo, concluindo ser uma t?cnica eficiente para avalia??o em peixe-boi amaz?nico

Photo-identification and telemetry studies have reported limited instances in which Florida manatees (Trichechus manatus latirostris) traversed the coastline of Florida. Manatee calls were recorded from four different locations in Florida. Using a single hydrophone, calls were recorded at two sites on the east coast and two sites on the west coast of Florida. These locations were representative of the four manatee management zones adopted by the Florida Fish and Wildlife Conservation Commission and the United States Geological Service. These include the Northwest, Southwest, Atlantic and Upper St. John’s River regions. Seven hundred calls from each site were selected for analysis to further quantify call parameters and evaluate differences within and across geographical locations. Fundamental and dominant frequencies, call duration, number of harmonics, and the percentage of frequency modulation, were measured, in addition to the first and third quartile frequency, energy, interquartile bandwidths. Spectrograms and statistical differences in frequency modulated vocalizations (one-way anova, p <0.0001) were used to classify calls into six categories; whistles, squeaks, high squeaks, squeak-squeals, chirps and squeals. (1) Whistles are narrow tonal calls with no frequency modulation. The frequency range for these calls is 1800 – 5000 Hz and a duration of 0.080 – 0.382 s. (2) Squeaks are more complex frequency modulated calls with 2 - 4 harmonics even at low intensities. They have a duration of 0.052 – 0.681 s and a frequency range of 562.1 – 10,312.5 Hz. (3) Squeals have no frequency modulation, are wideband signals, have a duration of 0.077 – 0.562 s and a frequency range of 468.4 – 6656.8 Hz. (4) Squeak-squeals have characteristics of squeaks and squeals. They may or may not have frequency modulation, have a duration of 0.090 – 0.612 s and a frequency range of 750.1 – 8625.5 Hz. High squeaks are strongly modulated, have a duration of 0.131 – 0.236 s, and a frequency range of 1,300.2 – 10,628.8 Hz. Chirps are characterized by having two or three dominant energy bands that are separated by short gaps, have frequency modulation, a duration of 0.031 – 0.283 s, and a frequency range of 1,265.3 – 6937.5 Hz. Since it was unknown which manatee was eliciting the call, group means of the variables center fundamental frequency and first and third quartile frequency where used to analyze differences or similarities within and between coastlines. A T test was used to compare means at a 95% confidence interval. Spectrograms of the categorized calls were analyzed within and between coastlines. Results from t-tests suggest there are no differences in calls for the variables studied within and between east and west coast populations of the Florida manatee (all p values > 0.05). Correlation of spectrographic images suggests there is a high degree of similarity among categorized calls and calls seem to differ mostly in call contour.

Polycyclic aromatic hydrocarbons (PAH) have been linked to cancer in humans. Subsequently, 16 of them were listed as priority pollutants by the Environmental Protection Agency in the Clean Water Act. The Florida manatee (Trichechus manatus latirostris) is an herbivorous endangered species that could have the potential to accumulate these compounds. The waters they inhabit have been shown to have PAH concentrations in the sediment from 0.035 μg/g w.w. (wet weight) to 0.686 μg/g w.w. PAH bioaccumulate due to their lipophilic nature and the manatee has a thick blubber layer that may allow for the accumulation of these compounds. Forty-eight archived subcutaneous manatee blubber samples were collected from Florida Fish and Wildlife Conservation Commission Marine Mammal Pathobiology lab and analyzed for 16 known priority pollutant PAH. Samples were then compared to a standard using HPLC analysis. Concentrations were found to range from 0.001 μg/g w.w. to 84.84 μg/g w.w. All 16 priority pollutant PAH were found, however not all 16 were found in any one animal. Forty-six of forty-eight manatee samples analyzed were found to have at least one form of PAH. The number of occurrences of each PAH out of 48 samples ranged from 1-19. The highest average PAH concentration was acenaphthylene with 12.60 μg/g w.w. There was no significant difference (p-value >0.10) between total, carcinogenic and noncarcinogenic PAH, with levels of 2.01 μg/g w.w., 2.18 μg/g w.w. and 1.84 μg/g w.w. respectively. No significant difference (p-value >0.10) was found between year or location of carcass recovery as well as sex of manatee. Averages ranged between 0.02 μg/g w.w. and 18.92 μg/g w.w. for year and 0.15 μg/g w.w. and 5.68 μg/g w.w. for location. Male average levels were 5.21 μg/g w.w., while female averages and perinatal averages were 1.51 μg/g w.w. and 1.147 μg/g w.w. respectively.

