The number of stranded whales being successfully refloated has plummeted in recent years, new figures show.
The survival rate was 70% in the 1990s, and now it's about 45%, figures released to NZME from the Department of Conservation (Doc) show.
The data follows the death of up to 250 whales that stranded at Farewell Spit last month.
Steve Whitehouse from Whale Rescue said New Zealand is now among the worst in the world at saving whales when it used to be with the best.
But Doc's Golden Bay operations manager Mike Ogle said each case should be treated separately.
He said some information is missing from Doc's records, which go back to the 1800s.
Whale Rescue's Jo Halliday said she believes stranding survival rates will go up if rescues resume at night.
Whales stranded at Farewell Spit last month were spotted at 8pm but rescue efforts couldn't start until daylight. By that time more than 100 had already died.
Ms Halliday says in the past generators have been used to light up beaches.
"There has been so much focus on namby-pamby health and safety, and I totally get that they need to have health and safety, but it has gone over the top."
But Doc said it had to put people first after some people were severely injured in a night-time rescue in 1993.
Whale Rescue has also raised concerns at the number of animals being euthanised. Figures show 11 whales were put down in 24 rescues in the 1990s. That figure blew out to 257 whales out of 23 rescues since 2000.
The figures were derived from strandings of at least 10 whales but did not include strandings on the Chatham Islands or Stewart Island, or whales already dead when rescuers arrived.
Doc said it was taking a more humane approach now, whereas in the past it left the whales to die.
Mr Whitehouse said Doc "doesn't have skills or the knowledge to rescue these animals, so they just shoot them, so everything is over and done with very quickly".
Mr Ogle defended the training and experience of the staff and said he believed the department was as well prepared for a mass stranding as it could be.
He said every stranding was different and insisted teams work efficiently and humanely.
"People know what they are doing and where to slot in, even during a change of shift."
