Return of the Sockeye

We were walking up a well-known river in the Mackenzie Basin, Otto and I, and we weren’t seeing any fish. It was the end of February, the last of the cicada season when the fishing is easy, and so we had already eked out a couple of decent browns by floating big buoyant dries down the current lines and letting the fish find them. A resident of Virginia, and used to fishing small streams and tiny trout, Otto was already elated with the action, like a kid on a dream trip, but quietly to myself I was growing concerned about not seeing any fish. The day was perfect: sunny and cloudless, and we were walking the high banks and looking down into clear water, along one of the best stretches of the river. And for several hours now we had not seen anything remotely resembling a trout, not even a spooked one. It was unlikely anyone had walked this beat before us, my strategising made sure of that. So why weren’t we seeing any fish? I promised Otto sight-fishing, something he had never done before and I was not really delivering on that promise. We were fishing, and catching, but sight unseen, not quite what I brought him here for. Then, suddenly, as we topped the rise of another high bank and looked into the water, there were fish everywhere, the length and width of the entire pool. “Otto, there’s something wrong with my eyes,” I said. “I’m hallucinating fish! Hundreds of them.” But he could see them too and so for a long while we stared at the water, mesmerised by the phenomenon neither of us had ever seen before. Then I remembered. Of course! They were the sockeye salmon on their spawning run. But, for a species not so long ago considered extinct in New Zealand, their numbers were unbelievable. Last season I saw them here in pods of dozens and when I mentioned this to a local farmer he said it was the most he’d ever seen in his whole life in the valley. But now, from our elevated vantage point, we were looking at hundreds of fish, just in one pool. The bottom shimmered with their green-and-red bodies, the salmon continually jostling and reshuffling, at times scattering in all direction as a newcomer hit the pod. The first time I had seen New Zealand sockeye salmon was during an autumn outing to fish another one of my favourite rivers in the Mackenzie Basin. Just before the trip I happened to read a heart-warming magazine article about how, completely of their own initiative, with a small digger and chainsaws, two engineers Ray Newman and Wayne Crisp cleared and restored one of the historical sockeye spawning streams in the lower Ohau area. I was four-wheel-driving en route to my river when I had to ford a stream and pausing for a moment partway across it, I realised it was the stream featured in the article. I stopped and walked a couple of pools, and sure enough, they were full of sockeyes. But this was late March, and the fish were all black. Their tails and bottom fins were gone, from abrasion against spawning gravels, and the fish, not yet dead but almost, were literally falling apart (like other Pacific salmon, the sockeye all die after their one-and-only spawning run.) I vowed to come back earlier another season, to see the fish in their full spawning colours, perhaps try to catch a few of them, but it never happened. Until now. The problem with trying to catch New Zealand sockeye is that they are not really predators so there is little to no chance of getting them to take a fly. They feed mainly on plankton — swimming in open water and filtering daphnia and copepods with their long and numerous gill rakers — though a 1986 study showed they also eat a good amount of snails and even bullies. By and large though, living as they do in the lakes of the Waitaki catchment — Ohau, Benmore, Aviemore and Waitaki — they are not really available to anglers, with only an odd fish being caught here and there, more a curiosity than a targeted quarry. In fact, many people had fished these lakes for years without ever realising sockeye salmon lived in them. It is only when the sockeyes begin their spawning run that they become both visible and available to an angler. This lasts only 2–3 weeks and is further foreshortened by the fact that, by regulation to protect their spawning, the season for sockeye salmon closes on the last day of February. So, considering that most of the spawning may occur in March, the window of time for catching sockeyes is only a few days long. Otto and I just happened to be here when it was open at its widest. Being innocent of human encounters sockeye salmon do not spook. You can stand above them, tall, visible, and casting a fly, and the fish do not consider you a threat. Of course, they don’t feed either so the only way to get them to take a fly is to trigger aggression by invading their space with a streamer that is both big and gaudy. I will never forget that first cast to a sockeye for it has given me what no trout ever had. There was a pod of fish below me and among them one actively aggressive male, so bright he looked almost orange. He was well at the back of the pool, chasing off all incoming intruders. Since you don’t aim at individual fish but the entire pods of them, I thought I’d just cast across and down and swing the streamer through to see if there were any takers. The moment my red-and-yellow streamer hit the water the dominant male shot forward to confront it. In a flash he covered over ten metres of fast riffly water to stop just as abruptly, face to face with my fly. But he did not take it. It was a few more casts, this time targeting this one fish and almost tickling his nose with the tail of the streamer before he got annoyed enough to snatch the fly. When he did, I learnt another thing about New Zealand sockeye: they don’t really fight. Landing one is like pulling a snag through fast water — steady and hard but without the usual jolts of electricity travelling up the line. If the fight was uneventful, the blurring speed and the raw aggression of his first attack burnt an indelible image in my memory. Nearby, Otto yelled in surprise as another fish took his fly so hard it nearly pulled the rod out of his hands. For a moment we had a double hook-up, one of