Clarke Gayford ponders the mystery of mega-trout in our hydro waterways
Our South Island hydro electricity canal systems are nothing short of an engineering work of art. The sheer scale of the river and lake diversions are hard to get your head around at first. Man-made water races funnelling glacial melted snow down miles of chutes to giant turbine generators. What's even more impressive is that the potential of the area was recognised way back in 1904, the momentum to create them not starting until the 1920s, and the project not completed till the 1980s - the result being enough clean power for more than 800,000 homes.
This diverted water has bubbled away ever since, creating nothing but clean power, until some bright spark one day thought to themselves, probably after many trips back and forth past these mesmerising tranches of liquid; "Hmm I wonder if we could use that water for something else?"
From this came salmon fish farms, cages anchored inside the canals, where fat fish flourish and occasionally escape from. Then around these arrived the fishers, although I suspect the chubby brown trout had found a way to introduce themselves much earlier, so good are they at populating NZ river systems.
The result? Well as one keen Australian angler I met on the banks told me, "Where else in the world would they let you do this?".
"Where in the world would they not only let you come and fish a waterway that is a power supply for a country, but also farm it?"
It was a perspective I hadn't thought of, this being a resource that not only supplied energy but grew a highly sought-after fresh water-raised salmon for export and also brought millions of dollars in extra revenue into the district through fishing tourism. The campervans parked up and down one causeway I visited, filled with happy visitors all casting a line, being testament to this.
And incredibly on top of that, the waterways, with absolutely stunning mountain backdrops, produce the biggest trout in the world. Fish have been pulled from here that wouldn't look out of place as a character in a Marvel film, so mind-bendingly large are they.
Have a go at absorbing this; the current pending world record for a brown trout was caught in one of these canals last Christmas, with a weight of 55lbs or 24.9kg.
I mean even a 25kg kingfish is a mountable fish, but a trout? Come on now, that is outrageous.
For a long time people assumed the trout had grown to these ginomous dimensions by feeding off the pellets of the nearby fish farms. However scientists did some tests, including studying a whole section of canal that was drained for repair, to learn that it was not necessarily the case.
It turns out that because the races never flood, with levels always controlled by the power companies, the weed bed within is allowed to flourish. Here the habitat is perfect for small fish and other ample food sources to thrive. The trout then basically plonk themselves in a bit of a hole, open their mouths and sit there while the current sends snacks downstream to fill their chubby cheeks.
The downside of this is that they can be notoriously tricky to catch, arguably able to be the fussiest fresh water fish on the planet.
Moon cycles are known trigger bite times, approaching weather systems can invigorate nibbles, a butterfly flapping its wings deep in a Fiordland valley can signal a feeding session. It's all quite mysterious, but when it's on, its on, and even if it's not, it's one heck of a destination to park up and take in some of NZ's most stunning landscapes.
Clarke Gayford hosts Fish of the Day, Sundays, 5.30pm on Three
Mt Cook Salmon, Bluff oysters, escabeche of vegetables, champagne sauce
Non stick fry pan
Mt Cook salmon & Bluff oysters:
4 x 170g Mt Cook salmon portions, skin off
1 dozen Bluff oysters, keep oyster sea water for below sauce
1 dozen Green Lip mussels, juices reserved for sauce
For garnish, ice plant, beech spinach, chervil
Escabeche of vegetables:
1 fennel bulb, julienned
1 red capsicum, julienned
1 yellow capsicum, julienned
1 courgette, julienned
1 onion, julienned
200ml sherry vinegar
Salt and pepper
Slice vegetables and set aside. Heat olive oil in a saucepan to a moderate heat, add the vegetables and cook for 3 minutes without colour, deglaze with sherry vinegar and cook for 2 minutes, season with salt and pepper.
3 sheets unseasoned nori
20g white sesame seeds
In food processor add both nori and sesame seeds. Blend until fine, scraping sides occasionally. Season according to taste.
Place on a plate and press salmon skin side down into nori crumb. Set aside.
300ml champagne or quality sparkling wine
2 shallots, finely diced
50ml oyster sea water, strained
50ml mussel juices, strained
50ml clarified butter
Sweat shallots in clarified butter until soft without colour, deglaze with champagne and reduce by half. Add the strained oyster juice and cream and reduce to sauce consistency, check seasoning. Keep warm.
Set oven to 170 degrees Celsius. Heat a non stick frying pan to a moderate heat, add olive oil, once hot carefully add seasoned salmon fillets, nori side down, lightly pressing down to ensure the nori is getting crispy. Once crispy, place in the oven for 5 minutes (time depends on how you like your salmon cooked). 5 minutes will yield a medium piece of salmon.
Whilst salmon is cooking, gently heat the escabeche of vegetables and in a separate pan heat the champagne sauce. When the salmon is almost cooked, gently place the oysters and mussels into the champagne sauce just to warm through. Once warm remove from the sauce. Use the stick blender to blend the sauce.
To plate dish, add the warmed escabeche of vegetables in the middle, place cooked salmon on top, arrange oysters around dish, froth up the champagne sauce with the stick blender and spoon over oysters and salmon. Garnish with sea herbs. Eat and enjoy.
Recipe by Chef James Draper, Louis Champagne bar