Mrs Graham said about 1500 little blue penguins live in the Mauao area, including surrounding islands, and almost 700 grey-faced petrel lived on Mauao.
"Luckily most of the penguin and petrel chicks would have left their nests when the fire broke out so there was a lot less impact on the wildlife than there could easily have been.
"I cried like a baby when I heard about the fire.
"I have also watched Mauao burn twice before, including in 1996, and to have someone deliberately light a fire, putting our beautiful mountain and our precious wildlife in danger, defies belief. It could have been a tragic outcome."
As far as we can tell there has been virtually no impact on the penguins and petrels population which is a huge relief.
Firefighters were alerted to the blaze at 11.24pm on January 13. It burnt between 800-900sq m of vegetation on the northeast side of the mountain.
Read more: Mauao likely to take years to recover
Pumicelands Rural Fire Authority zone manager Allan Pearce said the fire and police investigation pointed strongly towards a deliberate attempt to cause a fire by throwing fireworks from the top of Mauao. "This wasn't accidental," he said.
Mr Pearce said enquiries were continuing to identify those responsible.
Mrs Graham said on February 14 the trust was holding a clean-up day on and around Mauao and they desperately needed volunteers willing to collect rubbish for a couple of hours.
The clean-up involved collecting rubbish and other debris such as bottles, broken glass, fishing line and rope which were harmful to the birdlife.
"We will supply the gloves and rubbish bags, and all people need to do is to come along wearing sturdy shoes, a hat and sunscreen."
Volunteers should meet in front of the Mount Maunganui Surf Club at 2pm.
