Thesis (Ph. D.)--Montana State University--Bozeman, 2007. / Typescript. Chairperson, Graduate Committee: Daniel Goodman. Includes bibliographical references (leaves 124-144).

Scientists are extremely concerned that the Florida manatee, Trichechus manatus latirostris, does not have a sufficient population number nor reproductive rate to ensure long-term species viability. This research was done to investigate aspects of boater behavior in an effort to determine measures that might decrease boat-manatee collisions and help researchers plan intervention strategies in related areas. Initially, boat data was collected over a period of several months at a Miami waterway. Next, a detailed phone survey of boat owners was conducted. Although most boaters were found noncompliant with the speed zone, several questions from the survey showed that most valued manatees and almost half wanted them to remain listed as endangered. This is very encouraging as boater support for the manatee is possibly one of the most important indicators of manatee chances for survival. Suggestions included requiring mandatory boating classes and informing boaters of faster routes to their destinations.

First described by Plate (1906), Pyrodinium bahamense is a bioluminescent dinoflagellate species which forms a resting cyst as part of its life cycle.  P. bahamense forms large dense cyst beds in the flocculent layer of sediments and can remain dormant for decades before excysting and forming blooms.  The Atlantic strain has recently been discovered to produce a neurotoxin called saxitoxin.  Although saxitoxins are most commonly associated with paralytic shellfish poisoning, saxitoxin produced by P. bahamense has been implicated in a number of human illnesses following the consumption of contaminated puffer fish originating from the Indian River Lagoon, Florida.  The discovery of P. bahamense cysts on seagrass blades during an ongoing bloom raised the question of whether manatees, whose diet is composed mainly of seagrass, could be at risk of exposure to saxitoxins.  The aim of this study was to determine whether P. bahamense cysts can be digested in the manatee gastrointestinal tract or if they would pass through intact.  There are no known methods for purifying P. bahamense cysts from the contents of the manatee gastrointestinal tract, so it was necessary to develop an appropriate protocol using cysts purified from sediments in Tampa Bay, Florida.  These methods were then to be used to test whether P. bahamense cysts added to manatee digesta break down over time, and also to test archived digesta samples for presence of cysts.  A successful method for purifying cysts from manatee digesta could not be developed during the span of this study, and so no conclusions could be drawn about the likelihood of digestion.  However, archived samples were found to contain P. bahamense cysts, confirming that manatees are ingesting them while feeding.

Thesis (M.S.)--University of Florida, 2004. / Title from PDF title page (viewed on July 7, 2005). Includes vita. Includes bibliographical references (p. 83-85).

The West Indian manatee tongue was examined macroscopically, light microscopically, and electron microscopically (scanning and transmission). The tongue was slender, muscular, and firmly fixed in the oral cavity. Only the cranial tip was free and mobile. Numerous filiform papillae were distributed over the dorsal surface of the rostral lingual region. Caudal to the filiform papillae, multiple raised, round papillae were distributed over the majority of the dorsum. Fungiform papillae were restricted to the lateral margins of the tongue. Caudally, the dorsal and lateral regions showed numerous open fossae and pits. Microscopic examination showed the majority of the lingual dorsum to be covered with a thick stratified squamous epithelium. The caudal dorsal and lateral open pits led to well-developed mucous salivary glands. Foliate papillae, located on the caudal region of the tongue, contained taste buds embedded in the epidermis. Glands within the foliate papillae were mostly mucous, though some seromucous glands were evident. Throughout the tongue, striated muscle was abundant below the epidermis. Blood vessels, lymph channels, and nerve fibers were freely distributed throughout the intermuscular stroma. Nerve fibers reacted positively with neuron specific enolase antibody throughout the lingual structure, including nerve bundles, muscle bundles, glands, and taste buds. Electron microscopy revealed cytoplasmic vacuoles juxtaposed to the nucleus in the stratum spinosum of the foliate papillary region. / Master of Science

Thesis (M.S.)--Georgia Southern University, 2007. / Title from PDF title page (viewed on Feb. 19, 2008). Electronic version approved: May 2007. Vita. Includes bibliographical references.

Thesis (Ph. D.)--University of Missouri-Columbia, 2003. / Typescript. Vita. Includes bibliographical references (leaves 520-556). Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 2003. / Typescript. Vita. Includes bibliographical references (leaves 520-556). Also available on the Internet.

The Florida manatee (Trichechus manatus latirostris) is native to Florida and the Indian River Lagoon. Harbor Branch Oceanographic Institute (HBOI) is located in Indian River Lagoon and is frequently visited by manatees. The Manatee Project was created in 2009 to document and photograph the manatees visiting HBOI. Analyzing photographs of 146 manatee that visited HBOI showed that a majority of the injuries sustained were caused by boats. 97% of the manatee had at least one propeller injury and 31% of the manatee had at least one skeg injury. Other non-boat related injuries seen in the images included cold stress and entanglement injuries. This study looked at the prevalence of scar by anatomical region, the cause of injury, and compared injury locations between male and female manatees. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2018. / FAU Electronic Theses and Dissertations Collection

Florida manatees are semisocial marine mammals that vocalize when interacting with conspecifics and to maintain contact with offspring. While many aspects of their biology have been studied, there is a dearth of information on the diversity and complexity of vocal behavior during social, nonsocial, and stressful situations. Investigations of vocal communication repertoires which define, categorize, and correlate varied call types with behavior are needed in order to understand the behavioral and social function of associated calls. Arguably the most important social bond in manatees is the period of cow/calf dependency and empirical evidence indicates cows recognize the vocalizations of offspring. Exploration of individually distinctive vocal features can provide insight on which parameters might be salient to facilitate recognition between cows/calves. This study is focused on vocal communication in Florida manatees, how calls are structured, utilized and function while animals are distressed and during social interactions in their shallow water habitats. Hydrophones recorded vocalizations from individual calves and manatees in different behavioral contexts and varying size aggregations. Analysis of the vocal repertoire indicated manatee vocalizations can be parsed into five broadly defined call types which include the hill-shaped high squeak, tonal squeak, noisy squeal, two toned chirp, and the combinatorial squeak-squeal. Furthermore, the high squeak is likely a discrete call whereas the others are graded and do not have strict boundaries between call types (Chapter 2). Broadly defined call types were used to explore call usage with variations in behavior, group size, and group composition (Chapter 3). Manatees vocalized using few call types and altered structural parameters depending on behavioral state. Calls were longer and more frequency modulated when stressed. Vocalizations produced while cavorting were higher in entropy and more frequency modulated than when manatees were resting or feeding. Vocalizations obtained from individual calves suggest that the high squeak is a stereotypical call that is produced by smaller calves. All calves had individually distinctive acoustic features that could potentially be used in recognition (Chapter 4). Lower fundamental frequencies and higher emphasized frequencies from smaller calves suggest that the fundamental frequency may not be a reliable indicator of body size in calves. This research increases our knowledge of the vocal behavior and call characteristics of the Florida manatee. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2020. / FAU Electronic Theses and Dissertations Collection