Garth was first found to have melanoma at 24, and died eight years ago, when Karli was 6 and her brother Danny was aged 4 months.
Garth's widow, Tania McDonald, said it was likely the melanoma had been present for several years and if it had been detected three or four years earlier it might have been treatable.
Mother and daughter are emphasising the need for people to be aware of their "marks, moles and skin tags", to have them checked regularly and to seek prompt attention if they suspect anything is amiss.
"Don't leave it," Ms McDonald said.
She is concerned some people are still ignorant of the potential seriousness of the disease. She recently overheard a woman saying that people did not die from it.
Ms McDonald and Karli are supporting this month's Melanoma Foundation of New Zealand's awareness campaign, Wear a Scar Save a Life.
Removable stick-on "scars" are being sold in the campaign.
Ms McDonald (now remarried to Hamish McDonald) likes the use of the scar image to show that if melanoma is caught early, the best outcome is that you are left alive, with one scar.
Karli, who was very close to her father, said while she did not like to dwell on the dark side of her memories about her father, people needed to realise the disease "can break families up".
Dealing with the aftermath of her father's death had been "extremely hard".
Ms McDonald said her late husband would fully support their public stance.
"He always said to me, 'Do whatever you can to make sure nobody has to go through what I've gone through'."
She and Karli really wanted to get the message to young people about being aware of changes in skin.
It was more than just "the slip, slop, slap" SunSmart message, she said.
Some cancers, such as of the breast or bowel, meant "you don't see it", but that was not the case with melanoma.
"We're kind of lucky that we can measure and watch it," but people needed to be aware it "moves extremely fast".
Her late husband, whom she met when she was 11, was a builder. He was not a sun seeker as an adult. He wore hats and T-shirts and sunscreen, but had spent summers in Naseby when he was young, which probably had an impact, she said.
The foundation advises that excess exposure to UV radiation before the age of 20 was a particularly strong risk factor.
People should, however, not believe that because they lived in Dunedin - where there was not a lot of hot weather - they were unlikely to get the disease.
Mr Adams' melanoma was found when he went to the doctor for a check-up because he was feeling unwell.
The doctor noticed a mole in the middle of his back.
Ms McDonald said her recollection of it was that it was "very very dark" but otherwise did not appear unusual.
The doctor removed it, but indicated he did not expect that there would be anything wrong with it.
That was not the case. Melanoma was found and a further deeper and more extensive incision was made.
When the seriousness of the condition was evident, Ms McDonald said the family sought alternative treatment in Mexico. She believed that had helped for about two years, but the following years involved treatments virtually every three months.
By the time of his death, he had undergone 16 bouts of surgery.
• $2 fund-raising "scar tattoos" are available from selected branches of the BNZ, Hallensteins, Les Mills Gyms and Musicworks or directly from the foundation website.
