Nelson Nature fortnightly nature fix
Welcome to the Nelson Nature fortnightly nature fix - a regular snippet about Nelson's natural environment, and what we can do to look after it. If you know anyone who you think might enjoy getting a regular nature fix, please pass this on and encourage them to sign up.
Native Kōaro - photo Martin Rutledge/DOC
It is now the middle of the white-baiting season, with white-baiters a common sight near our river mouths trying their luck. You may be a fisher or you may enjoy eating whitebait, but how much do you know about these unique creatures?
Whitebait are the juveniles of five species of native fish: giant kōkopu (in decline), banded kōkopu, shortjaw kōkopu (threatened), inanga (in decline), and kōaro (in decline). They are part of a group called Galaxiids – the patterns of their skin look like a galaxy of stars. All these native fish are found in Nelson’s rural and urban streams and, if allowed to mature, grow into slender adult fish measuring about 9 cm long.
Inanga spawn in streamside vegetation near the estuary, with a preference for long fescue grass. Known spawning areas, such as Shakespeare Walk along the Maitai River, are left unmown and protected from human disturbance to protect the eggs.
Whitebait spawning site along the Maitai River
Koaro and Kokopu stay in the reaches of the stream. Their preferred environment is bushy streams, and they lay their eggs on leaf litter and forest plants on the stream edge .
In all cases, the eggs stay out of water for several weeks and need good cover to keep them damp. They hatch in spring, when immersed in water by spring tides or floods, and the larvae are swept out to sea where they grow over the winter. They migrate back up the stream in the spring – as whitebait.
The Department of Conservation regulate white-baiting activities. You can read about the regulations here.