Witika was diagnosed with a brain tumour and cancer on his lung earlier this year.
Mere posted to Facebook that her "heart is breaking" for the loss of her husband.
"How hard he fought to stay with us. All through his journey I was his first concern. He waited until we were alone and then he peacefully passed."
She said her husband wanted to stay at Red Beach School because of their love for him. His body will arrive at the school at 10am on Saturday for an 11am service and leave for Oruawharo Marae around 1pm.
Mere posted a video of Witika singing Red Beach School's waiata to the Facebook group Matua's Army on September 8.
Numerous posts flooded the Facebook group with condolences and admiration for the man. One woman called Witika the "best teacher I have ever had" while another said her fondest memory was seeing him at kapa haka practice.
"You would start to play the guitar, you had the warmest smile and was so loveable."
As well as kapa haka Witika ran a taiaha group, carried out blessings as a kaumatua and was a long-serving member of the Hibiscus Coast Community Centre. He was also a foundation member of the Te Herenga Waka o Orewa Marae, the Kaipara Festival Committee and the Hibiscus Coast Kapa Haka Festival.
"Whaea Mere and Matua Murray have worked with many families," stated the Givealittle page.
"They have opened their home to children when some parents have needed respite or to act as temporary guardians to avoid children being suspended from school.
"Murray has given so much to the community over the years and touched many with his generosity, knowledge and willingness to be the difference and is well known for his humble down to earth approach, his efforts have been noted not only by our schools but also by community and government agencies."
The Givealittle page asks for people to return some of Wikita's generosity and donate to help the family.
