Serene Sirens: USGS Sea Cow Science

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It may be hard to believe the legend that sailors long-at-sea once considered manatees to be mermaids. The manatee nickname – the “Sea Cow” – which comes from the herbivores’ affinity for grazing on vegetation and their slow, ambling way just makes more sense. But a 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.

 

A USGS video about manatees reveals that while the animals may act like the cows of the sea, they also have more than a bit of the magical siren or mermaid about them.  Go for a serene swim.Scott Horvath, USGS (Public domain.)

It may be hard to believe the legend that sailors long-at-sea once considered manatees to be mermaids. The manatee nickname – the “Sea Cow” – which comes from the herbivores’ affinity for grazing on vegetation and their slow, ambling way just makes more sense. But a 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.

Almost Four Decades of Manatee Research

For nearly four decades, researchers with the USGS Sirenia Project have been committed to understanding the biology and ecology of the threatened West Indian manatee to aid managers in actions that could best help the population. Through long-term, detailed studies on the life history, population dynamics, and ecological requirements of the manatee, USGS scientists work cooperatively with federal and state biologists and managers on research identified as essential for the recovery of the species. To do this, the USGS manatee researchers rely on a variety of tools and techniques; puzzle pieces that come together to form the expertise of the Sirenia Project.

Ready for a Close-Up

Manatees aren’t strangers to the camera. The Manatee Individual Photo-Identification System (MIPS) is a database containing photographs and life-history information for over 4,200 individual manatees. As seen in the video, USGS researchers sketch and take photos of the manatees’ prominent scars and injuries that result primarily from boat propellers or from becoming entangled in abandoned fishing gear. These scars allow the researchers to identify individual manatees in the MIPS database and to use that information to help monitor the population. This information is used to estimate adult survival and reproductive rates and to study the life history of manatees. It can even help when a manatee has traveled into waters far away from home, such as the famous Chessie, who traveled all the way to Chesapeake Bay, which is far outside the usual range for manatees. Seventeen years later, USGS scientists were able to identify the manatee thanks to his unique markings, which include a long, gray scar on his left side.

Capturing Baseline Health Information

USGS researchers also use manatee captures and health assessments to gather information on this easygoing aquatic mammal. Over the last decade, the USGS has captured, examined, and released more than 250 manatees in the waters of Crystal River, Florida, creating an extensive sample and data archive. A collaborative effort between federal, state, and local government agencies and institutions, the information collected on these health assessments provides a baseline understanding of manatee health and can be used to help determine the status of the manatee population.

Tag, You’re It

Radio and satellite tracking allows researchers to document manatee movement and habitat use patterns. Tagging manatees can reveal travel pathways and the time they spend in each area. When coupled with the distribution of resources such as seagrasses and fresh water, this information is valuable to environmental managers to determine the resources that manatees use most. Tracking information can be used not only to protect habitat, but also the manatees themselves, by showing where they may come into conflict with watercraft or other potential hazards.

Caribbean Cousins

Genetics are an informative tool when it comes to at-risk species, like the manatee. Molecular studies found low genetic diversity in the Florida manatee – a subspecies of the West Indian manatee population – as well as help determine genetic relationships between the Antillean manatee – the second sub-species of the West Indian manatee – and the Florida manatee. Genetics also can help USGS researchers follow a manatee’s life history, without using marks on its body, providing an opportunity to better assess the population.

Image: Manatee Health Assessment Capture
Researchers use a net to pull a threatened wild manatee onto the beach in order to conduct a physical examination. Information on manatee biology in Crystal River enables biologists to better understand the complex issues confronting this at-risk species. Public domain

 

Manatees with scars - WARC
Manatees with scars. These scars help identify individual manatees. Public domain