Whanganui Conservation Department staff have been hearing stories about whitebaiters flouting the rules - and they will be out and about to check up.
Supervisor biodiversity ranger Eddie Te Huia wants to remind all whitebaiters that the regulations are the same as last season.
He's enjoyed getting out and talking to whitebaiters, and said many have been disappointed that rain has muddied the waterways.
Keen recreational whitebaiter John Maslin has heard conflicting stories about the season, which began on August 15. Some have had poor catches, but he's heard of reasonable ones in the Waitotara River.
Maslin and his wife Nanette first tried whitebaiting at the Whangaehu River mouth. Now they spend a week or two on the Mokau River every season - a place where whitebaiting is taken seriously.
It's a good outdoor pursuit, and the Mokau has some remarkable characters. But you need extreme patience to catch the elusive little fish, Maslin said.
"We go and hope to catch enough for us, and that's not a lot."
Later this year the Conservation Department (DOC) will consult the public about whitebait management, including whitebait fishing regulations. In its last survey 90 per cent said the whitebait fishery had to change to stay sustainable.
Forest and Bird favours a ban on commercial sales and ecologist Mike Joy says no one should be eating endangered species.
One possible change could be a ban on selling the tiny fish. It would upset fishers on the West Coast, where commercial fishing has been going on for years and there are bigger runs of whitebait in the cleaner rivers.
If that happened people who don't fish themselves would also miss out on the delicacy, Maslin said.
He's not sure whether fish numbers are declining, because he's seen good seasons and poor seasons. But he said if the fishery is at risk then preventing commercial fishing would help.
"We have seen it happen with trawling off our coast. When they stopped inshore fishing, the fish stock revived."
Whitebait are the juveniles of six species of native fish: giant kōkopu, banded kōkopu, shortjaw kōkopu, inanga, kōaro and common smelt. Four of the six species are either threatened or at risk of extinction, DOC says.
During the season, whitebaiting is allowed between 5am and 8pm, and 6am and 9pm during daylight saving. Fishing regulations can be found on the DOC website, and in pamphlets at DOC offices and sporting shops.
People breaking the rules can be fined $5000 and have their equipment seized.