The following month, another person commented: "The letters are good but I'm starting to see kidnapping and murder are probably the way to stop it."
There were many vicious social media threats – some identifying individual staff members, others suggesting using rocket launchers or threatening violence against Conservation Minister Eugenie Sage.
But a few people went further.
In March, one security guard protecting a 1080 operation at Hokitika Airport was followed around the West Coast town, and couldn't safely return to his hotel room.
Elsewhere on the West Coast, Z-nails were found scattered around a loading zone for an operation.
One South Island worker was told: "You'll get what's coming to you."
DoC has described 1080 as the best tool it has for stopping pests from devastating threatened native birds like kiwi across New Zealand's large, remote and rugged conservation estate.
Opponents of 1080 argue that it's cruel and affects non-targeted species.
Anger over DoC's use of 1080 made up much of the 54 threats and 96 cases of abuse and harassment recorded by DoC since January 1, around half of which were referred to police.
The details, released to the Herald under the Official Information Act, also listed three assault incidents; however, just one – a worker attacked with a rock - was linked to 1080.
DoC put some of these down to an increase in 1080 activity this year, when it mounted a sweeping operation against the biggest plague-fuelling forest seeding event in decades.
Previous cases involved a DoC member being struck with a quad bike; threats to release 1080 into public places; substances being sent to DoC in the mail; and a radio station DJ encouraging listeners to "kidnap" a DoC employee.
One ranger who spoke under the condition of anonymity, and who had resorted to sleeping with a gun under his bed to protect his family, blamed social media for giving a potent new platform to anti-1080 hostility.
This year, the Government responded to the heightened threat by pouring an extra $10.7m into security - $4.1m of it going toward a dedicated team, and $1.6m toward beefing up physical security at DoC sites.
"The increased reporting and additional resources mean we now have a much better picture of the threat level to staff," DoC's security manager Neil Macrae said.
DoC was now recruiting more expert security personnel and strengthening its relationship with police.
"Unacceptable"
Under its zero tolerance approach, every case was recorded, assessed and referred to police if needed.
"The police check whether the person has a firearms licence or any previous convictions and takes action ranging from a warning to tone down their language, through to visiting them in person, removing firearms or laying charges."
Sage said DoC staff did "extraordinary work" helping nature and maintaining tracks and facilities.
"Harassment, threats, and abuse of departmental staff is unacceptable and fails to recognise the invaluable work conservation staff do."
Forest and Bird chief executive Kevin Hague agreed.
"There will be some who say it's better just to take no notice because these people are all talk. But the very fact that 1080 opponents believe what they do means they are not thinking the way most people do, and normal constraints on behaviour perhaps won't apply," he said.
"It is just a terrible shame that these resources are required to keep people safe, when they could do so much good protecting and restoring nature."
Dave Hansford, author of the book Protecting Paradise: 1080 and the Fight to Save New Zealand's Wildlife, has also been targeted.
Most DoC workers he knew were stoic and usually tried to laugh the harassment off.
"But the plain fact is that nobody has to put up with this sort of intimidation, just for going about their job."
He thought it was crucial for DoC to report every threat.
"The police are clear that even something that appears relatively innocuous helps them see patterns forming, and builds up a bigger picture of certain individuals."
'I kill DOC workers'
January 4: Three staff members receive anti-1080 abuse while fuelling their vehicle in the southern South Island.
January 19: A person knocks on the door of a private house with a DoC vehicle parked outside and seeks to talk about 1080.
January 31: A staffer is abused about 1080 while leaving a South Island dairy.
February 2: Spit and sand is hurled at a worker. The incident isn't reported as 1080-related.
February 21: A worker is assaulted with a thrown rock in the lower North Island.
March 20: Verbal abuse is levelled at a helicopter crew in the western South Island – who weren't involved in any 1080 operations.
March 22: A guard protecting contractors at Hokitika Airport was followed around town for an hour and couldn't return to his hotel.
March 29: A DoC worker is punched in the jaw on the South Island's West Coast. The incident isn't reported as 1080-related.
April 16: Photographs of contractors working in an operation at Perth Valley in the West Coast are shared on social media, along with some of their names.
April 18: A person comments on DoC's Facebook page: "I kill DOC workers".
April 20: An off-duty staff member is abused by a person after learning he works for DoC. The staffer is called a "f**ing idiot" and a "f**ing c**t".
May 22: Contractors are recorded as they fuel vehicles. The recording is later posted on social media.
June 21: Z nails are found scattered around a loading zone during a 1080 operation in the Western South Island.
July 10: A South Island staff member is told by an angry caller: "You'll get what's coming to you."
July 23: A person abuses a DoC worker in their vehicle, and then stands on the highway to block it, while continuing to berate them.
July 25: Details about DoC workers are shared on social media. One person comments: "She's on my hit list and so are a lot of others. We can pick them off one by one, two by two or whatever people have the energy for. It's going to get boring. There are a few of them. Got to start somewhere."
July 31: A photograph of Conservation Minister Eugenie Sage is posted on social media. A comment below threatens violence against her.
August 8: Another Facebook comment reads: "The letters are good but I'm starting to see kidnapping and murder are probably the way to stop it."
August 9: A DoC worker is verbally abused and gestured at while changing a car battery in the western South Island.
August 10: A DoC worker looking for accommodation is abused by several people with anti-1080 views on a community notice board site.
September 2: A driver flashes headlights and mimics shooting a DoC worker travelling in opposite direction in the lower North Island. It's unclear if the incident is 1080-related.
October 14: A DoC worker is verbally abused from a passing vehicle in the southern South Island.
October 21: A person films a 1080 operation in the southern South Island and follows the vehicle back to base.
October 22: A social media threat against DoC talks of using a "rocket launcher".
October 26: Eggs are thrown at the home of a DoC worker in the Central North Island.
November 5: A person threatens to set themselves on fire and walk into a DOC office. It's unclear if it's 1080-related.
• For evidence-based information on 1080, www.1080facts.co.nz.