Ospri's TBfree programme is designed to eradicate bovine tuberculosis (TB) from Molesworth which has a long history with TB infection in its cattle herd and wildlife, dating back to the early 1960s.
Eight helicopters using GPS dropped toxic bait at 2kg/ha on a 61,200ha area after "significant public and community engagement", OSPRI says.
"The justification for possum control was compelling and also carried significant conservation benefits," a spokesman said.
"Ospri recognises that there is always a risk of deer by-kill as a result of 1080 application for pest control and is committed to working with hunting groups to minimise the impacts on these populations through targeted use of deer repellent.
"Although possums are the main source of wildlife infection, it is difficult and costly to directly detect TB in the possum population itself, because the disease often only occurs in small population clusters."
Offers by local hunters to shoot as many deer as possible before the 1080 drop were not taken up by DoC, the Herald understands.
Experienced helicopter pilot Bill Hales, who has 40 years' experience as a wild animal recovery operator (WARO), is disappointed by a "crying shame of a wasted resource".
"Why not let us guys in there for three months before you have a poison drop and harvest the product? Why waste the resource?" said Hales, who operates Alpine Springs Helicopters from Hanmer Springs, a 3-minute flight from Molesworth.
"I understand the TB side of it, and the emotive side too, but commonsense would be to say to us guys, 'Come and clean the deer up before we poison them'. And they would get a full record of any TB in the deer because they're all processed."
Animal rights groups are opposed to the use of 1080.
The Molesworth poison drop has also angered some hunters with online forums suggesting as many as 345 dead deer have been counted.
"345 dead deer counted plus a quantity of pigs & goats, that's the news on Molesworth 1080 drop," one poster wrote on the FishnHunt.co.nz forum.
"Absolutely criminal. Total waste of our prime game animals," one person replied.
"Bloody disgusting to think that a prime red deer herd with the trophy potential I've seen first hand will be all but wiped out," another said.
The deerstalkers' subsequent aerial survey was carried out across two weekends last month using helicopters flying transect lines covering the poisoned area with observers conducting counts of deer carcasses.
Smith said Molesworth is home to a significant red deer trophy herd popular with hunters.
"After 1080 poison drops, there's a lot of anecdotal comment about how many deer have been killed, or not, and we thought it was time we stumped up and got a proper scientific survey undertaken so we can actually talk with some authority on it once the results are in and reports are written up]," Smith said.
The survey is expected to cost the NZDA Marlborough around $20,000. Funds have been contributed by the NZDA national office research fund as well as Nelson and South Canterbury branches, while a Givealittle page has also been set up asking for donations.