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Manatee

Manatees are large, fully aquatic, herbivorous mammals comprising the genus Trichechus in the family Trichechidae and order Sirenia, distinguished by their rounded bodies, paddle-like forelimbs, flattened tails, and absence of hind limbs. ^[1]^[2] They inhabit shallow, warm coastal waters, rivers, estuaries, and lagoons across tropical and subtropical regions, including the Caribbean Sea, Gulf of Mexico, Amazon and Orinoco basins, and West African coasts. ^[1]^[3] Three extant species exist: the West Indian manatee (T. manatus), African manatee (T. senegalensis), and Amazonian manatee (T. inunguis), with adults typically measuring 2.7 to 4.5 meters in length and weighing 200 to 600 kilograms. ^[2]^[4] Primarily sirenians feed on aquatic vegetation such as seagrasses and freshwater plants, consuming up to 10% of their body weight daily and spending much of their time grazing. ^[1]^[3] Reproduction involves a gestation period of approximately 12 months, yielding usually a single calf that nurses for up to two years, with breeding intervals of two to three years. ^[5] All manatee species face significant threats from habitat degradation, boat collisions, and incidental entanglement, leading to their classification as vulnerable or endangered under various conservation frameworks, including protections under the U.S. Endangered Species Act. ^[1]^[6]^[7]

Etymology

Origins and Linguistic Evolution

The term "manatee" derives from the Spanish manatí, first attested in the 1530s, which was borrowed from indigenous Caribbean languages of the Carib or Taíno peoples, where it meant "breast" (manati or manatɨ), likely referring to the animal's rounded pectoral glands or mammary-like appearance.^[8] ^[9] This Proto-Cariban root manatɨ appears in related languages such as Kari'na manaty and Trió manatï, indicating a shared linguistic heritage among Arawakan and Cariban-speaking groups in the Antilles and South America who encountered the West Indian manatee (Trichechus manatus).^[9] Early European explorers, including Spanish colonizers in the 16th century, adopted the term during voyages to the Caribbean and Florida, where manatees were abundant; the Spanish manatí may have been misinterpreted by some as implying "with hands" due to the flipper-like forelimbs, though primary etymological evidence supports the "breast" connotation.^[10] The word entered English by 1555, as recorded in nautical and natural history texts describing sirenians observed off West Indian coasts, evolving from direct phonetic borrowing without significant alteration.^[11] Over time, "manatee" became the standard English designation for the genus Trichechus, distinguishing it from related sirenians like the dugong, whose name derives from Malay duyong via Tagalog, unrelated to Caribbean roots.^[12] This linguistic path reflects broader patterns of colonial-era nomenclature, where indigenous terms for local fauna were Latinized or anglicized for scientific use, as seen in early accounts by explorers like Gonzalo Fernández de Oviedo y Valdés in his 1535 General y Natural Historia de las Indias.^[13] No evidence supports alternative derivations, such as from Latin manus ("hand"), despite superficial morphological similarities.^[8]

Taxonomy and Phylogeny

Classification and Species

Manatees are classified within the order Sirenia, a group of herbivorous, fully aquatic mammals that also includes the dugong family Dugongidae.^[1] The family Trichechidae encompasses all manatee species, characterized by rounded, paddle-shaped tails, unlike the fluked tails of dugongs.^[14] The genus Trichechus, established by Carl Linnaeus, contains the three extant manatee species, with no other genera in the family.^[15] The West Indian manatee (Trichechus manatus) inhabits coastal and estuarine waters from the southeastern United States to northeastern South America, including the Caribbean.^[16] It comprises two subspecies: the Florida manatee (T. m. latirostris), restricted to U.S. waters, and the Antillean manatee (T. m. manatus), found in the Caribbean and northern South America; these differ in cranial measurements and geographic range.^[1] Adults typically measure 2.8 to 4.0 meters in length and weigh 400 to 500 kilograms, with nail-bearing flippers.^[2] The Amazonian manatee (Trichechus inunguis) is the only strictly freshwater manatee species, confined to the Amazon River basin in South America.^[17] It is the smallest species, reaching up to 2.8 meters and 500 kilograms, and lacks nails on its flippers—reflected in its specific epithet meaning "nailless."^[17] Genetic and morphological analyses confirm its distinctiveness from other Trichechus species.^[18] The African manatee (Trichechus senegalensis), also known as the West African manatee, occurs in coastal marine, estuarine, and riverine habitats from the Senegal River to Angola.^[2] Comparable in size to T. manatus (up to 4.5 meters and 500 kilograms), it features more protruding eyes, a blunter snout, and subtle cranial differences distinguishing it taxonomically.^[19]

Evolutionary History

The order Sirenia, encompassing manatees and their relatives, originated around 50 million years ago in the early Eocene epoch from terrestrial, herbivorous ancestors within the Tethytheria clade, which also gave rise to proboscideans like elephants; these ancestors likely resembled wading mammals exploiting coastal vegetation.^[20]^[21] Fossils of Pezosiren portelli, dated to approximately 48 million years ago from Jamaica, represent the earliest known sirenian and demonstrate a transitional form between terrestrial and aquatic lifestyles, featuring a quadrupedal skeleton with weight-bearing hind limbs alongside a sirenian-style skull, dentition, and torso adapted for shallow-water foraging.^[22]^[23] Subsequent sirenian evolution involved progressive adaptations to obligate aquatic habitats, including the complete loss of external hind limbs and their associated pelvic girdle detachment from the vertebral column, as well as the development of a broad, horizontal tail fluke enabling efficient propulsion through vertical oscillations; these changes were driven by selective pressures for enhanced maneuverability in marine environments, where abundant seagrasses provided food but demanded streamlined forms to evade predators and optimize energy use in water's higher density.^[21]^[24]^[25] The manatee lineage (family Trichechidae) emerged later, with the West Indian manatee (Trichechus manatus) showing fossil and genetic evidence of continuous presence in Florida for at least the past 12,000 years, coinciding with post-glacial habitat stabilization rather than recent anthropogenic introduction.^[26]^[27]

Physical Characteristics

Anatomy and Morphology

Manatees possess a robust, fusiform body form optimized for buoyancy and slow aquatic movement, typically attaining adult lengths of 3 to 3.5 meters and weights of 400 to 600 kilograms, though exceptional individuals exceed 4 meters and 1,500 kilograms.^[28] Females consistently surpass males in size across species.^[29] The torso is barrel-shaped, lacking hind limbs and external hindquarter distinctions, with the integument consisting of thick, wrinkled, gray to dark brown epidermis sparsely covered in short, bristle-like hairs that provide minimal insulation but facilitate tactile detection.^[30] Pectoral flippers, modified forelimbs, measure up to 0.8 meters in span and feature five embedded digits sheathed in leathery skin, terminating in three to four keratinous nails; these structures enable steering, substrate contact, and object manipulation, with underlying osteology retaining phalangeal elements homologous to terrestrial mammal hands.^[31] The caudal region culminates in a horizontally flattened, rounded fluke divided into two lobes, generating thrust via dorsoventral oscillations at frequencies of 1 to 2 hertz, propelling the animal at sustained speeds of 5 to 7 kilometers per hour.^[31] Absent hind limbs reflect evolutionary paedomorphosis, with vestigial pelvic girdle bones embedded internally, unconnected to the axial skeleton.^[30] Cranially, the head is dorsoventrally compressed with a blunt muzzle, diminutive eyes positioned laterally, and no external pinnae, though subcutaneous auditory bullae amplify underwater sound reception.^[32] Facial vibrissae form distinct perioral fields—up to nine patches of innervated bristles—serving prehensile and mechanosensory roles in foraging and exploration, distinct from sparse body pelage.^[33] Dentition comprises continuously erupting, "marching" molars in a serial replacement system, with four generational sets of six to eight teeth each, adapted for grinding abrasive vegetation; incisors and canines are absent.^[31] Internally, the ribcage houses paired lungs extending longitudinally along the dorsal vertebral column, spanning up to 3 meters and comprising 15 to 20 percent of body volume for enhanced buoyancy control, separated from ventral viscera by a transverse septum.^[34] The gastrointestinal tract dominates abdominal volume, with intestines exceeding 45 meters in length to accommodate herbivorous fermentation, while the liver and kidneys exhibit lobulated morphologies supporting osmotic regulation in brackish environments.^[31] Skeletal density approaches that of seawater due to pachyosteosclerosis—thickened, avascular ribs and vertebrae—minimizing energy expenditure on postural maintenance.^[35]

Adaptations to Aquatic Life

Manatees possess morphological traits distinguishing them from terrestrial mammals, such as a robust, streamlined torso, modified forelimbs into paddle-like flippers, and a broadened, horizontal tail fluke, facilitating an exclusively aquatic existence.[web:44][web:42] Their skeletal structure features pachyosteosclerosis, with hyperdense bones that elevate body density to counteract buoyancy from voluminous intestinal gas generated by fermenting low-nutrient aquatic vegetation.[web:6] Physiologically, manatees achieve osmoregulation through multilobulated, reniculate kidneys that produce highly concentrated urine exceeding seawater osmolarity (up to 1,160 mOsm/L) in brackish conditions, while generating dilute urine in freshwater to expel surplus hypotonic intake and maintain internal balance.[web:15][web:10][web:11] This renal versatility supports tolerance for varying salinities in coastal and riverine habitats, though prolonged exposure to full seawater may elevate plasma osmolality without freshwater access.[web:13] Sensory adaptations include densely innervated vibrissae covering the body, particularly facial bristles specialized for tactile detection of submerged vegetation and hydrodynamic cues in low-visibility waters, enabling precise foraging without reliance on vision.[web:27][web:29][web:30] These mechanosensitive hairs function analogously to lateral lines in fish, processing water movements for environmental awareness.[web:31] Thermoregulation poses a limitation, as manatees cannot endure water below 20°C (68°F) for extended durations, incurring cold-stress syndrome akin to hypothermia due to scant blubber insulation and tropical ancestry.[web:20][web:21][web:24] Vascular countercurrent heat exchangers in the tail conserve core warmth but prove insufficient against sustained chill.[web:5][web:37] Growth trajectories underscore their herbivorous niche, with captive Amazonian manatees averaging 0.11 kg/month in males, slower than carnivorous dolphins' rapid early development, prioritizing energy conservation over velocity in a low-caloric diet context.[web:51][web:47][web:54] Lacking predatory defenses beyond bulk, adults face minimal threats, though calves risk crocodilian or shark attacks, reflecting evolved docility in predator-scarce ecosystems.[web:43]

