Lurking within the depths of a fair number of B.C.’s Interior lakes are a unique strain of trout that are strong, hard-hitting and fight like crazy all the way to the boat.
They will often leap out of the water, shaking their heads in an attempt to free themselves from the hook, and are every bit as scrappy and exciting to catch as any fish out there. They are triploids.
Triploid rainbow trout are aggressive, feisty and grow to a more than respectable size. The triploid strain of rainbow trout were developed by fisheries biologists with the idea of putting them into lakes where there were no natural spawning channels, or where there were already existing resident populations of natural wild trout, but, where increased fishing pressure had put existing fish numbers into a state of decline. Triploid trout are the same as other hatchery-raised trout except they have been sterilized. Since many fish die when they cannot spawn out, the triploid strain of trout was a fairly simple solution, as they do not suffer the ill effects of unsuccessful spawning.
Trout eggs are collected from wild trout on site at the hatchery and then subjected to high pressure “heat shocking” for a given period of time. The shocking usually takes place within 40 minutes of the fertilization process. Triploid trout are not genetically altered by the shocking process and cannot be distinguished in appearance from other reproductive fish stocks. They are raised and reared the same as non-sterilized fish stocks and display the same physical and behavioural attributes.
Triploid trout do, however, have the potential to grow considerably larger than wild stocks because they do not have to devote any energy or calories to the reproductive processes. Typically, fish such as rainbow trout grow for two to three years, mature, and then stop growing. Triploid trout never stop growing. When triploid trout are put into lakes with a fair abundance of food, they can, and often do, attain weights in excess of 10 pounds.
According to the Freshwater Fisheries Society of BC, stocked fish currently account for half of the fish taken by anglers in the approximately 1,000 lakes and streams stocked with hatchery fish in the province.
Among other strains, the triploid strain of rainbow trout serves to provide quality sport fishing in many lakes that would otherwise not be able to sustain a stable wild fish population.
As I recall, the first time that I encountered triploid rainbows was a good 20 years ago up at Lady King Lake near Pinaus Lake. All I knew was that there was supposed to be lots of little fish in the lake. I remember the first fish that hit. It swam up to me right in my boat. I figured I had a pretty decent-sized fish on my line – so much for only small fish – until I got my first glimpse of it when it came fishtailing right out of the water. I couldn’t believe what I was seeing. That trout could not have been any more than 12 inches or so long and yet it felt like I was fighting a fish two or three times that size. Needless to say, ever since then I have gone out of my way to fish any lakes that I know to have been stocked with triploids.
Another reason I like to fish lakes stocked with the triploid strain is that it takes the pressure off indigenous wild stocks. Both can co-exist in the same waters, but the wild stocks have to survive on their own while triploids are part of a ‘put and take’ sport fishery. Because triploids are sterile and cannot reproduce, they cannot dilute or alter the gene pool of existing wild stocks. Also, because triploids do not go through hormonal changes, they are a much better fish to eat if/when you decide to keep one or two.
Introducing triploids into certain lakes is a sensible way to maintain a sport fishery while, at the same time, also protecting the integrity of our wild stocks. They are also a lot of fun to catch.