Newshub can reveal that in just the past year-and-a-half, 50 skippers have refused to have government fishing observers on their vessels.

The Ministry for Primary Industries (MPI) says since 2009, it's had to take 10 skippers to court for saying no.

Most refusals were due to skippers claiming there were issues with "maritime manning limits", meaning there wasn't enough room on board.

Other cases include a skipper simply not responding to MPI's phone calls, a skipper refusing to take an observer because of the extra food costs, and another case where despite being under "placement notice" orders not to sail without an observer, the vessel left port anyway.

The industry says this is "unacceptable", but points out that most skippers do follow the rules.

Observers are the men and women who record details of the catch and ensure nothing illegal happens when the nets are hauled in. They're critical to fisheries management.

But data obtained by Forest and Bird shows some skippers simply don't want them around - 50 skippers in 18 months have simply refused to take them to sea.

"The industry has been evading scrutiny by refusing to have observers on board vessels, and that means the public doesn't get to see what is actually occurring at sea," says chief executive Kevin Hague.

Three skippers refused, arguing they had cameras so an observer wasn't needed. Another moved his vessel away from MPI's target area so he wouldn't have to take an observer.

One even "proposed changing his vessel so that it wasn't suitable for carrying an observer".

"It's not acceptable to make excuses not to take observers," says Dr Jeremy Helson from Fisheries Inshore NZ. "We value the work of observers and value the information they collect."

He says some skippers feel it's an "inconvenience" to have observers on board, particularly on small vessels.

Most refusals were reported as "due to maritime manning limits" - or limitations on space. But Mr Hague doesn't buy it.

"That was a smokescreen for just not wanting to have an observer on board."

Dr Helson disagrees, saying it's a legitimate maritime safety issue "rather than just thumbing their nose".

Whatever the case, refusals remain a current issue for MPI. It's become such a problem in some cases the agency has been forbidding boats from going to sea.

"Over the last year, we've put 21 placement notices on different vessels across the country to ensure they comply with the requirement to carry an observer," says MPI's Inshore Fisheries manager Steve Halley.

"We do use it as an option of last resort."

Perhaps most worrying was the reason observation wasn't possible on a Cook Strait Hoki vessel in July last year. It was noted an observer had to be removed due to "safety and wellbeing concerns".

"Our concern is that health and safety reasons for taking observers off a boat relate to intimidation or stand over tactics," says Mr Hague.

MPI says there are 100 observers who over the past 10 months have delivered around 9000 days of coverage at sea. It says the majority of skippers are very accepting of observers.

But Forest and Bird says 50 refusals in recent months is a worry, especially when some fisheries have a very low rate of observation already.

If you have further information, contact Michael Morrah - michaelmorrah@mediaworks.co.nz

Newshub.