Belize has been identified as an important location for Antillean manatees (Trichechus manatus manatus), harboring the highest known population density of this subspecies. Information about their dietary habit is important in determining habitat requirements and aiding in conservation efforts. The main objective of this study was to identify the key plant species consumed by manatees in Belize and to establish differences in diet based on location, sex, size classification, and season. Samples were collected from two different locations within Belize where manatees are known to aggregate: Southern Lagoon and the Drowned Cayes off of Belize City. The contents of thirteen mouth, six digestive tract (stomach, duodenum and colon), and 124 fecal samples were analyzed. Five species of seagrasses (Halodule wrightii, Thalassia testudinum, Ruppia maritima, Syringodium filiforme, and Halophila sp.) made up the highest percentage of plants consumed; undigested rhizome was most prevalent. A vascular plant, the red mangrove (Rhizophora mangle), was identified as an important food item of manatees in Belize. Algae (Chara sp., Lyngbia sp., and Ulvasp.) and invertebrates (diatoms and sponges) were represented as well. These items are comparable to other reports of manatee diets in areas near Belize and areas with similar habitat. Variation in the percentage of seagrass, mangrove, and algae consumption was analyzed as a 4-factor factorial Analysis of Variance (ANOVA) with main effects and interactions for locality (Southern Lagoon and the Drowned Cayes), sex, size classification (>245 cm & ˂245 cm), and season (December – May and June – November). Sex and season did not influence diet composition; differences for locality and size classification were observed. Seagrass was more often consumed in Southern Lagoon (P = 0.03), whereas mangroves and algae were more prevalent in the Drowned Cayes (P = 0.03). No differences among size classifications in consumption of seagrasses or mangroves were observed. A significantly higher number of samples from adults (>245 cm) than juveniles (˂245 cm) contained algae (P = 0.04). This is most likely attributed to inexperience in foraging. Findings from these results suggest that diet composition analysis can be used to interpret Antillean manatee habitat and resource utilization and can aid in the conservation of this endangered species.

Living at the northern limits of its geographic range, the Florida manatee is particularly susceptible to cold stress-related mortality during the winter months, with most deaths occurring in the lower two-thirds of the state. Contributing to this cold stress susceptibility is the manatee's limited physiological and behavioral responses available when thermally stressed. While capable of migrating south in response to falling water temperatures, manatees must still find warm water when ambient river temperature drops below 20°C for more than a few days. This is in part due to the species low metabolic rate, limited capacity for thermogenesis, and limited ability to raise its metabolic rate. Prolonged exposure to cold temperatures may result in cold stress syndrome, which involves a number of potentially life-threatening, if not fatal physiological changes. Survival during the winter months is therefore, dependent upon the manatee's ability to balance basic physiological needs, primarily the need to forage and to obtain fresh water with the need to stay warm. When identifying which animals are most susceptible and where, analyses of statewide manatee mortality records from 1996 through 2011 (n = 823) indicated that, size and location matter. Medium to large-sized calves accounted for the majority of documented death from cold stress (46.6%), while subadults and small calves were the least represented size classes (14.3 % and 9.5%, respectively). Adults slightly outnumbered subadults (15.8%). Males outnumbered females in all size classes but gender differences were not statistically significant. With regards to location, two areas of the state, the southwest and central east coasts showed the highest incidents of cold stress-related mortality. Both are regions with no primary, natural warm-water springs and whose principal warm-water refugia are power plant effluents. Brevard County on the central east coast is the area most at risk during cold weather events accounting for more than 25% of all cold stress deaths statewide. Warm-water sites within this region are few and relatively underrepresented in the literature in an area well-studied in terms of manatee abundance and distribution relative to the operational power plant. Results from cold stress data analyses emphasize the importance of identifying and characterizing the physical attributes of both known and suspected secondary warm-sites used by manatees in this region for both long and short term