What is one fish and six fish at the same time?
“Whitebait” are actually the juvenile forms of 6 different native fish species. Five of these are “galaxiids”, named for the beautiful galaxy like markings on the adult fish. These five galaxiids are the giant kōkopu, shortjaw kōkopu, banded kōkopu, kōaro and inanga. The odd one out is the common smelt or paraki, which is also defined as whitebait under fisheries regulations.
Four of the five species of galaxiids are categorised as either threatened or at risk. The shortjaw kōkopu is ‘threatened’, while the giant kōkopu, kōaro and inanga are ‘at risk-declining’. The banded kōkopu and common smelt are not threatened.
The whitebait that will be caught on rivers throughout New Zealand over the next three months, have grown from eggs laid by adult whitebait last autumn. These juveniles have spent winter out at sea and are migrating back up streams or waterways to develop into adults.
Some years are regarded as “good” for the whitebait catch, and others “poor” but the following paragraph describes a seemingly mythical scenario:
“A Christchurch gentleman returning from a holiday trip to the West Coast recently, has reported a remarkable thing while in Westport. He reported tons of whitebait being caught in the river and along the beach, and the enormous number secured proving too much for the local canning factory, which has run out of tins. The whitebait could not be shipped away, as no boat was in, and the residents are “sick of the sight of them”, so that several tons have been carted to the beach and buried.”
This was reported in an October 1910 issue of the Marlborough Express. Looking back in time reveals levels of resources (as well as waste) in the whitebait fishery that astounds most of us today.
These early accounts are a reminder that what we experience today hasn’t always been that way.
You can see how across just a few generations, we have a tendency to see a much depleted resource as “normal”.
Knowledge is a good counter to this tendency, but around whitebait there are still some knowledge gaps!
DOC has released a 2018 paper that summarises what is known about migratory galaxiids and the whitebait fishery and where the knowledge gaps are.
The pressures and threats to our whitebait species are well known: impeded fish passage in waterways, habitat degradation, decreased water flows, harvesting, introduced species and climate change.
What we don’t know is how much of an impact each of these pressures individually and also collectively have on whitebait. Understanding this better would give us a better understanding of how we could improve the health of the whitebait fishery.
The different whitebait species also vary in their habitat preference and where they live around New Zealand. The fish that make up the whitebait population in Taranaki, for example, is likely different to resident fish on the East Coast of the South Island.
Some species migrate considerable distances inland, due to their rock and waterfall climbing ability. Adults can live in any freshwater habitat from lowland wetlands to alpine tarns. All species maintain some landlocked populations, but some species more than others. At the moment…we know enough about whitebait to say we don’t know enough about whitebait! This means a lot of work is necessary to understand how we can help whitebait thrive.
What is DOC doing?
DOC has also been involved in work to improve the freshwater habitat of whitebait. Recently a set of national fish passage guidelines for structures up to 4m were developed and launched by NIWA and DOC, with input from the NZ Fish Passage Advisory Group. The guidelines are intended to be a key point of reference for anyone involved in planning, designing, constructing, managing and monitoring structures in waterways. These guidelines can be viewed at www.doc.govt.nz/fishpassage
What can you do?
If you enjoy heading out to the river to fish, be sure to fish within the rules, which include the dates, times, locations, net sizes and how these should be placed in the river, as well as how you should supervise your nets.