Behavior and Physiology

Locomotion and Sensory Capabilities

Manatees achieve locomotion through undulatory waves propagating along the body, culminating in powerful oscillations of the paddle-shaped caudal fluke, which generates primary thrust.^[36] Forelimb flippers facilitate steering, stability, and precise maneuvering, allowing capabilities such as tight turns and somersaults.^[37] Observed swimming velocities typically range from 0.06 to 1.14 m/s (0.13–2.55 mph), corresponding to routine foraging and transit, though short bursts can exceed 15 mph (24 km/h) during predator evasion or rapid escapes.^[36]^[38] This propulsion efficiency stems from their fusiform body shape and low metabolic demands, minimizing energy expenditure in shallow, coastal habitats.^[39] Manatees exhibit sensory adaptations optimized for murky, low-light aquatic environments, with vision providing limited utility; they possess moderate acuity for detecting brightness gradients, object sizes, and basic patterns but demonstrate myopia and reliance on other modalities for detailed perception.^[40] Auditory capabilities encompass a broad frequency range of approximately 400–46,000 Hz, enabling detection of conspecific vocalizations such as squeaks and chirps used in communication, though sensitivity peaks at frequencies relevant to social and environmental cues.^[41] Tactile sensing dominates via densely distributed vibrissae—roughly 2,000 facial and 3,300 postcranial hairs—that innervate specialized follicles acting as hydrodynamic receptors, akin to a lateral line system, for discerning water currents, prey proximity, and obstacles through mechanosensory deflection.^[42]^[43] These vibrissae support fine-scale discrimination during feeding and navigation, compensating for visual deficits in turbid conditions.^[44] Olfactory detection occurs via nares, aiding in chemosensory orientation to food sources or mates, though efficacy diminishes in saline waters.^[45]

Feeding Mechanisms and Diet

Manatees are obligate herbivores that primarily consume aquatic vegetation, including seagrasses, algae, and vascular plants, as evidenced by stomach content analyses from necropsied individuals.^[46]^[47] In the Indian River Lagoon, pre-seagrass die-off samples showed dominance of seagrasses, while post-die-off contents shifted to algae (49.5%) and remaining seagrasses (34%).^[46] These analyses, derived from direct examination of digestive tracts, confirm selective intake of available submerged and emergent plants, with over 60 species documented across habitats, though preferences favor nutrient-dense options like certain seagrasses in the wild.^[4]^[48] Daily consumption ranges from 4% to 9% of body weight in wet vegetation, equating to 15-49 kg (32-108 lb) for an average adult manatee weighing approximately 500 kg.^[49] This high-volume intake compensates for the low nutritional density of aquatic plants, with individuals spending 5-8 hours foraging daily.^[50] In captivity, opportunistic ingestion of invertebrates or fish occurs but constitutes negligible dietary contributions in wild populations, where empirical evidence from stomach and fecal samples shows exclusively plant matter.^[47] Feeding involves prehensile lips that grasp vegetation, followed by grinding via specialized dentition lacking incisors or canines. Manatees possess 6-8 molariform teeth per jaw quadrant in a unique "marching molars" system, where new molars erupt at the rear and migrate forward as anterior ones wear from abrasive silica in plants, ensuring continuous replacement throughout life.^[40]^[4] This adaptation supports processing tough, fibrous material, with teeth advancing at rates tied to wear, observed in both wild and captive specimens.^[51] Physiologically, manatees employ hindgut fermentation in a capacious cecum and colon, comprising up to 70% of gut mass, to break down cellulose via microbial action.^[52] Digestibility coefficients reach 80% for cellulose, among the highest for mammalian herbivores, though overall nutrient assimilation requires voluminous intake due to plant recalcitrance.^[53] Slow digesta passage rates enhance extraction efficiency, distinguishing manatees from less effective foregut fermenters despite their hindgut strategy.^[54] In wild settings, this supports selective grazing on higher-quality plants, contrasting captive diets like romaine lettuce, which offer lower fiber and may alter microbial communities.^[55]

Reproduction and Development

Manatees display a promiscuous mating system characterized by polygyny, in which multiple males form mating herds around a single female in estrus, competing vigorously through pushing and shoving to gain access for copulation. These herds typically involve 5 to 20 males pursuing the female for durations of days to weeks, with the female often twisting and turning to select mates.^[56]^[57] Breeding occurs opportunistically year-round in warm waters exceeding 20°C, without a defined season, as reproduction is closely tied to environmental temperature for calf survival.^[58] Gestation in female manatees lasts 12 to 14 months, after which a single calf is typically born, though twins are documented in approximately 2% of cases based on observational records. Births occur in shallow, warm coastal waters, with the calf emerging tail-first and immediately surfacing to breathe. Calves remain dependent on maternal care, nursing for up to 18 months while gradually incorporating solid foods, though weaning is protracted and variable among individuals tracked via photo-identification.^[4]^[5]^[59] Sexual maturity is attained by females around 7 years of age and by males at 9 to 10 years, though some males produce viable sperm as early as 2 to 3 years; successful breeding in females often begins between 7 and 9 years. Interbirth intervals average 2.5 to 3.5 years when calves survive to weaning, extending to 3 to 5 years under normal conditions, reflecting low reproductive rates observed in long-term studies of radio-tagged and photo-identified individuals in Florida.^[56]^[37]^[5] Manatee fecundity is inherently low, with perinatal mortality from natural causes—such as dystocia, hypothermia, or maternal neglect—accounting for 20 to 30% of early calf losses in monitored populations, as evidenced by carcass salvage data and longitudinal observations. In the wild, average lifespan is 20 to 30 years due to cumulative natural factors, though individuals can exceed 50 years in protected environments like captivity.^[34]^[59]^[60] Manatees exhibit semi-solitary behavior, typically traveling alone or in transient groups of 2 to 6 individuals without forming stable pods or hierarchical structures observed in delphinids.^[15] Loose aggregations of up to dozens or hundreds occur at resource hotspots like seagrass meadows or thermal springs, driven by environmental factors rather than social cohesion, with individuals joining and leaving freely.^[40] Interactions are predominantly affiliative or neutral, featuring play such as barrel rolling or body-surfing, while aggression remains rare and limited mainly to male shoving during mating herds.^[15] Cognitive assessments from field tracking and captive experiments reveal moderate intelligence, evidenced by robust spatial memory enabling navigation of intricate waterways and recollection of foraging or refuge sites over extended periods.^[61] Manatees display associative learning, such as cue-response training, and rudimentary problem-solving, aligning with capabilities in phylogenetic relatives like elephants but falling short of cetacean complexity.^[61] Absent are indicators of tool use or innovative manipulation in natural settings; instead, rapid habituation to human presence—approaching vessels or divers—demonstrates learned avoidance deficits that heighten injury risks without implying higher reasoning.^[61] Vocal communication consists of simple acoustic signals including chirps, squeaks, and whistles, chiefly employed for mother-calf bonding and potentially mate attraction.^[15] Calf isolation calls encode individual signatures via variations in fundamental frequency and duration, facilitating recognition and differing by sex (higher frequency in females) and age (shorter durations in juveniles).^[62] Analyses indicate graded signal modulation in response to ambient noise but no dialects, cultural transmission, or syntactic elaboration per acoustic field recordings.^[63]

Distribution and Habitat

Global Range by Subspecies

The genus Trichechus comprises three extant species of manatees, with the West Indian manatee (T. manatus) further divided into two subspecies distinguished primarily by geographic separation and minor morphological differences. The Florida manatee (T. m. latirostris) occupies the northernmost extent of the genus's range in the southeastern United States, while the Antillean manatee (T. m. manatus) inhabits broader tropical waters across the Caribbean and adjacent mainland coasts. The West African manatee (T. senegalensis) and Amazonian manatee (T. inunguis) represent distinct species adapted to specific continental riverine and coastal systems.^[2]^[16] The Florida manatee (Trichechus manatus latirostris) is restricted to coastal and inland waters of the southeastern United States, with core populations concentrated in Florida year-round. In winter, individuals aggregate in warm-water refuges along central and southern Florida's east and west coasts, while summer migrations extend northward to the Carolinas and westward to Louisiana and Texas, occasionally reaching as far as Massachusetts. Historical records indicate presence in additional southeastern states including Georgia, Alabama, Mississippi, and North Carolina, though current sightings outside Florida are sporadic and tied to seasonal warming. This subspecies marks the northern limit of manatee distribution, influenced by temperature constraints below 20°C.^[64]^[65]^[6] The Antillean manatee (Trichechus manatus manatus) exhibits a patchy distribution across subtropical and tropical waters from northern Mexico southward to northeastern Brazil, encompassing the Gulf of Mexico's western coasts, Central American shorelines, the Greater and Lesser Antilles, and northeastern South America. Key areas include southern Texas, the Yucatán Peninsula, Puerto Rico, and coastal Venezuela to French Guiana, favoring shallow coastal lagoons, estuaries, and rivers. Unlike the Florida subspecies, populations here do not face the same cold-induced migrations but show localized fidelity to warm, brackish habitats.^[50]^[66]^[16] The West African manatee (Trichechus senegalensis) ranges along the western African coast from the Senegal River in the north to the Cuanza River in Angola in the south, inhabiting rivers, estuaries, mangroves, and coastal marine waters. This distribution spans approximately 5,000 km of coastline, with inland penetration up to several hundred kilometers along major waterways like the Niger and Congo rivers, though populations are fragmented due to habitat barriers and human activity. Unlike congeners, it tolerates slightly more oceanic conditions but remains tied to sheltered, vegetation-rich shallows.^[67]^[68] The Amazonian manatee (Trichechus inunguis), the only exclusively freshwater manatee species, occupies the Amazon River Basin across northern South America, including Brazil, Peru, Colombia, Ecuador, Bolivia, and Venezuela, covering an estimated 7 million square kilometers of riverine and floodplain habitats. It inhabits slow-moving rivers, oxbow lakes, and flooded forests, with records from the main Amazon channel to tributaries like the Orinoco, but avoids fast-flowing or highly turbid sections. This species does not venture into coastal or brackish environments, reflecting adaptations to permanent freshwater systems.^[69]^[70]

