Media Inquiries on USGS Manatee Research
We appreciate your interest in USGS' Sirenia Project. To help inform members of the media and public, we have provided relevant publications, reports, and websites.
USGS scientists have devoted more than forty years to studying the biology and ecology of the West Indian manatee. Research conducted by our scientists is used to help inform management actions, including the recent U.S. Fish and Wildlife Service's announcement to downlist the West Indian manatee from endangered to threatened. Here, you will find information on the manatee science conducted by USGS. For more information, please use the contacts provided.
Every few years, USGS conducts a comprehensive analysis on the the status and threats for the Florida manatee. Those reports can be found here:
Population models developed by USGS are the primary decision-support tools used for status assessments, and rely on estimates of adult survival and reproduction rates from mark-recapture studies.
The Challenge: Florida manatees are threatened by watercraft-related mortality, the potential loss of warmwater habitat, red tide events, and other anthropogenic factors. The USFWS and the Florida Fish and Wildlife Conservation Commission have regulatory authorities under the Endangered Species Act (ESA), the Marine Mammal Protection Act (MMPA), and state statutes to recover manatees. To support management decision-making, these agencies need quantitative assessments of population status.
Long-term monitoring data in the Manatee Individual Photo-identification System (MIPS), developed and coordinated by WARC-Sirenia Project in collaboration with Florida’s Fish and Wildlife Research Institute and Mote Marine Laboratory, are the basis for modeling manatee demography rates.
Nuclear microsatellite markers have been developed and implemented on ~2,000 West Indian manatees. These markers provide individual genetic fingerprints for mark-recapture studies, population structure information for the conservation of unique or isolated populations, and pedigree and relatedness information for addressing inbreeding and breeding structure patterns.
A multi-agency effort assesses the health of manatees and provides baseline information on their health, reproductive status, and nutritional condition.
Since 1978, USGS scientists have photo-documented manatees in the Southeast United States. Now, more than 3,000 manatees can be found in the MIPS database.
Manatees are tropical to subtropical in distribution and, with few exceptions, Florida is the northern limit of their natural winter range. The availability of warm-water habitat during winter is critical for the future persistence of the population in Florida.
USGS works with partners to assess manatee distribution and habitat use throughout the Northern Gulf of Mexico.
Critical information predicting condition changes in manatee habitat resulting from the alteration of freshwater flows to estuaries is needed to develop the PSRP Detailed Design and PSRP Operations Plan components and complete consultation under the Endangered Species Act.
Turbid water conditions make the delineation and characterization of benthic habitats difficult by traditional in situ and remote sensing methods. Consequently, only a small fraction of this valuable resource has been mapped or characterized.
Morphometric body condition indices of wild Florida manatees (Trichechus manatus latirostris)
In many species, body weight (W) increases geometrically with body length (L), so W/L3 provides a body condition index (BCI) that can be used to evaluate nutritional status once a normal range has been established. No such index has been established for Florida manatees (Trichechus manatus latirostris). This study was designed to determine a normal range of BCIs of Florida manatees by comparing W...Harshaw, Lauren T.; Larkin, Iskande V.; Bonde, Robert K.; Deutsch, Charles J.; Hill, Richard C.
Baseline reference range for trace metal concentrations in whole blood of wild and managed West Indian Manatees (Trichechus manatus) in Florida and Belize
The West Indian manatee (Trichechus manatus) is exposed to a number of anthropogenic influences, including metals, as they inhabit shallow waters with close proximity to shore. While maintaining homeostasis of many metals is crucial for health, there is currently no baseline reference range that can be used to make clinical and environmental decisions for this endangered species. In this study,...Takeuchi, Noel Y.; Walsh, Michael T; Bonde, Robert K.; Powell, James A.; Bass, Dean A.; Gaspard, Joseph C.; Barber, David S.
