ORLANDO, Fla., April 8 (UPI) -- Scientists in Florida have developed a new way to identify the sex of sea turtle hatchlings, which they said is a crucial step in assessing the impact of climate change on the species, most of which face possible extinction.
The new method will allow a much clearer picture of any imbalance in the ratio of females to males, which has been a major threat to sea turtles for decades. Armed with that knowledge, conservationists said they will be able to make better decisions about how to save the turtles.
Determining the sex of many reptiles is difficult. Until a few decades ago, the only sure way to know the sex of a sea turtle was to kill it and analyze its tissue.
In recent years, laparoscopy has helped, but hatchlings have to grow to a certain size for that method. Now, however, the sex of turtle hatchlings can be determined by taking a small blood sample, according to researchers at Florida Atlantic University's Charles E. Schmidt College of Science in Boca Raton.
"It's really important because all sea turtles are listed as threatened or endangered," said Jeanette Wyneken, a professor of biological sciences and a co-author of the study. "If the population is struggling, it could be that we have such a skewed sex ratio that reproduction is inhibited."
The new test will allow hundreds or thousands of turtles to be sexed, as opposed to 10 at a time that used to be the normal, Wyneken said.
The advance provides "a crucial step in assessing the impact of climate change on imperiled turtle species," according to the study published in March in the journal Scientific Reports.
Sea turtle sex is determined by the nest's temperature. Warmer temperatures produce females and cooler temperatures produce males. With the rapid increase of global temperatures, the researchers said an urgent need exists to clearly assess sex ratios in the imperiled animals.
"Information from our study should enable other scientists and managers to precisely monitor changes in sex ratios that might arise as a consequence of changes in temperature over time," said Boris Tezak, the primary author, who conducted the research as part of his doctoral studies. He now is a post-doctoral researcher at Duke University Medical Center.
Wyneken said she has dedicated her career to better testing because since she started her career, she was appalled at the thought of killing endangered animals to determine their sex.
After the blood test was developed, its accuracy was verified using the older methods, according to the researchers.
Conservationists praised the new method. Knowing how local populations are breeding or not breeding could lead to a greater understanding of the best habitat for sea turtles, said Richard WhiteCloud, founding director of the Fort Lauderdale, Fla.-based non-profit Sea Turtle Oversight Protection.
He said overdeveloped shorelines tend to have hotter temperatures, while areas with more vegetation are cooler.
"This could help us conserve the habitats that are needed," WhiteCloud said. "It's right up there at the top of the list of important research advances we've had."