Environmental Preferences and Migration

Manatees select habitats in shallow coastal bays, rivers, estuaries, and connected waterways exceeding 1 meter in depth, prioritizing calm environments with water temperatures consistently above 20°C to prevent cold-induced physiological stress.^[71]^[72] These preferences favor protected areas supporting seagrass beds over regions with strong currents, which hinder their energy-efficient locomotion.^[73] Manatees demonstrate euryhaline tolerance, inhabiting fresh, brackish, and full-strength marine waters, yet they preferentially aggregate near freshwater inflows to access potable water essential for osmoregulation as mammals.^[71]^[74]^[75] In subtropical and temperate zones, manatees exhibit seasonal migrations to natural thermal refuges during winter, such as Florida's Crystal River springs maintaining approximately 22°C, enabling survival when ambient coastal waters drop below lethal thresholds.^[76]^[72] Satellite tracking data reveal consistent migratory routes and strong site fidelity, with individuals returning annually to designated warm-season foraging grounds and winter aggregation sites.^[77] In consistently warm tropical habitats, movements adopt a more nomadic pattern aligned with seagrass availability rather than thermal gradients.^[78]

Ecology

Predation and Natural Mortality

Manatees face negligible predation in the wild, attributable to their large adult body size—often exceeding 400 kilograms—and preference for shallow, coastal habitats that limit encounters with potential predators.^[40] Documented cases of predation are rare and primarily involve calves or juveniles; for example, shark attacks have been confirmed through bite marks on West Indian manatees, including a probable tiger shark incident in Puerto Rico.^[79] Crocodilians such as alligators and crocodiles occasionally prey on young manatees in overlapping ranges, while anecdotal reports note jaguar attacks in some freshwater systems.^[80] More recently, observations have recorded bottlenose dolphins aggressively attacking and killing manatee calves, an unusual intra-marine mammal predation event.^[81] These incidents do not constitute a significant population-level threat, as evidenced by the absence of predation as a distinct mortality category in long-term monitoring data.^[82] Natural mortality in manatees arises predominantly from environmental stressors and physiological limits rather than biotic interactions. Cold stress, induced by prolonged exposure to water temperatures below 20°C, represents a major cause, particularly affecting calves; analysis of Florida manatee subpopulations from 2001–2009 showed calf cold-stress mortality fractions ranging from 0.18 to 0.49 across regions, compared to 0.08–0.31 for adults.^[83] This vulnerability stems from manatees' tropical evolutionary origins and limited thermoregulatory capacity, leading to emaciation and organ failure during severe winters.^[82] Red tide blooms, caused by the dinoflagellate Karenia brevis (formerly Gymnodinium breve), drive episodic mass mortalities through neurotoxin inhalation and ingestion, with fractions up to 0.32 for adults and 0.23 for calves in southwest Florida during peak events.^[83] Other natural causes encompass infectious and non-infectious diseases, perinatal complications, and accidents, collectively categorized as comprising baseline mortality independent of human influences.^[82] Annual adult survival rates exceed 0.96 across monitored Florida subpopulations, underscoring that natural factors alone sustain viable populations absent anthropogenic pressures.^[83]

Ecosystem Role and Interactions

Manatees occupy a primary herbivore trophic position in coastal and riverine food webs, functioning as keystone grazers that crop seagrass blades to prevent overgrowth and maintain meadow balance.^[84] ^[85] Their selective grazing favors shorter, diverse seagrass species over taller monocultures, enhancing habitat complexity for invertebrates and juvenile fish.^[86] This activity indirectly curbs epiphytic algal accumulation on blades, reducing smothering that could degrade photosynthesis and oxygen levels in the ecosystem.^[84] Manatee feces facilitate nutrient cycling by depositing processed organic matter rich in nitrogen and phosphorus back into sediments, stimulating microbial decomposition and seagrass regrowth.^[87] ^[88] In floodplain systems like the Amazon, this fertilization boosts primary productivity, while in Caribbean seagrass beds, it supports localized eutrophication without exceeding natural thresholds under baseline population densities.^[87] Interspecific interactions include commensal associations with remora fish such as Echeneis naucrates, which attach via suction-cup dorsal fins to glean parasites and food scraps from manatee skin, gaining mobility and protection without evident host detriment.^[89] ^[90] Competition with dugongs remains negligible due to disjoint ranges—manatees in Atlantic and West African waters versus dugongs in Indo-Pacific realms—precluding resource overlap in seagrass foraging.^[91] Manatees serve minimally as disease vectors, with low pathogen transmission rates to co-occurring species documented in field studies.^[92] Population declines in manatee habitats correlate with seagrass loss from nutrient pollution, positioning them as indicators of water quality degradation, whereas observed recoveries in protected areas demonstrate ecosystem resilience to moderated anthropogenic pressures.^[92] ^[93] ^[86]

Physiological Vulnerabilities

Manatees possess limited thermoregulatory adaptations, rendering them highly vulnerable to cold stress when ambient water temperatures fall below 20°C for extended durations, which disrupts metabolic functions and can precipitate emaciation, immunosuppression, and death.^[94] Prolonged exposure below 18°C exacerbates this risk, as their thin blubber layer—typically about 2.5 cm thick—provides insufficient insulation compared to more robustly adapted marine mammals.^[64] Reproductive physiology further constrains population resilience, with females reaching sexual maturity around 7.5 years, a gestation period of 13 ± 1 months, and an average inter-calving interval of 3.5 years, typically yielding a single calf as twins occur rarely.^[5] This low fecundity rate—effectively one offspring every 2–5 years—amplifies susceptibility to stochastic demographic events, as small perturbations can significantly impair recovery without external interventions.^[95] Inherent disease vulnerabilities include infections from protozoan parasites like Toxoplasma gondii, which causes disseminated toxoplasmosis leading to morbidity and mortality in wild populations.^[96] ^[97] Viral papillomatosis, induced by manatee papillomavirus (TmPV1), manifests as cutaneous lesions, with seroprevalence indicating widespread exposure that compromises epithelial integrity.^[98] These pathogens exploit the manatee's aquatic lifestyle and limited immune diversity in immunoglobulin heavy chain variable regions, heightening overall infectious risk.^[99] A basal metabolic rate suited to herbivory results in protracted recovery from physiological insults, including slow wound healing tied directly to energy intake limitations and reduced cellular repair efficiency.^[100] ^[101] This sluggish regenerative capacity stems from their evolutionary adaptations for low-energy foraging, contrasting with the higher metabolic demands and agility of carnivorous cetaceans, which exhibit greater physiological robustness against injury and environmental stressors.^[102]

Conservation and Population Dynamics

Historical Population Changes

Historical analyses of zooarchaeological remains, natural history accounts, and early 20th-century records indicate that West Indian manatee populations in Florida were minimal during precolonial and colonial periods, likely consisting of sporadic migrants from Caribbean source areas rather than established large groups.^[103] Commercial hunting intensified in the 19th and early 20th centuries, targeting manatees for meat, oil, and hides, but populations began expanding around the cessation of organized harvesting in the 1920s, coinciding with legal protections such as Florida's 1893 ban on manatee hunting.^[103] By the mid-20th century, aerial surveys estimated fewer than 1,000 individuals in the 1960s, though this reflected improved detection rather than absolute lows, with subsequent growth to several thousand by the 1980s following federal protections under the Endangered Species Act of 1973. For the Antillean subspecies, historical records suggest once-wider distribution across the Caribbean, but mid-20th-century market hunting substantially reduced numbers in regions like Puerto Rico and the Greater Antilles, with sparse quantitative data limiting precise trend assessments.^[104] Amazonian manatee populations underwent severe declines from colonial-era exploitation through the early 20th century, with commercial operations in Brazil exporting thousands annually by the 1940s-1950s, prompting a 1967 hunting ban that halted large-scale harvest but left fragmented, low-density groups.^[105] ^[106] African manatee trends show chronic declines from sustained bushmeat hunting and habitat alterations over the past century, though baseline estimates remain elusive due to remote habitats and inconsistent surveys, with genetic evidence pointing to reduced diversity from historical pressures.^[20] Across subspecies, overhunting represented the dominant anthropogenic driver of early population contractions, with recovery varying by enforcement of prohibitions and ancillary threats like habitat loss.^[1]

Current Status and Trends

The Florida manatee (Trichechus manatus latirostris) population is estimated at a minimum of 8,350 individuals based on aerial surveys employing robust methodologies, marking a substantial increase from historical lows over the past three decades.^[107] This growth reflects a long-term upward trend, which continued after the official end of the 2020–2022 Unusual Mortality Event in March 2025, driven by improved survey techniques and population monitoring.^[108] In January 2025, the U.S. Fish and Wildlife Service proposed retaining threatened status under the Endangered Species Act for the Florida subspecies, emphasizing its recovery while proposing endangered status for the Antillean subspecies (T. m. manatus) due to more precarious conditions elsewhere in the West Indian range.^[109] Florida manatee mortality reached 525 documented cases by late August 2025, surpassing levels from the prior two years, yet analyses indicate many were perinatal—related to births—or cold-related, potentially signaling higher reproductive rates amid overall population rebound rather than systemic decline.^[110] Despite this, localized population segments show variability, with recovery uneven across habitats.^[110] Among other manatee taxa, the Antillean manatee maintains vulnerable status globally, with small, genetically limited populations in regions like the Caribbean prompting the proposed uplisting.^[111] The Amazonian manatee (T. inunguis) is assessed as vulnerable by the IUCN, with mature individual estimates ranging from 8,000 to 30,000 across its range and an observed decreasing trajectory based on habitat assessments.^[112] For the West African manatee (T. senegalensis), population data remain sparse due to elusive habits, but persistent poaching for bushmeat sustains vulnerability, as evidenced by ongoing enforcement challenges in coastal West African waters.^[113]

Primary Threats: Anthropogenic vs. Natural Factors

Anthropogenic threats to manatees, particularly the Florida subspecies, include watercraft collisions and habitat degradation from nutrient pollution. Watercraft strikes account for approximately 17-25% of documented manatee mortalities in Florida, with 89 such deaths recorded as of October 2025, aligning with recent annual figures.^[114]^[115]^[116] Nutrient runoff has fueled algal blooms in areas like the Indian River Lagoon, resulting in seagrass losses exceeding 50% since 2007 and contributing to starvation-related deaths during unusual mortality events from 2020-2022.^[117] Red tide events, while naturally occurring, have been intensified by coastal development and agriculture, leading to episodic mass mortalities, such as over 60 in 2017.^[118] Natural factors, however, form a baseline of mortality that predates intensified human activity. Cold stress from winter snaps causes significant die-offs, with 28 manatee deaths attributed to this in early 2025 alone, the highest since 2020.^[119] Perinatal mortality, often due to disease or complications, represents the leading overall cause, comprising up to 40% of such cases from natural pathologies.^[120]^[115] Predation remains minimal for adults but affects calves via crocodiles and sharks in shared habitats. While anthropogenic pressures amplify vulnerabilities—such as reduced seagrass forcing manatees into riskier boating channels—empirical trends show population resilience, with Florida manatee numbers rising from 1,267 in 1991 to over 10,000 by 2024, indicating natural recovery capacity amid targeted threat mitigation.^[121] Debates persist over attribution, particularly regarding algal blooms versus inherent estuarine cycles. Conservation narratives emphasize pollution as primary in the Indian River Lagoon's seagrass collapse, yet historical data reveal natural bloom variability, with human nutrients accelerating but not solely causing events.^[122]^[123] Boaters argue that expansive slow-speed zones impose undue economic burdens without proportional mortality reductions, advocating for data-driven adjustments in areas of stable populations.^[124] Overall, while human factors contribute 20-30% directly to mortalities, natural baselines like weather and reproduction sustain higher turnover, underscoring that overemphasis on anthropogenic causes overlooks manatee adaptability evidenced by rebounding counts post-interventions.^[110]^[125]

