If the woman is confirmed to be a victim of a shark attack, it will be the second fatality in Western Australia in less than a week.
Ben Gerring, 29, died on Friday night at Royal Perth Hospital after being mauled by a shark at Gearies break in Falcon, south of Perth, on Tuesday.
Mindarie is more than 100km north of Falcon and is an outer coastal suburb of Perth.
Gerring was looking forward to becoming a father but now people are rallying to raise money for the baby he'll never see.
The GoFundMe page was set up when the fly-in fly-out worker was placed in an induced coma, to help him and his fiancee Jasmine Boyer.
But since his death, friends, surfers and strangers have continued to donate money to the grieving family, raising more than A$42,400 in just a few days.
Erika Magness posted: "Ben you were the kindest soul and you will never be forgotten. You have left such a beautiful gift - your's and Jasmine's baby. Jas, wish I could take your pain away."
Gerring's brother, Rick, thanked the "heroes" who tried to save the surfer. "Ben was a naturally gifted sportsman, whether it was track and field, skateboarding, snowboarding or surfing," he told reporters on Saturday.
"Ben loved the ocean, crabbing and surfing, but his greatest love is and always will be Jasmine. "He was so proud to become a father and a husband."
Gerring's father, Shane, described those who tried to save his son as "angels of the ocean" and said he opposed a shark cull. "Instead of shooting sharks, let's tag them," he told the Sunday Times newspaper. "We've also got to get better at communications so people can get on their phone, get an App and go, 'Yep, there's a shark sighting, it's in the area', before they go for a surf. "If you kill sharks, you're going to kill that ocean. I don't blame the shark at all."
- AAP