A British grandmother was killed by a great white shark more than 16 feet long while she was diving off Australia’s west coast.

Doreen Collyer, a 60-year-old senior university nursing lecturer in midwifery, was killed by a giant shark while diving off Mindarie, 22 miles north of Perth in Western Australia over the weekend.

The Western Australian Fisheries Department believes a large white shark was responsible for the fatal attack on the woman on Sunday.

The woman’s 43-year-old diving companion managed to get her back on the boat, between One and Three Mile reefs, but Collyer died from her injuries.

Fishermen who rushed to help and who saw the killer shark said it was bigger than their 18-foot boat.

Collyer’s diving buddy John said about 25 minutes into the dive, he felt something brush past him and when he surfaced, he saw his friend had been badly attacked.

The shark has now been deemed an “imminent threat” to public safety, so it can legally be killed, with the department’s director-general issuing an order to fish for the shark.

Collyer’s husband, David, who made the move to Australia with his wife, said in a statement: “Doreen was a beautiful person and everyone loved her. She was a devoted grandmother, mother and loving wife.”

Tributes for the registered nurse, who moved from the UK to Australia about five years ago, have flowed in.

Edith Cowan University acting vice chancellor Professor Arshad Omari said Collyer’s tragic death was devastating to staff and students at the university where she worked.

“Doreen was the director of postgraduate studies and a lecturer with the School of Nursing and Midwifery. She was a much loved and respected colleague, mentor and teacher,’’ Omari said.

“Having obtained an impressive record of senior clinical and lecturing experience in her native UK, upon migrating to Australia she made many valued contributions to ECU in the area of children and young people’s nursing.

“On behalf of the entire ECU community, I extend my sincerest condolences to her family in what is a very difficult time.”

Omari said ECU had arranged for counseling for affected staff and students within the School of Nursing and Midwifery.

Collyer formerly worked as a senior lecturer at the University of Chester in England.

Perth Diving Academy paid tribute to Collyer on social media, saying: “It’s with heavy hearts that we are writing this post. Our thoughts and condolences go out to the family and friends of Doreen Collyer, [whose] life was tragically cut short while diving off Mindarie (Sunday).

“Doreen was a much loved customer in our store and her friendly nature will be greatly missed.”

View video

Other students paid tribute to the university lecturer, with Zara Yalda Aurang saying: “Doreen was such a kind and supportive teacher. You will be missed by all, especially by your students.

“RIP Doreen, condolences to her family.”

Another student, Stephanie Shy Chyn, said she would “always remember how nice and friendly you are when in your class.”

Western Australia’s Premier Colin Barnett defended the decision to kill sharks considered an imminent threat: “It was estimated to be over 18 feet long and if a shark like that stays in the vicinity, it is a continuing threat,” Barnett said.

“If that shark stays in the area, it will be presumed or judged to be a threat so we reserve that right.”

“We’re trying to balance the views of the public, but public safety will always come first.”

But Barnett ruled out setting permanent drumlines off the Western Australia coast after the attack on Collyer, which came just days after surfer Mandurah Ben Gerring was fatally mauled about 62 miles south.

He said: “I extend my, and the government and all of Western Australia’s, sympathy to the family and friends of those two people who have so tragically lost their lives.”

Collyer held qualifications from the Royal College of Nursing, was a Fellow in the Higher Education Academy and the Australian College of Children and Young People’s Nursing.

Collyer’s professional areas of interest included neonatal feeding methods, preparing children to visit an adult in an intensive care unit and preparing siblings to visit a patient in intensive care.

West Australian police confirmed on Sunday that Collyer’s body had severe injuries consistent with a shark attack.