I was catching up on reading some trout fishing articles and a recent piece from Field & Stream caught my attention. It was titled “Are New Zealand’s Record Trout Really Legit?” by Joe Cermele.
Joe made some good points, that I agree with the underlying argument of the article that some trout have an unfair advantage. There is a world of difference between a truly wild trout that lived its life eating mayfly nymphs, and some obese pellet junkie or some genetically modified triploid trout that was bred to grow extra large.
I personally feel, that the large trout that make their homes in the Tekapo and Twicel hydro canals within Mackenzie country, New Zealand are more natural than artificial. They do not deserve a reputation of being some sort of frankenfish. In this article, I will explain why I do not have a problem with them holding several world and line class records.
I use to live about 6 hours north of the Twizel canals, so have spent some time in the area. There was a time I held an opinion that the canal fishery was targeting fake fish in a fake river. That type of fishing is not really for me. There are trophy trout streams nearby with a much nicer ambiance than a crowded hydro canal.
But, with that said. I feel the obese trout of the canals are hard done by. They are wild fish after all, just living their lives in the water they were born.
Are the Tekapo canal trout supercharged by growth hormones?
I want to discuss the byline of the F&S article “Should rainbows that get big by chowing down on lab-created growth hormones qualify for record status?”. I know this question might be rhetorical, but the salmon that are farmed in the canals do not receive supplementary hormones, and I am pretty certain the practice is illegal.
I can quote directly from New Zealand King Salmon “We don’t use any antibiotics, anti-parasitics or hormones.”, it is a similar story from High Country Salmon another salmon producer in the Mackenzie country “Healthy salmon free from hormones, chemicals, and antibiotics”
I am not denying that the Tekapo trout feed upon specially formulated high energy salmon pellets. They certainly do. But they are certainly not getting supercharged from supplementary hormones.
Tekapo trout are wild fish, they have never seen a hatchery in their life
The second point why I feel they are more deserving. Is that the trout of the Tekapo and Twizel canals are wild fish. They have spent their entire lives in the canal, their parents would have spawned them somewhere in the upper reaches.
It used to be possible to go and target the monsters on their redds, although I think fishing for them is now restricted to prevent overfishing. This separates them from many of the infertile large trout overseas. So unlike the infertile triploid trout of Lake Diefenbaker, the Tekapo trout are fertile, each spring they need to use their energy to migrate upstream and spawn. They are genetically 100% wild fish.
The ancestors of these giant rainbow trout will likely wild steelhead trout, that use to spawn in Sonoma Creek, San Francisco Bay, California. Sometime in the early 1880s, someone scooped up their eggs and they were transported to New Zealand to form the basis of the NZ rainbow trout fisheries.
While they rarely run out to sea in New Zealand, they are absolutely wild trout, and they have been living wild in New Zealand for close to 120 years. They have never seen a hatchery in their lives.
It is a similar story with the monstrous brown trout. They are the descendants of wild sea and river trout sourced from the River Itchen in Southern England. Truly wild stock with minimal human interference.
Why do they grow so big?
Conditions in the hydro canals are nearly ideal for trout. A combination of a steady, energy rich food supply, stable flows, and year round cold temperatures allow the trout to pack on condition.
1) The Tekapo canals offer an abundance of trout food
The hydro canals provide the trout with a steady supply of energy rich food in great abundance. It is no secret that in the early days the canal was quite sterile. The few trout relied on a diet largely made up of wind blown terrestrial insects, caddis and the occasional snail.
But, as the aquatic environment matured, the food sources become more abundant. The upper canals have healthy numbers of small bait fish, mostly cockabullies and juvenile Salmonidae, along the canals large snails are common and I have heard multiple reports of large trout absolutely stuffed with them.
So yes, the pellets from the farms do play an important role, but they are only one part of the puzzle. The pellets are just the icing on an already rich cake, and that icing, might just turn a very large trout into a record.
One interesting observation, that depending on where in the canal a trout is caught there appearance can be quite different, the fish that live beneath the farms can be fat and bulbous, while fish closer to the tailwater at the heads of a canal are not less heavy but longer, more streamlined and even more powerful.
2) The Tekapo canals offer stable, ideal conditions for trout to grow large
I was going to break this down into a couple of topics, but they are both connected. Conditions in the canals such as temperature, oxygen levels, and flows are very stable.
For trout to grow large, they need stability. They need stable flows, temperatures, and oxygen levels. The canals provide all of that.
Temperatures in the canals, never get too hot in the summer, or too freezing in the winter. They are much more stable than the nearby freestone rivers that can widely fluctuate in temperatures.
This brings me to my final point because the power stations determine the flow rate, and the trout never have to worry about flood or drought. The water is always there, always oxygenated, cold, and pristine.
So I have to summarize this piece somehow. I feel the most important point I want to get across is that the trout that live in the Tekapo canals are wild fish, with unmodified genetics. They do not benefit from hormones or other chemicals to accelerate growth.
Yes, some feed upon salmon pellets, but the canals themselves are rich in food, and trout are well capable of growing to record sizes spending their entire lives many miles upstream of the farms.
Are they worthy of a world record? Well, I have to agree with Joe Cermele original conclusion. the IGFA says they count, and at the end of the day they set the standard.
For myself, the next time I am in the Mackenzie Country I will head to a mountain lake or freestone river. Sure the trout might be smaller, but I prefer the ambiance and solitude of catching trout surrounded by nature, rather than dredging for them in a canal over 30ft deep.