May, 1997

Test Tube Trophy Specs in Northwestern Ontario

Can trophy brook trout be created in a test tube? Judging from the results of an experimental program in the Thunder Bay district, the answer is yes.

A company called DAMSA, which is owned by Jon and Lauri Parks, of Nolalu, Ontario, has stocked sexually sterile, or triploid trout in several crown lakes in Adrian, Horne and Conmee townships. Triploid fish are rendered sterile by treating them with hot water when they are fry or eggs. Sexually sterile adult trout don't use energy up on egg or milt production, so they can theoretically put all energy into growth. The program has been controversial, and has received some public opposition, but the Parks have weathered the storms, and are now seeing their work pay off.

A number of scientific assessments have been undertaken since 1992, when the first trout were stocked, and there have been a number of remarkable findings in that time period. Lakes in the study area that were initially without sport fish are becoming good trophy fisheries. The four main lakes are protected under sanctuary status. Chemically sterilized, triploid and non sterile brook trout have all been grown in excess of five pounds, the minimum deemed necessary for a brook trout to be called a trophy in Ontario. A large variation in growth rates is evident across lakes, stockings and the kind of brook trout stocked. Growth rates of up to three pounds per year have been obtained for brook trout; and up to five pounds for year for rainbows.

The company (DAMSA) has achieved 100% sterility and monosexing of brook trout and rainbow trout. These capabilities have important implications in fisheries management. Sterile trout can be stocked without risk to the gene pool of indigenous fish. Monosexed trout can be stocked with no threats to the integrity of the ecosystem. In either case, the effects are limited to the life of the fish as they cannot reproduce.

Additional studies undertaken by the company suggest that technology for growing very large brook trout is much more valuable than the tourism application at the study site, consequently the science studies undertaken have a dual purpose. The first is to provide the science for the fishery expectations and proposed tourism resort on the lake. The second is to develop the technology for growing brook trout for application to others.

And how big could these triploid brook trout get? Last fall, I joined Thunder Bay Jon Parks for an afternoon of data collection on three of the lakes in the study. The first lake, little more than a beaver pond really, was known to be susceptible to winter kill. Parks had warned me not to be disappointed if nothing happened there. He paddled the canoe while I tossed a spinner fly to the cedar lined shore. Half way around the lake, something clamped the bait and I set the hook. I knew immediately it was a huge fish. The brookie flashed near the canoe and what I saw sent shivers up my spine. It was a monster. After an exciting fight Parks netted the giant spec. Using a brass Chatillon scale we weighed the fish in the net. The hump backed brook trout weighed eight and one half pounds. After a couple of quick photos, I released the beauty back to the lake. We left that spot elated, and tried another larger lake nearby.

Here I caught a half dozen specs on a large bead eye streamer. The smallest of these fish weighed two pounds, the largest over six. Most of the fish were fat and healthy looking. They fought with abandon. During the course of the day, Parks took notes and examined each fish carefully, looking for clips that would identify a certain type of mono sexed fish or year class. He handled each fish as if it were one of his babies, and in many ways, they were. Parks is confident that a ten pound spec is swimming around in one of these lakes. Judging from what I saw, I wouldn't doubt him.

While Parks can't offer anglers a crack at these fish (they're sanctuary lakes) he is interested in selling the technology he's been working on. He believes that people with private lakes or trout ponds might be interested in learning how to grow giant brookies in their backyard. For more information on the DAMSA program contact Parks at:

Contact him at
E-mail: john.parks@damsa.ca
Home: 807-345-7774.

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