One Man’s River, One Man’s War
In a garage studio on a cliff above the Ahaura River, on the South Island’s West Coast, Johnny Groome stepped back from his easel and regarded the canvas with a critical eye. A heavily-timbered stag, trotting up an alpine game trail and pausing momentarily to glance over its massive shoulder, looked back at him from the unfinished painting with a mixture of curiosity and defiance.
“Enough work for today,” Johnny said, stabbing his brushes into a tin of turpentine. “Let’s go for a fish. I’ll show you my best river in the world.”
I have come to see him about just that, my curiosity piqued by his book Arnold Gold, full of stories about large flies and amazing Coloburiscus hatches and a river that no one else seemed to care about. Years ago, during my exploratory forays to the West Coast, I looked at the Arnold but dismissed it after a cursory glance. It seemed too hard: intimidating fast water, so dark it was impossible to look into, all of it hemmed in and overhung with willows, with an impenetrable thicket of blackberries and brambles blocking all access like bales of barbed wire. I went on to Reefton instead, and this, Johnny was now telling me, was the mistake everyone made.
“There are three types of trout waters on the Coast,” he said as we drove down to the river. “Your lowland waters like La Fontaine and all the spring creeks, your backcountry rock-and-boulder rivers that everyone goes for, and then you’ve got the Arnold which I prefer above all the rest.”
Unlike most other trout rivers on the Coast—all of them rain-fed and thus prone to frequent and at times cataclysmic floods—the Arnold flows out of a large lake—Lake Brunner— and is thus uncommonly stable. This is apparent when you turn over one of the stones that cobble the riverbed: black with algae and trailing tendrils of weeds, and absolutely teeming with aquatic insects. But blink and you miss most of them because the water-blaster current washes them away instantly.
“One time I set up a fine mesh sampling net and then moved a few stones upstream of it,” Johnny said. “The net yielded over 1000 critters, mainly net-building caddis and Coloburiscus nymphs. I try not to do this too often because, really, the bottom here is so old, undisturbed and densely populated that when you pick up a stone you instantly want to put it back, feeling guilty about the havoc you’ve caused.”
It is this aquatic ecosystem—stable, long-established and unaffected by the heaviest of deluges—which makes the Arnold such a unique trout fishery. “It is a haven for brown trout,” Johnny says. “There is an overabundance of food here, unlimited shelter and almost no disturbance from anglers. The numbers of fish must be experienced to be believed. I have pulled out up to 20 good fish in a day from a patch of river the size of my kitchen. Based on my catch rates I’d guesstimate the numbers at 500 fish per kilometre, in places perhaps even more. This surely must be the highest density of trout anywhere in this country.”
None of it is immediately apparent as we walk upstream from the highway bridge and along the smaller channel of the main river called the Left Fork. If anything, my old impressions are reconfirmed. Absolutely no room to cast, arse-up territory wading and, worst of all, no sign of fish. The water is stained brown by the forest tannins, and it runs over a black bottom, frequently frothing into whitewater. No hope in hell to spot a trout, not even with a painter’s visual acuity like Johnny’s.
“What makes the Arnold such a Cinderella of a river is that it is a blind-fishing water in a region known for its sight fishing,” he says. “You try to spot fish here, you’ll fail almost every time. But here the trout are packed so tight you need to cover every square inch of the bottom.”