"Of course, times change, but we didn't have many options up our sleeves."
Iwi members had set up some signs around the park and Ashby said there had been anecdotal reports of just half the typical number of people seen on the tracks since Saturday.
But there were no plans to confront visitors in the park and the iwi would be taking a "softly, softly approach".
"As mana whenua, we have an obligation as guardians, or kaitiaki, but it really falls on the council to do something."
Five options being tabled by Auckland Council's Environment and Community Committee tomorrow morning include giving up the fight, maintaining the status quo, ramping up work, closing all medium and high-risk tracks, and closing the park.
Officers have recommended the council continue with its existing work programme but undertake some targeted closures of tracks and areas within the park.
Waitakere Ranges Protection Society spokesman John Edgar believed the spread would only worsen if the entire park wasn't closed.
"It's a big thing to say we're going to close the ranges, but we have to do something drastic now," said Edgar, whose group stands with The Tree Council, Forest and Bird and the Friends of Regional Parks on the issue.
"This is an invisible organism, it can kill a mighty kauri tree, and there's absolutely no cure at all - so the only way we can avoid this spreading is by keeping people away."