Management Strategies and Effectiveness

Implementation of boat speed zones and manatee sanctuaries in Florida since the 1990s has correlated with substantial declines in watercraft-related mortality, with known strike deaths dropping after zone establishment in key areas.^[126] These measures provide operators greater reaction time and reduce injury severity upon collision, though evidence indicates they may not fully eliminate encounters, as slow-moving vessels can still injure manatees if undetected.^[127] Compliance challenges persist, but overall, speed restrictions have proven effective in mitigating the primary anthropogenic threat of boat strikes.^[128] Rehabilitation and release programs, coordinated through partnerships like the Manatee Rescue & Rehabilitation Partnership, demonstrate high post-release survival for wild-born individuals, with 72% success rates documented over 26 years of monitoring from 1990 to 2016.^[129] In contrast, captive-born manatees exhibit lower adaptation success at 14%, highlighting the value of prioritizing rehabilitation of naturally rescued animals over captive propagation.^[130] These efforts contribute to population recovery by returning viable individuals, supported by tracking data that informs long-term viability assessments.^[131] Supplemental feeding trials initiated in 2022 at warm-water sites like the Indian River Lagoon have directly addressed cold-season starvation, delivering over 399,000 pounds of romaine lettuce during the 2022-2023 winter to supplement seagrass-scarce diets.^[64] These interventions, conducted by the Florida Fish and Wildlife Conservation Commission (FWC) and U.S. Fish and Wildlife Service (USFWS), reduced reliance on rehabilitation for emaciated manatees and coincided with a decline in starvation-linked deaths from 1,101 total mortalities in 2021 to 555 in 2023.^[132] Efficacy is corroborated by USFWS and FWC aerial synoptic surveys, which track population abundance—estimating around 6,350 individuals in recent assessments—and validate intervention impacts amid fluctuating counts influenced by weather and behavior.^[133] Despite these successes, management faces setbacks from litigation, including 2023 federal lawsuits challenging state wastewater regulations in manatee habitats, which delayed enforcement of pollution controls exacerbating seagrass loss.^[134] Appeals by Florida agencies against judicial orders for enhanced protections, such as in the Northern Indian River Lagoon, have prolonged implementation of critical habitat safeguards.^[135] Internationally, African manatee (Trichechus senegalensis) conservation lags due to remoteness hindering policy enforcement, persistent poaching for meat, and bycatch in fishing gear, with minimal structured interventions compared to U.S. programs.^[136] These gaps underscore uneven global efficacy, where data-driven U.S. strategies contrast with under-resourced African efforts.^[137]

Human-Manatee Interactions

Historical Harvesting and Exploitation

Indigenous peoples in Florida, such as the Seminole, relied on manatees as a significant food source, harvesting them from shallow bays and rivers where the species had been present for approximately 15 million years.^[138] Pre-Columbian cultures, including the Maya in circum-Caribbean regions, exploited manatees for meat and other resources, as evidenced by archaeological records.^[139] European colonists and early settlers in Florida and the Caribbean extended this practice, targeting West Indian manatees (Trichechus manatus) for their meat, hides, and fat, which were used for food, leather, and oil.^[140] In the Amazon Basin, historical documents from the 16th to 19th centuries document systematic exploitation of Amazonian manatees (Trichechus inunguis) by indigenous groups and later commercial interests for meat and oil, with early explorer accounts noting abundance despite ongoing harvest.^[105]^[141] Commercial operations in Brazil intensified from around 1785, focusing on T. inunguis and occasionally T. manatus, yielding meat production that peaked before declining in the 1960s due to overexploitation.^[142] Pioneers in the Florida Keys harvested manatees alongside other wildlife to support local needs, including feeding railroad workers in the early 1900s.^[143]^[144] Hunting pressure contributed to significant population declines across manatee ranges, leading to local extirpations such as in Guadeloupe and other Lesser Antilles islands by the early 20th century, where hunts persisted until that time.^[1] In Florida, despite protective legislation enacted in 1893 prohibiting manatee hunting, poaching remained common into the 20th century, exacerbating vulnerabilities from prior exploitation.^[145] Overall, such harvesting for meat, hides, and oil—practiced across cultures from prehistoric times through colonial and commercial eras—drove range contractions and reduced abundances, particularly for West Indian and Amazonian species, prior to widespread legal protections.^[146]^[147]

Captivity, Rehabilitation, and Research

Manatee rehabilitation efforts are coordinated primarily through the Manatee Rescue and Rehabilitation Partnership (MRP), a collaborative network of agencies, organizations, and oceanaria that rescues, treats, and releases injured or orphaned individuals back into the wild. Facilities such as the Miami Seaquarium, authorized by the U.S. Fish and Wildlife Service for manatee rehabilitation, have historically housed and treated animals, though long-term residents like the manatees Romeo and Juliet were relocated to sanctuaries in 2023 due to facility conditions.^[148]^[149] In regions like Guyana, wildlife rescue centers including the Guyana Zoological Park contribute to local rehabilitation, focusing on injured Amazonian manatees.^[150] Rehabilitation success varies by origin and size, with wild-born manatees achieving approximately 72% post-release survival over long-term monitoring periods, compared to only 14% for those born in captivity.^[151] For Antillean manatees in Brazil, release programs report over 75% success rates across 30 individuals tracked since the early 2000s, with time in captivity identified as a critical factor influencing outcomes.^[152] The MRP has demonstrated viability through efforts like the release of 12 Florida manatees in 2023, supported by post-release monitoring to assess adaptation.^[153] Research complements rehabilitation via satellite tagging to track movements and habitat use, with projects spanning over 20 years revealing fine-scale behaviors and aiding predictions of population responses to environmental changes.^[154]^[155] Genetic studies, including analyses of diversity in Antillean populations and identification of centromeric satellite DNA, inform conservation by evaluating inbreeding risks and subspecies structure.^[156]^[157] Challenges include heightened dependency risks for prolonged captives and ethical concerns over welfare in artificial environments, where concrete tanks may fail to replicate natural conditions, potentially compromising long-term viability.^[151]^[158] Captive breeding is not prioritized in some programs, such as in Mexico, due to sufficient wild recruitment potential and doubts about post-release fitness.^[158] Overall, while rehabilitation yields measurable release rates around 75-80% for suitable candidates, captive-raised individuals exhibit reduced adaptation success, underscoring the preference for minimizing captivity duration.^[152]^[151]

Regulatory Debates and Economic Impacts

Regulatory debates surrounding manatee protection in Florida center on boating speed restrictions, with boaters and commercial operators opposing expansive no-wake and slow-speed zones due to constraints on navigation, fishing access, and recreational enjoyment. In Indian River County, the Florida Fish and Wildlife Conservation Commission proposed easing speed limits in 16 manatee protection zones in August 2025, allowing higher speeds to alleviate perceived over-regulation amid recovering manatee populations.^[159] Similarly, in Hernando County, local residents advocated for maintaining no-wake designations on the Mud River in 2025, highlighting tensions between safety enforcement and user convenience, though county commissioners deferred decisions pending surveys of waterfront property owners.^[160] These conflicts reflect broader arguments that stringent zones impose undue economic burdens on the boating sector without proportional gains, given evidence that manatees can detect and evade vessels at moderate speeds if operators remain vigilant.^[161] Lawsuits exemplify disputes over causation and regulatory scope, such as the 2025 case filed by Bear Warriors United against the Florida Department of Environmental Protection, alleging that permitted sewage discharges into the northern Indian River Lagoon degraded seagrass beds, contributing to manatee starvation deaths in violation of the Endangered Species Act.^[162] A federal judge ordered protective measures in May 2025, including wastewater management steps, but the state appealed, contending that natural factors like red tide blooms—rather than solely anthropogenic pollution—drive habitat loss and die-offs, thus questioning the necessity of expansive liability for legacy pollutants.^[163] Property rights advocates further challenge habitat buffers and critical habitat designations, arguing they infringe on riparian landowners by limiting development near wetlands and waterways without sufficient empirical justification, as seen in Manatee County's 2024-2025 debates over buffer rollbacks that risked legal challenges under state environmental policies.^[164]^[165] Economically, manatee conservation yields substantial tourism revenue, with viewing tours in areas like Crystal River generating an estimated $20-30 million annually for local economies, while broader protection benefits in Citrus County have been calculated to outweigh foregone development by $8.2-9 million.^[166]^[167] However, compliance with speed zones and habitat restrictions elevates operational costs for boaters and developers, fueling claims that regulations disproportionately favor environmental advocacy over balanced resource use, particularly as the U.S. Fish and Wildlife Service denied uplisting the Florida manatee to endangered status in January 2025, affirming its threatened classification based on population stability and existing protections' adequacy.^[168] Empirical assessments indicate that slow-speed zones effectively mitigate collision severity by affording operators more reaction time and reducing impact forces, with studies documenting lowered risks of fatal injuries post-implementation.^[127]^[169] Yet, persistent non-compliance and incomplete strike reductions underscore debates on whether heightened alarmism justifies ongoing expansions, especially amid evidence that zones may not proportionally decrease encounter rates and could inadvertently prolong exposure durations.^[170]^[171] Pro-development perspectives emphasize that verifiable recoveries—evidenced by the 2017 downlisting and 2025 status denial—warrant recalibrating restrictions to minimize economic drag while sustaining core safeguards against verifiable anthropogenic threats like propeller strikes.^[172]

