Genetic Diversity Among Endangered Florida Manatees low, but not yet Critical

Share Article

An article recently published in the Journal of Mammalogy, Volume 94 Issue 6 focuses on the struggling Florida manatee population and analyzes the factors pertaining to their decline.

Journal of Mammalogy – There is a better than 49 percent probability that the Florida manatee population will fall below 500 individual animals in the next 100 years, according to one analysis. One of the factors that can drive population decline is a lack of genetic diversity. The Florida manatee, a species first listed as endangered in 1967, is struggling to maintain its diversity within a small population.

The Journal of Mammalogy reports on a genotype study of Florida manatees. This study yielded information about genetic diversity, population structure, and genetically effective population size. Loss of genetic diversity and ensuing inbreeding can reduce survival, reproduction, fitness, and the population persistence of a species.

The Florida manatee, a subspecies of the West Indian manatee, lives in the coastal waters of the southeastern United States. This mammal is protected as an endangered species both in the United States and internationally. Its future is uncertain because of many threats, including collision with watercraft, loss of habitat, entrapment, and entanglement.

Skin samples were taken from 362 manatees and tested for 18 microsatellite markers in this genotyping effort. Levels of genetic diversity were found to be lower for the Florida manatee than for other mammalian species with hunted and fragmented populations. Moderate inbreeding was present in this study population.

While this study found that the Florida manatee’s genetic diversity is low, it is not severe enough at this time to warrant concerns of inbreeding depression. However, further reduction in population size could worsen the situation.

Genetic diversity is necessary for a species to adapt to climate and other environmental changes. Results of this study indicate that genetic diversity is not the primary concern for the Florida manatee. Currently, its biggest threat remains human activities. Wildlife managers face the challenge of anticipating threats to the Florida manatee—from loss of genetic diversity to contact with boat propellers—and taking appropriate actions to minimize the impact on the species.

Full text of “Low genetic diversity and minimal population substructure in the endangered Florida manatee: implications for conservation,” Journal of Mammalogy, Vol. 93, No. 6, 2012, is available at

Share article on social media or email:

View article via:

Pdf Print

Contact Author

Taylor Fulton
Visit website