Let endangered native whitebait live, says ecologist Stella McQueen

Stella McQueen checks the Matarawa Stream for whitebait, in her campaigning T-shirt. Photo/Bevan Conley

The whitebait season starts soon but Whanganui's Stella McQueen won't be getting out her net.

She won't eat threatened native fish, and that goes for eels too.

"The long-finned eel is threatened, and the short-finned one is going in the same direction."

The freshwater ecologist and native freshwater fish specialist roves New Zealand in a motorhome investigating native fish. She has some thoughts for those who catch, sell and eat whitebait.

"They need to think that this is a species that's threatened. Do they want to be the last generation that gets to do this? Are they just taking? Are they giving back at all?"

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.