Cultural Representations and Public Perception

Manatees have long been depicted in folklore as inspirations for mermaid legends, with early European explorers, including Christopher Columbus in 1493, reportedly mistaking the animals' rounded bodies and flipper movements for mythical sirens while sailing near the Caribbean.^[173] This association persists in cultural narratives, though empirical observations confirm manatees' slow, non-aggressive swimming—reaching speeds of only 3-5 mph—rather than any enchanting allure, underscoring their vulnerability to faster human vessels rather than supernatural traits.^[174] The moniker "sea cow" emerged from their grazing habits on seagrasses, evoking bovine docility that symbolizes harmless coexistence in marine environments, a perception rooted in documented behaviors like group resting and minimal threat to humans.^[175] In modern media, manatees feature as gentle protagonists, such as in Disney's educational content portraying them alongside dugongs as "gentlest giants of the sea," reinforcing a narrative of peaceful aquatic mammals that aligns with their observed low predation and herbivorous lifestyle.^[176] Conservation organizations like Save the Manatee Club, founded in 1981, have amplified this image through awareness campaigns, including Manatee Awareness Month in November, which highlight the species' plight to foster public support for habitat protection and reduced boat speeds.^[177] These efforts have boosted donations and policy advocacy, yet they risk anthropomorphic sentimentality, as evidenced by increased tourist interactions leading to harassment via feeding or touching, which disrupts natural foraging and exposes calves to propeller injuries.^[178] Public perception divides along empirical lines: environmental advocates emphasize manatees' docility as justification for stringent protections, crediting awareness drives for population recoveries from historical lows of around 1,000 in the 1970s to over 6,000 by 2017.^[179] Conversely, some stakeholders, including fishers in regions like Colombia's Ayapel Swamp, view manatees as competitors for aquatic vegetation, perceiving conservation measures as overlooking human livelihoods without proportional evidence of manatee-driven ecological imbalances.^[180] In Florida, boating interests critique speed zones as overly restrictive, arguing that manatees' inherent sluggishness already minimizes collisions when humans maintain vigilance, though data show persistent watercraft strikes accounting for 20-30% of annual deaths despite regulations.^[181] This tension reflects causal realities where protective sentiment, while empirically aiding recovery, can impede balanced resource use absent rigorous cost-benefit analysis.^[182]

