SYDNEY - AUSTRALIA marked the first anniversary of the death of environmentalist and television 'crocodile hunter' Steve Irwin in a low-key manner with his family commemorating privately.

But tributes flowed for the way his widow Terri and daughter Bindi, 9, have conducted themselves since Irwin was killed by a stingray barb that pierced his chest during filming on Australia's Great Barrier Reef.

Bindi Irwin has become a media star in her own right since her father's death, promoting his causes, speaking at events to commemorate him and starring in her own television programs. The couple also had a three-year-old son, Bob.

'Behind the positive faces they have shown the world since that dreadful day, there can be no doubt there is still deep sorrow and lasting pain,' Sydney's Daily Telegraph said in an editorial.

'So too for those who respected and admired Irwin for his boundless enthusiasm for life, his determination to make every second of it worthwhile. They will have their own thoughts to content themselves with, their own sadness.'

Irwin, who was 44 when he died, became world-famous for his daring stunts with dangerous animals but he was also an environmentalist who put much of the money he made towards promoting related causes.

He also ran a zoo with is wife in northeastern Queensland state. The Australia Zoo continues to be open to visitors.

Irwin's death prompted a national outpouring of grief, with tributes flowing in from all sections of society, including Prime Minister John Howard, who described Irwin as a 'wonderful and colourful son' of Australia.

A public celebration of Irwin's life is to be held on September 15. -- AFP