Whitebait

Whitebait are five species of diadromous, migratory galaxiids. Four of the five whitebait species are threatened due to habitat loss, predation by trout, whitebaiting and obstacles in waterways that hinder their migration, such as culverts. Only the banded kōkopu is not threatened.

Except for īnanga, our whitebait species are nocturnal. The eggs of the whitebait species stay out of water for several weeks and need good plant cover to keep moist.

Young common smelt ( Retropinna retropinna ) are also sometimes called whitebait.

Transcript

Cheri van Schravendijk-Goodman

Whitebait is a sort of a collective term for those lovely sparkly fish that we collect and we put in our omelettes and they taste really good. But there’s actually five different galaxiid species in there. We have the giant kōkopu, the banded kōkopu, shortjaw kōkopu, kōaro and then the most common one which is the īnanga. Our people at Te Pūaha also talk about whitebait including at least one other species – they call it the number two whitebait – and that’s the common smelt, or our people call it pōrohe.

The īnanga is the most common one, and they tend to like spawning in the more estuarine, so the slightly salty water. They lay their eggs in the grassy verges, so literally a big king tide comes up the river from the ocean and lifts the water level, and the fish use that water level to get into the grassy verges on the edge, and they lay their eggs in there. And then the water level will drop again, and those eggs are sort of left there in these nice moist environments. And then the next king tide comes in, lifts the water surface up again and washes these larvae out to sea.

And so they are out there somewhere in the 200 nautical mile zone area, and there are question marks as to what is actually happening to them out there.

The other fish – the kōkopu and the kōaro – again, there’s question marks about their spawning habitat, so a lot’s known about īnanga because they’re the most obvious to see and there’s heaps of them, but the kōkopu and kōaro tend to like the rocky, densely overhanging streams and tributaries.

We’re working with NIWA to train some of our people who live in those tributary catchment areas, giving them the skills to go out and start monitoring and try find out more information about the kōkopu and kōaro.

Acknowledgement: © University of Waikato. Please refer to video credits for acknowledgements.