Sept. 13 (Bloomberg) -- ``Crocodile Hunter'' Steve Irwin's manager appealed to fans not to seek revenge against stingrays, as authorities investigate a spate of killings since the television star was fatally struck by one of the sea creatures.

``To hear that people are actually going out and killing stingrays and cutting off their tails is barbaric,'' said John Stainton, in an interview with Australian Broadcasting Corp. radio today. ``I can understand that some people probably are doing this out of vengeance, but they should not.''

At least 10 stingrays have washed up on beaches in Australia's Queensland state with their tails cut off since Irwin died on Sept. 4, Queensland's Department of Primary Industries and Fisheries said in a statement yesterday. Animal welfare officers are investigating, the department's General Manager Rick Symons said.

Irwin, 44, was struck in the heart by a stingray's barbed tail while filming a documentary at Batt Reef near the tourist resort of Port Douglas in Queensland.

The conservationist would be ``absolutely shocked'' if people had killed stingrays to avenge his death, Stainton said. ``The one thing you don't do is go out and kill wildlife because it may have hurt or maimed somebody,'' he told ABC radio. ``They're turning one tragedy into another.''

Wildlife Documentary

A public memorial service will be held for Irwin on Sept. 20 at the 5,500-seat ``Crocoseum'' stadium in his Queensland wildlife park, Australia Zoo, his widow Terri said in a statement.

Irwin was her ``soul mate,'' she said, and thanked fans across the world for their ``overwhelming outpouring of love, support and prayers.''

Irwin shot to fame when his first wildlife documentary, ``The Crocodile Hunter,'' became a global hit. He went on to film 53 episodes of the Emmy award-nominated ``Croc Files'' and ``The Crocodile Hunter Diaries'' which chronicled his day-to-day life working at Australia Zoo.

Irwin also appeared on ``The Oprah Winfrey Show'' and ``The Tonight Show with Jay Leno.''

Stingrays aren't aggressive and sting only when threatened, Bryan Fry, deputy director of the Australian Venom Research Unit, said Sept. 4. The fisheries department has encountered ``isolated incidences'' in the past of stingrays having their tails removed, department biologist Wayne Sumpton said in a statement.

Stingray Corpses

``It's usually where stingrays have been caught inadvertently and the people who caught them are concerned about getting stung, therefore they remove the tail as a precaution,'' said Sumpton, who examined two stingray corpses found yesterday at Deception Bay in Queensland.

Up to eight stingrays were found with their tails removed on Sept. 11 on Dundowran Beach, near the Queensland tourist resort of Hervey Bay, the department added.

``Stingrays are beautiful creatures and it is saddening to hear that they are being injured in Steve's name,'' said a statement yesterday by Irwin's conservation charity Wildlife Warriors Worldwide. ``Steve never would have blamed the stingray for his fatal injury and would not have wanted anyone to hurt them or any animal.''

There is no evidence that the stingrays were killed as an act of revenge following Irwin's death, Kirsten Phillips, a media spokeswoman for the department, said in a phone interview. Officers are looking into the possibility, she added.

When news of Irwin's death broke, visits to his Web site, http://www.crocodilehunter.com, leapt by 18,000 percent, according to online measurement company Hitwise, the Australian newspaper reported Sept. 7. Australian Prime Minister John Howard paid tribute to Irwin in parliament and Queensland state Premier Peter Beattie offered a state funeral.

To contact the reporter on this story: Ed Johnson in Sydney at ejohnson28@bloomberg.net.

Last Updated: September 13, 2006 01:15 EDT