The five native fish species that make up whitebait are predicted to be extinct by 2050. Catching them speeds the process, but the main reason they are threatened is because the places they need to live in are disappearing.
They need wetlands and healthy rivers and streams. They like clear, cool, shaded water that's not loaded with nutrients, and they need plenty of insects to eat and not much algae. Their requirements go well beyond New Zealand's debate about whether freshwater should be swimmable or wadeable.
"Swimmable for humans is not liveable for fish."
Banning the catch would buy time for the longer process of restoring their habitat.
"Stopping whitebaiting is something we can do right now that will make a change right now. Everything else takes too long," she said.
Four out of the five species that make up whitebait are threatened, and one is close to extinction. The unthreatened one, banded kokopu, used to be plentiful here but is now almost unknown.
The most plentiful species, inanga, is a skinny, round, spotted, 7-10cm long, mainly nocturnal little fish. It likes small streams, estuaries and backwaters.
The females lay hundreds or thousands of eggs, but that doesn't ensure the species' survival.
"They have a really risky life cycle. They go out to sea for two months, and get fed on by everything, including big inanga. Then they come inland, and it's the same."
Ms McQueen said 73 per cent of New Zealand's native fish speicies are threatened, and only one has formal protection. It's the grayling, common in Whanganui until about 1920, and now extinct.
The whitebait season here starts on August 15 and runs until November 30.