Model description and evaluation of the mark-recapture survival model used to parameterize the 2012 status and threats analysis for the Florida manatee (Trichechus manatus latirostris)
This report provides supporting details and evidence for the rationale, validity and efficacy of a new mark-recapture model, the Barker Robust Design, to estimate regional manatee survival rates used to parameterize several components of the 2012 version of the Manatee Core Biological Model (CBM) and Threats Analysis (TA). The CBM and TA provide scientific analyses on population viability of the...Langtimm, Catherine A.; Kendall, William L.; Beck, Cathy A.; Kochman, Howard I.; Teague, Amy L.; Meigs-Friend, Gaia; Peñaloza, Claudia L.
Post-release monitoring of Antillean manatees: an assessment of the Brazilian rehabilitation and release programme
Mammalian reintroduction programmes frequently aim to reconnect isolated sub-populations and restore population viability. However, these long-term objectives are rarely evaluated due to the inadequacy of post-release monitoring. Here, we report the results of a unique long term telemetry-based monitoring programme for rehabilitated Antillean manatees (Trichechus manatus manatus) reintroduced...Normande, Iran C.; Malhado, Ana C. M.; Reid, James P.; Viana Junior, P.C.; Savaget, P. V. S.; Correia, R. A.; Luna, F. O.; R. J. Lad
Influence of manatees' diving on their risk of collision with watercraft
Watercraft pose a threat to endangered Florida manatees (Trichechus manatus latirostris). Mortality from watercraft collisions has adversely impacted the manatee population’s growth rate, therefore reducing this threat is an important management goal. To assess factors that contribute to the risk of watercraft strikes to manatees, we studied the diving behavior of nine manatees carrying GPS tags...Edwards, Holly H.; Martin, Julien; Deutsch, Charles J.; Muller, Robert G; Koslovsky, Stacie M.; Smith, Alexander J; Barlas, Margie E.
Seasonal response of ghrelin, growth hormone, and insulin-like growth factor I in the free-ranging Florida manatee (Trichechus manatus latirostris)
Seasonal changes in light, temperature, and food availability stimulate a physiological response in an animal. Seasonal adaptations are well studied in Arctic, Sub-Arctic, and hibernating mammals; however, limited studies have been conducted in sub-tropical species. The Florida manatee (Trichechus manatus latirostris), a sub-tropical marine mammal, forages less during colder temperatures and may...Tighe, Rachel L; Bonde, Robert K.; Avery, Julie P.
Twenty-six years of post-release monitoring of Florida manatees (Trichechus manatus latirostris): evaluation of a cooperative rehabilitation program
The rescue, rehabilitation, and release of Florida manatees (Trichechus manatus latirostris) into the wild has occurred since 1974; however, a comprehensive evaluation of the outcomes of the releases has never been conducted. Herein, we examined data for 136 Florida manatees that were rehabilitated and released with telemetry tags between 1988 and 2013 to determine release outcome of each...Adimey, Nicole M.; Ross, Monica; Hall, Madison; Reid, James P.; Barlas, Margie E.; Keith Diagne, Lucy W; Bonde, Robert K.
A quantitative framework for estimating risk of collision between marine mammals and boats
Speed regulations of watercraft in protected areas are designed to reduce lethal collisions with wildlife but can have economic consequences. We present a quantitative framework for investigating the risk of deadly collisions between boats and wildlife. We apply encounter rate theory to demonstrate how marine mammal-boat encounter rate can be used to predict the expected number of deaths...Martin, Julien; Sabatier, Quentin; Gowan, Timothy A.; Giraud, Christophe; Gurarie, Eliezer; Calleson, Scott; Ortega-Ortiz, Joel G.; Deutsch, Charles J.; Rycyk, Athena; Koslovsky, Stacie M.
Status and threats analysis for the Florida manatee (Trichechus manatus latirostris), 2012
The endangered West Indian manatee (Trichechus manatus), especially the Florida subspecies (T. m. latirostris), has been the focus of conservation efforts and extensive research since its listing under the Endangered Species Act. On the basis of the best information available as of December 2012, the threats facing the Florida manatee were determined to be less severe than previously thought,...Runge, Michael C.; Langtimm, Catherine A.; Martin, Julien; Fonnesbeck, Christopher J.