many. We fished the long riffle for a couple of hours, merely moving up or down a bit to find fresher fish. Catching them was only a matter of putting out enough casts. These commonly resulted in refusals but often enough a fish more aggressive than most would attack the fly with the violence of a punch. These takes were the most exciting part of it all, and after a few fish, the only exciting part. Landing a sockeye is a mechanical necessity but since we fished barbless, at times it was enough to let the line go slack for the salmon to unhook itself. At one point we both reached our fill of catching sockeyes. Chancing upon them, and in such numbers, was as rare as it was unexpected, catching a few was even more so, but catching too many would have diluted the experience. More is not always better. We retired our chewed-up streamers, tied on big dries and resumed our search for trout. Trouble was, we still couldn’t find any of those. Later that day, out of the valley and back in cell reception I did some impromptu research on New Zealand sockeye because both Otto — who is a vet — and I were fascinated by the river spectacle we had just witnessed and wondering how this enigmatic and only wild Southern Hemisphere population of Oncorhynchus nerka had come back from the brink of apparent extinction so strongly and within only a decade. It turned out that no one knew more about the local sockeye than their advocate and champion Graeme Hughes, New Zealand’s longest-serving Fish & Game officer, who retired in early 2018 after 49 years of service, and who in his time had seen the sockeye through its heydays, apparent extinction, and remarkable comeback. The sockeye salmon were introduced in New Zealand in the upper Waitaki catchment in 1901, together with the chinook, under a government initiative to set up a commercial salmon canning industry and inspired by the said industry’s boom in British Columbia. The BC sockeye are anadromous (sea-going), reaching 80 cm and weighing around 15 lb, but in New Zealand none of the fish went out to sea — much less came back from there — which prompted Hughes to postulate that perhaps the salmon were not sockeye at all but the Kokanee, its landlocked variety. The fact that the introduced ‘sockeye’ more or less disappeared in the depths of the Waitaki lakes and never grew larger than 3 lb seemed to support his idea. For nearly seven decades the New Zealand sockeye was considered a complete failure and became nearly forgotten, until 1969 when they were again seen ascending the newly constructed fish pass of the Aviemore Spawning Race. Larch Stream, in the headwaters of Lake Ohau, was discovered to be their main spawning ground. But as the Waitaki hydro development surged ahead, the sockeye habitat and population were progressively truncated by more and more dams. This came to a nearly cataclysmic finale in 1982 when the Ruataniwha Spillway was constructed resulting in dewatering of the entire Ohau River and cutting the salmon off from Lake Ohau and its headwater spawning creeks. In late summer, thousands of fish gathered at the bottom of the spillway but could go no further. In a major effort to rescue them, some 8,000 Kokanee were netted and relocated to other Benmore tributaries — Ahuriri, Omarama Stream, and the Mary Burn — but this seemed to do no good. ‘This relocation failure and the subsequent failure to save the Lake Benmore Kokanee appears to have brought about the final demise of this species,’ Hughes reported. ‘In the 1993 spawning season, no Kokanee were observed in any known spawning stream.’ Then, in March 2006, the sockeye dramatically reappeared, their return a puzzle and a mystery. Perhaps the local salmon farm — formerly Southern Sockeye Salmon, and now Mount Cook Alpine Salmon — annually releasing 2,000 juvenile fish into the watershed since 1993, has played a major part in this turnaround. In any case, since their reappearance, the numbers of sockeyes seem to be rising almost exponentially, something that, come February and March, trout anglers in Mackenzie cannot fail to notice. Their massive presence explains a certain absence of trout because, as Graeme Hughes put it, ‘when they’re moving in the trout are moving out!’ However, it would be foolish to dismiss the sockeye as a nuisance getting between you and the trout because their true value to anglers goes far beyond being just another fish to add to your species list. They are poor eating once they acquire their spawning colours and they are not really a sporting proposition as a game fish. After you’ve caught a few as a matter of curiosity you probably wouldn’t want to do it again, and to me now, they seem a lot more interesting to look at in the river than to actually catch. In fact, the sight of hundreds of fish passing and spawning under the Twizel River bridge has become Mackenzie Country’s latest tourist attraction. You see, great trout fishing and the resurgence of the sockeye are intimately linked, and in the best possible way. In his almost half a century as the Waitaki ranger, Graeme Hughes noted that the watershed of Lake Ohau used to be known for trophy trout, especially ‘double-figure’ rainbows, and that the heydays of that fishery coincided with the highest numbers of sockeye salmon. ‘Although the catch of Kokanee by recreational anglers is inconsequential, the indirect value is the vast food source Kokanee fry provide for the trout populations,’ Hughes wrote. ‘Big fish need big food items and the many thousands of spawning “sockeye” will ensure an ample supply.’ Now, having miraculously come back from a near extinction, the sockeye/Kokanee are on the rapid rise again, and not just in Ohau but the entire Waitaki catchment. So watch this space! The Mackenzie Basin already has some of the best trout fishing in the world and there is now every chance that, with tens of thousands, if not millions, of Kokanee fry entering the riverine ecosystem, the quality and the size of trout is about to go off the charts. And we’ll all have the resolute pint-size battler to thank for it.

Current FlyLife Subscribers can login to read the full article.
To access this article, back issues & more Subscribe to FlyLife today.