A leaked survey shows staff at the Department of Conservation feel underpaid, have little confidence in their senior managers, and more than half of those surveyed are thinking about looking for a new job.
The agency went through a major restructure two years ago, when it combined 12 regions into six super-regions with the loss of about 70 jobs.
The survey covered 86 percent of DoC staff, or 1699 employees.
It found that only a quarter had a clear vision of where the agency was going, 27 percent had confidence in senior leadership and two-thirds felt they did not receive fair pay and benefits.
There were some positives; 52 percent of staff felt their contribution was valued and 61 percent felt they got recognition when they did a good job.
Labour Conservation spokesperson Ruth Dyson said DoC was clearly in the doldrums.
"When the earlier restructuring was done of the Department of Conservation, I along with many others in the conservation advocacy world said this is not the right way to go.
"Combine that with a clear lack of commitment to conservation values from the Government, you end up with this sort of situation."
Director General of Conservation Lou Sanson was not available to be interviewed but released a written statement.
"The results show that staff remain committed to the organisation but they're also frustrated by some of the ways we work and they want more clarity, accountability and leadership.
"I acknowledge that and that's why DoC is starting to roll out a new internal leadership programme and new ways of working across the organisation."
Ms Dyson said she understood further changes were being made to the leadership team at DoC, which she said was positive.
"I would certainly back the Director-General and the foreshadowing changes that he has already talked about, he talked about it at the select committee recently, I think they are much needed.
"But I do think that staff will continue to flounder a bit and be despondent if they don't see the values that they clearly hold dearly and the work that they want to do being valued by the Government, that's the big gap."
The Public Service Association represents about 1500 DoC staff.
National secretary Erin Polaczuk said the low staff morale was disappointing.
"We do know that there is a level of anger and frustration at their management.
"But recently there have been some positive changes and signs that we're moving into an era of higher engagement between the union and the DoC management, which is a positive first step."
Ms Polaczuk said the union hoped to see the situation at DoC turnaround within the next 12 months.