References

[1]
Manatee (Trichechus manatus) | U.S. Fish & Wildlife Service
Manatees are federally protected under the Endangered Species Act and under the Marine Mammal Protection Act.
[2]
All About Manatees - Scientific Classification | United Parks & Resorts
Manatees are classified as Mammalia, Order Sirenia, Family Trichechidae. Species include West Indian, West African, and Amazonian manatees.<|separator|>
[3]
Manatee Fact Sheet | Blog | Nature - PBS
Jul 7, 2023 · Habitat: Manatees inhabit the shallow, marshy coastal areas and rivers. Geography: They can be found in the Caribbean Sea, the Gulf of ...
[4]
Trichechus manatus (West Indian manatee)
The West Indian manatee (Trichechus manatus) is a mammal, about 2.7-3.5m long, weighing 200-600kg, found in shallow coastal areas, and is classified as ...
[5]
Initial Information on the Reproductive Biology of the Florida Manatee
Manatee puberty is at 7.5 years, gestation is 13 +/- 1 months, and the normal calving interval is 3.5 years.
[6]
Species Profile for West Indian Manatee(Trichechus manatus) - ECOS
May 1, 2025 · General Information. Manatees are protected under the Endangered Species Act and the Marine Mammal Protection Act (MMPA).
[7]
Endangered Ocean: Manatees
While manatees don't have any true natural predators, they have still become endangered. There are three manatee species worldwide – West Indian, West African, ...
[8]
Manatee - Etymology, Origin & Meaning
Manatee, from Spanish manatí (1530s) and Carib manati meaning "breast," refers to a gregarious, herbivorous aquatic mammal, named for its fin-like "hands."
[9]
manatee - Wiktionary, the free dictionary
English. edit. West Indian manatee (Trichechus manatus). Etymology. edit. Borrowed from Spanish manatí, from a Cariban-language term meaning 'breast', ...
[10]
How The Manatee Got Its Name - Florida Wildlife Viewing
The name "manatee" comes from the Carib word "manati," meaning "woman's breast," which the Spanish/Portuguese thought meant "with hands." It was also called " ...
[11]
MANATEE Definition & Meaning - Merriam-Webster
Oct 15, 2025 · Word History ; Etymology. Spanish manatí, probably of Carib origin; akin to Antillean Carib manattoüi manatee ; First Known Use. 1555, in the ...
[12]
manatee, dugong - Sesquiotica
Dec 6, 2012 · Manatee comes from manatí, which is a Taino word meaning “breast”. Dugong – the other sea cow – comes from Tagalog, which took it from Malay duyong; both mean ...
[13]
10 Facts About Manatees - ThoughtCo
Apr 5, 2019 · The word manatee is thought to come from the Carib (a South American language) word, meaning "woman's breast," or "udder." It may also be ...Missing: linguistic origin
[14]
Manatees: Trichechus manatus, T. senegalensis, and T. inunguis
Morphologically, manatees differ sharply from their close relative, the dugong. Manatees have a rounded fluke, whereas dugongs have split flukes similar to ...
[15]
Trichechus (manatees) | INFORMATION - Animal Diversity Web
The genus Trichechus was named by Linnaeus. The family, Trichechidae includes three existing species of manatees, T. inunguis , T. senegalensis , and T. manatus ...
[16]
Trichechus manatus - West Indian Manatee - NatureServe Explorer
One of only four living species in the order Sirenia; the two other manatee species occur along the coast of West Africa (T. senegalensis) and in rivers of ...<|separator|>
[17]
Trichechus inunguis (Amazonian manatee)
The genus name Trichechus, comes from Latin meaning "hair", referencing the whiskers around the manatee's mouth. ... The Amazonian manatee is the smallest member ...Missing: etymology | Show results with:etymology
[18]
Manatees (Genus Trichechus) - iNaturalist
Manatees (family Trichechidae, genus Trichechus) are large, fully aquatic, mostly herbivorous marine mammals sometimes known as sea cows.
[19]
Traits - Jacksonville University
West African Manatee - Trichechus senegalensis, is roughly the same size as a West Indian manatee, but has more protruding eyes, a blunter snout, a less robust ...
[20]
The genome of African manatee Trichechus senegalensis reveals ...
Jun 28, 2024 · For locomotion, all extant sirenians and cetaceans have lost their hind limbs and modified the forelimbs into flippers.
[21]
8. Manatees and dugongs - Earth History
There have been other adaptations over time. The pelvis has grown smaller and no longer attaches to the backbone. The hindlimbs have gone completely. The ...
[22]
Walking With Sea Cows | National Geographic
Jan 16, 2013 · Sea cows once walked on land. Pezosiren leaves no doubt of that. This roughly 48 million year old mammal once trod over prehistoric Jamaica.
[23]
Manatees that walked on land - Evolution For Skeptics
Nov 16, 2016 · Pezosiren has been found in rocks estimated to be ~47.8 million years in age, similar to the age that walking 'whales' were also found roaming ...<|separator|>
[24]
Anatomical adaptations of aquatic mammals - Reidenberg
May 21, 2007 · Sirenians (manatees and dugongs) have lost their hind limbs, but can either propel themselves with their tail fluke(s) or walk along the sea or ...<|separator|>
[25]
Protein signaling and morphological development of the tail fluke in ...
Speculation has suggested that the outgrowth of tail flukes has an intimate association with the regression of the hindlimb buds, 28 and may develop using an ...
[26]
The Florida manatee a 'nonnative'? It's been here for millennia
Jan 21, 2025 · Moreover, genetic and fossil evidence indicate manatees have been present in Florida for the last 12,000 years.
[27]
Historical ecology reveals the “surprising” direction and extent of ...
A reconstruction of the natural history of the West Indian Manatee in Florida in the past 12,000 years from archaeological, ethnographic, and other data.
[28]
Florida manatee - Volusia County Government
The average adult Florida manatee weighs around 1,200 pounds and is about 10 feet long, but they can reach up to 13 feet in length and weight 3,500 pounds.
[29]
Florida Manatee - Chesapeake Bay Program
It grows to be nine to ten feet in length. Manatees weigh between 800 to 2,200 pounds, with females larger than males.
[30]
Manatees: what is a sea cow? | Natural History Museum
Early forms appeared about 55 million years ago and one of the first true manatees, Potamosiren, lived 13-16 million years ago during the Miocene epoch.
[31]
Manatee Anatomy | Ocean Today - NOAA
Manatees are one of the only animals that keep replacing their teeth their entire lives. They have four sets of six to eight marching molars.
[32]
[PDF] The West Indian Manatee (Trichechus Manatus) - Regulations.gov
away. Morphological evidence supports these con clusions of exceptional hearing ability, for manatees possess unusually large and bulky ear ossicles (Robineau ...
[33]
Microanatomy of facial vibrissae in the Florida manatee - PubMed
Some of these bristles and hairs are known to be used in tactile exploration and in grasping behaviors. In the present study we characterized the ...Missing: skin | Show results with:skin
[34]
[PDF] Florida Manatee Recovery Plan - ECOS
Mar 27, 2001 · 2.5.1 Develop a better understanding of manatee anatomy, physiology, and health factors . ... morphology of manatees; (2) assess certain ...
[35]
Wetland and Aquatic Research Center - Publications | U.S. ...
Synonymies, diagnoses, descriptions, illustrations, an identification key, and meristic frequency tables are provided for all species of Lonchopisthus. Most of ...<|separator|>
[36]
Swimming kinematics of the Florida manatee (Trichechus manatus ...
Jul 15, 2007 · Manatees swam at velocities of 0.06–1.14 ms –1. Locomotion was accomplished by undulation of the body and caudal fluke.
[37]
Trichechus manatus (West Indian manatee) - Animal Diversity Web
Manatees use their tail to propel themselves forward and are surprisingly agile in the water. They are capable of complex maneuvering including somersaults, ...
[38]
Anatomy of a Boat Strike | Save the Manatee Club
Mar 6, 2025 · While they are able to swim at speeds up to 18 miles per hour in short bursts, manatees typically cruise along at three to five miles per hour.Missing: locomotion | Show results with:locomotion
[39]
The Graceful Waltz Underwater: How Does a Manatee Swim?
Dec 3, 2023 · However, they can surge up to 20 miles per hour in short bursts when necessary. Manatees use their powerful tail to propel themselves through ...
[40]
Manatee FAQ
Do manatees see in color? Based on the internal structure of the manatee eye, which possesses rods and cones, manatees have color vision. Behavioral ...Missing: organs | Show results with:organs
[41]
Neuroscience for Kids - Manatee Senses
They found that manatees have good hearing abilities at high frequencies, but not at low frequencies. Manatees hear in a range of 400-46,000 hertz. The peak ...<|separator|>
[42]
Manatee cognition and behavior: a neurobiological perspective on ...
Apr 11, 2025 · Some rodents use vibrissae in tactile exploration, and harbor seals and water rats have been shown to be able to track prey with the vibrissal ...
[43]
Manatee vibrissae: evidence for a “lateral line” function - Reep - 2011
Apr 28, 2011 · The BLHs are used during tactile investigation of novel objects or food items. The BLHs are everted when contraction of superficial ...
[44]
Tactile hair in Manatees - Scholarpedia
May 28, 2015 · Tactile hairs function to detect mechanosensory stimuli rather than for warmth or protection, which is the main function of pelage hair.Manatee hair · Facial vibrissae · Postfacial vibrissae · Innervation of FSCs
[45]
[PDF] The Use of Multiple Sensory Modalities by the Antillean Manatee ...
Manatee sensory abilities include touch, hearing, vision, and chemoreception, similar to other mammals. Manatees have vibrissae on their face as well as ...
[46]
Evidence of a dietary shift by the Florida manatee (Trichechus ...
Mar 4, 2022 · In contrast, stomach samples from the post-seagrass die-off primarily contained algae (49.5%), followed by seagrasses (34%) and vascular plants ...Missing: empirical | Show results with:empirical
[47]
The diet of the manatee (Trichechus Manatus) in Puerto Rico
Aug 7, 2025 · A wide range of estimates exists with regard to the amount of food manatees consume in a given day, from 9 to 80 kg (Severin, 1955;Crandall, ...<|separator|>
[48]
(PDF) Feeding preferences of West Indian manatees in Florida ...
Aug 6, 2025 · In situ manatees eating seagrasses had significantly higher Dm than long-term ex situ animals consuming seagrass for short periods of time (46.9 ...Missing: empirical | Show results with:empirical
[49]
All About Manatees - Diet & Eating Habits | United Parks & Resorts
Food Intake Manatees consume about 4% to 9% (15 to 49 kg or 32-108 lb. for an average adult manatee) of their body weight in wet vegetation daily.Missing: percentage | Show results with:percentage
[50]
West Indian Manatee | National Wildlife Federation
There are two subspecies of West Indian manatee—the Florida manatee (Trichechus manatus latirostris) and the Antillean manatee (Trichechus manatus manatus).Missing: extant | Show results with:extant<|separator|>
[51]
Journey North Manatees
The rate at which the manatee's "marching molars" migrate forward along the jawbone depends on how quickly front row teeth wear out. Some studies indicate that ...Missing: mechanisms dentition
[52]
Variation in the hindgut microbial communities of the Florida ...
Fibre fermentation is a slow process but is optimised in the manatee by the capacious hindgut (20–30 m long) that weighs up to 70% of total gut mass (Reynolds, ...Abstract · Introduction · Discussion · References
[53]
The digestive strategy and efficiency of the west indian manatee ...
Manatees have one of the highest digestibility coefficients for cellulose (80%) of any known mammalian herbivore. This high efficiency of cellulose ...Missing: assimilation | Show results with:assimilation
[54]
Digesta passage rates in the Florida manatee (Trichechus manatus ...
Although manatees are hindgut fermenting herbivores, they are very efficient at extracting nutrients from the plants on which they feed. Slow passage rates ...Missing: assimilation | Show results with:assimilation
[55]
Proximate Nutrient Analyses of Four Species of Submerged Aquatic ...
Aug 9, 2025 · Concerns have been raised that these diets may predispose captive manatees to obesity, diabetes mellitus, dysbiosis, thermoregulatory disorders, ...
[56]
All About Manatees - Reproduction | United Parks & Resorts
Sexual Maturity · Male manatees (bulls) are sexually mature by about nine to ten years, although some have produced viable sperm at two to three years of age.Missing: period interbirth interval
[57]
Animal Sex: How Manatees Do It | Live Science
Dec 20, 2015 · The animals will form a so-called mating herd, in which up to a dozen males will follow and huddle around a single female to mate with her.Missing: polygyny | Show results with:polygyny
[58]
Habitat, Niche, and Evolution of Sirenian Mating Systems
Aug 6, 2025 · The Florida manatee mating strategy has been labeled as "scramble promiscuity," with groups of up to 20 males pushing and shoving each other to ...
[59]
Reproduction in female manatees observed in Sarasota Bay, Florida
Aug 7, 2025 · A mature female's inter-birth interval is one to three years with an interval less than two only when a dependent calf does not survive the ...<|separator|>
[60]
[PDF] Species Status Assessment Report for Florida Manatee
Apr 1, 2024 · Calf survival rates for Florida manatee cannot be estimated based on mark recapture data; however, early observational data from the USJ ...
[61]
Manatee cognition in the wild: an exploration of the ... - PubMed
Sep 7, 2022 · Manatee cognition in the wild: an exploration of the manatee mind and behavior through neuroanatomy, psychophysics, and field observations.
[62]
