There is a call for an audit of the fishing industry, following a newspaper report of sweatshop conditions for foreign fishermen.
The Maritime Union says foreigners working in New Zealand waters are sometimes paid as little as $260 per month.
Some complain of being beaten and the union says there have been a number of drownings, sinkings and other accidents.
General secretary Joe Fleetwood says it is time the industry was examined.
The union wants a full audit of the whole industry and all the players in it.
It is also calling for stronger health and safety rules and regulations within the fishing industry.