Convergent evolution of the genomes of marine mammals
Marine mammals from different mammalian orders share several phenotypic traits adapted to the aquatic environment and therefore represent a classic example of convergent evolution. To investigate convergent evolution at the genomic level, we sequenced and performed de novo assembly of the genomes of three species of marine mammals (the killer whale, walrus and manatee) from three mammalian orders...Foote, Andrew D.; Liu, Yue; Thomas, Gregg W.C.; Vinař, Tomáš; Alföldi, Jessica; Deng, Jixin; Dugan, Shannon; van Elk, Cornelis E.; Hunter, Margaret; Joshi, Vandita; Khan, Ziad; Kovar, Christie; Lee, Sandra L.; Lindblad-Toh, Kerstin; Mancia, Annalaura; Nielsen, Rasmus; Qin, Xiang; Qu, Jiaxin; Raney, Brian J.; Vijay, Nagarjun; Wolf, Jochen B. W.; Hahn, Matthew W.; Muzny, Donna M.; Worley, Kim C.; Gilbert, M. Thomas P.; Gibbs, Richard A.
Inferring spatial and temporal behavioral patterns of free-ranging manatees using saltwater sensors of telemetry tags
Diving or respiratory behavior in aquatic mammals can be used as an indicator of physiological activity and consequently, to infer behavioral patterns. Five Antillean manatees, Trichechus manatus manatus, were captured in Chetumal Bay and tagged with GPS tracking devices. The radios were equipped with a micropower saltwater sensor (SWS), which records the times when the tag assembly was submerged...Castelblanco-Martínez, Delma Nataly; Morales-Vela, Benjamin; Slone, Daniel H.; Padilla-Saldívar, Janneth Adriana; Reid, James P.; Hernández-Arana, Héctor Abuid
Variation in the hindgut microbial communities of the Florida manatee, Trichechus manatus latirostris over winter in Crystal River, FloridaMerson, Samuel D.; Ouwerkerk, Diane; Gulino, Lisa-Maree; Klieve, Athol; Bonde, Robert K.; Burgess, Elizabeth A.; Lanyon, Janet M.
It may be hard to believe the legend that sailors long-at-sea once believed manatees to be mermaids. The manatee nickname the “Sea Cow” – named so for their affinity for grazing on vegetation and their slow, ambling way – just makes more sense. But a new U.S. Geological Survey video reveals that while they may be cow-like, they also have more than a bit of the magical mermaid to them.
The risk of extinction for the endangered Florida manatee appears to be lower, according to a new U.S. Geological Survey led study.
Gainesville, FL. -- The first genetic study to compare nuclear DNA of endangered Antillean manatees in Belize with Florida manatees confirmed their designation as separate subspecies. Belize’s manatees, however, were found to have extremely low genetic diversity, raising questions about their long-term genetic viability.
The importance of a ‘blanket effect’ caused by layers of fresh and salt water in two warmwater manatee refuges along the coast of southwest Florida has been documented by a team of U.S. Geological Survey (USGS) and U.S. Fish and Wildlife Service scientists.
Manatee populations are growing at healthy rates in two of four regions off Florida’s coast, but may be stalled or declining in the remaining regions, according to a recently released report by the U.S. Geological Survey.
Florida Manatee with a tracking devise attached
Florida manatee population uses warm-water discharges from power plants during winter
Health assessment of a manatee
Manatee swims in a Florida spring
Two manatees with radio transmitters attached
USGS researcher collects data on manatee in Florida spring.
USGS conducts long-term, detailed studies on the life history, population dynamics, and ecological requirements of the West Indian manatee. Federally listed as endangered, the manatee is a large, gentle, plant-eating, and slow-moving marine mammal.
A manatee feeds on sea grass beds in Ten Thousand Islands region of Florida.