17 August 2006
Whitebait don’t like muddy waters
The good news is the whitebait season is upon us. The bad news is that whitebait populations do not like muddy, turbid
waters.
“Whitebait populations have declined since the early 1900s says,” Greater Wellington’s Pollution Control Officer, Nic
Conland. “Over-fishing, the introduction of exotic fish species, and habitat change are all probable culprits. Another
interesting observation is that juvenile fish prefer clean, clear rivers and streams rather than muddy ones,” says Mr
Conland.
All whitebait species spawn in autumn, and around one month later, the newly hatched larvae are washed to sea where they
spend their first six months. The annual spring migration, so eagerly anticipated by fishers, is the time when juvenile
fish leave the sea to return to freshwater rivers and streams.
“Juvenile fish avoid returning to turbid streams, preferring instead clean, clear water,” says Mr Conland. “If rivers or
streams are muddy for a prolonged period, there will be no re-stocking and fish populations will decline. Floods and
slips can cause natural turbidity during storms, but man’s activities such as subdivisions and forestry can cause turbid
conditions to persist for much longer periods. So we need to spare a thought for whitebait in small urban streams.
Bulldozers working to clear land for housing can dramatically increase turbidity in nearby streams.”
“It’s difficult to manage the effects of flooding on water turbidity in rivers and streams but developers should
seriously consider doing major earthworks outside the whitebait season,” says Mr Conland. “Greater awareness around the
impact of earthworks on nearby streams will help the region’s whitebait numbers to restock and improve.”
The season runs from August until December and taking whitebait is permitted only between 5am and 8pm, or between 6am
and 9pm during daylight saving. Only one whitebait net can be used at a time, and the net must meet strict size
regulations. For further information on whitebaiting rules, the Department of Conservation has a useful summary
available on its website www.doc.govt.nz.
ENDS