A Facebook page, set up in Jamie's honour, has posts of condolence to his family.
Lynda Frisby posted on the page: "Trident lost a true gentleman and ambassador today. No words can ever express how we are all feeling. Sleep well Jamie. Love and hugs to your whanau."
Another Facebook user wrote, "R.I.p bro .. Was pretty mean playing rugby with you .. Loves [sic]".
Sapphire Awa-Moana Patuwai wrote: "Jamie, You were so young and had a long bright future ahead of you. I wasn't as close to you as other friends but you always had a cheeky smile on your face.
"So sorry for your loss Ms Bellamy and the rest of your whanau but Kia kaha whanau. Im gonna give you a big hug when I see you RIP JAMIE."
Another wrote: "Jamie you were such a awesome guy to have around and always kept the vibe going. Rest well Jamie. We'll all miss you sooo much."
Others wrote of their favorite memories of the youth and posted photos.
Whakatane police are investigating the death but are treating it as a hunting incident.
Eastern Bay of Plenty police Detective Senior Sergeant Greg Standen said police had completed initial investigations and would be working with the families involved over the ensuing days to provide the appropriate support.
"This was a tragic incident and we urge all firearms users to please take extra care, as we don't want to see any more tragedies this season."
Trident High School this afternoon sent out a newsletter to parents at the school.
"It is with deep sorrow and sadness that Jamie Johnston in Year 11 passed away during a hunting trip on Sunday," Mr Gurney said in the newsletter.
"Jamie was a well-loved, respected student, friend and sportsman to so many, and his loss will be deeply felt by both students and staff."
Mr Gurney invited students and staff members to seek support in dealing with the tragedy.
"As Jamie has touched so many lives with his positive and loving nature there will be many who will be seeking support.
"Please try to treat each other with kindness and we ask that you respect that grieving looks different for all of us."
The school will host Jamie's funeral on Thursday at 11am in the school auditorium and school would be closed for that day.
"Trident community and the wider community are welcome to attend," Mr Gurney said.