The Department of Conservation is looking at installing an alarm system in a cool room where 800 rare giant snails have been accidentally frozen to death.
A technical glitch in the room resulted in a drop in temperature, which the snails could not survive.
Some 6000 snails were taken from the Stockton Plateau several years ago to make way for coalmining. About 4000 have since been relocated to new habitats.
Forest and Bird conservation advocate Nicola Vallance says keeping the snails in ice cream containers for years was never going to end well.
Ms Vallance says New Zealand needs to look at how it allowed the snails to be removed from their habitat, for the benefit of Solid Energy's profits.
The Green Party says the deaths are embarrassing for DoC but the main problem is with the company that took away their habitat.
Confident programme will recover
John Lyall from the West Coast Conservancy says it's a setback but not critical to the breeding programme. He says 360 eggs have hatched in the past year, and they're confident the programme will recover.
Solid Energy environment manager Mark Pizey says the accident may delay the release of some of the other snails. The programme to preserve the snails costs the company about $125,000 a year.
