Sci-Tech | Feb 03

Nationwide Turtle Survey Highlights Invasive Spread and Native Decline

TOKYO, Feb 03 (News On Japan) - The Japan Nature Conservation Association revealed the results of its nationwide turtle survey on Thursday, February 1, with more than half the collected samples being the 'Red-Eared Slider,' as this invasive species continues to expand its habitat, while there are concerns over the declining population of the native Japanese Pond Turtle.

Before the onset of winter last November, reporters accompanied experts to a river in Aichi Prefecture for an investigative report.

Yabe, a turtle researcher for 40 years, pointed out, "There's a turtle over there."

What was found in the river was the Mississippi Red-Eared Slider, an invasive species also known as the "Green Turtle."

Yabe, reflecting on the situation, expressed concern: "The Red-Eared Slider is becoming more prevalent. Thinking about Japan's turtles, it's quite despairing."

The expansion of the Red-Eared Slider's habitat was confirmed by a survey conducted for the first time in ten years.

The Japan Nature Conservation Association announced the results of the "Nationwide Turtle Survey" (conducted from July 1 to September 30, 2023, with a sample size of 2,147 turtles), which collected turtle sighting information across the country...

Ohno from the Japan Nature Conservation Association reported, "55.3% of all turtles were Red-Eared Sliders."

The survey found that over half of the turtles observed were Red-Eared Sliders.

Ohno added, "We've received reports from Honshu, Shikoku, Kyushu, and even Naha in Okinawa, showing it has truly spread nationwide."

This spread might be contributing to the decline of native species like the Japanese Pond Turtle.

The proportion of sightings of the Japanese Pond Turtle, a native species, has decreased with each survey, indicating a potential decline in their population.

In the river in Aichi Prefecture, almost all of the many turtles observed were Mississippi Red-Eared Sliders, with only one turtle believed to be a Japanese Pond Turtle.

Yabe, with 40 years of turtle research experience, concluded, "It's virtually impossible to eradicate invasive species. The key is to reduce the Red-Eared Slider's population to a level where it minimally impacts the ecosystem."