Tributes flow for teen killed by shark in Swan River

Family and friends of a 16-year-old girl who was fatally mauled by a shark in the Swan River have paid tribute to the "vibrant and happy girl".

Stella Berry was riding a jet ski with friends near the North Fremantle traffic bridge on Saturday afternoon when police say she jumped into the water to swim with a pod of dolphins.

Moments later she was attacked by a shark.

Despite the desperate attempts of emergency services, Stella could not be revived.

Luke Smith and Joshua Warwick were there when the attack unfolded.

"There was this big scream and then we see a girl just jump off and we see a few fins," Smith told 9NEWS.

"We saw the police running down the hill, and we thought maybe they were chasing someone and then we saw a girl on the ground getting resuscitated," Warwick said.

Stella's parents Matt and Sophie released a statement on Sunday.

“We are devastated and deeply shocked by the loss of our beautiful daughter Stella. We want to acknowledge the amazing support we have received from our family, friends, authorities and the WA community,” they said.

“Stella was a vibrant and happy girl with plans of living in Europe after school. She was a caring person and was a dear friend to many, across a variety of schools in the area.

“She had an infectious laugh which we couldn’t help laughing at too when we heard it. Our thoughts are with Stella’s many friends at this time.

“Stella loved creating art and spending time with her friends, particularly at the river and beach. She had her skipper’s ticket and often took friends out on the river for a day of ‘scurfing’.

“She was a beautiful and loving big sister and the best daughter we could have hoped for."

Fisheries officers spent Saturday afternoon and Sunday searching for the shark but it has not been located.

Part of the Swan River where the attacked occurred remains closed.