published12. August 2022, 21:47
due to the heatIn Florida almost only female sea turtles are born
In recent years, nearly all newly hatched sea turtles in Florida have been females. This is probably due to global warming.
- von
- Fee Anabelle Riebeling
According to researchers, this is due to the increasing heat.
Unsplash
The past four summers in Florida have been the hottest on record, according to Bette Zirkelbach (pictured), director of the Turtle Hospital in Marathon in the Florida Keys.
via REUTERS
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Hot temperatures not only cause problems for people, but also for sea turtles.
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In Florida, the heat meant that recently only female animals were born.
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This endangers their survival.
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An association between heat and predominantly female offspring has also been reported for sea turtles in Australia.
The news about the sea turtle situation in America’s Sunshine State is not good. According to researchers, almost only female animals have been born in Florida in recent years. Recently even exclusively, like Bette Zirkelbach, head of the Turtle Hospital in Marathon on the Florida Keys, the news agency Archyde.com said: “Scientists who deal with the hatching of sea turtles have not found any male animals in the last four years.”
The disappearance of males is a growing concern for researchers. They fear that the sea turtle population will dwindle over time. According to experts, the reason for the development is global warming.
Heat makes for females
Because warm or even hot air temperatures have, according to the US Maritime Administration National Ocean Service NOS has a significant influence on the sex of the animals: If the ambient temperature is below 27 degrees Celsius, the turtle babies become male. At over 31 degrees Celsius they become female. Temperatures in between result in a mix of both sexes (see box).
But the soil temperature also plays a role, as the NOS writes. Accordingly, the proportion of females is higher, the warmer the sand is. “The frightening thing is that the last four summers in Florida have been the hottest on record,” Zirkelbach said. Because the heat heats up the sand properly.
This is how sex develops in turtles
As with various egg-laying reptiles—including alligators, lizards, and crocodiles—most turtle species are sexed after fertilization and are affected by the temperature surrounding the eggs. Such formation of sex is referred to as “temperature-dependent sex determination” (TSD) – as temperature-dependent sex determination.
“Over the years, we’re going to see a sharp decline in population because we just don’t have the genetic diversity,” says Melissa Rosales Rodriguez, a turtle keeper at Miami Zoo’s Sea Turtle Hospital Archyde.com. “We don’t have the male-to-female ratio that is required for successful breeding.”
«Extreme – in capital letters and with an exclamation mark»
Observations similar to those in Florida were also made in Australia four years ago Nationalgeographic.com citing a published in the journal «Current Biology» published study writes. According to turtle researcher Camryn Allen’s team at Hawaii’s National Oceanic and Atmospheric Administration, “female turtles outnumbered at least 116 to 1 in the largest and most important green sea turtle den in the Pacific Ocean.”
That was extreme, quotes Allen magazine: “Extreme in capital letters, extreme with an exclamation mark. We’re talking anywhere from a handful of males to hundreds of females. We were shocked.”
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