Felix Walton of RNZ

A sustainable tourism expert says environmental damage from cruise ships far outweigh any economic benefits for local businesses.

Studies have found cruise passengers spend less money than other tourists, while the ships themselves cause widespread pollution.

But business leaders say cruise ships bring tens of millions of dollars to their communities.

In the Bay of Islands, cruise ships are big business.

Far North Holdings cruise manager Irwin Wilson said visiting ships brought stacks of cash to his region.

"This last year we've had 42 ships visit the bay. Average spend in the bay is about $180 per person.…