He said there were several key regulations that the public needed to be aware of.
Fishing was only permitted between 5am and 8pm or between 6am and 9pm when New Zealand Daylight Saving was being observed.
No one was allowed to fish for whitebait within 20m of any tide gate, floodgate, confluence or culvert.
Nor was anybody permitted to do any fishing for whitebait from a bridge or from a vessel.
And whitebait nets must have a mouth no larger than 4.5m (measured around the inside of the net frame) and framing material no wider than 120mm.
Mr Campbell said that from today, DOC staff and honorary rangers would be patrolling waterways to ensure compliance with the rules and be available to answer any questions.
The season closes on November 30.
Whitebait is the only fish amateurs are allowed to catch and sell. The delicacy is expected to fetch more than $100 per kg this season.