Signature information and individual recognition in the isolation calls ...
Acoustic signals are assumed to form the basis of manatee communication. Empirical evidence of individual vocal recognition has been reported.
[63]
Manatee (Trichechus manatus) vocalization usage in relation to ...
These results suggest that ambient noise levels do have a detectable effect on manatee communication and that manatees modify their vocalizations as a function ...
[64]
Florida Manatee - Marine Mammal Commission
Range / Distribution. In winter, East and West Coasts of central and southern Florida. In summer, East Coast manatees range north into the Carolinas, ...
[65]
Trichechus manatus latirostris - NatureServe Explorer
This subspecies, T. m. latirostris, is generally regarded as restricted to the southeastern US and considered separate from Caribbean populations.
[66]
Antillean manatee (Trichechus manatus manatus) and ... - CAR-SPAW
Global distribution : The Antillean manatee can be observed from the North of Mexico to Northeast Brazil, but also around the islands of the Greater Antilles.
[67]
Trichechus senegalensis (African manatee) - Animal Diversity Web
Geographic Range Trichechus senegalensis occurs along the west coast of Africa. The Senegal River marks the northern limit of their range while the Cuanza ...
[68]
[PDF] African Manatee (Trichechus senegalensis)
Jan 6, 1978 · DISTRIBUTION. The range of T. senegalensis includes rivers, estuaries, and coastal regions of West Africa from Senegal to Angola (figure 3) ...
[69]
Amazonian Manatee - Discovery of Sound in the Sea
Oct 5, 2023 · The Amazonian manatee is endemic to the Amazon River Basin of northern South America and is found exclusively in freshwater. Distribution of the ...
[70]
3.11 Manatees
The Amazonian manatee (T. inunguis) is widely distributed throughout Amazonia and up to Peru, Ecuador and Colombia. Distribution of both species is ...
[71]
All About Manatees - Habitat and Distribution | United Parks & Resorts
West Indian manatees may be found in any waterway over 1 m (3.25 ft.) deep and connected to the coast. They prefer waters with temperatures above 21°C (70°F).
[72]
West Indian Manatee - The Cousteau Society
Since manatees cannot survive in water below 68°F (20°C), they migrate seasonally between feeding grounds and warm winter refuges. Many Florida manatees rely on ...
[73]
[PDF] Species Status Assessment Report for the Antillean Manatee ...
May 1, 2024 · The West Indian manatee is one of three living species of the genus Trichechus and includes two recognized subspecies, the Florida manatee ...
[74]
Do manatees need to drink fresh water? - UCF College of Sciences
Wild manatees may need fresh or brackish water. Captive manatees in salt water without fresh water showed increased osmolality. They do not actively drink salt ...Missing: kidneys | Show results with:kidneys
[75]
Journey North Manatees
Because manatees are mammals and need to seek out fresh water to drink, the high level of salinity in the habitat waters can affect manatee movement patterns.
[76]
Crystal River National Wildlife Refuge | U.S. Fish & Wildlife Service
Crystal River National Wildlife Refuge establishes and maintains critical winter habitat for the Florida manatee, and protects island habitat necessary for ...Visit Us · Activities · Ranger-led Program page · Map
[77]
Seasonal movements, migratory behavior, and site fidelity of West ...
Seasonal movements, migratory behavior, and site fidelity of West Indian manatees along the Atlantic coast of the United States. January 1, 2003. The West ...
[78]
West Indian Manatees Use Partial Migration to Expand Their ...
One study of 48 satellite telemetry tagged manatees found 87% of manatees migrated short (50–150 km), medium (150–400 km), or long (>400 km) distances from ...
[79]
Evidence of shark attack on a West Indian manatee (Trichechus ...
Sharks are confirmed predators of the dugong (Dugong dugon), but evidence of shark predation on the West African manatee (Trichechus senegalensis) and Amazonian ...
[80]
[PDF] Anecdotal Accounts of Manatee Behavior: Conservation and ...
Herein, we report anecdotes of manatee (family. Trichechidae) behavior based upon accounts made by experienced observers. We have categorized the.
[81]
[PDF] Bottlenose dolphins observed attacking manatee calves - Phys.org
Jan 23, 2024 · They do not have claws or sharp teeth, which makes them vulnerable to attack by other marine predators such as orca, sharks, alligators and ... In ...
[82]
Descriptions of Manatee Death Categories - FWC
Manatee deaths resulting from infectious and non-infectious diseases, birth complications, natural accidents, and natural catastrophes (such as red tide blooms) ...
[83]
[PDF] Status and Threats Analysis for the Florida Manatee (Trichechus ...
This report presents survival rates for Florida manatees, fractions of mortality resulting from various causes, and the probability of the adult population ...<|separator|>
[84]
Oh Man-atee! Where Did the Seagrass Go?
Feb 6, 2024 · A keystone species, manatees not only indicate a healthy habitat but also help maintain a balanced ecosystem. They prevent overgrowth in rivers ...
[85]
Manatees and Seagrass
Manatees play a role in shaping the health of seagrass ecosystems. Through their grazing, they help maintain the balance of seagrass beds, preventing ...
[86]
The Role of Manatees in Ecosystems: Guardians of Aquatic Health
Dec 18, 2024 · Manatees' grazing habits help preserve critical habitats such as seagrass beds and mangrove forests. These habitats are not only important for ...
[87]
A giant gardener of the Floodplains: The Amazonian manatee
The Amazonian manatee can be considered a gardener of the Amazon floodplains, as it fertilizes the waters with nutrients that favor plant productivity.
[88]
Human waste is threatening Florida's manatees and seaweed ...
Their grazing not only controls plant overgrowth but also helps prevent invasive species from spreading and improves nutrient cycling in seagrass beds. In many ...Missing: feces | Show results with:feces
[89]
Echeneis naucrates attached to a West Indian manatee Trichechus ...
They attach to the host using a modified dorsal fin that acts as a suction cup, an adaptation to provide enhanced protection from predators and feeding ...
[90]
[PDF] Echeneid–sirenian associations, with information on sharksucker diet
A whitefin sharksucker. Echeneis neucratoides Zouiev was collected from a West Indian manatee captured in Puerto Rico (Williams & Bunkley-Williams, 1996; ...
[91]
Manatees and Dugongs | The Marine Mammal Center
Manatees and dugongs are related to each other and while they are very similar in appearance and behavior, there is one key difference – their tails.Missing: competition | Show results with:competition
[92]
Manatees as sentinels of marine ecosystem health
May 13, 2004 · The manatee may serve as a sentinel species, prognosticating the deleterious effects of unhealthy marine and aquatic ecosystems on humans. We ...
[93]
[PDF] Manatees as Sentinels of Marine Ecosystem Health - CAR-SPAW
May 13, 2004 · Changes in water quality and the health of seagrass beds may affect a manatee population, as well as the pop- ulations of organisms ...
[94]
Cold-related Florida manatee mortality in relation to air and water ...
Nov 21, 2019 · The Florida manatee, in particular, is highly susceptible to cold stress and death when water temperatures drop below 20°C.
[95]
Manatee Facts
Members of the extant order Sirenia are found in aquatic habitats throughout the tropics and subtropics. Sirenians are the only completely aquatic mammals that ...
[96]
Toxoplasma gondii in Florida Manatees (Trichechus manatus ... - VIN
Toxoplasma gondii is a protozoan parasite of felids recently reported to cause mortality in Antillean manatees (Trichechus manatus manatus) in Puerto Rico.
[97]
(PDF) Disseminated toxoplasmosis Toxoplasma gondii in a wild ...
Nov 5, 2016 · Toxoplasma gondii is a feline protozoan reported to cause morbidity and mortality in manatees and other marine mammals. Given the herbivorous ...Missing: poxvirus | Show results with:poxvirus
[98]
Seroepidemiology of TmPV1 infection in captive and wild Florida ...
No antibody-positive wild animal showed PV-induced cutaneous lesions, whereas papillomatosis was observed in 72.7% of antibody-positive captive manatees. Our ...<|separator|>
[99]
The Florida manatee (Trichechus manatus latirostris ...
Manatees have limited IGHV clan and combinatorial diversity. This suggests that clan III V segments are essential for maintaining IgH locus diversity.Missing: susceptibility poxvirus protozoans
[100]
[PDF] Antillean Manatee Response Plan
Their slow healing rate also appears to be due to their low metabolic rate. Manatees spend approximately 5-8 hours a day feeding and in that time consume 4 ...
[101]
[PDF] BASIC CLINICAL MEDICINE FOR MANATEES - CABI Digital Library
The healing rate of wounds involved is directly related to the intake of energy.
[102]
Physiological constraints on marine mammal body size - PMC
Apr 4, 2018 · However, most marine mammals are carnivores and evolved from carnivores, except for herbivorous dugongs and manatees, which evolved from ...Missing: resilience | Show results with:resilience
[103]
Historical ecology reveals the “surprising” direction and extent of ...
Nov 20, 2024 · Our data reveal that manatee populations in Florida were very small in the Precolonial and Colonial Periods, possibly representing infrequent in-migration from ...
[104]
Distribution, status, and traditional significance of the West Indian ...
Local market hunting in the middle of this century probably greatly reduced manatee populations in these areas. Recent protection laws, education efforts, and ...<|separator|>
[105]
Analyses of historical documents reveal past trends of exploitation of ...
Aug 18, 2025 · ... Amazonian manatee population decreased significantly over a period of four centuries. Even if underestimated these data are relevant for ...
[106]
You can't see them to count them, but Amazonian manatees seem to ...
Nov 26, 2021 · In Brazil, a ban on hunting manatees was enacted in 1967. By then, commercial exploitation had led to a drastic drop in the population of ...
[107]
Florida Manatee (Trichechus manatus latirostris)
Manatees are federally protected under the Endangered Species Act and under the Marine Mammal Protection Act. Scientific Name. Trichechus manatus latirostris.
[108]
Positive manatee trend triggers official end to Unusual Mortality Event
Mar 31, 2025 · An Unusual Mortality Event from December 2020 to April 2022, when 1,255 manatees died along Florida's Atlantic coast, is now officially over ...
[109]
Federal Register :: Endangered and Threatened Wildlife and Plants
Jan 14, 2025 · Cold stress is not known to affect Antillean manatees because they inhabit warmer subtropical waters. However, for the Florida manatee, past and ...<|separator|>
[110]
Manatee deaths on the rise, but expert points to 'good' signs
Sep 17, 2025 · As of late August 2025, the FWC reported 80 manatee deaths resulting from watercraft collisions, on par with August 2021 numbers. It also has ...
[111]
U.S. Fish and Wildlife Service Publishes Finding on Two West Indian ...
Jan 13, 2025 · Currently, the West Indian manatee is considered one species and federally listed as a threatened species. “For almost 60 years, the Service has ...
[112]
Manatee Population by Country 2025
West Indian Manatee: Estimated 8,197-11,328 mature individuals across full range, per-country totals are rare and unreliable. Data sources, counting methodology ...
[113]
[PDF] English African Manatee - MBZ CF
The biggest threats to African manatees are poaching for their meat, as bycatch in fisheries, entrapment in and behind dams, and habitat loss.
[114]
By the Numbers: Rescues and Deaths in 2024
Mar 6, 2025 · ... manatee deaths (100), with 55 classified as perinatal. According to the Florida Fish and Wildlife Conservation Commission, manatee carcasses ...
[115]
Manatee mortality facts - Volusia County Government
Death by impact kills slightly more than 50 percent of manatees killed by collisions with watercraft. Over the last ten years there has been an increase in the ...
[116]
https://www.mysuncoast.com/2025/10/21/florida-manatee-deaths-watercraft-reach-high-totals-officials-not-alarmed/
[117]
IRLNews:2021-04-01/Indian River Lagoon Manatee Mortality Update
The IRL estuary has lost around 54% of the record high seagrass coverage recorded in 2007. This loss of seagrass is due to an excess of Phosphorus and Nitrogen ...
[118]
Disastrous 2018 Brings Record Manatee Deaths - PEER.org
Mar 8, 2018 · Notably, 2018 has yet to record a red-tide caused manatee death but that may soon change. In 2017, FWCC identified 63 manatee deaths where red ...
[119]
Florida manatee deaths again raising alarms - POLITICO Pro
Jun 23, 2025 · So far, 28 manatees have died in 2025 from cold stress, the most recorded in a year since 2020.Missing: causes | Show results with:causes
[120]
Boat strikes top 5-year average for manatee deaths - Florida Today
Aug 20, 2025 · So-called "perinatal" manatee deaths also were 27% of the overall 565 manatee deaths last year, an almost 60% increase over the 91 perinatal ...
[121]
Trends of the Florida manatee (Trichechus manatus latirostris ... - NIH
Jul 9, 2020 · The Florida manatee population has climbed from 1,267 in 1991 to 6,620 in 2017 and estimates are now as high as 10,280 [9]. This population ...
[122]
Algae Blooms and Seagrass Loss | Save the Manatee Club
Jun 9, 2025 · The Indian River Lagoon has suffered harmful algal blooms, leading to massive losses in seagrass coverage and the deaths of a heart-rending ...
[123]
Wasting Away: Rampant pollution caused manatees to starve ...
Apr 2, 2025 · Some of the most contaminated areas suffered crippling algae blooms and seagrass losses.