protection of the species, and its critical habitat. Three locations within Brevard County identified as passive thermal basins (PTBs), and classified as secondary warm-water sites, have been documented supporting in excess of 100 manatees on numerous occasions, and during winters of varying severity. Unique in physical appearance, distance to forage, hydrology including thermal profiles, and when it was used by manatees, each site challenged the accepted definitions and criteria of what constitutes an acceptable and appropriate warm-water site. Through analyses of photo-identification records, site fidelity at two of these warm-water sites, the Berkeley Canal and the Desoto Canal, was established for a minimum of 20 highly identifiable animals, 15 of which used adjacent sites within the same year, and 6 that used both sites but during different years. Observations of daily use patterns within the sites supported optimization of thermoregulation through adjustments in both vertical and horizontal movement, the latter of which seemed to follow the path of the sun. Manatees using the sites also made use of bottom sediment presumably to stay warm at all three locations. Temperature data indicated that water temperatures monitored in the sediment at secondary sites were some of the highest in the county. The predictable movements during all but the coldest weather fronts indicated that manatees utilized these sites during the early morning and afternoon hours when ambient river temperatures were coldest, gradually returning to the river to feed as ambient temperatures began to rise later in the afternoon. The availability of PTBs in proximity to primary warm-water sites within the region may provide an important component needed for manatees to successfully balance the need to forage with the need to stay warm by providing a network that allows for more efficient foraging while reducing exposure to sub-critical ambient river temperatures. The challenge of balancing the need to forage and to maintain homeostasis in the face of thermal stress is complex. This complexity was best approached and better understood through use of a manatee energetics model. The model was designed to facilitate simulation of an unlimited number of different case scenarios involving the exposure of virtually created manatees to a variety of winter conditions as might be experienced by real manatees in a natural system. Sixty-four different simulations were run using six virtual manatees of differing ages, gender, physical parameters, and knowledge of warm-water sites. Simulations were conducted using actual winter water temperature data from Brevard secondary sites and the ambient river from both a mild and a severe winter season. Outcomes, measured as changes in physical parameters indicative of body condition (i.e. mass, percent body fat, blubber depth, girths, etc.), showed that all else being equal, calves in the 2 year-old range fared poorly in all scenarios when compared to individuals of larger size. Subadults fared better than larger adults. This outcome illustrates the complex relationship between size, energy requirements and the synergistic effects of body mass, body fat and blubber thickness on SA:V ratio. Model outcomes agree closely with manatee cold stress mortality analyses predicting that medium to large-sized calves are most susceptible to CS, followed by adults, then subadults. Because all models are simplifications of complex systems, the manatee energetics model is not without its flaws and limitations. The current version of the model could not predict the point at which cold stress mortality would occur. However, a cold stress warning system incorporated into the design alerts the user if potential CSS is likely based on changing physical parameters. Another limitation was the inability of the model to account for the behavioral plasticity of individual subjects since virtual manatees respond to water temperatures based on the user defined rules. A number of additional limitations related to gaps in existing manatee data the gaps were identified and defined. Despite these gaps, the model is designed to allow for incorporation of additional interactions, feedback loops and relevant data as it becomes available and as additional physiological interactions and energy requirements are more clearly defined. Sensitivity analyses, a feature of the model that allowed for modifications in a number of physical as well as environmental parameters, provided an otherwise unlikely opportunity to see how incremental changes in input values, specifically the starting values for mass, percent body fat and blubber depth affected the model's outcome. Ultimately the goal of the model was to facilitate a better understanding of complex relationships by challenging our preconceived understanding of the manatee and its environment.

