The Department of Conservation says attacks on their staff have become "more frequent and more acute" – with anti-1080 activists now sabotaging vehicles.
Rangers have also come under attack from freedom campers.
New figures released to 1 NEWS show the number of incidents of abuse and harassment have increased to 33 in the last year – up from between 20-25 in previous years.
But it's attacks on staff vehicles – both branded DoC trucks and private cars – that's got department bosses worried.
Harry Maher, DoC's safety boss said: "In the last year or so we have seen a number of incidents – six or seven now – where we believe that vehicles have been tampered with deliberately. In particular, we have had wheel nuts loosened and obviously this puts our staff at immediate threat."
Staff are also subject to online abuse and harassment. 1 NEWS found examples of activists talking about burning down a hut, and knee-capping and castrating rangers.
Mr Maher said: "There are people out there – and I think it is only a very small minority of people who are against 1080 – that are quite vociferous in their protest against it. I think it is the combination of the availability of social media and the deeply held beliefs they have."
But it's not just environmental activists – rangers have also come under attack from freedom campers.
As a result in the spike DoC are taking more precautions. Staff now have to carry out five minute safety checks around a vehicle before they drive away. And DoC are carrying out a series of physical security checks on all 100 of their public-facing premises.
National's conservation spokeswoman Sarah Dowie says the attacks are unacceptable. But she says 1080 is an effective pest control measure, and a campaign of public education might soothe tensions.
"There needs to be more work done on education as to as the social license - so yes people can protest but when it comes to taking it that step further into criminal activity, that's completely inappropriate," she said.
But Graeme Sawyer, a Coromandel based protestor, says DoC staff can be heavy-handed. He was was charged with assaulting a DoC security guard but the court case was thrown out last year.
"We had a two day trial and the findings where I was acting in self-defence. A security guard does not have the power to drag someone out of the car - especially someone who was doing no harm ."
Mr Maher says people do have the right to protest – but his staff should be left alone to do their job.