With salmon and trout season in full-steam, Fish and Game is warning anglers to play by the rules.

The organisation is planning to crack the whip on anglers fishing without a licence.

North Canterbury head of compliance Dirk Barr says it's not a massive issue for regular fishers.

He says it's the "one-offs" who cause the problems.

"Everybody sort-of wants to catch one of these big boy salmons that's in our rivers, but what happens then is a lot of people that are just new to the sport and they don't necessarily think they need a licence."

Dirk Barr says people making that mistake could find themselves in deep water.

"They've made the conscious decision to take that risk then their gear is confiscated.

"That's often not returned, depending on the outcome of the court case."