[124]
Manatee bill keeps boaters in mind - Soundings Online
Senate bill 540 would make it more difficult to enact new manatee protection rules in parts of Florida where manatee population goals are achieved. It would ...
[125]
Surprising Surge: How Florida's Manatees Are Thriving More Than ...
Nov 20, 2024 · A new study highlights that Florida manatees are more numerous now than ever before, likely due to improved conservation efforts and environmental changes.
[126]
Manatee behavioral response to boats - Rycyk - Wiley Online Library
Feb 28, 2018 · The number of known manatee deaths from watercraft strikes declined substantially after the imposition of speed zones in one study (Laist and ...
[127]
Slower boat speeds reduce risks to manatees
Oct 18, 2007 · The purpose of this paper is 2-fold: (1) to discuss the conceptual basis for slowing down boats as a means of reducing risks to manatees; and (2) ...<|separator|>
[128]
Manatee Zones—More Than Just Signs
Jun 19, 2025 · We know that the most effective way to protect manatees from death and injury from boat strikes is by reducing boat speeds and adhering to ...
[129]
Twenty-six years of post-release monitoring of Florida manatees ...
Sep 1, 2016 · Manatees born in captivity experienced poor success after release (14%), whereas the overall success of wild-born individuals was higher (72%).Missing: survival rates
[130]
Twenty-Six Years of Post-Release Monitoring of Florida Manatees ...
Manatees born in captivity experienced poor success after release (14%), whereas the overall success of wild-born individuals was higher (72%). When compared ...Missing: survival | Show results with:survival
[131]
[PDF] Twenty-Six Years of Post-Release Monitoring of Florida Manatees ...
Determination of manatee population trends along the Atlantic coast using a Bayesian approach with temperature-adjusted aerial survey data. Marine Mammal ...
[132]
Closed Manatee Mortality Event Along The East Coast - FWC
A total of 1,039 out the the 1,255 mortalities occurred during the winters of 2020-2021 and 2021-2022. After extensive review of all available data on the UME, ...
[133]
[PDF] Stock Assessment Report for the West Indian Manatee Florida Stock ...
The most recent adult-survival-rate analysis for the 5 Page 6 Florida manatee identifies mean adult survival rates of over 97% and reproductive rates of over ...Missing: longitudinal | Show results with:longitudinal
[134]
Florida agency asks court to overturn judge's decisions on protecting ...
Jul 31, 2025 · The lawsuit argued, in part, that sewage discharges into the lagoon led to the demise of seagrass, a key food source for manatees, and resulted ...
[135]
Federal Judge Orders Florida to Address Pollution That Led to ...
Apr 18, 2025 · The litigation is centered on state wastewater discharge regulations that have failed to control nutrient pollution in the Indian River Lagoon, ...Missing: delays | Show results with:delays
[136]
Mysterious African manatees inspire a growing chorus of champions
Sep 5, 2024 · The African manatee faces numerous threats: poaching, drowning as bycatch in fishing nets, landscape degradation, and dam construction all ...Missing: historical | Show results with:historical
[137]
Occurrence patterns of African manatees, conflicts with humans, and ...
Aug 30, 2019 · First, there is insufficient implementation of policy measures (control, benefits, and education about laws) owing to the extreme remoteness ...Missing: gaps | Show results with:gaps
[138]
Manatees were once important Seminole food source
Apr 1, 2019 · Manatees first appeared in the shallow bays and rivers of the state about 15 million years ago, according to the Florida Fish and Wildlife Conservation ...
[139]
[PDF] Manatees across borders: Introduction to the special issue on the ...
manatus showing similarities with other species of the order Sirenia. Manatees are generalist herbivores, and their diet includes many species of subaquatic, ...
[140]
A Brief History of Manatee Hunting | MeatEater Conservation News
Jan 8, 2025 · Manatee hunting was a practice shared by many cultures, including the Seminole Indians of Florida. Primary accounts, accompanied by photographs of 20th-century ...
[141]
[PDF] Ecology, Distribution, Harvest, and Conservation of the Amazonian ...
Recent summaries of the distribution of the Amazonian manatee Trichechus inunguis record specimens from much of the Central. Amazon Basin in Brazil, eastern ...
[142]
Commercial exploitation of manatees Trichechus in Brazil c. 1785 ...
Decline of meat production in the 1960s may reflect overexploitation. Evidence was also found of some exploitation for meat of West Indian manatees T. manatus ...
[143]
Historical Manatee Hunting in the Florida Keys - Facebook
Apr 11, 2025 · It's true that the pioneers in The Keys killed and harvested manatees, turtles, key deer, crocodiles, alligators, birds from the Everglades, ...
[144]
Protecting manatees - Keys Weekly
Sep 6, 2018 · Manatees were supposedly harvested to feed the throngs of railroad workers. The name dates back to at least 1910, which would be the Flagler ...
[145]
[PDF] Commonly Asked Questions About: - Volusia County Government
In 1893, laws were passed to protect manatees in Florida by making the hunting of manatees illegal. However, manatee poaching was common in parts of Florida ...
[146]
Manatees | National Geographic
Manatee numbers declined throughout the last century, mostly because of hunting pressure. Today, manatees are at-risk. Though protected by laws, they still face ...
[147]
As Amazonian rivers recede under drought, manatees are left ...
Aug 27, 2024 · Hunting of Amazonian manatees (Trichechus inunguis) was banned nearly 60 years ago due to a significant population decline caused by the annual ...Missing: history | Show results with:history
[148]
Reef Rangers - Miami Seaquarium
Miami Seaquarium® is one of only three facilities in the State of Florida with a letter of authorization from the US Fish and Wildlife Service as a Manatee ...
[149]
Manatees Romeo and Juliet freed from Florida theme park following ...
Dec 1, 2023 · The 67- and 61-year-old sea cows have been at the Miami Seaquarium since 1956 and will be moved to a sanctuary.
[150]
Guyana Zoological Park & Wildlife Rescue Center
The Guyana Zoo, opened in 1952, is now a wildlife rescue and rehabilitation center, planned to be a wildlife education center, and is part of the National ...
[151]
Twenty-Six Years of Post-Release Monitoring of Florida Manatees ...
Nov 23, 2016 · Manatees born in captivity experienced poor success after release (14%), whereas the overall success of wild-born individuals was higher (72%).<|separator|>
[152]
Eighteen years of Antillean manatee Trichechus manatus manatus ...
Aug 19, 2014 · So far 30 manatees have been released at three sites, with a high rate of success (> 75%). Time in captivity appears to be a key variable ...
[153]
Manatee Rescue and Rehabilitation Partnership (MRP) Returns a ...
Feb 14, 2023 · The Manatee Rescue and Rehabilitation Partnership (MRP) today announced it has successfully released an unprecedented 12 manatees back to their natural habitat ...
[154]
Manatee Conservation Research
The MIPS database plays a crucial role in approximating vital statistics for Florida manatees, including survival and reproductive rates. These metrics are ...
[155]
Dauphin Island Sea Lab Renews Manatee Tagging Research
Aug 26, 2022 · The captured manatees were given complete health assessments and fitted with floating satellite tracking tags to locate them and to track their movements in ...
[156]
Genetic Diversity and Structure From Antillean Manatee (Trichechus ...
Jan 1, 2020 · The aims of this research were to survey on the possible regional genetic structure in the southern Gulf of Mexico and to compare genetic status ...
[157]
First Description of a Satellite DNA in Manatees' Centromeric Regions
Aug 23, 2021 · We report the first description of TMAsat, a satDNA comprising ~0.87% of the genome, with ~684bp monomers and centromeric localization.
[158]
Is captive breeding a priority for manatee conservation in Mexico?
May 2, 2018 · Manatees can be injured or orphaned as a result of anthropogenic or natural events and become dependent on rescue and rehabilitation in ...
[159]
FWC proposes changes to manatee zone boat speeds, Indian River ...
Aug 15, 2025 · Boaters will be able to increase their speed in 16 manatee protection zones in Indian River County if the state approves a proposal to ease ...Missing: opposition | Show results with:opposition
[160]
Manatee Protection Ordinance to Return to Hernando Board of ...
Aug 31, 2025 · The majority of the Mud River and all of its canals is currently a “no wake” zone, except for an approximate 1-mile portion in question closest ...<|separator|>
[161]
Slower Boat Speeds May Cause Manatees More Harm than Good
Jul 20, 2017 · While a slow speed zone may reduce the chance of death during a collision, they have not mitigated the number of collisions that kill and may ...
[162]
https://www.floridatrend.com/article/41165/judge-refuses-to-dismiss-manatees-case/
[163]
Florida DEP appeals manatee ruling over Indian River Lagoon
Jul 30, 2025 · The lawsuit, filed by Bear Warriors United, alleges that sewage discharges have harmed manatee food sources, leading to deaths. TALLAHASSEE — ...
[164]
Challenge to Manatee County wetland buffer rollback dies. Is new ...
May 16, 2024 · The state recommends minimum buffer widths of 15 feet with a 25-foot average, but developers can apply for exceptions to that rule.<|separator|>
[165]
Critical Habitat Designations for Florida Manatee and Antillean ...
Sep 24, 2024 · We propose to revise the existing designated critical habitat for the Florida manatee and designate critical habitat for the Antillean manatee.
[166]
Manatee tour companies hope for economic boom after storms - WTSP
Nov 15, 2024 · Manatee tour companies are estimated to have a $20-$30 million impact on the local economy each year. They hope for an economic boom after ...
[167]
(PDF) The Florida manatee and eco-tourism: toward a safe minimum ...
Aug 10, 2025 · The study found that the benefits of manatee protection in Citrus County greatly exceeded the development benefits foregone by approximately 8.2–9 million.
[168]
Florida Manatees Denied Greater Endangered Species Act ...
Jan 13, 2025 · Nearly 2,000 manatees died in just 2021 and 2022 combined. This two-year record represents more than 20% of all manatees in Florida. State and ...
[169]
(PDF) REVIEW: Slower boat speeds reduce risks to manatees
Aug 6, 2025 · The implementation of slow-speed zones allows greater time for the boat operator to react to manatees and reduces the severity of injuries if a ...
[170]
[PDF] Collision Course: The Government's Failing System for Protecting ...
Since 2000, an average of 82 manatees per year have been killed by watercraft and the proportion of watercraft collision mortalities compared to overall ...
[171]
[PDF] PRELIMINARY EVIDENCE THAT BOAT SPEED RESTRICTIONS ...
Dec 1, 2005 · The absence of a clear decline could be due to at least four causes: (1) the assumption that manatees are able to avoid slow-moving boats is ...
[172]
Florida manatees won't be listed as an endangered species - WUSF
Jan 14, 2025 · The proposed rule would keep the Florida manatee as a threatened species, continuing its status since being delisted as endangered in 2017.
[173]
Myths, Manatees, and Mermaids in the Age of Exploration - Snopes
Feb 15, 2021 · Evidence exists that some early seafarers and colonial explorers may have mistaken manatees for the mythical half-fish, half-human creatures known as mermaids.
[174]
How Did Manatees Inspire Mermaid Legends? - National Geographic
Nov 25, 2014 · Manatees and dugongs are both known to rise out of the sea like the alluring sirens of Greek myth, occasionally performing tail stands in shallow water.Missing: gentleness | Show results with:gentleness
[175]
The Gentle Nature of Manatees - River Ventures
Jan 29, 2024 · With their gentle demeanor and impressive size, they are often referred to as sea cows. Manatees are aquatic mammals and are known for their ...Missing: gentleness Disney
[176]
Disney Animals - Manatees | Under the Sea with Ariel - YouTube
Jul 29, 2024 · What to meet some of the gentlest giants of the sea? Then check out this special episode about Manatees and Dugongs, the slow-moving ...Missing: cow gentleness
[177]
Advocacy and Public Awareness - Save the Manatee Club
Save the Manatee Club is committed to reviewing and advocating for manatee protection in strategically significant "key" manatee counties in Florida.Missing: perception | Show results with:perception
[178]
Swim With Caution: The Impact of Human Interaction on Manatees
Jan 30, 2024 · The influx of tourist boats disrupts their daily lives, threatening their ability to find food, raise their young, and navigate safely.<|control11|><|separator|>
[179]
Protecting Manatees | National Wildlife Federation
Unfortunately, poor water quality in Florida has been causing a decline in seagrass for many years, leaving manatees to quite literally starve to death. Today, ...
[180]
(PDF) Not Everyone Likes Manatees: Fishers' Perceptions Unveil ...
Oct 3, 2024 · Not Everyone Likes Manatees: Fishers' Perceptions Unveil Opportunities and Challenges for Manatee Conservation in the Swamp Complex of Ayapel, ...
[181]
The People vs. the Florida manatee: A review of the laws protecting ...
This paper reviews the past and present laws protecting manatees in Florida, chronicles the impacts manatees are facing presently and in the future, and details ...
[182]
More Problems For Manatees Due To Human Interference
Mar 18, 2024 · When humans mess with Mother Nature almost always they cause problems. Such is the case with the manatee, which Florida leaders have managed ...