The cruise ship industry is taking steps to try prevent seabirds getting stunned by bright lights at night and dying.
In a dramatic incident in Auckland last year, about 60 seabirds ended up on the deck of a cruise ship after being attracted by the vessel's bright lights.
Some died because they were boxed up together and became distressed.
The Department of Conservation (DOC) has been consulting with international cruise companies on how to keep the birds safe.
NZ Cruise Association chief executive Kevin O'Sullivan said advice sheets had been distributed to cruise ships when they sailed into local ports.
Some of the recommendations included dimming exterior lights when sailing at night, as well as the best ways to look after seabirds if they ended up on deck.
Mr O'Sullivan said the measures also kept passengers safe from dazed and confused birds.
"There's no evidence that it would happen at any other time - it's because it's an attraction thing - the birds are just attracted to bright lights," he said.
He said there would be about 140 sailings into Auckland this season.
DOC principal science advisor Graeme Taylor said in the Hauraki Gulf, many seabirds flew at night.
"This includes mature seabirds foraging for food and young birds departing from their breeding colonies on their first trip to sea.
"These seabirds have better night vision than humans. But this means they're more likely to be dazzled by a cruise ship's lights, especially on foggy overcast nights with no moonlight. Young seabirds are most at risk of crash landing on a ship at night."