Whitebait season begins on Monday and the Conservation Department is asking fishers to stick to the rules and not be greedy.
In most of New Zealand, including Whanganui, the season runs from August 15 until November 30.
Whitebait are juveniles of five species of native fish: giant kokopu, banded kokopu, shortjaw kokopu, inanga, and koaro. Those that escape the whitebait net grow into adults ranging from 10 to 60 centimetres long.
Conservation Department (DOC) freshwater scientist Jane Goodman said whitebait are iconic in New Zealand.
"Unfortunately four of the five species are categorised as either threatened or at risk due to declining numbers and habitat. Fishers are encouraged to only take what they need and to think about the sustainability of the fishery for future generations."