'Most dangerous' exotic: Red-eared turtles threat in Vietnam and Australia

Red-eared turtles threaten Hanoi’s symbolic lake
Vietnam Net 18 Nov 10;

VietNamNet Bridge – Though the capital city authorities have instructed relevant agencies to collect and destroy red-eared turtles, the number of the world’s most dangerous exotic species is growing at the Hoan Kiem Lake.

They are also abundant at the Thien Quang ancient well in Van Mieu (Temple of Literature) – Vietnam’s first university.

It is observed that the turtles often float to the Hoan Kiem lake’s surface at 9am and hang themselves on twigs to stay out in the sun. Many twigs that are near the lake surface are occupied by dozens of turtles. The biggest turtles are around one kilo and the smallest ones are as small as one’s big toe.

Local residents said that every first day or fifteen day of the month, many people bring red-eared turtles to the lake to release. Some people often fish turtles to sell.

Prof., Dr. Ha Dinh Duc, a renowned scholar of Hanoi culture and history, said that he took the first photos of red-eared turtles at the Hoan Kiem Lake in 2004. Some people even took pictures of the dangerous turtles at the lake in 1997.

“I don’t know how many red-eared turtles are living in the lake but the number of exotic turtles has grown drastically. They multiply very quickly like yellow snails, which destroyed a vast area of rice in Vietnam in the past,” Dr. Duc said.

He said the turtles don’t directly harm the legendary ancient turtle in the lake but they compete with him in seeking foods. They also threaten smaller species in the lake.

The Thien Quang ancient well inside Hanoi’s Van Mieu (Temple of Literature) – Vietnam’s first university – also has many red-eared turtles.

The Van Mieu Scientific-Cultural Center’s director Dang Kim Ngoc said that red-eared turtles infiltrated the well in two ways. Firstly, Van Mieu is often flooded in downpours and turtles can get into the well through underground pipes. Some visitors brought turtles to the temple for worshipping and then released them to the well.

Nguyen Minh Tuan, chief manager of Hoan Kiem Lake area, said that to destroy red-eared turtles, it is necessary to have a specific policy and programs to educate people about this dangerous exotic species.

Invasion of the slider turtle on the North Shore
North Shore Times 19 Nov 10;

THIS turtle has been likened to the cane toad as a pest - and it has arrived on the North Shore.

It is the red-eared slider turtle, from North America.

Mature turtles are aggressive and can bite. They grow up to 30cm and prey on native species such as aquatic reptiles, frogs, fish, crustaceans and insects.

When an injured turtle was brought to Turramurra Vet Clinic, vet Jim Thompson recognised it straight away as a red-eared slider.

The turtle, brought in last week, later died from its injuries.

“A client from West Pymble brought it in. I presume it was found in the Lane Cove River Park,” Dr Thompson said.

“I have heard of a breeding population in Centennial Park.”

Likened to the cane toad and european carp, the slider turtle is in the world’s top 100 worst invaders according to the World Conservation Union.

It originates from America and northern Mexico but breeding populations have been found in all Australian states.

Invasive Animals Co-operative Research Centre officer Wendy Henderson said the turtles posed a huge problem. “In Queensland, where they have found several hundred, there is an eradication program where they dredge dams and bring in a specially-trained sniffer dog,” she said.

“It doesn’t surprise me that one has been found on the North Shore. There’s not a massive population in NSW but in routine checks last year they were found in the Sydney area, including the Hawkesbury-Nepean and around Wolli Creek.”

The exotic turtles can adapt to a range of temperatures and water conditions. “They also compete with the native turtles for food,” Dr Henderson said.

The turtle found on the North Shore was 6cm in diameter.

FACE TO FACE WITH A PEST:
*The slider turtle retracts its head straight back into its shell, whereas a native turtle retracts its head sideways.
*Male slider turtles have long claws on their front feet.
*Most have a red patch behind their eyes and pale yellow stripes on their face and front legs.
*The undershell of slider turtles has 12 scales with dark patches, whereas native turtles have 13 scales which are often plain with dark lines.
*The slider turtle can lay up to 70 eggs a year. It grows up to 30cm and its lifespan is about 40 years.
*Mature slider turtles are aggressive and can bite.
*They prey on native species such as aquatic reptiles, frogs, fish, crustaceans and insects.