Esperance police acting senior sergeant Ben Jeffes said the girl was a competent surfer.
Her broken surfboard has been recovered and will be analysed to determine what kind of shark it was.
"What we have now are the debris which make a complete board," Jeffes told ABC radio today. It will be sent to scientists at the Department of Fisheries for examination.
"There's a real sense of sadness and loss in the community here, it's just terrible," Jeffes said.
Professional local fisherman Neville Mansted told local Perth radio 6PR: "There's a lot of people in shock. It was one of my favourite surf spots but I think I might be crossing it off the list, together with a few other places."
The Shark Smart WA website recorded two public shark sightings in the Esperance area on Tuesday last week.
A medium-sized white shark was seen 150m offshore at Two Mile Beach in Hopetoun and another was seen 300m offshore at Crazies Reef.
"The fact that there was a couple of sightings out there during the week, and with Easter coming, on I can't believe that somebody hasn't done something, like a fisheries patrol," Mansted said.
"Trouble is, nobody seems to be interested because it's not them that's being bitten. That's the tragic part."
Mansted said WA needed shark nets.
The beach at Wylie Bay remained closed today and the Department of Fisheries is conducting beach and water patrols.
Surfers and swimmers have been told not to go into the water for at least two days.
Esperance Shire president Victoria Brown said she had been inundated with people asking how they could help.
In June last year, shark attacks resulted in the deaths of surfer Ben Gerring at Mandurah and diver Doreen Collyer at Mindarie Marina in Perth.
In 2014, attack survivor Sean Pollard lost his right hand and left arm above the elbow.
- AAP