It was just a shadow passing across the blurred white line under the water. Then another thin shadow appeared, and another, and a third which widened into a mass of tiny, wriggling fish.
The man waited patiently. He knew that a sudden move would frighten the small fish.
They were just under the surface, vulnerable to fluttering gulls and sleek, black shags, and wary of any movement.
With gnarled hands the man slowly grasped the long handle of his scoop net and lowered the wide mouth deeply behind the small school of fish, pushing it surely along before lifting it firmly with both hands.
His heart pounding, he swung the dripping net on to the mud and grass and grabbed the cold, wet mesh lifting and shaking it to ensure none of the tiny fish stuck to the steep sides.
At the bottom the hanging net narrowed to a few centimetres and there, in the pocket, was a dense greenish mass of shimmering whitebait. Although he had done it a thousand times the man still felt a thrill flutter through his body when he saw the catch secure in the net.
"I'll have a heart attack one of these days," he muttered to his wife, who sat nearby on a folding camp chair, not looking up from her book. He knew how a prospector must feel when he strikes gold after years of searching. To him, the whitebait which turned up every year were like liquid gold.
This weekend there will be lovers of the delicate fish all over the country sitting on stream and river banks, eyes glued to the gliding water, hoping for the thrill which always surges when they spot the moving shadows.
For the whitebait season opened two days ago and runs through until the end of November.
The exception is on the West Coast of the South Island, where the season does not start until September 1, and closes earlier on November 14. This is to allow enough of the migrating fish to pass upstream to replenish the population. For the West Coast is the remaining bastion of the large runs of whitebait.
The main reason is the preservation of the indigenous bush which cloaks the river catchments, while elsewhere it has gone to make way for exotic forests and grasslands.
There are rules covering the length of nets and how much of a river's flow may be fished, and fishing is permitted only between 5am and 8pm which changes to 6am and 9pm under daylight saving.
But the story of the whitebait remains an enigma. Few people understand what the tiny fish are and where they come from.
Theories abound as to the best tides and moon phases for sparking runs of whitebait, but all agree that the days are long gone when catches filled kerosene tins and unwanted fish were buried in gardens as fertiliser or used to feed the chooks.
Clues as to their origins can be seen on rural road signs marking streams, and the name Kaikokopu Stream can be found in the Bay of Plenty.
Kai suggests food and kokopu is the name for the adult whitebait, which belong to the Galaxiidae family of freshwater fish found throughout New Zealand and Australia.
The adults are secretive creatures, living in dark, bush-clad pools. There are four members of the family which make up the most highly sought after whitebait — banded kokopu, giant kokopu, dwarf kokopu and short-jawed kokopu.
A cousin, the koaro, is also involved, as is the inanga. The kokopu require clean mountain streams and do not adapt readily to changes in their habitat and have disappeared from much of the country outside the West Coast, but the banded kokopu can still be found in many streams and lakes in the North Island.
The hardy inanga can tolerate water which carries sediment and effluent, and 80 per cent of the whitebait caught in rivers which run through farming country such as the Waikato River are inanga. They are larger and stronger in flavour than the delicate, translucent Galaxiidae.
In autumn, the adults migrate downstream to where the rivers join the sea and lay their eggs on reeds and grasses covered by the highest tides, and remain exposed until a month later when the next king tide covers the eggs which hatch, and the millions of tiny larval fish are swept out to sea.
It is a hazardous existence and many fall prey to larger fish, but the survivors grow in the plankton-rich environment until in the spring they migrate back into the rivers and streams as the whitebait we know.
The strong currents in the middle of the rivers force the poor swimmers close to the banks, where anglers set traps involving sophisticated wings culminating in a box or simply scoop the water with long-handled nets.
But it is not just the impact of predators and fishing which has caused the whitebait runs to diminish steadily. Cows grazing on river banks can destroy eggs with their diet of long grass, floods at the critical time can sweep the fish out to sea, and as ancient trees are stripped from the hills the once-strong banks of the dark pools scour and muddy easily.
Whitebaiters still boast of record catches occasionally during the season, and most are content to mix their catch with eggs into fritters.
• Bite times
Bite times are 5.50am and 6.15pm tomorrow and 6.40am and 7pm on Sunday. More fishing action can be found at GTTackle.co.nz