The West Indian manatee (Trichechus manatus) is an herbivorous marine mammal that occupies freshwater, estuarine, and marine habitats. Despite being considered endangered, relatively little is known about the feeding ecology of either of the two recognized subspecies, the Florida manatee (T.m. latirostris) and Caribbean or Antillean manatee (T.m. manatus). A better understanding of their respective feeding preferences and habitat use is essential to establish criteria on which conservation plans can be based. The present study expands on previous work on manatee feeding ecology by both assessing the application of stable isotope analysis to manatee tissue and providing critical baseline parameters for accurate isotopic data interpretation. The present study was the first to calculate stable isotope turnover rate in the skin of any marine mammal. Stable carbon and nitrogen isotope ratios were examined over a period of more than one year in the epidermis of rescued Florida manatees that were transitioning from a diet of aquatic forage to terrestrial forage (lettuce) in captivity. Mean half-life for 13C turnover in manatee epidermis was 55 days and mean half-life for 15N turnover was 42 days. Due to these slow turnover rates, carbon and nitrogen stable isotope analysis in manatee epidermis is useful in summarizing average dietary intake over a long period of time rather than assessing recent diet. In addition to turnover rate, a diet-tissue discrimination value of 2.8‰ for 13C was calculated for long-term captive manatees on a lettuce diet. Turnover and diet-tissue discrimination results were subsequently used to interpret carbon and nitrogen stable isotope data in epidermis samples collected from free-ranging manatees in Florida, Belize, and Puerto Rico. This study was the first application of stable isotope analysis to Antillean manatees. Regional differences in stable isotope ratios in manatee skin were consistent with ratios in plant samples collected in those regions. Signatures in the skin of manatees sampled in Belize and Puerto Rico indicated a diet composed mainly of seagrasses, whereas those of Florida manatees exhibited greater variation. Mixing model results indicated manatees sampled from Crystal River and Homosassa Springs had an overall average intake of primarily freshwater vegetation whereas manatees sampled from Big Bend Power Plant, Ten Thousand Islands, and Warm Mineral Springs fed primarily on seagrasses. Possible diet tissue discrimination values for 15N ranged from 1.0 to 1.5‰. Stable isotope analysis can be successfully applied to interpret manatee feeding behavior over a long period of time, specifically the use of freshwater vegetation vs. seagrasses, and can aid in improving conservation efforts.

This thesis is a research design that will serve as a baseline for further research and as a more inclusive interpretation at the Judah P. Benjamin Memorial at the Gamble Plantation Historic State Park in Ellenton, Florida. It reviews the history and archaeology of Robert Gamble's nineteenth-century enslaved labor-worked sugar plantation, focusing on how the demands of this capitalistic enterprise were expressed in the plantation's culture and on the landscape. This thesis reviews the literature on the archaeology of slavery in the United States and the Caribbean to provide a critical lens through which new directions in research might be seen and conceived. At the same time, it reviews the archaeological and historical resources associated with the plantation. The thesis is motivated by the following main research question: What was the nature of slavery on the Gamble Plantation? Subsidiary questions include the following: How was slavery evident in the plantation landscape? What were the day-to-day lifeways and activities of the enslaved labor force on the Gamble Plantation? While direct evidence of slave life at the Gamble Plantation might be scant, through a consideration of the literature we can infer how slave activity might be reflected in the archaeological record. It offers research methods to assist in obtaining answers to how is this plantation's landscape built which might illustrate slavery activity. The thesis also proceeds from the assumption that Gamble Plantation's history can be made more complete and relevant to park visitors. Public presentation is critically examined and stakeholders are identified. It concludes with suggestions on how can a more comprehensive and inclusive history can be told.