DNA testing of water samples can determine whether manatees are present in the area, a new study has found.
A United States Geological Survey-led team of researchers isolated DNA from tissue samples previously collected from West Indian, Amazonian, and African manatee species as well as from the Florida and Antillean West Indian manatee subspecies to develop quantitative PCR and droplet digital PCR eDNA assays for their presence. As the team reports in Endangered Species Research, it then validated the assays by testing them on water collected from manatee-rich waters off of Florida's east coast. The team reports detection and occupancy rates, higher than what aerial surveys have uncovered. All three manatees species are considered vulnerable by the International Union for Conservation of Nature.
The researchers also tested samples collected from the locations in the Florida Panhandle, Cuba, and Cameroon to find eDNA from manatees at all the Florida locations, all five in Guantanamo Bay, and one site in Cameroon.
"In some instances manatees just cannot be detected even though we know they're there," first author Margaret Hunter from USGS says in a statement. "But our study found that eDNA surveys improved the detection of manatees in the wild, compared to the more traditional aerial survey methods. And it is relatively easy for field biologists to collect the samples."